# GCN_circulars

GRB_name: GRB180102A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22303
SUBJECT: GRB 180102A AROMA-N optical observation
DATE:    18/01/06 00:57:23 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Kitaoka, T. Sakamoto (AGU)

We observed the field of GRB 180102A detected by Swift
(Page et al. GCN circ. 22292) with the 0.3 m AROMA-N telescope
located at Aoyama Gakuin University (Sagamihara, Japan).

10 images of 60 sec exposures were taken in the R filter starting
from January 2 on 15:52:26 (UT) about 3 minutes after the trigger
and stopped on 16:04:28 (UT).  We do not detect the optical afterglow
both in the individual images and the stacked image at the location of
the X-ray afterglow (Beardmore et al. GCN circ. 22294).  The estimated
five sigma upper limit is ~16.0 mag using the USNO-B1 catalog.


GRB_name: GRB171229A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22304
SUBJECT: GRB 171229A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/06 12:56:48 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Nakahira (RIKEN), A. Yoshida, T. Sakamoto, V. Pal'shin,Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171229A (Konus-Wind trigger time on 09:59:28.212)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:59:37.40 on
29 December 2017.  This GRB is also clearly seen by the publicly available
INTEGRAL SPI-ACS light curve.  The burst signal was seen only by the SGM
instrument.

The light curve of the SGM shows a single pulse followed by a weak extended
emission.  The emission starts at T-10 sec, peaks at T0 and ends at T+67 sec.
The T90 duration measured by the SGM data is 70.8 +- 6.9 sec (40-1000 keV).
The T50 duration measured by the SGM data is 38.1 +- 17.7 sec (40-1000 keV).

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1198576596/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB180103A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22305
SUBJECT: GRB 180103A: Swift detection of a burst
DATE:    18/01/06 22:34:58 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. P. Beardmore (U Leicester), A. Y. Lien (GSFC/UMBC) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 01:08:30 UT on 3 Jan 2018, BAT detected a rate increase.  
However further analysis was truncated by a pre-planned slew.  
Using the limited data available (including 10 seconds of 
event-by-event data from the rising edge of the burst overlapping 
the start of the slew) ground analysis finds a strong peak
in the reconstructed image, which is GRB 180103A (Trigger #803066). 
The image peak is at
RA,Dec =  159.585, -53.555 which is
  RA(J2000) = 10h 38m 20.3s 
  Dec(J2000)  -53d 33' 16.9"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 170 sec.  The peak count rate
was ~37,000 counts/sec (15-350 keV), at ~103 sec after the trigger. 

Due to the lack of onboard image detection, Swift did not slew to the
GRB and so there were no immediate XRT or UVOT follow-up observations. 

Burst Advocate for this burst is A. P. Beardmore (apb AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180103A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22306
SUBJECT: GRB 180103A: Swift ToO observations
DATE:    18/01/07 00:44:16 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Swift/BAT GRB 180103A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020786

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB171230A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22307
SUBJECT: GRB 171230A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/08 05:53:18 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

I. Takahashi (IPMU), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 171230A (Fermi-GBM trigger #536288993;
Konus-Wind trigger time on 01:09:48.119) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 01:09:46.31 on 30 December 2017.
The burst signal was seen by the all CGBM instruments.  This GRB is also
clearly seen by the publicly available INTEGRAL SPI-ACS light curve.

The light curve of the SGM shows a FRED-like structure.  The emission
starts at T+1.5 sec, peaks at T+5 sec and ends at T+15 sec.  The T90 and
the T50 durations measured by the SGM data are 11.7 +- 2.1 sec and
4.0 +- 1.1 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1198631204/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB180103A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22308
SUBJECT: GRB 180103A: Swift-XRT observations
DATE:    18/01/08 08:02:51 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Melandri (INAF-OAB), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A.
Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-detected burst GRB 180103A (Beardmore et al. GCN Circ.
22305), collecting 2.0 ks of Photon Counting (PC) mode data between
T0+344.2 ks and T0+350.7 ks. 

One uncatalogued X-ray source has been detected consistent with being
within 296 arcsec of the Swift/BAT position, it is below the RASS limit
and shows no definitive signs of fading. Therefore, at the present time
we cannot confirm this as the afterglow. Details of this source are
given below:

Source 1:
  RA (J2000):  159.6016  =  10:38:24.37
  Dec (J2000): -53.5560  =  -53:33:21.6
  Error: 3.8 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.0207 +/- 0.0054 ct s^-1   
  Distance: 35 arcsec from Swift/BAT position.
  Flux: (4.9 +/- 1.3)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020786.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180103A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22309
SUBJECT: GRB 180103A: Swift/UVOT Upper Limits
DATE:    18/01/08 14:02:56 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N.P.M. Kuin (UCL-MSSL) and A..P. Beardmore (U. Leicester) report
on behalf of the Swift/UVOT team:

The Swift/UVOT performed observations of the field of GRB 180103A
(Beardmore et al. GCN Circ. 22305).  No optical afterglow consistent
with the XRT position (Melandri et al. GCN. Circ. 22308) is
detected in the UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are:

Filter         T_start(ks)   T_stop(ks)      Exp(s)         Mag

v                  344.2       350.7         1044         >19.9
u                  344.2       350.7          848         >20.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.48 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180103A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22310
SUBJECT: GRB 180103A: AstroSat CZTI detection
DATE:    18/01/08 15:30:54 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of a long GRB 180103A, which was also detected by Swift (Beardmore A. P. et al., GCN 22305).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 01:10:08.500 UT, ~98 s after the Swift-BAT trigger. The measured peak count rate is 2009.4 cts/s above the background in combined data of four quadrants, with a total of 56951 cts. The local mean background count rate was 459 cts/s. Using cumulative rates, we measure a T90 of 147.1 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB171223A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22312
SUBJECT: GRB 171223A; AstroSat CZTI detection
DATE:    18/01/10 06:16:48 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of a short GRB 171223A, which was also detected by Fermi-GBM (Stanbro M. et al., GCN 22278) and Insight-HXMT/HE (Li Z. W. et al., GCN 22286).

The source was clearly detected in the 40-200 keV energy range. The light curve shows single peak structure with peak at 19:38:15.150 UT. The measured peak count rate is 1464.1 cts/s above the background in combined data of four quadrants, with a total of 2594 cts. The local mean background count rate was 485 cts/s. Using cumulative rates, we measure a T90 of 0.27 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB171227A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22313
SUBJECT: GRB 171227A: AstroSat CZTI detection
DATE:    18/01/10 09:49:08 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of bright GRB 171227A, which was also detected by AGILE/MCAL (Verrecchia F. et al., GCN 22288), Fermi-GBM (Hui C. M. et al., GCN 22289), IPN Triangulation (Kozlova A. et al., GCN 22290) and Konus-Wind (Tsvetkova A. et al., GCN 22291).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 00:00:32.500 UT, ~19 s after the Fermi-GBM trigger. The measured peak count rate is 2066.8 cts/s above the background in combined data of four quadrants, with a total of 15305 cts. The local mean background count rate was 471 cts/s. Using cumulative rates, we measure a T90 of 25.4 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180103A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22314
SUBJECT: Konus-Wind observation of GRB 180103A
DATE:    18/01/10 16:49:22 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The bright long-duration GRB 180103A
(Swift-BAT detection: Beardmore et al., GCN Circ. 22305;
AstroSat-CZTI detection: Sharma et al., GCN Circ. 22310)
triggered Konus-Wind at T0=4122.424 s UT (01:08:42.424).

The burst light curve shows a multipeaked structure
which starts at ~T0-19.5 s and has a total duration of ~237 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180103_T04122/

As observed by Konus-Wind, the burst
had a fluence of 3.41(-0.36,+0.33)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+91.200 s,
of 1.86(-0.27,+0.26)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+219.136 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.31(-0.06,+0.06),
the high energy photon index beta = -2.30(-0.30,+0.15),
the peak energy Ep = 282(-33,+40) keV
(chi2 = 81/96 dof).

The spectrum near the maximum count rate
(measured from T0+81.664 to T0+93.952 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.00(-0.04,+0.04),
the high energy photon index beta = -2.81(-0.99,+0.31),
the peak energy Ep = 589(-48,+52) keV
(chi2 = 107/97 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180103A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22315
SUBJECT: GRB 180103A: LCO Sutherland 1-m telescope observations
DATE:    18/01/10 18:59:27 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large collaboration report:

We observed the field of Swift GRB180103A (Beardmore et al. GCN 22305) on January 06, from 22:12 to 22:35 UT (3.9 days post burst) with one of the 1-m LCO telescopes in Sutherland in the SDSS-I filter. Within the XRT error circle of the source mentioned by Melandri et al. (GCN 22308) we see two sources, for which we measure the following magnitudes:

RA(J2000)  DEC(J2000)     Exposure       Filter       Magnitude (AB)
                                (s)
-------------------------------------------------------------------------
10:38:24.24  -53:33:17.3     9x120          SDSS-I        19.68 +- 0.07
10:38:24.64  -53:33:21.3     9x120          SDSS-I        19.19 +- 0.05
-------------------------------------------------------------------------

as calibrated against USNO UCAC4 field stars. Although we presently cannot make any statement about possible variability, the crowded field suggests that both sources are likely to be unrelated to the GRB. No other sources down to i<20.8 mag are seen within the same XRT error circle.


GRB_name: GRB171230B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22316
SUBJECT: GRB 171230B: Insight-HXMT/HE detection
DATE:    18/01/11 09:17:11 GMT
FROM:    Xufang Li at IHEP  <lixufang@ihep.ac.cn>

C. Z. Liu, X. F. Li, S. L. Xiong, X. B. Li, C. K. Li, Z. W. Li, Z. Chang, 
J. L. Zhao, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, 
Z. Zhang (THU), T. P. Li (IHEP/THU),F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, 
Y. P. Xu, S. N. Zhang (IHEP),report on behalf of the Insight-HXMT team:


At 22:55:34.00 UT on December 30 2017, the Insight-HXMT/HE detected 
GRB 171230B(trigger ID: HEB171230955) in a routine search of the data, 
which was also triggered by Fermi/GBM and Integral.


It's a long GRB. The Insight-HXMT light curve consists of multiple pulses
with a duration (T90) of 40.891 s measured from T0+0.065 s.
The 1s peak rate, measured from T0+0.929 s, is 1261.5 cnts/sec.
The total counts from this burst is 13212.3 counts.


URL_LC: http://www.hxmt.org/images/GRB/HEB171230955_lc.jpg


All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.


The analysis results presented above are preliminary,
final results will be published elsewhere.


Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome.

[GCN OPS NOTE(11jan18): Per author's request, the GRB in the Subject-line
was corrected from 171223B to 121730B.]


GRB_name: GRB171230B
Detection_method: Insight-HXMT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22317
SUBJECT: Correction to GCN Circular 22316: GRB 171230B: Insight-HXMT detection
DATE:    18/01/11 13:25:01 GMT
FROM:    Xufang Li at IHEP  <lixufang@ihep.ac.cn>

X.F. Li reports on behalf of the Insight-HXMT team:

We just find that the GRB name (GRB 171223B) used in our pervious
GCN circular ( C.Z. Liu et al. GCN 22316) is wrong. The correct GRB name
is GRB 171230B. Apologies for any confusion caused.


GRB_name: GRB180111A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22318
SUBJECT: GRB 180111A: Swift detection of a burst with an optical counterpart
DATE:    18/01/11 17:12:29 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Y. Lien (GSFC/UMBC), A. P. Beardmore (U Leicester),
A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU),
S. W. K Emery (UCL-MSSL), J.D. Gropp (PSU), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester),
D. M. Palmer (LANL), M. H. Siegel (PSU), A. Tohuvavohu (PSU) and
T. N. Ukwatta (LANL) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 16:42:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180111A (trigger=804692).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 149.841, +48.265 which is 
   RA(J2000) = 09h 59m 22s
   Dec(J2000) = +48d 15' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 80 sec.  The peak count rate
was ~11000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 16:43:34.1 UT, 87.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 149.77814,
48.26769 which is equivalent to:
   RA(J2000)  = 09h 59m 06.75s
   Dec(J2000) = +48d 16' 03.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 150 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.08 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 5.7
(+3.91/-3.29) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 5.71e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 97 seconds after the BAT trigger. An afterglow
candidate has  been found in the initial data products at RA=9:59:7.0
Dec=+48:16:03.3 which is RA=149.77938, Dec=48.26758 deg (J2000)  
matching the XRT position. This source lies in the wings of a bright 
star and we will provide a magnitude after further ground processing. 

Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180111A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22319
SUBJECT: GRB 180111A: Enhanced Swift-XRT position
DATE:    18/01/11 20:37:43 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 461 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 180111A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 149.77977, +48.26769 which is equivalent
to:

RA (J2000): 09h 59m 7.14s
Dec (J2000): +48d 16' 03.7"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180111A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22320
SUBJECT: GRB180111A: Xinglong TNT possible optical detection
DATE:    18/01/11 23:20:38 GMT
FROM:    L.P. Xin at NAOC  <xlp@nao.cas.cn>

L. P. Xin,   C. Liu,  J. Y. Wei,  Y. L. Qiu, J. S. Deng,  
J. Wang,  X. H. Han, X. M. Meng and C. Wu report:
 
We began to observe GRB 180111A (Lien et a l., GCN22318)  
with Xinglong  0.8-m TNT telescope at 2018-01-11, 14:43:34(UT),
about 93 sec the burst.
 
We obtained several white and R-band images.
In any single white band frame, no any new optical transient 
was detected within UVOT circle and XRT circle 
(Lien et a l., GCN22318, Evens et al., GCN 22319) 
down to 18.5 magnitude at the mid time of 113 sec after the burst  .

However, there is a marginal source in the 20*20sec coadded image 
within the XRT circle  (Evens et al., GCN 22319),  whose position is consistent 
with  the location of the reported optical counterpart (Lien et a l., GCN22318). 
The brightness is about 20.0+/-0.3 calibrated by the local USNO B1.0 R2 mag
at the mid time of 300 sec after the burst. 


We are making further analysis for the possible low S/N detection 
since there is a bright star near the GRB location.
 
The message may be cited.

[GCN OPS NOTE(11jan18):  The latter 'A' was added to the GRB name
in the Subject-line.]


GRB_name: GRB180111A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22321
SUBJECT: GRB 180111A: AGILE/MCAL detection
DATE:    18/01/12 00:02:25 GMT
FROM:    Francesco Verrecchia at ASDC  <francesco.verrecchia@ssdc.asi.it>

F. Verrecchia (SSDC and INAF/OAR), A. Trois (INAF/OA-Cagliari), A.Ursi
(INAF/IAPS), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
N. Parmiggiani (INAF/IASF-Bo), C. Pittori (SSDC and INAF/OAR), M. Marisaldi
(INAF/IASF-Bo and Bergen University), F. Longo (Univ. Trieste and INFN
Trieste), A. Bulgarelli (INAF/IASF-Bo), M. Cardillo (INAF/IAPS), F. Lucarelli
(SSDC and INAF/OAR), M. Pilia (INAF/OA-Cagliari), G. Piano (INAF/IAPS),
I. Donnarumma (ASI), G. Minervini, A. Argan, Y. Evangelista (INAF/IAPS),
V. Fioretti, F. Fuschino (INAF/IASF-Bo), A. Giuliani (INAF/IASF-Mi),
report on behalf of the AGILE Team:

The AGILE Mini-CALorimeter (MCAL) detected at T0 = 2018-01-11 16:42:06.0
+/- 0.02 UTC the long GRB 180111A reported by Swift (Lien et al., GCN 22318),
in the acquired data interval (following an internal trigger) started at
T1=16:42:05.50 UTC and ended at 16:42:12.40 UTC.
The MCAL light curve shows three main peaks starting at T0-0.15 s till ~6 s,
with the main part within T0-0.10 s and T0+5.40 s. The main GRB interval
released a total number of ~5537 counts at E>400 keV in the detector, above
an average background rate of 18 counts/32ms.

The AGILE-MCAL detector has a full solid angle acceptance, and is operational
in the range 0.4 - 100 MeV.


GRB_name: GRB180111A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22322
SUBJECT: GRB 180111A: Swift-XRT refined Analysis
DATE:    18/01/12 01:25:41 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU),
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), S.L. Gibson
(U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA) and A.Y. Lien report on behalf of the Swift-XRT team:

We have analysed 6.1 ks of XRT data for GRB 180111A (Lien et al. GCN
Circ. 22318), from 94 s to 23.6 ks after the  BAT trigger. The data
comprise 117 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN Circ. 22319).

The late-time light curve (from T0+4.0 ks) can be modelled with a
power-law decay with a decay index of alpha=1.46 (+0.38, -0.29).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.48 (+/-0.09). The
best-fitting absorption column is  4.0 (+3.0, -2.6) x 10^20 cm^-2, in
excess of the Galactic value of 1.1 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.66 (+0.21, -0.12)
and a best-fitting absorption column of 1.17 (+4.88, -0.09) x 10^20
cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.8 x 10^-11 (3.9 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.17 (+4.88, -0.09) x 10^20 cm^-2
Galactic foreground: 1.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.66 (+0.21, -0.12)

If the light curve continues to decay with a power-law decay index of
1.46, the count rate at T+24 hours will be 9.2 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.5 x
10^-14 (3.6 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00804692.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180111A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22323
SUBJECT: GRB 180111A: RATIR Optical and NIR Observations
DATE:    18/01/12 15:36:30 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 180111A (Lien, et al., GCN 22318) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2018/01 12.21 to 2018/01 12.56 UTC (12.35 to
20.68 hours after the BAT trigger), obtaining a total of 5.31 hours
exposure in the r and i bands and 2.22 hours exposure in the Z and Y bands.

We find a source within the Swift-XRT error circle (Evans, et al., 22319).
In comparison with the SDSS DR9 and 2MASS catalogs, we measure:

 r = 20.90 +/- 0.10
 i = 20.41 +/- 0.10
 Z = 20.61 +/- 0.15
 Y = 20.41 +/- 0.15

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  We note that there is an r=22.7
mag SDSS source, perhaps the host galaxy, within the XRT error region and
at a position consistent with our source position.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180111A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22324
SUBJECT: GRB 180111A: Swift-BAT refined analysis
DATE:    18/01/12 16:04:27 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180111A (trigger #804692)
(Lien et al., GCN Circ. 22318).  The BAT ground-calculated position is
RA, Dec = 149.782, 48.254 deg which is
  RA(J2000)  =  09h 59m 07.7s
  Dec(J2000) = +48d 15' 14.6"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 70%.

The mask-weighted light curve shows several overlapping pulses that starts
at ~ T0 and ends at ~ T+70 s. The main peak occurs at ~ T+ 14 s.
T90 (15-350 keV) is 50.6 +- 1.9 sec (estimated error including systematics).

The time-averaged spectrum from T-0.30 to T+68.59 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.30 +- 0.03.  The fluence in the 15-150 keV band is 1.02 +- 0.02 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+13.89 sec in the 15-150 keV band
is 4.9 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/804692/BA/


GRB_name: GRB180113A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22325
SUBJECT: GRB 180113A: Swift detection of a burst
DATE:    18/01/13 02:58:25 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

T. N. Ukwatta (LANL), J. R. Cummings (NASA/UMBC),
A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU) and M. H. Siegel (PSU) report on
behalf of the Neil Gehrels Swift Observatory Team:

At 02:47:06 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180113A (trigger=804999).  Due to an observing constraint,
Swift could not slew to this burst. 
The BAT on-board calculated location is 
RA, Dec 19.215, +68.682 which is 
   RA(J2000) = 01h 16m 52s
   Dec(J2000) = +68d 40' 55"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 20 sec.  The peak count rate
was ~9000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not be able to observe
this location until at least T0+36 hours.  There will be no 
XRT or UVOT data until this time. 

Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180103A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22326
SUBJECT: GRB 180103A: Swift-XRT afterglow detection
DATE:    18/01/13 06:08:29 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Melandri (INAF-OAB), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A.
Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
Swift/BAT-detected burst GRB 180103A (Beardmore et al. GCN Circ.
22305). The observations now extend from T0+344.2 ks to T0+849.2 ks.
The source previously reported by Melandri et al. (GCN Circ. 22308),
"Source 1", is fading with 3-sigma significance, and is therefore
likely the GRB afterglow. Using 995 s of PC mode data and 1 UVOT image,
we find an enhanced XRT position (using the XRT-UVOT alignment and
matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
159.60155, -53.55600 which is equivalent to:

RA (J2000): 10h 38m 24.37s
Dec(J2000): -53d 33' 21.6"

with an uncertainty of 3.8 arcsec (radius, 90% confidence). This
position is 35 arcsec from the Swift/BAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=2.53 (+0.05, -1.07).

The results of the XRT-team automatic analysis of the likely afterglow
are at http://www.swift.ac.uk/ToO_GRBs/00020786/Source1.php.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020786.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180111A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22327
SUBJECT: GRB 180111A: Swift/UVOT Detection
DATE:    18/01/13 13:53:26 GMT
FROM:    Jeffrey Gropp at PSU  <jdg44@psu.edu>

J. D. Gropp (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180111A
98 s after the BAT trigger (Lien et al., GCN Circ. 22318).
A fading source consistent with the XRT position
(Evans et al. GCN Circ. 22319)
is detected in the initial UVOT exposures.

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures
are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               84           233          147          19.95+-0.21
white               86          6202         552           20.37+-0.16
v                     64           5181         206         >19.23
b                 4365           6002         393         >20.60
u                   296           5795         639           20.25+-0.35
w1               5391           5591         196         >19.50
m2                650             670            19         >17.15
w2               4776           6407          393           19.60+-0.27


The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180113A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22328
SUBJECT: GRB 180113A: Fermi GBM observation
DATE:    18/01/13 17:45:19 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH) reports on behalf of the Fermi GBM Team:

"At 02:47:06.14 UT on 13 January 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180113A (trigger 537504431 / 180113116).
which was also detected by the Swift/BAT (Ukwatta et al., GCN 22325).
The GBM on-ground location is consistent with the Swift position.

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the best location is 51 degrees.

The GBM light curve shows overlapping peaks
with a duration (T90) of about 11 s (50-300 keV).
The time-averaged spectrum from T0-1.4 s to T0+15.0 s is
best fit by a Band function with Epeak = 247 +/- 12 keV,
alpha = -0.59 +/- 0.04, and beta = -2.32 +/- 0.10.

The event fluence (10-1000 keV) in this time interval is
(1.007 +/- 0.012)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.45 s in the 10-1000 keV band
is 9.3 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180113B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22329
SUBJECT: GRB 180113B: Fermi GBM detection
DATE:    18/01/13 17:46:40 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres and C. Meegan (both UAH)
report on behalf of the Fermi GBM Team:

"At 00:16:00.47 UT on 13 January 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180113B (trigger 537495365 / 180113011).

The on-ground calculated location, using the GBM trigger
data, is RA = 354.0, DEC = 13.5 (J2000 degrees,
equivalent to 23 h 36 m, 13 d 28 '), with an uncertainty
of 1.2 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The angle from the Fermi LAT boresight at the GBM trigger time is 88 degrees.

The GBM light curve consists of multiple pulses
with a duration (T90) of about 15.9 s (50-300 keV).
The time-averaged spectrum from T0-5.6 s to T0+17.0 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.95 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 670 +/- 41 keV.

A Band function fits the spectrum equally well with Epeak = 647 +/- 46 keV,
alpha = -0.95 +/- 0.02, and beta = -2.70 +/- 0.37.

The event fluence (10-1000 keV) in this time interval is
(1.539 +/- 0.017)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.2 s in the 10-1000 keV band
is 36.9 +/- 0.5 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180113A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22330
SUBJECT: GRB 180113A: KAIT Optical Observations
DATE:    18/01/13 18:22:57 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on
behalf of the KAIT GRB team:

The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 180113A (Ukwatta et al.,
GCN 22325) starting at 03:57:49 UT, 70 minutes after the burst,
and lasted for about 1.5 hours. Observations were performed with
a sequence in the clear (roughly R), V, and I filters, and the
exposure time was 60 s per image. The field is relative crowded,
after a preliminay analysis using the subtraction method, we do
not detect any optical afterglow candidate within the Swift-BAT
error circle (Ukwatta et al., GCN 22325). The typical limiting
magnitude of our single clear image is about 19.5 mag calibrated
to the APASS catalog.


GRB_name: GRB180111A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22331
SUBJECT: GRB 180111A: AbAO optical observations
DATE:    18/01/13 19:36:34 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  A. Pozanenko (IKI), R. Inasaridze (AbAO),  S. Schmalz 
(ISON), V. Ayvazian  (AbAO),  O. Kvaratskhelia (AbAO), G. Inasaridze 
(AbAO),  A. Volnova  (IKI),  I. Molotov (KIAM), report on behalf of larger 
GRB follow-up  collaboration:

We observed the field of the Swift  GRB 180111A (Lien et al., GCN 22318) 
with AS-32 (0.7m) telescope of Abastumani Observatory starting on Jan., 11 
(UT)  23:53:51. We obtained several unfiltered images of the field.   Within 
enhanced XRT error circle  (Evans et al., GCN   22319) we detected the 
afterglow (Lien et al., GCN  22318; Xin et al., 22320; GCN  Butler  et al., 
GCN  22323; Gropp  et al., GCN   22327).
Preliminary photometry of the afterglow is following

Date             UT start    t-T0       Filter    Exp.   OT      Err  UpLim 
(3 sigma)
                       (mid, days)                       (s)

2018-01-11 23:53:51   0.3213  CR     62*60  20.7  0.2  22.0

Photometry is based on nearby USNO-B1.0 stars (R2 magnitudes)
USNO-B.1_id    R2
1382-0239231 15.78
1383-0226386 16.52
1383-0226440 15.90

 


GRB_name: GRB180113A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22332
SUBJECT: GRB 180113A: Swift-BAT refined analysis
DATE:    18/01/14 12:24:33 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), (i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180113A (trigger #804999)
(Ukwatta et al., GCN Circ. 22325).  The BAT ground-calculated position is
RA, Dec = 19.211, 68.682 deg which is
  RA(J2000)  =  01h 16m 50.7s
  Dec(J2000) = +68d 40' 55.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.

The mask-weighted light curve shows some weak emissions that starts at ~T-15 s,
followed by the main structure with several overlapping pulses from ~ T0 to ~T+15 s,
and a weak tail that lasts until ~T+70 s. T90 (15-350 keV) is 64 +- 16 sec
(estimated error including systematics).

The time-averaged spectrum from T-12.98 to T+67.02 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.08 +- 0.06.  The fluence in the 15-150 keV band is 4.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+10.52 sec in the 15-150 keV band
is 2.5 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/804999/BA/


GRB_name: GRB180111A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22333
SUBJECT: GRB 180111A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/14 12:55:13 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Asaoka (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 180111A (Lien et al., GCN circ. 22318; Verrecchia
et al., GCN circ. 22321) triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 16:42:04.15 on 11 January 2018.  The burst signal was seen by the all CGBM
instruments.

The light curve of the SGM shows two overlapping peaks.  The emission
starts at T+2.1 sec, peaks at T+2.6 sec and ends at T+43.4 sec.  The T90 and
the T50 durations measured by the SGM data are 34.3 +- 6.6 sec and
11.0 +- 2.4 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1199723921

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB180113C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22334
SUBJECT: GRB 180113C: Fermi GBM detection
DATE:    18/01/14 14:09:26 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH), C. Meegan (UAH) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 10:02:05.41 UT on 13 January 2008, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180113C (trigger 537530530 / 180113418).

The on-ground calculated location, using the GBM trigger
data, is RA = 174.6, DEC = -64.7 (J2000 degrees,
equivalent to 11 h 39 m, -64 d 44 '), with an uncertainty
of 1 degree (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the GBM ground location is 63 degrees.

The GBM light curve shows multiple overlapping pulses
with a duration (T90) of about 24.6 s (50-300 keV).
The time-averaged spectrum from T0+3.1 s to T0+34.8 s is
best fit by a Band function with Epeak = 307 +/- 4 keV,
alpha = -0.68 +/- 0.01, and beta = -2.09 +/- 0.01.

The event fluence (10-1000 keV) in this time interval is
(6.838 +/- 0.017)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+10. s in the 10-1000 keV band
is 26.3 +/- 0.3 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180115A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22335
SUBJECT: GRB 180115A: Swift detection of a burst with an optical counterpart. 
DATE:    18/01/15 04:27:22 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. K. Cannizzo (NASA/UMBC), J. R. Cummings (NASA/UMBC),
A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC), A. Deich (PSU),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 04:16:03 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180115A (trigger=805318).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 12.073, -15.608 which is 
   RA(J2000) = 00h 48m 18s
   Dec(J2000) = -15d 36' 27"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual for an image trigger, the
immediately available light curve shows no obvious variation. 

The XRT began observing the field at 04:18:14.7 UT, 131.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 12.03953, -15.62924 which
is equivalent to:
   RA(J2000)  = 00h 48m 09.49s
   Dec(J2000) = -15d 37' 45.3"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 138 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.  We cannot determine whether the source is
fading at the present time. No spectrum from the promptly downlinked
event data is yet available to determine the column density. 

The initial flux in the 2.5 s image was 3.57e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 140 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 00:48:09.25 =  12.03856
  DEC(J2000) = -15:37:49.8  = -15.63051
with a 90%-confidence error radius of about 0.75 arc sec. This position is 5.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.54 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.02. 

Burst Advocate for this burst is J. K. Cannizzo (cannizzo AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180111A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22336
SUBJECT: Konus-Wind observation of GRB 180111A
DATE:    18/01/15 10:37:21 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The bright long-duration GRB 180111A
(Swift-BAT detection: Lien et al., GCN Circ. 22318;
AGILE-MCAL detection: Verrecchia et al., GCN Circ. 22321)
triggered Konus-Wind at T0=60130.616 s UT (16:42:10.616).

The burst light curve shows a multipeaked structure
which starts at ~T0-0.2 s and has a total duration of ~61 s.
The emission is seen up to ~6 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180111_T60130/

As observed by Konus-Wind, the burst
had a fluence of 8.44(-0.57,+0.64)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.018 s,
of 1.06(-0.21,+0.22)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+39.424 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.94(-0.06,+0.06)
and Ep = 894(-95,+113) keV (chi2 = 106/98 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.7
(chi2 = 106/97 dof).

The spectrum near the maximum count rate
(measured from T0+0.000 to T0+7.424 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
with  alpha = -0.51(-0.08,+0.09)
and Ep = 895(-82,+94) keV (chi2 = 89/98 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.8
(chi2 = 89/97 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180115A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22337
SUBJECT: GRB 180115A: Enhanced Swift-XRT position
DATE:    18/01/15 10:45:08 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3943 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 180115A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 12.03876, -15.63065 which is equivalent
to:

RA (J2000): 00h 48m 9.30s
Dec (J2000): -15d 37' 50.3"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180115A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22338
SUBJECT: GRB 180115A: Swift-XRT refined Analysis
DATE:    18/01/15 11:09:44 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), P.A. Evans (U.
Leicester), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), V.
D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), D.N.
Burrows (PSU) and J.K. Cannizzo report on behalf of the Swift-XRT team:

We have analysed 6.6 ks of XRT data for GRB 180115A (Cannizzo et al.
GCN Circ. 22335), from 137 s to 13.1 ks after the  BAT trigger. The
data comprise 86 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN Circ. 22337).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.6 (+0.6, -0.5), followed by a break at T+269 s to an
alpha of 0.71 (+/-0.04).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.26 (+0.13, -0.12). The
best-fitting absorption column is  consistent with the Galactic value
of 1.7 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.94 (+0.12, -0.11) and a best-fitting absorption
column of 3.6 (+2.4, -2.0) x 10^20 cm^-2. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 3.3 x 10^-11 (3.6 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.6 (+2.4, -2.0) x 10^20 cm^-2
Galactic foreground: 1.7 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.94 (+0.12, -0.11)

If the light curve continues to decay with a power-law decay index of
0.71, the count rate at T+24 hours will be 0.025 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.3 x
10^-13 (9.0 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00805318.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180113A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22339
SUBJECT: GRB 180113A: Swift ToO observations
DATE:    18/01/15 11:28:20 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Swift/BAT GRB 180113A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00804999

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180115A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22340
SUBJECT: GRB 180115A: MITSuME Akeno optical upper limits
DATE:    18/01/15 11:42:54 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. L. Murata, R. Itoh,T. Yoshii, Y. Tachibana, S. Harita, K. Morita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 180115A (Cannizzo et al.,
GCN Circular #22335) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.

The observation started on 2018-01-15 09:25:40 UT. We did not find the
previously reported candidate afterglow (Cannizzo et al., GCN Circular
#22335) in all three bands.
We obtained following limits for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
-------------------------------------------------------------------------------------------------------
~5.16       10:06:44      4320       >19.8    >19.6     >19.0
-------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB180111A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22341
SUBJECT: GRB 180111A: Insight-HXMT/HE observation
DATE:    18/01/15 12:20:59 GMT
FROM:    Shaolin Xiong at IHEP  <xiongsl@ihep.ac.cn>

G. Li, S. L. Xiong, X. B. Li, C. K. Li, J. Y. Liao, C. Z. Liu, X. F. Li, 
Z. W. Li, X. F. Lu, Z. Chang, J. L. Zhao, A. M. Zhang, C. L. Zou (IHEP), 
Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, H. 
Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the 
Insight-HXMT team:

At 2018-01-11T16:42:06 (T0), Insight-HXMT/HE detected 
GRB 180111A (trigger ID: HEB180111695) in a routine search of the 
data,which is also triggered by Swift/BAT (Lien et al.,GCN 
22318),AGILE/MCAL(Verrecchia et al.,GCN 22321),and CALET(Asaoka et 
al.,GCN 22333).

The Insight-HXMT/HE light curve mainly consists of 
multi-pulses with a duration (T90) of 19.94 s measured from T0+0.185 s. 
The 500-ms peak rate, measured from T0+0.422 s, is 2332.29 cnts/sec.
The total counts from this burst is 13972.02 counts. URL_LC: 
http://www.hxmt.org/images/GRB/HEB180111695_lc.jpg

All measurements above are made with the CsI detectors operating in the GRB mode, in 
which the energy range is increased to about 200 - 3000 keV (record 
energy), compared to the normal mode of 80 - 800 keV. Only gamma-rays 
with energy greater than about 200 keV can penetrate the spacecraft and 
leave signals in the CsI detectors installed inside of the telescope. 

The analysis results presented above are preliminary; final results will 
be published elsewhere. Insight-HXMT is the first Chinese space X-ray 
telescope, which was funded jointly by the China National Space 
Administration (CNSA) and the Chinese Academy of Sciences (CAS). More 
information about it could be found at: 
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB180113B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22342
SUBJECT: GRB 180113B: Insight-HXMT/HE observation
DATE:    18/01/15 14:30:16 GMT
FROM:    Shaolin Xiong at IHEP  <xiongsl@ihep.ac.cn>

C. K. Li, S. L. Xiong, X. B. Li, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang,
J. L. Zhao, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. 
Jin,
Z. Zhang (THU), T. P. Li (IHEP/THU),F. J. Lu, L. M. Song, H. Y. Wang, M. Wu,
Y. P. Xu, S. N. Zhang (IHEP),report on behalf of the Insight-HXMT team:

At 2018-01-13T00:16:00.00 UT (T0), the Insight-HXMT/HE detected
GRB 180113B(trigger ID: HEB180113011) in a routine search of the data,
which was also triggered by Fermi/GBM (Veres et al. GCN 22329) and
INTEGRAL/SPI-ACS.

The Insight-HXMT light curve consists of multiple pulses
with a duration (T90) of 11.7 s measured from T0+1.06 s.
The 1-s peak rate, measured from T0+1.30 s, is 13236.7 cnts/sec.
The total counts from this burst is 31306.5 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB180113011_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB180113C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22343
SUBJECT: GRB 180113C: Insight-HXMT/HE observation
DATE:    18/01/15 14:37:31 GMT
FROM:    Shaolin Xiong at IHEP  <xiongsl@ihep.ac.cn>

C. K. Li, S. L. Xiong, X. B. Li, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang,
J. L. Zhao, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP),
Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),F. J. Lu, L. M. Song,
H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

At 2018-01-13T10:02:07.50 UT (T0), the Insight-HXMT/HE detected
GRB 180113C (trigger ID: HEB180113418) in a routine search of the data,
which was also triggered by Fermi/GBM (Veres et al. GCN 22334) and
INTEGRAL/SPI-ACS.

The Insight-HXMT light curve consists of multiple pulses
with a duration (T90) of 22.05 s measured from T0+4.17 s.
The 1-s peak rate, measured from T0+7.85 s, is 21741.2 cnts/sec.
The total counts from this burst is 235458.8 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB180113418_lc.jpg

All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB180113A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22344
SUBJECT: Konus-Wind observation of GRB 180113A
DATE:    18/01/15 15:37:30 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 180113A (Swift/BAT detection: Ukwatta et al.,
GCN 22325, GCN 22332; Fermi-GBM detection: Veres, GCN 22328)
triggered Konus-Wind at T0=10027.005 s UT (02:47:07.005).

The KW light curve shows a single pulse with a total duration
of ~13 s. The emission is seen up to ~1 MeV.

As observed by Konus-Wind, the burst had a fluence of
(1.36 Â± 0.10)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+0.448, of (3.1 Â± 0.3)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.80(-0.12,+0.13),
and the peak energy Ep = 293(-29,+36) keV,
chi2 = 72/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of ~-3.0.

The spectrum near the peak count rate (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range by
the CPL function with the following model parameters:
the photon index alpha = -0.72(-0.12,+0.13),
and the peak energy Ep = 308(-30,+36) keV,
chi2 = 83/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of ~-3.0.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180113_T10027/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB180115A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22345
SUBJECT: GRB 180115A: NOT detection of optical counterpart
DATE:    18/01/15 22:47:53 GMT
FROM:    Zach Cano at U of Iceland  <zewcano@gmail.com>

Z. Cano (HETH/IAA-CSIC), K. E. Heintz (Univ. Iceland & DARK/NBI), A. de
Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), I. Marquez & S. Cazzoli
(IAA-CSIC) report on behalf of a larger collaboration:

We observed the field of GRB 180115A (Cannizzo et al.; GCN Circ. 22335)
with the 2.5-m Nordic Optical Telescope equipped with ALFOSC, starting at
19:40:26 UT on 15 January 2017.  We obtained 3x300 s in the r-band.  In our
co-added image a faint, new object is detected in the enhanced XRT error
circle (Goad et al.; GCN Circ. 22337), with an apparent magnitude of r =
21.3 +- 0.1, at a mean post-explosion epoch of +15.53 hours.  The
calibration was performed using local Pan-STARRS standards in the GRB
field.  This apparent magnitude is not corrected for foreground extinction.


GRB_name: GRB180115A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22346
SUBJECT: GRB 180115A: Redshift from OSIRIS/GTC
DATE:    18/01/15 22:57:40 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), Z. Cano, L. Izzo, 
C.C. Thoene, D.A. Kann (HETH/IAA-CSIC), N. Castro-Rodriguez 
(Grantecan, IAC, ULL), D. Perez Valladares (Grantecan) report on 
behalf of a larger collaboration:

We observed the afterglow of GRB 180115A (Cannizzo et al. GCN 22335, 
Cano et al. GCN 22345) with OSIRIS at the 10.4m GTC telescope. The 
observation consisted of 3x900s exposure with grism R1000B, covering 
the range between 3700 and 7800 Angstrom and was performed under 
bad seeing conditions.

The observation started at 20:32 UT (16.28 hr after the burst), and the 
acquisition image shows the afterglow at r=21.2+/-0.2. The spectrum 
shows a weak continuum over all the spectral range. The low signal to 
noise ratio of the spectrum only allows us to detect a single broad spectral 
feature that we identify as Lyman alpha at a redshift of 2.487.


GRB_name: GRB180116A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22347
SUBJECT: GRB 180116A: MAXI/GSC detection
DATE:    18/01/16 01:26:53 GMT
FROM:    Motoko Suzuki at RIKEN  <motoko@crab.riken.jp>

H. Kawai (Chuo U.), H. Negoro (Nihon U.), M. Serino (AGU), S. Nakahira (RIKEN),
S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai (JAXA),
T. Mihara, M. Sugizaki, W. Iwakiri, M. Shidatsu, F. Yatabe, Y. Takao, M. Matsuoka (RIKEN),
N. Kawai, S. Sugita, T. Yoshii, Y. Tachibana, S. Harita, Y. Muraki, K. Morita (Tokyo Tech),
A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka, T. Hashimoto (AGU),
H. Tsunemi, T. Yoneyama (Osaka U.),
M. Nakajima, T. Kawase, A. Sakamaki (Nihon U.),
Y. Ueda, T. Hori, A. Tanimoto, S. Oda, T. Morita, S. Yamada (Kyoto U.),
Y. Tsuboi, Y. Nakamura, R. Sasaki, T. Sato (Chuo U.),
M. Yamauchi, C. Hanyu, K, Hidaka (Miyazaki U.),
T. Kawamuro (NAOJ),
K. Yamaoka (Nagoya U.)

report on behalf of the MAXI team:
The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient 
source at 00:37:30 UT on 16 January 2018.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (215.655 deg, 18.959 deg) = (14 22 37, +18 57 32) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.13 deg and 0.11 deg, respectively.
The roll angle of long axis from the north direction is 158.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 609 +- 65 mCrab
(4.0-10.0keV, 1 sigma error).
Without assumptions on the source constancy,we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (214.873, 19.864) deg = (14 19 29, +19 51 48) (J2000)
(R.A., Dec) = (214.781, 19.788) deg = (14 19 07, +19 47 16) (J2000)
(R.A., Dec) = (216.314, 18.226) deg = (14 25 15, +18 13 31) (J2000)
(R.A., Dec) = (216.405, 18.300) deg = (14 25 37, +18 18 01) (J2000)
There was no significant excess flux in the previous transit at UT 23:04
with an upper limit of 20 mCrab. 


GRB_name: GRB180115A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22348
SUBJECT: GRB 180115A: Swift-BAT refined analysis
DATE:    18/01/16 02:02:07 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+446 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180115A (trigger #805318)
(Cannizzo et al., GCN Circ. 22335).  The BAT ground-calculated position is
RA, Dec = 12.040, -15.632 deg which is
  RA(J2000)  =  00h 48m 09.6s
  Dec(J2000) = -15d 37' 55.0"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 57%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~ T+25 s and ends at ~T+70 s. The main peak occurs at ~T+66 s.
T90 (15-350 keV) is 40.9 +- 3.0 sec (estimated error including systematics).

The time-averaged spectrum from T+26.49 to T+70.28 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.66 +- 0.22.  The fluence in the 15-150 keV band is 7.6 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+65.96 sec in the 15-150 keV band
is 0.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/805318/BA/


GRB_name: GRB180113C
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22349
SUBJECT: IPN Triangulation of GRB 180113C
DATE:    18/01/16 05:35:16 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D.Svinkin,
and T. Cline on behalf of the Konus-Wind team,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 180113C (Fermi GBM detection: Veres et al.,
GCN 22334) was detected by Fermi(GBM), Konus-Wind, INTEGRAL(SPI-ACS),
Mars-Odyssey (HEND), and Swift(BAT) at about 36125 s UT (10:02:05).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   175.300 (11h 41m 12s) -63.261 (-63d 15' 40")
  Corners:
   173.892 (11h 35m 34s) -62.126 (-62d 07' 33")
   176.415 (11h 45m 40s) -64.502 (-64d 30' 07")
   176.856 (11h 47m 26s) -64.371 (-64d 22' 16")
   174.311 (11h 37m 15s) -62.002 (-62d 00' 07")
  ---------------------------------------------
The error box area is 2174 sq. arcmin, and its maximum
dimension is 2.67 deg (the minimum one is 13.8 arcmin).
The Sun distance was 82 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180113_T36129/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.


GRB_name: GRB171205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22350
SUBJECT: e-MERLIN detection of GRB 171205A
DATE:    18/01/16 08:29:20 GMT
FROM:    Miguel Perez-Torres at IAA-CSIC  <torres@iaa.es>

Miguel Perez-Torres (IAA-CSIC), J. Moldon (JBCA), E. Varenius (JBCA), R. Beswick
(JBCA), Antxon Alberdi (IAA-CSIC), S. Bradley Cenko (NASA), and Assaf Horesh
(HUJI) report:

We observed GRB 171205A (D'Elia et al., GCN 22177) with the electronic
Multi-Element Radio Linked Interferometer Network (eMERLIN) on 2017 Dec 20 (from
20.06 UT until 20.35 UT) and on 2017 Dec 21 (from 21.06 UT until 21.31 UT), for
a total of 12.7 hr.

The observations were carried out with a five-array telescope (Mk2, Pi, Da, De,
Cm) at a central frequency of 5.1 GHz, with a bandwidth of 512 MHz.  The
synthesized beam was of 0.22x0.030 sq. arcsec at a position angle of 17.7 deg. 

We clearly detected GRB 171205A with a peak flux density of 7.9 mJy/beam.  The
off-source rms was of 0.05 mJy/b, and the calibration uncertainty is about 5%,
for a total uncertainty in the GRB flux density of 0.4 mJy.  

We thank the e-MERLIN staff for the time allocation and their help with the
observations.


GRB_name: GRB180113C
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22351
SUBJECT: Konus-Wind observation of GRB 180113C
DATE:    18/01/16 10:25:27 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 180113C (Fermi-GBM detection: Veres et al., GCN 22344;
Insight-HXMT/HE observation: Li et al., GCN 22343;
IPN Triangulation: Hurley et al., GCN 22349)
triggered Konus-Wind at T0=36129.524 s UT (10:02:09.524)

The burst light curve shows a bright, multi-peaked pulse
with a total duration of ~80 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(2.9 Â± 0.1)x10^-4 erg/cm2 and a 64-ms peak energy flux,
measured from T0+6.400, of (3.1 Â± 0.3)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+37.888 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.78 (-0.05,+0.05),
the high energy photon index beta = -2.14 (-0.06,+0.05),
the peak energy Ep = 368 (-22,+24) keV,
chi2 = 108/96 dof.

The spectrum near the peak count rate (measured from T0+6.400 s
to T0+6.912 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.35 (-0.16,+0.20),
the high energy photon index beta = -2.09 (-0.18,+0.13),
the peak energy Ep = 429 (-76,+85) keV,
chi2 = 59/63 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB80113_T36129/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB180111A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22352
SUBJECT: GRB 180111A AROMA-N optical observation
DATE:    18/01/16 14:15:09 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Kitaoka, T. Sakamoto (AGU)

We observed the field of GRB 180111A detected by Swift
(Lien et al. GCN circ. 22318) with the 0.3 m AROMA-N telescope
located at Aoyama Gakuin University (Sagamihara, Japan).

10 images of 60 sec exposures were taken in the R filter starting
from January 11 on 16:44:50 (UT) about 3 minutes after the trigger
and stopped on 16:56:51 (UT).  We do not detect the optical afterglow
both in the individual images and the stacked image at the location of
the optical afterglow (Lien et al. GCN circ. 22318).  The estimated
five sigma upper limit is ~16.6 mag using the USNO-B1 catalog.


GRB_name: GRB180112A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22353
SUBJECT: GRB 180112A: Insight-HXMT/HE detection/observation
DATE:    18/01/16 14:16:28 GMT
FROM:    Xufang Li at IHEP  <lixufang@ihep.ac.cn>

C. Z. Liu, X. F. Li, S. L. Xiong, X. B. Li, C. K. Li, Z. W. Li, Z. Chang, 
J. L. Zhao, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, 
Z. Zhang (THU), T. P. Li (IHEP/THU),F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, 
Y. P. Xu, S. N. Zhang (IHEP),report on behalf of the Insight-HXMT team:

At 16:30:38.00 UT on January 12 2018, the Insight-HXMT/HE detected 
GRB 180112A(Insight-HXMT internal trigger ID: HEB180112687 and HEB180112689, 
corresponding to two main pulses) in a routine search of the data, 
which was also triggered by Swift/BAT and Integral/SPI-ACS and CALET/CGBM.

It's a pulsating GRB event. The Insight-HXMT light curve consists of 
two bursts triggered respectively at 16:30:38.00 UT and 16:32:56.00 UT, 
each of the two bursts consists of multiple pulses. The GRB event totally has a 
duration (T90) of 151.788 s measured from T0-5.2385 s. The 1s peak rate, 
measured from T0+139.541 s, is 1383.0 cnts/sec. The total counts from 
this GRB event is 4935.2 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB180112687_lc.jpg

All measurements above are made with the CsI detectors operating in the
GRB mode with the energy range of about 200-3000 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The analysis results presented above are preliminary;
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB180113B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22354
SUBJECT: IPN Triangulation of GRB 180113B
DATE:    18/01/16 15:03:48 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team, and

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report:

The bright long-duration GRB 180113B (Veres and Meegan, GCN Circ. 22329)
was detected by Fermi (GBM trigger 537495365), Konus-Wind,
and INTEGRAL (SPI-ACS) at about 960 s UT (00:16:00).

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
     6.697 (00h 26m 47s) +24.021 (+24d 01' 15")
  Corners:
     3.866 (00h 15m 28s) +27.572 (+27d 34' 20")
     8.260 (00h 33m 03s) +22.591 (+22d 35' 29")
     7.772 (00h 31m 05s) +22.219 (+22d 13' 07")
     3.373 (00h 13m 29s) +27.185 (+27d 11' 07")
  ---------------------------------------------
The error box area is 3.7 sq. deg, and its maximum
dimension is 6.4 deg (the minimum one is 35 arcmin).
The Sun distance was 82 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180113_T00958/IPN

The Konus-Wind time history and spectrum will be given a forthcoming GCN 
Circular.


GRB_name: GRB180113B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22355
SUBJECT: Konus-Wind observation of GRB 180113B
DATE:    18/01/16 15:18:46 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 180113B (Fermi-GBM detection: Veres & Meegan, GCN 22329;
Insight-HXMT/HE observation: Li et al., GCN 22342;
IPN Triangulation: Svinkin et al., GCN 22354)
triggered Konus-Wind at T0=958.621 s UT (00:15:58.621).

The KW light curve shows a multiple pulses in the interval
from ~T0 to ~T0+20 s. The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(4.05 Â± 0.29)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+3.200 s, of (2.2 Â± 0.1)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+20.224 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.97(-0.07,+0.08),
and the peak energy Ep = 559(-58,+71) keV,
chi2 = 81/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of ~-2.0.

The spectrum near the peak count rate (measured from T0 to T0+3.840 s)
is best fit in the 20 keV - 15 MeV range by
the CPL function with the following model parameters:
the photon index alpha = -0.80(-0.06,+0.06),
and the peak energy Ep = 611(-47,+53) keV,
chi2 = 93/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of ~-2.0.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180113_T00958/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB180116A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22356
SUBJECT: GRB 180116A: Fermi GBM Detection
DATE:    18/01/16 17:11:44 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001@uah.edu>

M. Stanbro and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 00:36:52.81 UT on 16 January 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180116A (trigger 537755817 / 180116026)
which was also detected by the MAXI/GSC (H. Kawai et al. 2018, GCN 22347).
The GBM on-ground location is consistent with the MAXI/GSC position.

The angle from the Fermi LAT boresight at the GBM trigger time is 39
degrees.

The GBM light curve consists of several episodes
with a duration (T90) of about 60 s (50-300 keV).
The time-averaged spectrum from T0-3.07 s to T0+58.37 s is
best fit by a simple power law function with index -1.72 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(3.54 +/- 0.28)E-06  erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.47 s in the 10-1000 keV band
is 1.98 +/- 0.24 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180115A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22357
SUBJECT: GRB 180115A: Swift/UVOT Detection
DATE:    18/01/16 20:26:27 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and J. K. Cannizzo (NASA/UMBC)
report on behalf of the Swift/UVOT team:

Additional observations of the optical afterglow of GRB 180115A
discovered with Swift/UVOT (Cannizzo et al., GCN Circ. 22335)
reveal an initially brightening and then fading source.
The source is not detected in any of the UV filters, consistent
with the redshift of 2.487 reported by de Ugarte Postigo et al. (GCN Circ. 22346).

The preliminary UVOT position is:
    RA  (J2000) =  00:48:09.27 =  12.03862 (deg.)
    Dec (J2000) = -15:37:49.9  = -15.63054 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              140          290          147         17.61 +/- 0.04
white              753          773           20         16.95 +/- 0.07
white             5663         5863          197         19.18 +/- 0.08
v                  628          648           20         16.50 +/- 0.16
b                  554          574           20         16.93 +/- 0.11
u                  299          548          246         16.32 +/- 0.04
w1                1109        13068         1165        >20.7
m2                4743        12296         1279        >21.8
w2                5769         7329          318        >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180112A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22358
SUBJECT: GRB 180112A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/17 05:40:23 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Ozawa (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 180112A (INTEGRAL SPI-ACS trigger #7990;
Konus-Wind trigger time on 16:29:11.736) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 16:29:08.39 on 12 January 2018.  The burst signal
was seen by the all CGBM instruments.

The light curve of the SGM shows three isolated episodes.  The first weak
episode peaks around T+2 sec with the duration of 4 sec.  The second
episode has two overlapping pulses, and its emission starts at T+80 sec,
peaks at T+100 sec and ends at T+110 sec.  The third brightest episode
has a single pulse, and its emission starts at T+200 sec, peaks at T+230 sec
and ends at T+250 sec.  The T90 and the T50 durations measured by the
SGM data are 155 +- 80 sec and 134.5 +- 1.2 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1199809543

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB180113A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22359
SUBJECT: GRB 180113A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/17 05:44:00 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Torii (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 180113A (Ukwatta et al., GCN circ. 22325; Veres et al.,
GCN circ. 22328; Frederiks et al., GCN circ. 22344) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 02:47:03.27 on 13 January 2018.  The burst
signal was seen by the all CGBM instruments.

The light curve of the SGM shows two overlapping pulses.  The emission
starts at T+3 sec, peaks at T+4 sec and ends at T+16 sec.  The T90 and
the T50 durations measured by the SGM data are 11.3 +- 1.3 sec and
7.0 +- 0.6 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1199846617

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB171209A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22360
SUBJECT: Konus-Wind observation of GRB 171209A
DATE:    18/01/17 13:39:48 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A.Kozlova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko,
and T. Cline on behalf of the Konus-Wind team, report:

The long GRB 171209A (Swift-BAT trigger #796100: LaPorte et al.,
GCN 22213; Cummings et al., GCN 22229)
was detected by Konus-Wind (KW) in the waiting mode.

The burst light curve shows a multi-peaked structure
with a duration of ~ 147 s.

As observed by KW, the burst had a fluence of
1.56(-0.17,+0.16)x10^-5 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(BAT)+22.4 s, of 3.06(-0.62,+0.61)x10^-7 erg/cm2/s
(both in the 20 - 10000 keV energy range).

Modeling the KW 3-channel time-integrated spectrum
(from ~T0(BAT)-1.2 s to ~T0(BAT)+146 s)
by a power law with exponential cutoff model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.13 (-0.23,+0.40), and Ep = 279 (-86,+141) keV.

The KW light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB171209A/

All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.


GRB_name: GRB180116A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22361
SUBJECT: GRB 180116A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/18 14:31:46 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration, soft and weak GRB 180116A (Kawai et al., GCN circ. 22347;
Stanbro et al., GCN circ. 22356) was detected by the CALET Gamma-ray Burst
Monitor (CGBM) in the survey mode.  The burst signal is only seen below 100 keV
in all CGBM instruments, confirming its soft nature.

The light curve of the HXM shows several overlapping pulses.  The emission
starts at T-5 sec, peaks at T+11 sec and ends at T+47 sec, where T0 is the
Fermi-GBM trigger time at 00:36:52.81 UT.  The T90 and the T50 durations
measured by the combined HXM data (HXM1+HXM2) are 46 +- 10 sec and
27 +- 10 sec (10-300 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1200098002/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB180115A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22362
SUBJECT: GRB 180115A: SEDM Observations
DATE:    18/01/18 20:21:52 GMT
FROM:    Virginia Cunningham at U of MD  <vcunning@astro.umd.edu>

V. Cunningham, J. D. Neill, S. B. Cenko, and R. Walters report on
behalf of the SEDM team:

We obtained a spectrum of the optical afterglow of GRB181105A
(Cannizzo et al., GCN 22335; Cano et al., GCN 22345; de Ugarte
Postigo et al., GCN 22346; Marshall et al., GCN 22357) with the
Spectral Energy Distribution Machine (SEDM) on the 60 inch
telescope at Palomar Observatory.  The SEDM is a low resolution
(R ~ 100) integral field unit spectrometer with a multi-band (ugri)
â€œrainbowâ€ camera imager (see Blagorodnova et al., 2017,
astro-ph/1710.02917).

Observations began at 4:30 UTC on January 15 (14 minutes after
the Swift BAT trigger) and covered the wavelength range from
3800-9200 A with an exposure time of 2700 s.  Continuum emission
is clearly seen at wavelengths redder than 4500 A and is well fit by
a relatively steep power-law spectrum with index alpha = 1.93
(f_nu ~ nu^-alpha).  No obvious emission or absorption features are
clearly detected in the spectrum; due to the low SNR at wavelengths
shorter than 4500 A we cannot confirm the detection of Ly-alpha at
z = 2.487 reported by de Ugarte Postigo et al. (GCN 22346).

[GCN OPS NOTE(07sep19): Per author's request, in the last paragraph
the "alpha = 1.93" was changed to "alpha = 0.93".]


GRB_name: GRB180113A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22363
SUBJECT: GRB 180113A: AstroSat CZTI detection
DATE:    18/01/20 18:19:33 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of bright GRB 180113A, which was also detected by Swift (Ukwatta T. N. et al., GCN 22325), Fermi-GBM (Veres P. et al., GCN 22328), Konus-Wind (Frederiks D. et al., GCN 22344) and CALET (Torii S. et al., GCN 22359).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 02:47:07.500 UT, ~1.5 s after the Swift-BAT trigger. The measured peak count rate is 345 cts/s above the background in combined data of four quadrants, with a total of  2536 cts. The local mean background count rate was 628 cts/s. Using cumulative rates, we measure a T90 of 14.3 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180113B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22364
SUBJECT: GRB 180113B: AstroSat CZTI detection
DATE:    18/01/20 18:21:39 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of bright GRB 180113B, which was also detected by Fermi-GBM (Veres P. et al., GCN 22329), Insight-HXMT/HE (Li C. K. et al., GCN 22342), IPN Triangulation (Svinkin D. et al., GCN 22354) and  Konus-Wind (Frederiks D. et al., GCN 22355).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 00:16:01.500 UT, ~1 s after the Fermi-GBM trigger. The measured peak count rate is 1344.6 cts/s above the background in combined data of four quadrants, with a total of 3534 cts. The local mean background count rate was 520 cts/s. Using cumulative rates, we measure a T90 of 10.8 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180120A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22366
SUBJECT: GRB 180120A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/23 08:44:54 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 180120A (Fermi-GBM trigger #538117098;
Konus-Wind trigger time on 04:58:18.23) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 04:58:09.54 on 20 January 2018.
The burst signal was seen by the all CGBM instruments.

The light curve shows two bright overlapping pulses.  The first pulse starts
at T-2 sec, peaks at T+6 sec and ends at T+20 sec.  There is a possible
additional pulse around T+15 sec.  The second pulse starts at T+15 sec,
peaks at T+25 sec and ends at T+40 sec.  The T90 and the T50 durations
measured by the SGM data are 24.9 +- 4.1 sec and 16.3 +- 0.4 sec
(40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1200459271/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB180120A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22367
SUBJECT: GRB 180120A: Fermi GBM Detection
DATE:    18/01/23 22:32:28 GMT
FROM:    Matthew Stanbro at UAH/Fermi  <mcs0001@uah.edu>

M. Stanbro and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 04:58:13.00 UT on 20 January 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180120A (trigger 538117098 / 180120207)
which was also detected by the CALET Gamma-ray Burst Monitor
(Y. Shimizu et al. 2018, GCN 22366).

The on-ground calculated location, using the GBM trigger
data, is RA = 151.77, DEC = 27.79, with an uncertainty
of 1 degree (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32].

The angle from the Fermi LAT boresight at the GBM trigger time is 85
degrees.

The GBM light curve consists of several episodes
with a duration (T90) of about 29 s (50-300 keV).
The time-averaged spectrum from T0+0.90 s to T0+30.59 s is
best fit by a Band function with Epeak = 130 +/- 2 keV,
alpha = -1.05 +/- 0.01, and beta = -2.58 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(6.27 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+17.66 s in the 10-1000 keV band
is 36.70 +/- 0.50 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180120A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22370
SUBJECT: GRB 180120A: AstroSat CZTI detection
DATE:    18/01/26 05:36:19 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA),  A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of a long GRB 180120A, which was also detected by Fermi-GBM (Stanbro M. et al., GCN 22367) and CALET (Shimizu Y. et al., GCN 22366).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 04:58:15.5 UT, 2.5 s after the Fermi-GBM trigger. The measured peak count rate is 695.2 cts/s above the background in combined data of four quadrants, with a total of 7955 cts. The local mean background count rate was 557 cts/s. Using cumulative rates, we measure a T90 of 26.8 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB170817A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22371
SUBJECT: LIGO/Virgo GW170817: Chandra X-ray Emission Continues to Rise ~156 Days Post-Merger
DATE:    18/01/29 19:21:22 GMT
FROM:    Daryl Haggard at McGill U  <daryl.haggard@mcgill.ca>

Daryl Haggard, Melania Nynka, John J. Ruan (McGill/MSI), Phil Evans 
(Leicester), and Vicky Kalogera (Northwestern/CIERA) report:

We have obtained new X-ray observations of GW170817 via Chandra 
Director's Discretionary Time (PI: Wilkes, Program Number 19408607). The 
X-ray counterpart to GW170817/GRB170817A/SSS17a continues to be detected 
and the X-ray emission continues to brighten approximately 156 days 
after the neutron star merger. This contradicts previous claims of the 
X-ray fading of GW170817 in XMM-Newton observations at 135 days 
(D'Avanzo et al. 2018, arXiv: 1801.06164).

This new Chandra program acquired several exposures of GRB170817A:

ObsID,  ExpTime,  StartDate,           Days Post-Burst
-----   -------   ---------            ---------------
20936   31.75 ks  2018-01-17 21:55:17  153.5 days
20938   15.86 ks  2018-01-21 13:45:18  157.1 days
20939   22.25 ks  2018-01-24 08:18:48  159.9 days

Since these new Chandra exposures are close in time and the X-ray 
emission of GRB170817A is not expected to vary significantly over <10 
day timescales, we co-add these three data sets into one 69.86 ks 
exposure at 156.4 days post-burst.

We perform spectral extractions assuming an absorbed power-law spectral 
model with fixed NH = 7.5e20 cm^âˆ’2 and find that the X-ray flux of 
GRB170817A has an absorbed flux of f(0.3âˆ’8 keV) = 1.93(+0.39/-0.32)eâˆ’14 
erg s^âˆ’1 cm^âˆ’2  (with Gamma ~ 1.67) at 156.4 days post-burst, which 
corresponds to an unabsorbed luminosity of L(0.3âˆ’10 keV) = 
5.23(+1.30/-0.95)e39 erg s^âˆ’1 (assuming a luminosity distance of 42.5 Mpc).

This represents continued X-ray brightening compared to Chandra 
observations at 15.6 and 109.2 days post-burst, for which we find an 
absorbed flux of f(0.3âˆ’8 keV) = 0.36(+0.1/-0.07)eâˆ’14 erg s^âˆ’1 cm^âˆ’2 
(with Gamma = 2.4 +/- 0.8, unabsorbed L(0.3âˆ’10 keV) = 10.4(+2.0/-1.6)e38 
erg s^âˆ’1; Haggard et al. 2017) and f(0.3âˆ’8 keV) = 1.58(+0.14/-0.13)eâˆ’14 
erg s^âˆ’1 cm^âˆ’2 (with Gamma = 1.6 +/- 0.3, unabsorbed L(0.3âˆ’10 keV) = 
42.5(+3.7/-3.5)e38 erg s^âˆ’1; Ruan et al. 2018), respectively.

Our findings here contradict recent reports of dimming in the X-ray flux 
from XMM Newton at 135 days (D'Avanzo et al. 2018), which was reported 
to be 2.1(+0.7/-0.5)e-15 erg s^âˆ’1 cm^âˆ’2 (0.3-10 keV unabsorbed). 
However, this reported flux value is a typo, and should be 
2.1(+0.7/-0.5)e-14 erg s^âˆ’1 cm^âˆ’2 (Dâ€™Avanzo 2018, private 
communication). Taking this corrected flux and rescaling to a 0.3-8 keV 
absorbed flux for comparison to the previous Chandra measurements above 
gives 1.67(+0.87/-0.64)e-14 erg s^âˆ’1 cm^âˆ’2. Thus, the recent X-ray data 
at 15.6 days (Chandra), 109.2 days (Chandra), 135 days (XMM), and 156.4 
days (Chandra) are all consistent with continued X-ray brightening. We 
provide a light curve table summarizing these measurements:

Days,  Telescope,  Flux* (0.3-8 abs),     Ref
----   ---------   ----------------       ---
15.6   Chandra     0.36(+0.10/-0.07)eâˆ’14  Haggard et al. (2017)
109.2  Chandra     1.58(+0.14/-0.13)eâˆ’14  Ruan et al. (2018)  
135    XMM         1.67(+0.87/-0.64)e-14  D'Avanzo et al. (2018) 
156.4  Chandra     1.93(+0.39/-0.32)e-14  This work

*Flux units: erg s^âˆ’1 cm^âˆ’2; all uncertainties are 90% confidence interval

Current post-merger models suggest that the origin of the X-rays could 
be afterglow emission from either a mildly-relativistic cocoon or a 
structured jet. For a cocoon, the continued rise of X-ray emission 
suggest that the cocoon has not yet reached a deceleration phase. For a 
structured jet, the rising X-ray emission suggest emission from the jet 
core has not yet entered the observed line of sight. Continued 
monitoring of GW170817 will be critical for discriminating between these 
and other models.

Note that another ~30 ks of Chandra observations during this same time 
interval are forthcoming.

We thank Belinda Wilkes and the Chandra scheduling, data processing, and 
archive teams for making these observations possible.


GRB_name: GRB170817A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22372
SUBJECT: GW170817/GRB170817A: Preliminary results of Chandra monitoring
DATE:    18/01/29 20:42:49 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

E. Troja (UMD/GSFC) and L. Piro (INAF/IAPS) report on behalf of
a larger collaboration:

The Chandra X-ray Observatory re-observed the field of GW170817
starting on January 17th, 2018, and performed five short exposures
observations as part of its on-going monitoring program (PI: Wilkes).

Only three of these exposures (ObsID: 20936, 20938, 20939) are currently
archived and available to the public. Here we report the preliminary 
findings
from these observations.

The X-ray afterglow is detected with high significance in all the exposures
at an average count rate of 0.0016 cts/s in the 0.5-8.0 keV energy band.
A preliminary inspection of the hardness ratio does not show any 
significant
spectral variation. Therefore, we perform a spectral analysis using an 
absorbed
power-law model with absorption column fixed at the Galactic value of
7.5E20 cm^-2 and a photon index Gamma=1.575 as derived from our broadband
analysis (Troja et al. 2018, arXiv:1801.06516).

We derive an unabsorbed X-ray flux of (3.2 +/- 0.3)E-14 erg/cm2/s in the
0.3-10 keV energy band. The quoted error is at the 68% confidence level.
This new measurement is higher than the value measured by Chandra
at ~110 days (~2.5E-14 erg/cm2/s, Troja et al. 2018), and higher than the
value measured by XMM-Newton at ~135 days (D'Avanzo et al., 2018).

The latest measurement is consistent with a rising afterglow with F~t^0.8,
although, within the errors, a slow turn-over of the X-ray light curve
cannot be excluded.

Further analysis is on-going.


GRB_name: GRB180126A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22373
SUBJECT: GRB 180126A CALET Gamma-Ray Burst Monitor detection
DATE:    18/01/29 21:18:24 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

T. Tamura (Kanagawa U), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (RIKEN), I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 180126A (Fermi-GBM trigger #538625796; INTEGRAL
SPI-ACS trigger #8000; Konus-Wind trigger time on 02:16:30.33)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 02:16:29.19 UTC
on 26 January 2018.  The burst signal was seen by all CGBM detectors.

The light curve shows a single pulse which starts at T+2 sec, peaks at
T+7 sec and ends at T+10 sec.  The T90 and the T50 durations measured
by the SGM data are 6.3 s +- 1.2 sec and 2.6 s +- 0.5 sec (40-1000
keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1200967960/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB170817A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22374
SUBJECT: GW170817/GRB170817A: Updated results from the full Chandra dataset
DATE:    18/01/30 13:00:12 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

E. Troja (UMD/GSFC) and L. Piro (INAF/IAPS) report on behalf of
a larger collaboration:

We analyzed the full set of five observations of GW170817
performed by the Chandra X-ray Observatory between January 17th
and January 28th, 2018, i.e. ~153 and ~164 days after the merger.
A log of observations is reported below:

ObsID     Exposure [ks]   0.5-8.0 keV count rate [cts/s]

20936     31.75           0.0018 +/- 0.0002
20937     20.77           0.0014 +/- 0.0003
20938     15.86           0.0019 +/- 0.0003
20939     22.25           0.0011 +/- 0.0002
20945     14.22           0.0010 +/- 0.0003

The average net count-rate is 0.00148 +/- 0.00011 cts/s,
consistent with the value of 0.00145 +/- 0.00014 observed
at 110 days (Troja et al. 2018, arXiv:1801.06516).
The average spectrum, obtained by coadding the five exposures,
is well described by an absorbed power-law model with
N_H=7.5E20 cm^-2 and photon index Gamma=1.65+/-0.16 (68% c.l.),
consistent with the value derived from the broadband spectrum
at earlier times (Troja et al. 2018, arXiv:1801.06516).
Based on this new analysis, we estimate an unabsorbed X-ray flux
of (2.6 +/- 0.3)E-14 erg/cm2/s (68% c.l.) in the 0.3-10 keV band,
consistent with the X-ray flux measured at 110 days.

Our results do not support the claim of a decreasing X-ray flux,
as suggested by D'Avanzo et al. (2018, arXiv:1801.06164), and
are consistent either with a slowly rising afterglow or a slow
turn-over of the X-ray light curve expected when the afterglow
reaches its peak (e.g. Lazzati et al. 2017, arXiv:1712.03237;
Troja et al. 2018, arXiv:1801.06516).

We note that the X-ray afterglow displays a marginal level of
variability on timescales of a few days, being the count-rate
from the last two exposures (20939,20945) consistently lower.
The spectrum from these two observations is characterized by a
photon index Gamma= 1.9 +/- 0.3 (68% c. l.), slightly softer
than the value measured in the first three exposures (20936,20937,
and 20938) Gamma = 1.59+/-0.17 (68% c. l.), yet consistent within
the large uncertainties. The lower count-rate and soft spectral
shape could be indicative of the cooling frequency entering the
X-ray band, although the limited statistics prevent us to draw
any firm conclusion.


GRB_name: GRB180204A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22375
SUBJECT: GRB 180204A: Swift detection of a short burst
DATE:    18/02/04 02:58:47 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

K. L. Page (U Leicester), A. P. Beardmore (U Leicester),
A. Deich (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), A. Tohuvavohu (PSU) and T. N. Ukwatta (LANL)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 02:36:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180204A (trigger=808483).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 330.118, +30.846 which is 
   RA(J2000) = 22h 00m 28s
   Dec(J2000) = +30d 50' 45"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 1.5 sec.  The peak count rate
was ~17000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 02:37:43.8 UT, 87.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 330.13359, 30.83807 which is equivalent
to:
   RA(J2000)  = 22h 00m 32.06s
   Dec(J2000) = +30d 50' 17.1"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 56 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 92 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.10. 

Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180204A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22376
SUBJECT: GRB 180204A: Swift-XRT refined Analysis
DATE:    18/02/04 10:26:23 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows
(PSU), A. Tohuvavohu (PSU), S. J. LaPorte (PSU) and K.L. Page report on
behalf of the Swift-XRT team:

We have analysed 8.0 ks of XRT data for GRB 180204A (Page et al. GCN
Circ. 22375), from 90 s to 21.2 ks after the  BAT trigger. The data
comprise 32 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The best available XRT position  (using the
promptly downlinked event data, the XRT-UVOT alignment and matching
UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 330.1333,
30.8381 which is equivalent to:

RA (J2000): 22 00 32.00
Dec(J2000): +30 50 17.1

with an uncertainty of 2.1 arcsec (radius, 90% confidence).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.15 (+/-0.03).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.02 (+0.23, -0.22). The
best-fitting absorption column is  6.9 (+1.7, -1.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.0 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.3 x 10^-11 (7.6 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      6.9 (+1.7, -1.5) x 10^21 cm^-2
Galactic foreground: 1.0 x 10^21 cm^-2
Excess significance: 6.5 sigma
Photon index:      2.02 (+0.23, -0.22)

If the light curve continues to decay with a power-law decay index of
1.15, the count rate at T+24 hours will be 2.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-13 (2.0 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00808483.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180204A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22377
SUBJECT: GRB 180204A: Enhanced Swift-XRT position
DATE:    18/02/04 10:47:55 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 6274 s of XRT Photon Counting mode data and 9 UVOT
images for GRB 180204A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 330.13329, +30.83785 which is equivalent
to:

RA (J2000): 22h 00m 31.99s
Dec (J2000): +30d 50' 16.2"

with an uncertainty of 1.4 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180204A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22378
SUBJECT: GRB 180204A: Fermi GBM detection
DATE:    18/02/04 14:24:46 GMT
FROM:    Adam Goldstein at Fermi-GBM/UAH  <adam.m.goldstein@msfc.nasa.gov>

P. Veres and C. Meegan (both UAH)
report on behalf of the Fermi GBM Team:

"At 02:36:16.93 UT on 04 February 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180204A (trigger 539404581 / 180204109) which was also detected by the Swift/BAT (Page et al., GCN 22375).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 68 degrees.

The GBM light curve shows two peaks
with a duration (T90) of about 1.2 s (50-300 keV).
The time-averaged spectrum from T0-0.1 s to T0+1.2 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.92 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 781 +/- 161 keV.

The event fluence (10-1000 keV) in this time interval is
(8.48 +/- 0.32)E-7 erg/cm^2. The 64-msec peak photon flux measured
starting from T0 in the 10-1000 keV band
is 19.7 +/- 1.6 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180204A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22379
SUBJECT: GRB 180204A: Swift/UVOT Upper Limits
DATE:    18/02/04 16:50:12 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180204A
92 s after the BAT trigger (Page et al., GCN Circ. 22375). A star is
present in the GSC whos position is consistent with the enhanced XRT
position (Osborne et al. GCN Circ. 22377).   No optical afterglow above
the stellar flux has been detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            92          242          147         >20.3
u_FC               304          554          246         >19.9
white               92        17884         1210         >20.8
v                  633        10587         1107         >19.0
b                  560        23622         1840         >20.7
u                  304        23062         2409         >21.1
w1                3943        22148         1917         >21.0
m2                 658        11492         1095         >20.8
w2                 609         6398          413         >20.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.10 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180204A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22380
SUBJECT: GRB 180204A: Swift-BAT refined analysis
DATE:    18/02/04 22:02:03 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

J. R. Cummings (CPI), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), J. P. Norris (BSU),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-186 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180204A (trigger #808483)
(Page et al., GCN Circ. 22375).  The BAT ground-calculated position is
RA, Dec = 330.123, 30.852 deg which is
  RA(J2000)  =  22h 00m 29.5s
  Dec(J2000) = +30d 51' 07.5"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 70%.

The mask-weighted light curve shows two distict pulses. The first
pulse starts and peaks at ~T0, and ends at ~T+0.2. The second pulse
starts at ~T+0.6 s, peaks at ~T+1 s, and ends at ~T+1.3 s.
T90 (15-350 keV) is 1.16 +- 0.12 sec (estimated error including systematics).

For the first pulse, the lag analysis finds a lag of -0.2 +- 1 ms for the
100-350 keV to 25-100 keV, and 0.2 +- 1.5 ms for the 50-100 keV to 15-25 keV
band. The second pulse has a lag of 5.6 +- 3.9 ms for the 100-350 keV to
25-100 keV, and 3.2 +- 6.6 ms for the 50-100 keV to 15-25 keV band.
These values are consistent with those of a short GRB.

The time-averaged spectrum from T-0.05 to T+1.29 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.09 +- 0.10.  The fluence in the 15-150 keV band is 4.8 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.05 sec in the 15-150 keV band
is 3.6 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/808483/BA/


GRB_name: GRB180205A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22381
SUBJECT: GRB 180205A: Swift detection of a burst with a bright optical counterpart
DATE:    18/02/05 04:45:57 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

P. A. Evans (U Leicester), J. A. Kennea (PSU),
K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of
the Neil Gehrels Swift Observatory Team:

BAT has detected GRB 180205A (trigger #808625), leading to a slew
and follow-up observations by Swift.  However, due to missing 
telemetry packets, no further BAT information is available at 
this time. 

The XRT began observing the field at 04:28:23.6 UT. XRT found 
a bright, uncatalogued X-ray source
located at RA, Dec 126.8206, 11.5419 which is equivalent to:
   RA(J2000)  = +08h 27m 16.94s
   Dec(J2000) = +11d 32' 30.8"
with an uncertainty of 5.6 arcseconds (radius, 90% containment). No
event data are yet available to determine the column density using
X-ray spectroscopy. 

The initial flux in the 2.5 s image was 9.50e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
at 04:28:30.79 UT. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 08:27:16.73 = 126.81970
  DEC(J2000) = +11:32:30.7  =  11.54185
with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.2
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.65 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.03. 

Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22382
SUBJECT: GRB 180205A: KAIT optical afterglow confirmation
DATE:    18/02/05 05:15:27 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

WeiKang Zheng and Alex Filippenko (UC Berkeley) report on behalf
of the KAIT GRB team:


The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 180205A (Evans, et al.,GCN
22381), starting at 04:31:40 UT immediately after receiving the
trigger. Observations were performed with an automatic sequence
in the clear (roughly R), V, and I filters, and the exposure time
was 20 s per imag. We detect the bright optical afterglow reported
by UVOT (Evans, et al.,GCN 22381). It faded from clear ~15.6 mag
from our first clear band image to ~16.8 mag 22.5 minutes later,
we therefore confirm it to be the optical afterglow of GRB 180205A.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22383
SUBJECT: GRB 180205A: GROND detection of the NIR/optical afterglow
DATE:    18/02/05 06:02:56 GMT
FROM:    Jan Bolmer at MPE/Garching  <jan@bolmer.de>

J. Bolmer (ESO/MPE) and D.A. Kann (HETH/IAA-CSIC) report:

We observed the field of GRB 180205A (Swift trigger 808625; P.A. Evans et al.,
GCN 22381) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 04:38 UT on February 05, 2018, 13 minutes after
the GRB trigger. They were performed at an average seeing of 1".1 and at
an average airmass of 1.33.

We clearly detect the NIR/optical transient of GRB 181205A reported
also by Zheng et al., GCN 22382.

Based on total exposures of 200 seconds in gâ€™r'i'zâ€™ and 180 seconds in JHK
at a midtime of 04:43 UT, 17 minutes after the burst, we measure
the following preliminary magnitudes (AB magnitude
system):

g' = 16.83 +/- 0.01 mag,
r' = 16.68 +/- 0.01 mag,
i' = 16.56 +/- 0.01 mag,
z' = 16.38 +/- 0.01 mag,
J  = 16.22 +/- 0.02 mag,
H  = 16.05 +/- 0.02 mag, and
K  = 16.08 +/- 0.14 mag.

Magnitudes and are calibrated against PanSTARRS and 2MASS
field stars and are not corrected for the Galactic foreground extinction
corresponding to a reddening of E_(B-V)= 0.03 mag in the direction of the
burst (Schlegel et al. 1998).

Observations are continuing.

We thank Markus Rabus for the excellent support from La Silla.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22384
SUBJECT: GRB 180205A: VLT/X-shooter redshift
DATE:    18/02/05 10:09:25 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir (U. Leicester), K. E. Heintz (U. Iceland, DARK/NBI),
J. Selsing (DARK/NBI), J. Japelj (API, U. Amsterdam), 
J. Bolmer (ESO/MPE), D. A. Kann (HETH/IAA-CSIC), D. Xu (NAOC), 
A. de Ugarte Postigo (HETH/IAA-CSIC and DARK/NBI),
D. Malesani (DARK/NBI), J. P. U. Fynbo (NBI), G. Pugliese (API, U. Amsterdam)
report on behalf of the STARGATE Consortium:

We observed the bright optical counterpart of the Swift
GRB 180205A (Evans et al. GCN 22381; Zheng et al. GCN 22382;
Bolmer et al. GCN 22383) with the ESO Very Large Telescope UT 2 (Kueyen)
equipped with the X-shooter spectrograph, covering the wavelength
range 3500-24000 AA.  Observations started on February 05.25 UT
(approx 1.5 hr after the GRB) and consisted of 4 exposures of
600 s each.

The spectrum exhibits many absorption features including
C II, Si II, Si II*, Al II, Fe II, Mg II, Mg I at a common redshift of
z=1.409. We conclude this is the redshift of the GRB.

We acknowledge the expert support from the ESO observing
staff, in particular Jesus Corral-Santana and Cedric Ledoux.


GRB_name: GRB180204A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22385
SUBJECT: Konus-Wind observation of GRB 180204A
DATE:    18/02/05 12:16:14 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The short-duration GRB 180204A (Swift-BAT detection and
analysis: Page et al., GCN 22375; Cummings et al., GCN 22380;
Fermi-GBM observation: Veres&Meegan, GCN 22378)
triggered Konus-Wind at T0=9372.902 s UT (02:36:12.902).

The burst light curve shows two peaks in the interval
from ~T0-0.1 s to ~T0+1.1 s. The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst
had a fluence of 3.81(-0.57,+0.66)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.038 s,
of 2.95(-0.80,+0.87)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst
(measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.36(-0.29,+0.38)
and Ep = 843(-177,+263) keV (chi2 = 37/45 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.5
(chi2 = 37/44 dof)

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180204_T09372/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180205A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22386
SUBJECT: GRB 180205A: Fermi GBM observation
DATE:    18/02/05 19:12:58 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:

"At 04:25:25.39 UT on 05 February 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180205A (trigger 539497530 / 180205184), 
which was also detected by the Swift/BAT (Evans et al. 2008, GCN 22381)
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 94
degrees.

The GBM light curve shows several pulses with a duration (T90) of about 15 s
(50-300 keV).
The GBM detectors were turned off for SAA entry about 70 seconds after the
trigger. The time-averaged spectrum from T0-2.048 s to T0+9.216 s is
well fit by a power law function with an exponential high-energy cutoff. 
The power law index is -1.38 +/- 0.15 and the cutoff energy, 
parameterized as Epeak, is 85.0 +/- 14.4  keV

The event fluence (10-1000 keV) in this time interval is
(1.5 +/- 1.4)E-06  erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+3.71204 s in the 10-1000 keV band
is 4.7 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22387
SUBJECT: GRB 180205A: Mondy optical observations
DATE:    18/02/05 19:19:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI),  A. Pozanenko (IKI),  E. Klunko (ISTP), E. Mazaeva 
(IKI)  report on behalf of of larger GRB follow-up collaboration:

We observed the field of GRB 180205A (Evans  et al., GCN 22381)    with
AZT-33IK telescope of Sayan observatory (Mondy).  We took several images 
in R-filter starting on Feb. 05 (UT) 12:54:29.  The afterglow of GRB 
180205A (Evans  et al., GCN 22381; Zheng et al., GCN 22382; Bolmer et 
al., GCN 22383)  is  clearly detected in a stacked image. Preliminary 
photometry is following.

Date        UT start  t-T0      Filter Exp.   OT      Err.  UL
                      (mid, days)    (s)


2018-02-05  12:54:29  0.372*    R      30*120 19.47   0.07  21.8

* The time after XRT observation start  at (UT) 04:28:23.69.

The photometry is based on several nearby SDSS DR9 stars

SDSS_id                 R_Lupton
J082719.98+113324.0 16.206 0.013
J082717.26+113400.0 16.092 0.013
J082715.06+113230.6 15.553 0.013


GRB_name: GRB180205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22388
SUBJECT: GRB 180205A: VLT polarimetry 
DATE:    18/02/05 19:20:24 GMT
FROM:    Klaas Wiersema at U of Warwick  <K.Wiersema@warwick.ac.uk>

K. Wiersema (Warwick) & S. Covino (INAF / OAB) report on behalf of the
Stargate consortium:

We observed the afterglow of GRB 180205A (Evans et al. GCN 22381; 
Zheng et al. GCN 22382; Bolmer et al. GCN 22383, Tanvir et al. GCN 22384) 
with the ESO Very Large Telescope equipped with FORS2. We obtained
a set of imaging polarimetry observations in R band, starting at 07:07 UT
(approximately 2.67 hours after burst). Using archival calibration data, we 
find a low level of polarisation, P ~ 0.9%, similar to the majority of 
late-time GRB afterglow measurements (Covino & Gotz 2016, A&AT 29, 205). 

We acknowledge excellent support from the ESO staff.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22390
SUBJECT: GRB 180205A: Nickel telescope optical observations
DATE:    18/02/06 00:10:25 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

Edward Falcon, Sameen Yunus, WeiKang Zheng and Alex Filippenko (UC Berkeley)
report on behalf of the KAIT GRB team:

We observed the field of GRB 180205A (Evans et al., GCN 22381) with
the 1-m Nickel telescope located at Lick observatory, California.
Observations started about 1.32 hours after the burst and lasted for
~1.4 hours. We detected the optical afterglow (Evans et al. GCN 22381;
Zheng et al. GCN 22382; Bolmer et al. GCN 22383; Tanvir et al. GCN 22384;
Volnova et al. GCN 22387) in all the images taken with B,V,R and I filters.
A preliminary light curve is posted at the following link along with KAIT
observations (Zheng et al. GCN 22382):
http://astro.berkeley.edu/~zwk/grb/GRB180205A/GRB180205A_nickel_kait.png


GRB_name: GRB180205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22391
SUBJECT: GRB 180205A: Further GROND Observations reveal Afterglow is still bright
DATE:    18/02/06 02:28:56 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

J. Bolmer (ESO/MPE) and D.A. Kann (HETH/IAA-CSIC) report:

We once more observed the field of GRB 180205A (Swift trigger 808625; 
P.A. Evans et al., GCN 22381) simultaneously in g'r'i'z'JHK with GROND 
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope 
at ESO La Silla Observatory (Chile).

Observations started at 01:28 UT on February 06, 2018, 0.8765 days after 
the GRB trigger. They were performed at an average seeing of 1".1 and at 
an average airmass of 1.68.

Based on total exposures of 1320 seconds in g'r'i'z' and 1200 seconds in 
JHK at a midtime of 01:40 UT, 0.8854 days after the burst, we measure 
the following preliminary magnitudes (AB magnitude system):

g' = 20.29 +/- 0.03 mag,
r' = 20.03 +/- 0.03 mag,
i' = 19.81 +/- 0.03 mag,
z' = 19.66 +/- 0.03 mag,
J  = 19.47 +/- 0.12 mag,
H  = 19.16 +/- 0.19 mag, and
K  > 17.6 mag.

These magnitudes are significantly brighter than the extrapolation of 
our GROND data from the first night (Bolmer & Kann, GCN 22383). We point 
out that the Nickel/KAIT light curve (E. Falcon, GCN 22390) shows a 
plateau phase setting in beyond 10ks, at a time we were not able to 
observe with GROND anymore. This plateau would explain why the afterglow 
remains bright.

Magnitudes and are calibrated against SDSS and 2MASS field stars and are 
not corrected for the Galactic foreground extinction corresponding to a 
reddening of E_(B-V)= 0.03 mag in the direction of the burst (Schlegel 
et al. 1998).

Further observations are encouraged.

We thank Markus Rabus for the excellent support from La Silla.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22392
SUBJECT: GRB 180205A:  Xinglong TNT optical observation
DATE:    18/02/06 02:43:28 GMT
FROM:    L.P. Xin at NAOC  <xlp@nao.cas.cn>

L. P. Xin,   F. Q. Pi,  J. Y. Wei,  Y. L. Qiu, J. S. Deng,  
J. Wang,  X. H. Han, X. M. Meng, C. Wu, D. TURPIN, H. L. Li report:

We began to observe GRB 180205A  (Evens et al., GCN 22381)  
with Xinglong  0.8-m TNT telescope, China,  at 2018-02-05, 16:11:42(UT),
about 12.6 hours the burst.

We obtained several  R-band images with an exposure time of 300 sec for each frame.  
The optical afterglow (Evens et al., GCN 22381; Zheng et al., GCN 22382; 
Bolmer et al., GCN 22383, 22391; Tanvir et al., GCN 22384;  Volnova et al., GCN 22387,
Wiersema et al., GCN 22388; Falcon et al., 22390 ) is clearly detected in our stacked image with 5*300 sec.
The brightness is estimated to be about R~19.97 mag  calibrated 
by USNO B1.0 R2 mag at about 12.7 hours after the burst,

We acknowledge the excellent support from Xinglong staff Miao Zhang. 


GRB_name: GRB180205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22393
SUBJECT: GRB 180205A: Swift-BAT refined analysis
DATE:    18/02/06 02:57:19 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), P. A. Evans (U Leicester),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+700 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180205A (trigger #808625)
(Evans et al., GCN Circ. 22381).  The BAT ground-calculated position is
RA, Dec = 126.819, 11.536 deg which is
  RA(J2000)  =  08h 27m 16.5s
  Dec(J2000) = +11d 32' 11.1"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-7 s and ends at ~T+11 s. The two major peaks occur at ~T-5 s
and ~T0 s, respectively. T90 (15-350 keV) is 15.5 +- 3.1 sec (estimated
error including systematics).

The time-averaged spectrum from T-7.04 to T+10.87 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.04 +- 0.13.  The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.20 sec in the 15-150 keV band
is 3.4 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/808625/BA/


GRB_name: GRB180205A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22394
SUBJECT: GRB 180205A: Swift-XRT refined Analysis
DATE:    18/02/06 04:46:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Tohuvavohu
(PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU) and P.A. Evans report on
behalf of the Swift-XRT team:

We have analysed 5.0 ks of XRT data for GRB 180205A (Evans et al. GCN
Circ. 22381), from 180 s to 33.8 ks after the  BAT trigger. The data
comprise 85 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. Using 3849 s of PC mode data and 7 UVOT images, we
find an enhanced XRT position (using the XRT-UVOT alignment and
matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
126.81966, +11.54210 which is equivalent to:

RA (J2000): 08h 27m 16.72s
Dec(J2000): +11d 32' 31.6"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

The light curve can be modelled with an initial power-law decay with an
index of alpha=4.8 (+0.6, -0.5), followed by a break at T+279 s to an
alpha of 1.00 (+/-0.04).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.72 (+0.18, -0.17). The
best-fitting absorption column is  8.7 (+2.8, -2.5) x 10^21 cm^-2, at a
redshift of 1.409, in addition to the Galactic value of 3.4 x 10^20
cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index
of 1.89 (+0.15, -0.14) and a best-fitting absorption column of 3.1
(+3.0, -2.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10
keV flux conversion factor deduced from this spectrum  is 3.5 x 10^-11
(4.0 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 3.4 x 10^20 cm^-2
Intrinsic column:    3.1 (+3.0, -2.6) x 10^21 cm^-2 at z=1.409
Photon index:      1.89 (+0.15, -0.14)

If the light curve continues to decay with a power-law decay index of
1.00, the count rate at T+24 hours will be 0.013 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.5 x
10^-13 (5.2 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00808625.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22395
SUBJECT: GRB 180205A: Nanshan-1m optical observations
DATE:    18/02/06 12:02:12 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

Z.P. Zhu, H.X. Feng, D. Xu (NAOC), B.Y. Yu (HNU), J.H. Liu, X. Zhang, 
H.B. Niu, S.G. Ma, J.Z. Liu, A. Esamdin, L. Ma, Y. Zhang (XAO) report on 
behalf of a larger collaboration:

We observed the field of GRB 180205A (Evens et al., GCN 22381) using the 
1m telescope located at Nanshan, Xinjiang, China, and 10x60s R-band 
frames, starting at 16:31:07 UT on 2018-02-05.

The optical afterglow (e.g., Evens et al., GCN 22381; Zheng et al., GCN 
22382) is clearly detected in our stacked image.

Preliminary photometry results are as follows:

Tmid-T0  Exposure  Filter   Mag   MagErr
  (hr)           (s)
12.15     10x60       R       19.67    0.10

Photometry is calibrated with nearby SDSS stars, and errors are only 
statistical values.


GRB_name: GRB180205A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22396
SUBJECT: GRB 180205A: Swift/UVOT Detection
DATE:    18/02/06 12:58:32 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and P. A. Evans (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180205A
182 s after the BAT trigger (Evans et al., GCN Circ. 22381).
A fading source consistent with the XRT position
(Page et al., GCN Circ. 22394),
also detected by (Zheng et al. GCN 22382;
Bolmer et al. GCN 22383; Tanvir et al. GCN 22384;
 Volnova et al. GCN 22387; Falcon et al. GCN 22390; Xin et al. 22392;
Zhu et al. GCN 22395)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  08:27:16.74 = 126.81975 (deg.)
    Dec (J2000) = +11:32:30.9  =  11.54191 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373)
for the first finding chart (FC) exposure and the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag
white_FC           182          331          147         15.75 +/- 0.02
white              540          732           36         16.33 +/- 0.02
v                  158          612           52         16.11 +/- 0.09
b                  515          710           39         16.65 +/- 0.07
u                  490          686           39         16.82 +/- 0.07
uvw1               466          661           39         16.04 +/- 0.10
uvm2               441          636           39         16.32 +/- 0.15
uvw2               391          585           39         17.06 +/- 0.17

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22397
SUBJECT: GRB 180205A: Optical observations
DATE:    18/02/06 14:45:44 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Changsu Choi, Gregory S. Paek, Sung A O, Sophia Kim
(CEOU/SNU), Yuji Urata (NCU), H.-I. Sung (KASI) on behalf of a larger
collaboration


We observed the afterglow of GRB 180205A (Evans et al., GCN 22381; Zheng et
al. GCN 22382; Bolmer et al. GCN 22383; Tanvir et al. GCN 22384; Volnova et
al. GCN 22387; Falcon et al. GCN 22380; Xin et al. 22392; Zhu et al. 22395;
Emery et al. 22396) with the 1-m telescope at the Mt. Lemmon Optical
Astronomy Observatory (LOAO) and the 0.8m and 0.25 telescopes at the
McDonald Observatory. The observation started at about 1 hour after the
initial alert, using B, V, R, I, z, and Y filters. The observation
continued throughout the night.

We clearly identify the optical afterglow in these bands, and
â€‹a â€‹
preliminary photometry in R-band shows R ~ 18 mag at 1.3 hours post-burst.

Further observations and analysis are being carried out
â€‹, including telescopes in Koreaâ€‹
. Additional
â€‹results â€‹
will be reported
â€‹ as they become availableâ€‹
.


GRB_name: GRB180205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22398
SUBJECT: GRB 180205A: confirmation of Swift-BAT trigger time.
DATE:    18/02/06 16:04:12 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester) and D.M. Palmer (LANL) report on behalf of the
Swift team:

Due to a telemetry gap, the trigger time of GRB 180205A was not reported 
in the early GCN Circulars.

The BAT trigger time was 04:25:29.3 UT (on 2018 Feb 5). We apologise for 
any inconvenience caused by the omission.

This circular is an official product of the Swift team.

[GCN OPS NOTE(06feb18): Per author's request, "UT" was added to the
time listed in the second sentence.]


GRB_name: GRB180204A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22399
SUBJECT: GRB 180204A: MITSuME Okayama optical upper limits
DATE:    18/02/07 08:04:10 GMT
FROM:    Kotaro Morita at Tokyo Tech  <morita@hp.phys.titech.ac.jp>

 K. Morita, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 180204A (K. L. Page et al.,
GCN Circular #22375) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Okayama Astrophysical
Observatory, Japan.
The observation started on 2018-02-04 9:37:11.83 UT. We did not find any
new point source within the XRT circle (J. P. Osborne et al., GCN Circular
#22377) in all three bands.
We obtained following limits for the magnitudes.

T0+[h]    MID-UT      T-EXP[sec]    g'        Rc        Ic
------------------------------------------------------------
-------------------------------------------
~7.0         9:48:54         1140       >17.5     >17.4      >17.0
------------------------------------------------------------
-------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration


GRB_name: GRB180202A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22400
SUBJECT: GRB 180202A: Insight-HXMT/HE detection
DATE:    18/02/07 09:18:13 GMT
FROM:    Yue Huang at IHEP  <huangyue@ihep.ac.cn>

Y. Huang, Y. Zhu, S. L. Xiong, X. B. Li, C. K. Li, C.Z. Liu,
X.F. Li, Z. W. Li, Z. Chang, J. L. Zhao, A. M. Zhang, Y. F. Zhang,
X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
 
At 2018-02-02T05:04:28.00 UT, the Insight-HXMT/HE detected
GRB 180202A(trigger ID: HEB180202211) in a routine search of the data,
which was also triggered by INTEGRAL/SPI-ACS and KONUS-Wind.
 
The Insight-HXMT/HE light curve consists of a single pulse
with a duration (T90) of 7.2 s measured from T0+0.2 s.
The 500-ms peak rate, measured from T0+4.2 s, is 4245.7 cnts/sec.
The total counts from this burst is 15793.7 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB180202211_lc.jpg
 
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.
 
The analysis results presented above are preliminary, 
final results will be published elsewhere.
 
Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome.


huangyue@ihep.ac.cn


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22401
SUBJECT: GRB 180205A optical observations
DATE:    18/02/07 10:52:14 GMT
FROM:    Arto Oksanen at Nyrola Obs., Finland  <oksanen@nyrola.jklsirius.fi>

Arto Oksanen (Hankasalmi Obs., Hankasalmi, Finland) and D. Malesani (DARK/NBI) 
report the following observations of GRB 180205A (Evans et al., GCN 22381):

A. Oksanen observed the location of GRB 180205A using the Hankasalmi
Observatory 0.4-m Richey-Chretien telescope with an SBIG STL-1001E
camera. Forty 60-second frames were obtained with clear filter 
between 18:19 UT and 19:41 UT on 2018 February 5.
  
The afterglow is detected in co-added image.

Photometry of co-added image yields the following:

t-t0(d)     m(CR)   err(CR)
0.605       19.43    0.06

Photometry was performed using comparison stars from the Pan-STARRS survey 
(Chambers et al. 2016; arXiv:1612.05560), after adopting the conversion 
formulae by Lupton (2005).


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22403
SUBJECT: GRB 180205A: AbAO optical observations
DATE:    18/02/08 07:52:59 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  A. Pozanenko (IKI),  A. Volnova  (IKI), R. Inasaridze 
(AbAO),  V. Ayvazian  (AbAO),  O. Kvaratskhelia (AbAO), G. Inasaridze 
(AbAO),  I. Molotov (KIAM), report on behalf of larger GRB follow-up 
collaboration:

We observed the field of GRB 180205A (Evans  et al., GCN 22381) with 
AS-32 (0.7m) telescope of Abastumani Observatory starting on Feb., 06 
(UT)  23:53:51. We obtained several unfiltered images  starting on Feb. 
05 (UT) 12:54:29.  The afterglow of GRB 180205A (Evans et al., GCN 
22381; Zheng et al. GCN 22382; Bolmer et al. GCN 22383; Tanvir et al. 
GCN 22384; Volnova et al. GCN 22387; Falcon et al. GCN 22380; Xin et al. 
22392; Zhu et al. 22395; Emery et al. 22396; Im et al., GCN 22397)  is 
clearly detected in a stacked image. Preliminary photometry is following.

Date        UT start  t-T0      Filter Exp.   OT      Err.  UL
                      (mid, days)    (s)


2018-02-06  17:09:23  1.54515   CR     24*60 20.32   0.10  21.2

The photometry is based on several nearby SDSS DR9 stars

SDSS_id                R_Lupton
J082719.98+113324.0    16.206    0.013
J082717.26+113400.0    16.092    0.013
J082715.06+113230.6    15.553    0.013


GRB_name: GRB180205A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22404
SUBJECT: GRB180205A: Optical observations with DOAO 1m telescope
DATE:    18/02/08 13:46:01 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Changsu Choi, Myungshin Im (CEOU/SNU), Tae-Woo Kim, Wonseok Kang (KYSC), on
behalf of a larger collaboration.


We observed the field of GRB 180205A (Evans et al., GCN 22381) with the 1m
telescope of Deokheung Optical Astronomy Observatory (DOAO) in Korea,
starting from 2018/02/05 11:22:11 for three consecutive nights.

We obtained B, V, R-band images and clearly detected the afterglow in a
series of 300s exposure images. The afterglow in R band The afterglow is
dimming at a rate of about 0.75 mag per day fon average rom 02/05 to 02/07
(Evans et al., GCN 22381; Zheng et al. GCN 22382; Bolmer et al. GCN 22383;
Tanvir et al. GCN 22384; Volnova et al. GCN 22387; Falcon et al. GCN 22380;
Xin et al. GCN 22392; Zhu et al. GCN 22395; Emery et al. GCN 22396; Im et
al., GCN 22397; Oksanen et al. 22401; Mazaeva et al., GCN 22403).


Date UT mid Filter Exp. Mag(Vega) Err

2018-02-05 11:14:41 R 300s 19.47 0.12

2018-02-05 11:56:58 R 300s 19.48 0.08

2018-02-06 12:04:55 R 1200s 20.38 0.05

2018-02-06 14:07:30 R 1200s 20.29 0.04

2018-02-07 12:20:31 R 1200s 20.88 0.06

2018-02-07 13:57:28 R 1200s 21.14 0.07


The photometric calibration is based on the APASS stars within 6' radius
from GRB. The observation is continuing.


GRB_name: GRB180210A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22407
SUBJECT: GRB 180210A: Fermi GBM detection
DATE:    18/02/10 17:28:41 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico & INFN Bari)
reports on behalf of the Fermi GBM Team:


"At 12:24:38.55 UT on 10 February 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180210A (trigger 539958283 / 180210517).
The on-ground calculated location, using the GBM trigger data, is

RA = 3.33, DEC = 21.01 (J2000 degrees),

with an uncertainty of 1.5 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error [Connaughton et al. 2015, ApJS, 216, 32]).

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux of the GRB.
This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the GBM ground location is 31 degrees.

The GBM light curve consists of a multi-peaked
emission episode with a duration (T90) of about 40 s (50-300 keV).
The time-averaged spectrum from T0 to T0+31 s is best fit by
a Band function with Epeak = 145 +/- 3 keV,
alpha = -0.45 +/- 0.02, and beta = -2.60 +/- 0.06.

The event fluence (10-1000 keV) in this time interval is
(4.21 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+24 s in the 10-1000 keV band
is 16.7 +/- 0.3 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180210A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22408
SUBJECT: GRB 180210A: Fermi-LAT detection
DATE:    18/02/10 20:00:21 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

F. Dirirsa (U. Johannesburg) and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi-LAT team:


"At 12:24:38.55 UT on February 10, 2018 Fermi-LAT detected
high-energy emission from GRB 180210A, which was also
detected by Fermi-GBM (trigger 539958283/180210517)
(E. Bissaldi, GCN 22407).

The best LAT on-ground location is found to be

RA, Dec = 1.80, 18.35 (J2000 deg)

with an error radius of 0.18 deg (90 % containment, statistical error only).
This was 30 deg from the LAT boresight at the time of the trigger
and triggered an autonomous repoint of the spacecraft.

The data from the Fermi-LAT show a significant increase in the event rate
that is spatially correlated with the trigger with high significance.
The highest-energy photon is a 4 GeV event
which is observed 363 seconds after the GBM trigger.

A Swift ToO has been approved for this burst.

The Fermi-LAT point of contact for this burst is
Feraol F. Dirirsa (fdirirsa@uj.ac.za).


The Fermi-LAT is a pair conversion telescope designed
to cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration
between NASA and DOE in the U.S. and many scientific
institutions across France, Italy, Japan and Sweden."


GRB_name: GRB180210A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22409
SUBJECT: GRB 180210A: Swift ToO observations
DATE:    18/02/10 21:10:45 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Fermi/LAT GRB 180210A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020787

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/LAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22411
SUBJECT: GRB 180205A: BAO optical observations
DATE:    18/02/11 10:53:10 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI),  A. Novichonok (KIAM), A. Pozanenko (IKI), S. Kotov  (SAO 
RAS), T. Movsesyan (BAO),  E. Mazaeva (IKI)  report on behalf of of
larger GRB follow-up collaboration:

We observed the field of GRB 180205A (Evans  et al., GCN 22381) with 
Schmidt-1m telescope of Byurakan Astrophysical Observatory (BAO).  We took 
several images in r (Sloan)-filter  starting on Feb. 08 (UT) 12:54:29.  The 
afterglow of GRB 180205A (Evans et al., GCN 22381; Zheng et al. GCN 22382; 
Bolmer et al. GCN 22383;Tanvir et al. GCN 22384; Volnova et al. GCN 22387; 
Falcon et al. GCN 22380; Xin et al. GCN 22392; Zhu et al. GCN 22395; Emery 
et al. GCN  22396; Im et al., GCN 22397; Oksanen et al. 22401; Mazaeva et 
al., GCN 22403)  is  clearly detected in a stacked image. Preliminary 
photometry  is following.

Date              UT start     t-T0          Filter  Exp.   OT      Err.  UL
                                         (mid, days)        (s)


2018-02-08  18:00:00  3.59550    r     12*300 21.3    0.2  21.9

The photometry is based on several nearby SDSS DR9 stars

SDSS_id                         r
J082719.98+113324.0 16.357 0.005
J082717.26+113400.0 16.292 0.005
J082715.06+113230.6 15.744 0.004


GRB_name: GRB180210A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22412
SUBJECT: GRB 180210A: Tiled Swift observations
DATE:    18/02/11 19:31:45 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
Fermi/LAT GRB 180210A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00069

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the Fermi/LAT event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180210A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22413
SUBJECT: GRB 180210A: Swift-XRT afterglow detection
DATE:    18/02/12 14:45:50 GMT
FROM:    Valerio D'Elia at ASDC  <valerio.delia@ssdc.asi.it>

A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA),
A. Melandri (INAF-OAB), S. J. LaPorte (PSU), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U. Leicester) and P.A. Evans
(U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 180210A (Dirirsa et al. GCN Circ. 22408),
collecting 7.5 ks of Photon Counting (PC) mode data between T0+31.0 ks
and T0+117.4 ks. 

Four uncatalogued X-ray sources are detected, of which one ("Source 1",
the brightest) is fading with 3-sigma significance, and is therefore
likely the GRB afterglow. Using 4922 s of PC mode data and 4 UVOT
images, we find an enhanced XRT position (using the XRT-UVOT alignment
and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
1.84177, +18.55274 which is equivalent to:

RA (J2000): 00h 07m 22.02s
Dec(J2000): +18d 33' 09.9"

with an uncertainty of 1.7 arcsec (radius, 90% confidence). This
position is 12.4 arcmin from the Fermi/LAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.57 (+0.36, -0.28).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.3 (+/-0.4). The
best-fitting absorption column is  3.6 (+1.7, -1.4) x 10^21 cm^-2, in
excess of the Galactic value of 3.7 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 2.7 x 10^-11 (5.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.6 (+1.7, -1.4) x 10^21 cm^-2
Galactic foreground: 3.7 x 10^20 cm^-2
Excess significance: 3.7 sigma
Photon index:      2.3 (+/-0.4)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020787.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020787.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22414
SUBJECT: GRB 180205A: SEDM Observations
DATE:    18/02/13 15:30:27 GMT
FROM:    Virginia Cunningham at U of MD  <vcunning@astro.umd.edu>

V. Cunningham (U of Maryland), J. D. Neill (Caltech), S. B. Cenko
(NASA GSFC), and R. Walters (Caltech) report on behalf of the
SEDM team:

We observed the optical counterpart to GRB 180205A (Evans et al.,
GCN 22381) with the Spectral Energy Distribution Machine (SEDM)
on the 60 inch telescope at Palomar Observatory. The SEDM is a low
resolution (R ~ 100) integral field unit spectrometer with a multi-band
(ugri) â€œrainbowâ€ camera imager (see Blagorodnova et al., 2017,
 astro-ph/1710.02917).

The SEDM began observing the optical counterpart at 04:44 UTC
(18 minutes after the burst trigger time). We performed 2 x 1350 s
exposures over the wavelength range 3800-10600 A. We see no strong
evidence for emission or absorption features at the quoted redshift of
z=1.409 (Tanvir et al., GCN 22384). The continuum emission is well-fit
by a power law spectrum with index alpha = 0.77 (f_nu ~ nu^-alpha).

[GCN OPS NOTE(07sep19): Per author's request, in the last sentence
the "alpha = 0.67" was changed to "alpha = 0.77".]


GRB_name: GRB180210A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22415
SUBJECT: Konus-Wind observation of GRB 180210A
DATE:    18/02/14 13:27:42 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 180210A
(Fermi-GBM detection: Bissaldi, GCN Circ. 22407;
Fermi-LAT detection: Dirirsa and Bissaldi, GCN Circ. 22407)
triggered Konus-Wind at T0=44678.454 s UT (12:24:38.454).

The burst light curve shows a multipeaked structure
which starts at ~T0-6 s and has a total duration of ~65 s.
The emission is seen up to ~5 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180210_T44678/

As observed by Konus-Wind, the burst
had a fluence of 4.81(-0.30,+0.36)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+20.224 s,
of 5.35(-1.07,+1.10)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+47.360 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.49(-0.13,+0.15),
the high energy photon index beta = -3.12(-0.54,+0.30),
the peak energy Ep = 153(-8,+8) keV
(chi2 = 84/97 dof).

The spectrum near the maximum count rate
(measured from T0+16.128 to T0+22.784 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.08(-0.24,+0.27),
the high energy photon index beta = -3.25(-1.02,+0.37),
the peak energy Ep = 152(-11,+12) keV
(chi2 = 106/91 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180112A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22421
SUBJECT: GRB 180112A: AstroSat CZTI detection
DATE:    18/02/19 07:17:20 GMT
FROM:    Varun Bhalerao at Indian Inst of Tech  <varunb@iitb.ac.in>

Y. Sharma (IITB), V. Sharma (IUCAA), Arvind B. (IISER Pune), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of long duration GRB 180112A, which was also detected by Insight-HXMT (C. Z. Liu et al., GCN 22353), CALET (S. Ozawa et al., GCN 22358), Konus Wind (Trigger time: 16:29:11.736) and INTEGRAL SPI-ACS (Trigger time : 16:30:38).

The source was clearly detected in the 40-200 keV energy range. The light curve shows three distinc peaks, starting with a weak peak at 16:29:09 (UT) followed by two strong peaks at 16:30:45 (UT) and 16:32:54 (UT) respectively. The measured peak count rate is 96 cts/s above the background in combined data of four quadrants, with a total of 37730 cts. The local mean background count rate was 479 cts/s. Using cumulative rates, we measure a T90 of 209 s.

All three peaks of GRB were also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180204A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22422
SUBJECT: GRB 180204A: 15 GHz upper limits from AMI
DATE:    18/02/19 11:31:28 GMT
FROM:    Joe Bright at U of Oxford  <joe.bright@physics.ox.ac.uk>

J. Bright, R. Fender (Oxford), and K. P. Mooley (NRAO, Caltech; Jansky Fellow)

We have initiated the AMI short-GRB program. We observed the field of GRB 180204A (Page et al., GCN 22375) with the AMI Large Array at 15.5 GHz. Our observations on 2018 Feb 04.54, Feb 05.55, Feb 06.62 and Feb 09-11 (0.43 d, 1.44 d, 2.51 d and 5-7 d coadd post-burst) do not reveal any radio source at the XRT location (Osborne et al., GCN 22377), with 3sigma upper limits of 55 uJy, 54 uJy, 76 uJy and 63 uJy respectively.

Results from the AMI short-GRB program will be posted on the AMI-GRB database available at http://4pisky.org/ami-grb/ <http://4pisky.org/ami-grb/>. We thank the MRAO staff for scheduling these observations.


GRB_name: GRB180218A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22423
SUBJECT: IPN Triangulation of GRB 180218A (long/bright)
DATE:    18/02/19 16:54:13 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D.Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team, and

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report:

The long-duration, very bright GRB 180218A has been detected by
Fermi(GBM; trigger 540659650), Konus-Wind, INTEGRAL(SPI-ACS), and 
Swift(BAT) at about 54845 s UT (15:14:05). The burst was outside the 
coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    46.279 (03h 05m 07s) +52.589 (+52d 35' 20")
  Corners:
    49.798 (03h 19m 12s) +45.859 (+45d 51' 34")
    50.993 (03h 23m 58s) +46.050 (+46d 03' 00")
    41.217 (02h 44m 52s) +59.126 (+59d 07' 35")
    39.654 (02h 38m 37s) +58.828 (+58d 49' 40")
  ---------------------------------------------
The error box area is 12.13 sq. deg, and its maximum
dimension is 14.48 deg (the minimum one is 51 arcmin).
The Sun distance was 89 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180218_T54845/IPN/

The time history and spectrum will be given in forthcoming
GCN Circulars.


GRB_name: GRB180218A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22424
SUBJECT: GRB 180218A: Fermi GBM Detection
DATE:    18/02/19 21:26:35 GMT
FROM:    Suraj Poolakkil at UAH  <sp0076@uah.edu>

S. Poolakkil (UAH) and C. Meegan (UAH) report on
behalf of the Fermi GBM Team:

"At 15:14:05.49 UT on 18 February 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180218A (trigger 540659650 / 180218635). This GRB
was also triangulated by IPN (Svinkin et al., GCN 22423).

The on-ground calculated location, using the GBM trigger
data, is RA = 47.23, DEC = 46.65, with an uncertainty
of 4 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The GBM light curve consists of a single bright peak
with a duration (T90) of about 6 s (50-300 keV).
The time-averaged spectrum from T0-1.02 s to T0+10.24 s is
best fit by a Band function with Epeak= 388 +/- 13 keV, alpha = -0.62 +/-
0.03 and beta = -2.36 +/- 0.06.

The event fluence (10-1000 keV) in this time interval is
 (5.51 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+4.28 s in the 10-1000 keV band
is 65.9 +/- 0.86 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180218A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22425
SUBJECT: GRB 180218A CALET Gamma-Ray Burst Monitor detection
DATE:    18/02/20 06:02:34 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

W. Ishizaki (ICRR), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The bright GRB 180218A (Svinkin et al., GCN circ. 22423;
Poolakkil et al., GCN circ. 22424) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 15:14:05.326 UTC on 18 February 2018.
The burst signal was seen by all CGBM detectors.

The burst light curve shows a single multi-peaked pulse which starts at
T+0.5 sec, peaks at T+4.6 sec and ends at T+8.5 sec.  The T90 and the
T50 durations measured by the SGM data are 4.75 +- 1.27 sec and
1.88  +- 0.13 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1203001776/

The CALET data used in this analysis are provided by the Waseda CALET
Operation Center located at the Waseda University.


GRB_name: GRB180218A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22426
SUBJECT: Konus-Wind observation of GRB 180218A
DATE:    18/02/20 13:20:00 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 180218A (IPN Triangulation: Svinkin et al., GCN 22423;
Fermi-GBM detection: Poolakkil et al., GCN 22424;
CALET Gamma-Ray Burst Monitor detection: Ishizaki et al., GCN 22425)
triggered Konus-Wind at T0=54845.382 s UT (15:14:05.382)

The burst light curve shows a single, bright, multi-peaked pulse.
The total duration of the burst is ~17 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(7.6 Â± 0.6)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+3.648, of (3.2 Â± 0.3)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+14.080 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.52 (-0.08,+0.09),
the high energy photon index beta = -2.27 (-0.15,+0.11),
the peak energy Ep = 361 (-31,+33) keV,
chi2 = 82/97 dof.

The spectrum near the peak count rate (measured from T0
to T0+4.096 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.40 (-0.11,+0.12),
the high energy photon index beta = -2.39 (-0.24,+0.16),
the peak energy Ep = 384 (-39,+43) keV,
chi2 = 88/95 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180218_T54845/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB180221A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22427
SUBJECT: Swift Trigger 811074: possible GRB 180221A
DATE:    18/02/21 06:50:00 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

M. Stamatikos (OSU/NASA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and
A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 06:30:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located possible GRB 180221A (trigger=811074).  Swift did not slew 
immediately due to an observational constraint. 
The BAT on-board calculated location is 
RA, Dec 326.772, -72.868 which is 
   RA(J2000) = 21h 47m 05s
   Dec(J2000) = -72d 52' 05"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 20 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~2 sec after the trigger. 

Due to an observing constraint, Swift will not slew until T0+43.6
minutes. There will be no XRT or UVOT data until this time. 

Due to the marginal significance of this event (7.01 sigma)
and the proximity of Swift to the SAA at the time of the
trigger, we cannot confirm that this is an actual GRB. 
Observations with XRT will help to determine the
nature of this event. 

Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180221A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22428
SUBJECT: GRB180221A: MASTER-OAFA optical observations
DATE:    18/02/21 07:57:28 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

E.Gorbovskoy, V. Lipunov, N.Tyurina, V.Kornilov, D.Zimnukhov, V.Vladimirov, 
A.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.Chazov, D. Kuvshinov
(Lomonosov Moscow State University, SAI),

R.Podesta, C.Lopez, F. Podesta
(Observatorio Astronomico Felix Aguilar (OAFA),National University of San Juan, 
Argentina),

H. Levato, C. Saffe
(Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San 
Juan, Argentina),

D.Buckley, S. Potter
(South African Astronomical Observatory),

R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),

O.Gres,  N.M.Budnev
(Irkutsk State University),

A. Tlatov, V.Senik, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory)

V.Yurkov, A.Gabovich, Yu.Sergienko
(Blagoveschensk Educational State University, Blagoveschensk),


MASTER-OAFA  robotic telescope (MASTER-Net: http://observ.pereplet.ru) located 
in Argentina was pointed to the Swift possible GRB 180221A (Stamatikos et al GCN 22427)
  119 sec after notice time and 257 sec after trigger time at 2018-02-21 06:35:01 UT.
On our first (50s exposure)  set we didn't find optical transient  within 
SWIFT-BAT error-box (RA, Dec 326.772, -72.868, radius 3arcmin).

The 5-sigma upper limit has been about 18.3  mag at single (50 sec) and 
19.5  at coadd (310 sec) images.

The message may be cited.

====================================================================
The observations were made on
zenit distance 73 degrees,
The Sun  altitude  is -40.6 degree.
Dist. to Moon: 92.17 (Moon coord. 35.522966 d, 8.630816 d)


GRB_name: GRB180219A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22429
SUBJECT: GRB 180219A CALET Gamma-Ray Burst Monitor detection
DATE:    18/02/21 12:19:27 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

M. L. Cherry (LSU), A. Yoshida, T. Sakamoto, V. Pal'shin, Y. Kawakubo,
M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), S. Ricciarini (U of Florence),
A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long GRB 180219A (Fermi-GBM trigger #540732857; Konus-Wind trigger
time on 11:34:41.20) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
11:36:05.118 UTC on 19 February 2018.  CGBM triggered on the second pulse,
~2 min after the Fermi GBM trigger.  The signal of the initial pulse was
significantly attenuated due to the large incident angle.  The burst emission
was seen by all CGBM detectors.

The light curve shows two broad multi-peaked pulses, which started at T+115 sec
and ended at T+2 sec.  The T90 and the T50 durations measured by the SGM data
are 109.5 +- 7.5 sec and 76.9 +- 7.0 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1203075094/

The CALET data used in this analysis are provided by the Waseda CALET Operation
Center located at the Waseda University.


GRB_name: GRB180205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22430
SUBJECT: GRB 180205A: Mondy optical observations
DATE:    18/02/21 16:55:22 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Volnova (IKI),  A. Pozanenko (IKI),  E. Klunko 
(ISTP)  report on behalf of of larger GRB follow-up collaboration:

We observed the field of GRB 180205A (Evans  et al., GCN 22381)    with
AZT-33IK telescope of Sayan observatory (Mondy).  We obtained several 
images in R and B-filter on Feb. 05  - Feb. 19.  The afterglow of GRB
180205A (Evans et al., GCN 22381; Zheng et al. GCN 22382; Bolmer et al. 
GCN 22383;Tanvir et al. GCN 22384; Volnova et al. GCN 22387; Falcon et 
al. GCN 22380; Xin et al. GCN 22392; Zhu et al. GCN 22395; Emery et al. 
GCN  22396; Im et al., GCN 22397; Oksanen et al. 22401; Mazaeva et al., 
GCN 22403; Volnova et al., GCN 22411;  Cunningham et al., GCN 22414)  is 
  detected in  stacked images. Preliminary photometry is following.

Date        UT start  t-T0      Filter Exp.   OT      Err.  UL
                       (mid, days)    (s)


2018-02-05  15:21:12  0.49438    R      30*120 19.32  0.04  21.9
2018-02-05  16:23:51  0.53094    B      20*120 20.70  0.17  21.3
2018-02-05  20:03:02  0.69011    R      60*60  19.60  0.08  21.7
2018-02-06  16:07:42  1.50850    R      30*120 20.25  0.07  22.0
2018-02-14  15:48:28  9.50557    R      45*120 22.46  0.13  23.9
2018-02-18  13:23:22  13.40481   R      45*120 n/d    n/d   23.0
2018-02-19  14:37:56  14.45658   R      45*120 23.6   0.3   23.6

The photometry is based on nearby SDSS DR9 stars

SDSS_id                 R_Lupton
J082719.98+113324.0 16.206 0.013
J082717.26+113400.0 16.092 0.013
J082715.06+113230.6 15.553 0.013


GRB_name: GRB180221A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22432
SUBJECT: Swift trigger 811074 (possible GRB 180221A): Swift refined analysis
DATE:    18/02/22 04:48:13 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. P. Beardmore (U. Leicester), C. B. Markwardt (GSFC), M. H. Siegel (PSU),
S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), J. R. Cummings (CPI),
P. A. Evans (U Leicester), J. A. Kennea (PSU), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
report on behalf of the Swift team:

Using the data set from the recent telemetry downlink, we report further
analysis of the possible GRB 180221A (trigger #811074)
(Stamatikos et al., GCN Circ. 22427).

Using the BAT data from T-239 to T+963 sec,
the BAT ground-calculated position is
RA, Dec = 326.787, -72.891 deg which is
   RA(J2000)  =  21h 47m 08.9s
   Dec(J2000) = -72d 53' 27.3"
with an uncertainty of 2.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 31%.

The BAT mask-weighted light curve shows a hint of a weak pulse that starts
at ~ T+2 s and ends at ~T+15 s. However, the mask-weighted light curve also
suggests a negative average count rate for the background interval (~T-200 s
to ~T0), which indicates incorrect background estimation that is likely caused
by the high count rates around the SAA. When performing the analysis without
subtracting the background image, the image significance of the pulse in the
15-350 keV drops to ~ 3.5 sigma, which is consistent with noise fluctuation.

Because of the uncertainty in the background estimation, it is difficult to
confirm the nature of the source with BAT data alone.

Swift-XRT observed the field of the possible GRB 180221A (BAT trigger
811074) in Photon Counting mode for 5.73 ks from 3.1 ks to 16.4 ks
after the trigger. We detect a candidate counterpart within the BAT
error circle with an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue) of
RA, Dec (J2000) = 326.77306, -72.86947, which is equivalent to:

RA (J2000):  21h 47m 05.53s
Dec(J2000): -72d 52' 10.1"

with an uncertainty of 2.2 arcsec (radius, 90% confidence).

Although faint, with a peak rate of 0.035 c/s (over the 0.3-10.0 keV
energy band), the source appears to be fading with a power-law decay
slope alpha = 0.57 +/- 0.31.

A spectrum formed from the PC mode data over this interval can be
fitted with an absorbed power-law with a photon index 1.8 (+0.5 -0.4)
and column density of 4.4(+14.2 -4.4)E20 cm^-2, in addition to the
Galactic column density of 3.98e20 cm^-2 in the direction of the
source. The observed 0.3-10 keV flux is 7.8E-13 erg cm^-2 s^-1.

The Swift/UVOT began settled observations of the field of the possible
GRB 180221A 2950 s after the BAT trigger.  No optical afterglow consistent
with the XRT position is detected in the initial UVOT exposures nor is any
other optical transient detected down to a 3-sigma upper limit of 21.4 in
the white filter.

Further Swift observations are planned to determine if the
source fades further.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/811074/BA/


GRB_name: GRB180222A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22433
SUBJECT: GRB 180222A: Swift detection of a burst
DATE:    18/02/22 13:37:12 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

J. K. Cannizzo (NASA/UMBC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
P. A. Evans (U Leicester), J.D. Gropp (PSU), J. A. Kennea (PSU),
A. Y. Lien (GSFC/UMBC), Z. Liu (NAOC/U. Leicester),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 13:10:03 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180222A (trigger=811235).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 256.571, -36.803, which is 
   RA(J2000)  =  17h 06m 17s
   Dec(J2000) = -36d 48' 08"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single FRED-like peak
with a duration of about 25 sec.  The peak count rate
was ~1400 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 13:11:22.7 UT, 79.2 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 256.54119, -36.80929 which
is equivalent to:
   RA(J2000)  = 17h 06m 09.89s
   Dec(J2000) = -36d 48' 33.4"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 88 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (6.65 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 7.9
(+11.04/-4.96) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 82 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 97% of
the XRT error circle. Because of the density of catalogued stars, further
analysis is required to report an upper limit for any afterglow in the
sub-image. The 8'x8' region for the list of sources generated on-board covers
100% of the XRT error circle. Because of the density of catalogued stars,
further analysis is required to report an upper limit for any afterglow in the
region. No correction has been made for the large, but uncertain, extinction
expected. 

Burst Advocate for this burst is J. K. Cannizzo (cannizzo AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180222A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22434
SUBJECT: GRB 180222A:  A long GRB detected by INTEGRAL
DATE:    18/02/22 14:19:25 GMT
FROM:    Sandro Mereghetti at IASF-Milano/INAF  <sandro@iasf-milano.inaf.it>

S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, 
V.Savchenko (ISDC, Versoix), L. Ducci (IAAT, Germany and ISDC, Versoix) 
and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team 
report:

a gamma ray burst lasting about 20 s has been detected by IBAS in the
IBIS/ISGRI data at 13:10:02  UT of February 22, 2018

The refined coordinates (J2000) are:

R.A.= 256.5418 deg
DEC.= -36.8016  deg

with an uncertainty of  1.5   arcmin (90% c.l.).

The burst had a peak flux of about 1 counts/cm2/s (20-200 keV, 1-s 
integration time) and a fluence in the same energy range of about 6e-7 
erg/cmq.

This burst was also detected by the Swift/BAT (Cannizzo et al., GCN 
22433).

A plot of the light curve will  be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html


GRB_name: GRB180222A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22435
SUBJECT: GRB 180222A: Enhanced Swift-XRT position
DATE:    18/02/22 18:01:44 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2537 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 180222A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 256.54179, -36.81207 which is equivalent
to:

RA (J2000): 17h 06m 10.03s
Dec (J2000): -36d 48' 43.4"

with an uncertainty of 6.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180222A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22436
SUBJECT: GRB 180222A: Swift-BAT refined analysis
DATE:    18/02/22 21:35:52 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  J. K. Cannizzo (NASA/UMBC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+423 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180222A (trigger #811235)
(Cannizzo, et al., GCN Circ. 22433).  The BAT ground-calculated position is
RA, Dec = 256.537, -36.819 deg which is
  RA(J2000)  =  17h 06m 08.8s
  Dec(J2000) = -36d 49' 08.2"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 98%.

The mask-weighted light curve consists of a single FRED pulse beginning at ~T-8 sec,
peaking at T+0 sec and decaying to background by T+60 sec. T90 (15-350 keV) is 
64.0 +- 22.6 sec (estimated error including systematics).

The time-averaged spectrum from -15.1 to 48.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.40 +- 0.21.  The fluence in the 15-150 keV band is 7.9 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+8.44 sec in the 15-150 keV band
is 0.4 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/811235/BA/


GRB_name: GRB180222A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22437
SUBJECT: GRB 180222A: Swift-XRT refined Analysis
DATE:    18/02/23 01:10:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB),
J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU),
P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester) and J.K. Cannizzo report on behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 180222A (Cannizzo et al. GCN
Circ. 22433), from 82 s to 24.2 ks after the  BAT trigger. The data
comprise 54 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Beardmore et al. (GCN Circ. 22435).

The light curve can be modelled with a power-law decay with a decay
index of alpha=2.25 (+0.19, -0.18).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.7 (+0.6, -0.5). The
best-fitting absorption column is  1.7 (+0.9, -0.8) x 10^22 cm^-2, in
excess of the Galactic value of 6.6 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 5.4 x 10^-11 (9.2 x 10^-11) erg
cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      1.7 (+0.9, -0.8) x 10^22 cm^-2
Galactic foreground: 6.6 x 10^21 cm^-2
Excess significance: 2.3 sigma
Photon index:      1.7 (+0.6, -0.5)

If the light curve continues to decay with a power-law decay index of
2.25, the count rate at T+24 hours will be 1.1 x 10^-6 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.7 x
10^-17 (9.7 x 10^-17) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00811235.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180221B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22438
SUBJECT: GRB 180221B CALET Gamma-Ray Burst Monitor detection
DATE:    18/02/23 10:45:37 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Ricciarini (U of Florence), A. Yoshida, T. Sakamoto, V. Pal'shin,
Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
I. Takahashi (IPMU), Y. Asaoka, S. Ozawa, S. Torii (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR),
M. L. Cherry (LSU), A. V. Penacchioni, P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long GRB 180221B (Konus-Wind trigger time on 12:30:00.79) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 12:29:59.616 UTC on
21 February 2018.  The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure which starts at T0,
peaks at T0+16 sec and ends at T0+78 sec.  The T90 and the T50 durations
measured by the SGM data are 66.6 +- 6.8 sec and 21.1 +- 6.3 sec
(40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1203251126/

The CALET data used in this analysis are provided by the Waseda CALET
Operation Center located at the Waseda University.


GRB_name: GRB180222A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22439
SUBJECT: GRB 180222A: Swift/UVOT Upper Limits 
DATE:    18/02/23 20:49:37 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

S. A. Sebzda (PSU) and J. K. Cannizzo (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180222A
83 s after the BAT trigger (Cannizzo et al., GCN Circ. 22433).
No optical afterglow consistent with the XRT position
(Cannizzo et al. GCN Circ. 22433)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            83          233          147         >20.6
u_FC               295          545          246         >19.5
white               83         1196          353         >21.6
v                  624         1073           58         >18.0
b                  551         1171           58         >18.6
u                  295         1146          285         >19.7
w1                 673         1122           58         >18.0
m2                 649         1097           58         >18.0
w2                 600         1221           78         >19.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.68 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180218A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22441
SUBJECT: GRB 180218A: AstroSat CZTI detection
DATE:    18/02/24 15:17:31 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma (IUCAA), D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a bright GRB 180218A, which was also detected by IPN Triangulation(Svinkin D. et al., GCN 22423), Fermi-GBM (Poolakkil S. et al., GCN 22424), CALET (Ishizaki W. et al., GCN 22425) and Konus-Wind (Frederiks D. et al., GCN 22426).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 15:14:10.5 UT. The measured peak count rate is 1360.5 cts/s above the background in combined data of four quadrants, with a total of 4651 cts. The local mean background count rate was 491.4 cts/s. Using cumulative rates, we measure a T90 of 4.9 s. In Preliminary analysis, we find that 380.4 compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180224A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22442
SUBJECT: GRB 180224A: Swift detection of a burst with an optical counterpart
DATE:    18/02/24 22:32:57 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J.D. Gropp (PSU),
H. A. Krimm (NSF/USRA), S. J. LaPorte (PSU),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and A. Tohuvavohu (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 22:21:07 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180224A (trigger=811561).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 202.661, +38.088 which is 
   RA(J2000)  =  13h 30m 39s
   Dec(J2000) = +38d 05' 17"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single FRED peak
with a duration of about 15 sec.  The peak count rate
was ~2200 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 22:22:28.1 UT, 80.5 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 202.68324, 38.07881 which is equivalent
to:
   RA(J2000)  = 13h 30m 43.98s
   Dec(J2000) = +38d 04' 43.7"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 71 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 8.24
x 10^19 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 85 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 13:30:44.09 = 202.68370
  DEC(J2000) = +38:04:44.6  =  38.07906
with a 90%-confidence error radius of about 0.63 arc sec. This position is 0.9
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.94 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01. 

Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180224A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22443
SUBJECT: GRB 180224A: Enhanced Swift-XRT position
DATE:    18/02/25 00:57:27 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1326 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 180224A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 202.68383, +38.07876 which is equivalent
to:

RA (J2000): 13h 30m 44.12s
Dec (J2000): +38d 04' 43.5"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180224A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22444
SUBJECT: GRB180224A: Global MASTER-Net bright OT detection 
DATE:    18/02/25 10:33:21 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V.Vladimirov, V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov, 
D.Zimnukhov,   A.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.Chazov, 
D. Kuvshinov (Lomonosov Moscow State University, SAI)

A. Tlatov, V.Senik, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory)

D.Buckley, S. Potter
(South African Astronomical Observatory),

O.Gres,  N.M.Budnev
(Irkutsk State University),

V.Yurkov, A.Gabovich, Yu.Sergienko
(Blagoveschensk Educational State University, Blagoveschensk),

R.Podesta, C.Lopez, F. Podesta
(Observatorio Astronomico Felix Aguilar (OAFA),
National University of San Juan,  Argentina),

H. Levato, C. Saffe
(Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), 
San
Juan, Argentina),

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
(The Instituto de Astrofisica de Canarias),



MASTER-Kislovodsk (Russia)  robotic telescope (MASTER-Net: 
http://observ.pereplet.ru) located in Kislovodsk was pointed to
the  GRB180224.93 21 sec after  notice time and 37 sec after trigger time 
at 2018-02-24 22:21:44 UT. On our  unfiltered polarizing  exposures
set we  found 1 bright optical transient within  SWIFT
error-box (ra=202.658 dec=38.0878 r=0.05) 
brighter then 18.1.

RA,DEC  = 13h 30m 44.057s , +38d  04m 44.55 s
Error = 0.1 arcsec
maximal magnitute ~ 16.7


The 5-sigma upper limit has been about 18.1mag
The message may be cited.


====================================================================



The observations made on zenit distance = 23 degrees, galaxy latitude b = 
76 degree.
The moon (68 % bright part) is 16 degrees above the horizon. The distance 
between  moon and  object is 97 degrees.
The sun  altitude  is -53.0 degree.
The object can be observed till sunrise at 2018-02-25 03:53:29 UT.


MASTER-SAAO  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was pointed to the  GRB180224.94 92 sec after notice time 
and 176 sec after trigger time at 2018-02-24 22:24:12 UT. On our first
  set we  not found optical transient within SWIFT error-box 
(ra=202.638 dec=38.0819 r=0.1) brighter then 15.8.

The 5-sigma upper limit has been about 15.8 mag
The message may be cited.


The observations made on high zenit distance = 82 degrees, galaxy latitude 
b = 76 degree.
The moon (68 % bright part) is  6 degrees above the horizon. The distance 
between  moon and  object is 97
The sun  altitude  is -48.3 degree.
The object can be observed till sunrise at 2018-02-25 04:21:26.


This message can be cited.


GRB_name: GRB180224A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22445
SUBJECT: GRB 180224A: Swift-XRT refined Analysis
DATE:    18/02/25 13:55:08 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), B. Sbarufatti
(INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S.L. Gibson
(U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester),
V. D'Elia (ASDC) and A.Y. Lien report on behalf of the Swift-XRT team:

We have analysed 7.2 ks of XRT data for GRB 180224A (Lien et al. GCN
Circ. 22442), from 84 s to 47.4 ks after the  BAT trigger. The data
comprise 35 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Evans et al. (GCN Circ. 22443).

The light curve can be modelled with an initial power-law decay with an
index of alpha=0.70 (+/-0.08), followed by a break at T+3451 s to an
alpha of 2.00 (+0.30, -0.25).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.65 (+0.17, -0.16). The
best-fitting absorption column is  9.2 (+5.4, -4.7) x 10^20 cm^-2, in
excess of the Galactic value of 8.2 x 10^19 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.1 x 10^-11 (4.6 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.2 (+5.4, -4.7) x 10^20 cm^-2
Galactic foreground: 8.2 x 10^19 cm^-2
Excess significance: 2.9 sigma
Photon index:      1.65 (+0.17, -0.16)

If the light curve continues to decay with a power-law decay index of
2.00, the count rate at T+24 hours will be 5.7 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.3 x
10^-14 (2.6 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00811561.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180224A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22446
SUBJECT: GRB 180224A: RATIR Optical Observations 
DATE:    18/02/25 17:01:05 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 180224A (Lien et al., GCN 22442) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2018/02 25.23 to 2018/02 25.53
UTC (7.24 to 14.42 hours after the BAT trigger), obtaining a total of
3.91 hours exposure in the r and i bands.

We detect a source at 13:30:44.11 38:04:44.2 (J2000, Â± 0.5 arcsec),
within the Swift-XRT error circle, in comparison with the SDSS DR9, with
the following magnitudes:

  r = 22.94 +/- 0.13
  i = 22.08 +/- 0.06

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

The position and magnitudes of this source are consistent with the SDSS
DR9 galaxy SDSS J133044.06+380443.0, which has r = 22.56 +/- 0.18 and i
= 21.83 +/- 0.14. We suggest that this might be the host galaxy of the
GRB.

Vladimirov et al. (GCN 22444) report a early 16.1 mag transient in the
Swift XRT error circle. Our non-detection 7 hours later suggests that
the afterglow faded extremely quickly.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180224A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22447
SUBJECT: GRB 180224A: Swift-BAT refined analysis
DATE:    18/02/25 18:19:11 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180224A (trigger #811561)
(Lien et al., GCN Circ. 22442).  The BAT ground-calculated position is
RA, Dec = 202.675, 38.073 deg which is
  RA(J2000)  =  13h 30m 41.9s
  Dec(J2000) = +38d 04' 23.0"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 93%.

The mask-weighted light curve shows a FRED-like pulse that starts at ~ T0,
peaks at ~ T+1 s, and ends at ~T+15 s. T90 (15-350 keV) is 10.9 +- 3.6 sec
(estimated error including systematics).

The time-averaged spectrum from T-0.48 to T+14.57 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.11 +- 0.18.  The fluence in the 15-150 keV band is 4.7 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.40 sec in the 15-150 keV band
is 1.4 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/811561/BA/


GRB_name: GRB180224A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22448
SUBJECT: GRB 180224A: AbAO optical observations
DATE:    18/02/25 20:06:13 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  A. Pozanenko (IKI),  A. Volnova  (IKI), R. Inasaridze 
(AbAO),  V. Ayvazian  (AbAO),  O. Kvaratskhelia (AbAO), G. Inasaridze 
(AbAO),  I. Molotov (KIAM), report on behalf of larger GRB follow-up 
collaboration:

We observed the field of GRB 180224A  (Lien  et al., GCN 22442) with AS-32 
(0.7m) telescope of Abastumani Observatory starting on Feb. 25  (UT) 
01:07:37.   The afterglow of GRB 180224A (Lien  et al., GCN 22442; 
Vladimirov et al., GCN 22444) is  clearly detected in a stacked image. 
Preliminary photometry is following.

Date              UT start      t-T0         Filter   Exp.    OT       Err. 
UL
                      (mid, days)                            (s)

2018-02-25  01:07:37   0.15162   CR     60*60  21.88   0.15  22.6

The photometry is based on nearby SDSS DR9 stars

SDSS_id                            R_Lupton
J133038.17+380528.6    17.45
J133040.16+380535.7    17.10
J133051.85+380146.4    17.91

We confirm the fast decay of the afterglow and possible host galaxy 
association  SDSS DR9 J133044.06+380443.0 with the afterglow source (Watson 
et al., GCN 22446). 


GRB_name: GRB180210A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22450
SUBJECT: GRB 180210A: Insight-HXMT/HE observation
DATE:    18/02/26 02:59:43 GMT
FROM:    Xuefeng Lu at IHEP  <luxf@ihep.ac.cn>

X. F. Lu, J. Y. Liao, C. K. Li, Y. Huang, Y. Zhu, S. L. Xiong, X. B. Li,
C. Z. Liu, Z. W. Li, J. L. Zhao, Y. F. Zhang, X.F. Li, Z. Chang, Y. J. Jin, 
C. L. Zou (IHEP), A. M. Zhang, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
 
At 2018-02-10T12:24:38.55 UT, the Insight-HXMT/HE detected
GRB 180210A(trigger ID: HEB180210517) in a routine search of the data,
which was also triggered by Fermi/GBM(GCN Circ. 22407),Fermi/LAT(GCN Circ. 22408), 
Swift/XRT(GCN Circ. 22413) and KONUS-Wind(GCN Circ. 22415).
 
The Insight-HXMT/HE light curve consists of a multi-peaked pulse
with a duration (T90) of 26.7 s measured from T0+3.9 s.
The 1-s peak rate, measured from T0+23.9 s, is 3173.8 cnts/sec.
The total counts from this burst is 40447.9 counts.

URL_LC: http://www.hxmt.org/images/GRB/HEB180210517_lc.jpg
 
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.

The time-averaged spectrum from T0-8 to T0+30 s is adequately fit by a Power
Law model with spectral index = -1.86 +/- 0.03. The energy fluence is 
(4.5 +/- 0.2) E-05 erg/cm^2 in 200 - 5000 keV in this time interval.
 
The analysis results presented above are preliminary, 
final results will be published elsewhere.
 
Insight-HXMT is the first Chinese space X-ray telescope, which was funded
jointly by the China National Space Administration (CNSA) and the Chinese
Academy of Sciences (CAS). More information about it could be found at:
http://www.hxmt.org/index.php/enhome.

[GCN OPS NOTE(26feb18): "2018-02-10T17:29:06.000" was changed to "2018-02-10T12:24:38.55"
and "HEB180210728" was changed to "HEB180210517".]


GRB_name: GRB180223A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22451
SUBJECT: IPN Triangulation of GRB 180223A (long)
DATE:    18/02/26 05:26:13 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

A long-duration GRB 180223A was detected
by Konus-Wind, INTEGRAL (SPI-ACS), Mars-Odyssey (HEND),
and Swift (BAT) at about 22171 s UT (06:09:31).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    33.144 (02h 12m 35s) +40.407 (+40d 24' 25")
  Corners:
    32.485 (02h 09m 56s) +38.962 (+38d 57' 43")
    33.550 (02h 14m 12s) +42.132 (+42d 07' 57")
    33.877 (02h 15m 30s) +41.789 (+41d 47' 22")
    32.819 (02h 11m 16s) +38.591 (+38d 35' 28")
  ---------------------------------------------
The error box area is 1.1 sq. deg, and its maximum
dimension is 3.6 deg (the minimum one is 19.8 arcmin).
The Sun distance was 71 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180223_T22171/IPN

The time history and spectrum will be given in forthcoming GCN 
Circulars.


GRB_name: GRB180224A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22452
SUBJECT: GRB 180224A: OASDG optical observations
DATE:    18/02/26 10:10:08 GMT
FROM:    Luca Izzo at IAA-CSIC  <Luca.Izzo@ICRA.it>

L. Izzo (IAA-CSIC), A. Noschese (AC-OASDG) report:

We observed the field of GRB 180224A (Lien et al. GCN 22442) with the 0.5m telescope of the Osservatorio Astronomico S. Di Giacomo located in Agerola, Italy ( http://acgo.it/oa ). 
We obtained a series of 9x180 s images in the Rc filter, starting at 23:33:36 UT, ~ 1.21 hrs after the GRB detection. In our stacked image, we find no source at the position of the observed optical counterpart (Vladimirov  et al. GCN 22444, Watson et al. GCN 22446, Mazaeva et al. GCN 22448) down to a 3-sigma limit of Rc (Vega) > 20.2.  The calibration was performed using nearby stars in the USNO B1 catalog.


GRB_name: GRB180223A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22453
SUBJECT: Konus-Wind observation of GRB 180223A
DATE:    18/02/26 11:22:09 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 180223A (IPN Triangulation: Hurley et al., GCN 22451)
triggered Konus-Wind at T0=22171.045 s UT (06:09:31.045)

The burst light curve shows a bright, multi-peaked structure,
which started at ~T0-20 s and peaked at ~T0+30 s.
The total duration of the burst is ~200 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(8.9 Â± 1.0)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+30.912, of (1.0 Â± 0.1)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+62.464 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.00 (-0.10,+0.12),
the high energy photon index beta = -2.31 (-0.32,+0.18),
the peak energy Ep = 284 (-31,+33) keV,
chi2 = 83/97 dof.

The spectrum near the peak count rate (measured from T0+24.832
to T0+38.656 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.95 (-0.09,+0.10),
the high energy photon index beta = -2.44 (-0.40,+0.21),
the peak energy Ep = 310 (-37,+43) keV,
chi2 = 98/97 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180223_T22171/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB180224A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22454
SUBJECT: GRB 180224A: Swift/UVOT Detection
DATE:    18/02/26 17:54:14 GMT
FROM:    Sam LaPorte at PSU  <sjl5346@psu.edu>

GRB 180224A: Swift/UVOT Detection

S. J. LaPorte (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180224A
85 s after the BAT trigger (Lien et al., GCN Circ. 22442).
A fading source consistent with the XRT position
(Evans et al. GCN Circ. 22443) also detected by (Lipunov et al. GCN Circ.
22444; Watson et al. GCN Circ. 22446; Pozanenko et al. GCN Circ. 22448)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  13:30:44.10 = 202.68377 (deg.)
    Dec (J2000) = +38:04:44.5  =  38.07902 (deg.)
with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric
system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: 

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               61          211          294         18.9 +/- 0.07
white              553         5337          287         20.7 +/- 0.33
v                  603         1397           97        >18.4
b                  552         1348           78        >19.5
u                  273         5063          500        >20.3
w1                 652         1446           97        >18.7
m2                 824          844           19        >18.2
w2                 751          771           19        >17.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180221B
Detection_method: Insight-HXMT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22456
SUBJECT: GRB 180221B: Insight-HXMT/HE observation
DATE:    18/03/03 09:46:14 GMT
FROM:    Yue Zhu at IHEP  <zhuyue@ihep.ac.cn>

Y. Zhu, X. Ma, S. L. Xiong, X. B. Li, C. K. Li, Y. Huang, J. Y. Liao,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao, A. M. Zhang, 
Y. F. Zhang, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU),
F. J. Lu, L. M. Song, H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:

At 2018-02-21T12:30:01.000 (T0), the Insight-HXMT detected 
GRB 180221B (trigger ID: HEB180221520) in a routine search of the data, 
which was also observed by CALET/CGBM (GCN Circ. 22438).

The Insight-HXMT light curve mainly consists of multi-pulses 
with a duration (T90) of 65.8 s measured from T0+1.05 s.  
The 1-second peak rate, measured from T0+13.0 s, is 2888.2 cnts/sec. 
The total counts from this burst is 44805.8 counts. 

URL_LC: http://www.hxmt.org/images/GRB/HEB180221520_lc.jpg 

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (record energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

The analysis results presented above are preliminary; 
final results will be published elsewhere.

Insight-HXMT is the first Chinese space X-ray telescope, which was funded 
jointly by the China National Space Administration (CNSA) and the Chinese 
Academy of Sciences (CAS). More information about it could be found at: 
http://www.hxmt.org/index.php/enhome .


GRB_name: GRB180305A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22457
SUBJECT: GRB 180305A: Fermi-LAT detection
DATE:    18/03/05 15:32:53 GMT
FROM:    Magnus Axelsson at Stockholm U.  <magaxe@kth.se>

M. Axelsson (KTH and Stockholm Univ.) and E. Bissaldi (Politecnico and INFN Bari), report on behalf of the Fermi-LAT team:

At 09:26:08.66 UT on March 05, 2018, Fermi-LAT detected high-energy emission from GRB 180305A, which was also detected by Fermi-GBM (trigger 541934773 / 180305393).

The best LAT on-ground location is found to be

RA, Dec = 49.7, 32.1 (J2000)

with an error radius of 0.12 deg (90 % containment, statistical error only).

This location was a few degrees outside the LAT field of view at the time of the trigger. It entered the FoV approximately 200s later, and remained visible until around 2600s after the trigger time.

The data from the Fermi-LAT show a significant increase in the event rate that is spatially correlated with the trigger with high significance. More than 10 events above 100 MeV are detected. The highest-energy photon is a 9 GeV event which is observed ~1630 seconds after the GBM trigger.

A Swift ToO has been approved for this burst.

The Fermi-LAT point of contact for this burst is Magnus Axelsson (magaxe@kth.se<mailto:magaxe@kth.se>).

The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.


GRB_name: GRB180305A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22458
SUBJECT: GRB 180305A: Fermi GBM detection
DATE:    18/03/05 17:10:52 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 09:26:08.66 UT on 05 March 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180305A (trigger 541934773 / 180305393) which
was also detected by the Fermi LAT (Axelsson et al., GCN 22457).
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 70 degrees.

The GBM light curve consists of a single bright pulse
with a duration (T90) of about 12.5 s (50-300 keV).
The time-averaged spectrum from T0 to T0+24.1 s is best fit by
a Band function with Epeak= 334 +/- 10 keV, alpha = -0.48 +/- 0.02
and beta = 2.29 +/- 0.07.

The event fluence (10-1000 keV) in this time interval is
(3.302 +/- 0.023)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.65 s in the 10-1000 keV band
is 32.2 +/- 0.5 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180305A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22459
SUBJECT: GRB 180305A: Swift ToO observations
DATE:    18/03/05 18:06:15 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Fermi/LAT GRB 180305A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020789

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/LAT event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180305A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22460
SUBJECT: GRB 180305A: RATIR Optical Afterglow Candidate
DATE:    18/03/06 11:24:41 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM),
Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),
Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and
Vicki Toy (UMD) report:

We observed the field of the LAT GRB 180305A (Axelsson, et al., GCN 22457)
with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2018/03 6.11 to 2018/03 6.20 UTC
(17.28 to 19.45 hours after the burst), obtaining a total of 1.36 hours
exposure in the r and i bands.

At the position of source #2 found by Swift-XRT  (Evans, et al., GCN 
22459),
we detect a faint uncatalogued optical source. In comparison with the
USNO-B1 catalog, we obtain the following detections:

   r    = 21.95 +/- 0.12
   i    = 21.48 +/- 0.08

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
The source is located at RA,Dec = 03:18:28.33,+32:06:36.2 (J2000, +/-0.5").

Further observations to establish fading of the optical source are planned.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180305A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22461
SUBJECT: Konus-Wind observation of GRB 180305A
DATE:    18/03/06 14:42:58 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, bright GRB 180305A
(Fermi-LAT detection: Axelsson and E. Bissaldi, GCN Circ. 22457;
Fermi-GBM detection: Veres and von Kienlin, GCN Circ. 22458)
triggered Konus-Wind at T0=33967.647 s UT (09:26:07.647).

The burst light curve shows a single emission episode
which starts at ~T0-2.4 s and has a total duration of ~44 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180305_T33967/

As observed by Konus-Wind, the burst
had a fluence of 8.43(-0.58,+0.59)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+3.168 s,
of 2.02(-0.32,+0.32)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+16.128 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.51(-0.09,+0.10),
the high energy photon index beta = -2.41(-0.17,+0.13),
the peak energy Ep = 348(-27,+30) keV
(chi2 = 139/97 dof).

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+4.352 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.25(-0.15,+0.17),
the high energy photon index beta = -2.59(-0.44,+0.23),
the peak energy Ep = 467(-56,+64) keV
(chi2 = 113/81 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180305A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22462
SUBJECT: GRB 180305A: Swift-XRT afterglow detection
DATE:    18/03/06 15:38:42 GMT
FROM:    Boris Sbarufatti at PSU  <bxs60@psu.edu>

P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S. J.
LaPorte (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester),
A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA)
and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 180305A (Axelsson et al. GCN Circ. 22457),
collecting 4.7 ks of Photon Counting (PC) mode data between T0+30.6 ks
and T0+53.0 ks. 

Four uncatalogued X-ray sources are detected, of which one ("Source 2")
is above the RASS limit and fading with 3-sigma significance, and is
therefore likely the GRB afterglow. Using 3574 s of PC mode data and 6
UVOT images, we find an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue):
RA, Dec = 49.61821, +32.10994 which is equivalent to:

RA (J2000): 03h 18m 28.37s
Dec(J2000): +32d 06' 35.8"

with an uncertainty of 1.7 arcsec (radius, 90% confidence). This
position is 2.7 arcmin from the Fermi/LAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=2.7 (+0.5, -0.8).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.5 (+/-0.4). The
best-fitting absorption column is  4.7 (+3.2, -2.3) x 10^21 cm^-2,
consistent with the Galactic value of 2.4 x 10^21 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 5.4 x 10^-11 (6.9 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.7 (+3.2, -2.3) x 10^21 cm^-2
Galactic foreground: 2.4 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.5 (+/-0.4)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020789.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020789.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180305A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22463
SUBJECT: GRB 180305A: Mondy optical observations
DATE:    18/03/06 17:07:13 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  A. Pozanenko (IKI),  E. Klunko (ISTP),  A. Volnova 
(IKI) report on behalf of of larger GRB follow-up collaboration:

We observed the field of LAT/Fermi GRB 180305A (Axelsson, et al., GCN 
22457) and Konus-Wind (Svinkin et al., GC 22461) with AZT-33IK telescope 
of Sayan observatory (Mondy).  We obtained several images in R-filter 
starting on Mar. 06 (UT) 12:35:17.  The afterglow candidate  (Troja  et 
al., GCN 22460) is clearly detected within XRT/Swift error circle 
(D'Avanzo et al., GCN 22462). Preliminary photometry is following.

Date        UT start  t-T0      Filter Exp.   OT      Err.  UL
                       (mid, days)    (s)


2018-03-06  12:35:17  1.15219    R     30*120 22.69   0.15  23.7

The photometry is based on nearby USNO-B1.0 stars
USNO-B1_id   R2

1221-0050419 18.60

1221-0050432 16.39

1221-0050407 19.31


Since the source has faded in comparison with the previous observation 
(Troja  et al., GCN 22460) we can confirm the afterglow of GRB 180305A.


GRB_name: GRB180305A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22464
SUBJECT: GRB 180305A: Swift/UVOT Upper Limits
DATE:    18/03/06 18:03:54 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (MSSL-UCL) and M. H. Siegel (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180305A
30621 s after the Fermi/LAT trigger (Axelsson et al., GCN Circ. 22457).
No optical afterglow consistent with the enhanced XRT position
(D'Avanzo et al., GCN Circ. 22462)
or the RATIR and Mondy detections (Troja et al., GCN Circ. 22460;
 Mazaeva et al., GCN Circ. 22463)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) in the
initial exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white            30808        52964          961         >21.4
u                30621        52533         2623         >20.7
v                30994        48392          712         >19.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.454 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180305A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22465
SUBJECT: GRB 180305A: RATIR Optical Observations
DATE:    18/03/07 14:59:49 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and
Vicki Toy (UMD) report:

We observed the field of GRB 180305A (Axelsson, et al., GCN Circ. 22457)
with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
AstronÃ³mico Nacional on Sierra San Pedro MÃ¡rtir from 2018/03 7.11 to
2018/03 7.20 UTC (41.30 to 43.46 hours after the BAT trigger), obtaining
a total of 1.64 hours exposure in the r and i bands.

The source reported by Troja et al. (GCN Circ. 22460) is still detected,
but has faded to:

 r = 23.15 +/- 0.21
 i = 22.80 +/- 0.15

These magnitudes are in the AB system, are calibrated against the
USNO-B1 catalog, and are not corrected for Galactic extinction in the
direction of the GRB.

The combination of the optical fading reported here and the X-ray fading
reported by Dâ€™Avanzo et al. (GCN Circ. 22462) confirm that this is the
afterglow of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180305A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22467
SUBJECT: GRB 180305A CALET Gamma-Ray Burst Monitor detection
DATE:    18/03/11 05:23:23 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

A. V. Penacchioni (U of Florence), A. Yoshida, T. Sakamoto, V. Pal'shin,
Y. Kawakubo, M. Moriyama, Y. Yamada, A. Tezuka, S. Matsukawa (AGU),
K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), I. Takahashi (IPMU),
Y. Asaoka, S. Ozawa, S. Torii (Waseda U), Y. Shimizu,
T. Tamura (Kanagawa U), W. Ishizaki (ICRR), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long, bright GRB 180305A (Fermi-LAT detection: Axelsson &  Bissaldi,
GCN circ. 22457; Fermi-GBM detection: Veres & von Kienlin, GCN circ. 22458;
Konus-Wind detection: Svinkin et al., GCN circ. 22461) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 09:26:09.218 UTC on 5 March 2018.
No real time CGBM GCN notice was distributed about this trigger because
the real time communication from the ISS was off (loss of signal) between
9:00 and 9:36.  The burst signal was seen by all CGBM detectors.

The burst light curve shows a single multi-peaked pulse which starts at T-0.5 sec,
peaks at T+3.4 sec and ends at T+14.6 sec.  The T90 and the T50 durations measured
by the SGM data are 10.0 +- 0.8 sec and 3.88 +- 0.13 sec (40-1000 keV), respectively.
CGBM HV was turned off at ~T+95 sec due to entering the radiation belts,
so no CGBM data are available from that time until ~T+1300 sec.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1204276876/

On March 2, the CGBM on-board event data capture end time was changed from
8 sec to 512 sec, so from that time in the Event mode CGBM collects time tagged
events up to T0+512 sec, where T0 is the trigger time.

The CALET data used in this analysis are provided by the Waseda CALET
Operation Center located at the Waseda University.


GRB_name: GRB180311A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22468
SUBJECT: GRB 180311A: Swift detection of a burst
DATE:    18/03/11 18:18:00 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

K. L. Page (U Leicester), A. Deich (PSU), S. W. K Emery (UCL-MSSL),
J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 18:03:49 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180311A (trigger=813721).  Swift slewed to the burst after
a brief delay to clear the Earth limb observing contraint. 
The BAT on-board calculated location is 
RA, Dec 3.433, -54.479 which is 
   RA(J2000) = 00h 13m 44s
   Dec(J2000) = -54d 28' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex peak
structure with a duration of about 30 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 18:08:24.5 UT, 275.3 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 3.39027, -54.49162 which
is equivalent to:
   RA(J2000)  = 00h 13m 33.66s
   Dec(J2000) = -54d 29' 29.8"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 100 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.59 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 4.9
(+3.32/-2.86) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 279 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 26% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.01. 

Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180311A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22469
SUBJECT: GRB 180311A: Prompt enhanced Swift-XRT position
DATE:    18/03/11 19:03:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Using  promptly downlinked XRT event data for GRB 180311A, we find an
enhanced XRT position of the afterglow: RA, Dec: 3.3872, -54.4914 which
is equivalent to:
   RA (J2000)  = 00 13 32.93
   Dec (J2000) = -54 29 29.0
with an uncertainty of 2.1 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/813721.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180311A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22470
SUBJECT: GRB 180311A: Enhanced Swift-XRT position
DATE:    18/03/11 22:50:21 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3908 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 180311A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 3.38761, -54.49145 which is equivalent
to:

RA (J2000): 00h 13m 33.03s
Dec (J2000): -54d 29' 29.2"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180311A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22473
SUBJECT: GRB 180311A: Swift-XRT refined Analysis
DATE:    18/03/12 03:53:59 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Tohuvavohu (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), A.P.
Beardmore (U. Leicester), P.A. Evans (U. Leicester), V. D'Elia (ASDC),
A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) and K.L. Page report on
behalf of the Swift-XRT team:

We have analysed 8.3 ks of XRT data for GRB 180311A (Page et al. GCN
Circ. 22468), from 284 s to 20.1 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Goad et al. (GCN Circ. 22469).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.1 (+0.9, -0.6), followed by a break at T+636 s to an
alpha of 0.57 (+0.10, -0.09).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.07 (+0.20, -0.19). The
best-fitting absorption column is  5.5 (+4.3, -3.7) x 10^20 cm^-2, in
excess of the Galactic value of 1.6 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.1 x 10^-11 (3.6 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.5 (+4.3, -3.7) x 10^20 cm^-2
Galactic foreground: 1.6 x 10^20 cm^-2
Excess significance: 1.7 sigma
Photon index:      2.07 (+0.20, -0.19)

If the light curve continues to decay with a power-law decay index of
0.57, the count rate at T+24 hours will be 0.012 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.6 x
10^-13 (4.2 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00813721.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180311A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22474
SUBJECT: GRB 180311A, Swift-BAT refined analysis
DATE:    18/03/12 13:00:00 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), K. L. Page (U Leicester),
T. Sakamoto (AGU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180311A (trigger #813721)
(Page et al., GCN Circ. 22468).  The BAT ground-calculated position is
RA, Dec = 3.379, -54.491 deg which is
  RA(J2000)  =  00h 13m 31.0s
  Dec(J2000) = -54d 29' 26.6"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 94%.

The mask-weighted light curve shows a single-peaked structure that starts
at ~ T0, peaks at ~T+3 s, and ends at ~T+26 s. T90 (15-350 keV) is
23.0 +- 8.7 sec (estimated error including systematics).

The time-averaged spectrum from T-0.2 to T+26.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.78 +- 0.29.  The fluence in the 15-150 keV band is 3.3 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+2.88 sec in the 15-150 keV band
is 0.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/813721/BA/


GRB_name: GRB180311A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22475
SUBJECT: GRB 180311A: Swift/UVOT Upper Limits
DATE:    18/03/12 16:42:41 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180311A
280 s after the BAT trigger (Page et al., GCN Circ. 22468).
No optical afterglow consistent with the enhanced XRT position
(Goad et al. GCN Circ. 22470)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           280          430          147         >20.3
white              280         6742          589         >21.2
v                  437         7155          333         >19.4
b                  536         8600          488         >20.9
u                  511         7770          561         >20.5
w1                 486         7565          330         >20.2
m2                7160         7360          197         >20.3
w2                1187         6950          255         >20.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180305A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22476
SUBJECT: GRB 180305A: AstroSat CZTI detection
DATE:    18/03/13 16:37:50 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a bright GRB 180305A, which was also detected by Fermi/GBM (Veres P. et al., GCN 22458), Konus-Wind (Svinkin D. et al., GCN 22461), Swift/XRT (D'Avanzo P. et al., GCN 22462) and CALET (Penacchioni A. V. et al., GCN 22467).

The source was clearly detected in the 40-200 keV energy range. The light curve shows single peak emission with strongest peak at 09:26:12.5 UT, ~4 s after Fermi/GBM trigger. The measured peak count rate is 427.3 cts/s above the background in combined data of four quadrants, with a total of 2358 cts. The local mean background count rate was 490.6 cts/s. Using cumulative rates, we measure a T90 of 8.9 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180314A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22478
SUBJECT: GRB 180314A: Swift detection of a burst with an optical counterpart
DATE:    18/03/14 00:57:37 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

P. D'Avanzo (INAF-OAB), A. Deich (PSU), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), B. Sbarufatti (PSU),
M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 00:43:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180314A (trigger=814129).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 99.276, -24.491 which is 
   RA(J2000) = 06h 37m 06s
   Dec(J2000) = -24d 29' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 40 sec.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 00:46:10.6 UT, 159.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 99.26519, -24.49603 which
is equivalent to:
   RA(J2000)  = 06h 37m 03.65s
   Dec(J2000) = -24d 29' 45.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 39 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.50
x 10^21 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 1.58e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 166 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 06:37:03.68 =  99.26532
  DEC(J2000) = -24:29:46.0  = -24.49612
with a 90%-confidence error radius of about 0.61 arc sec. This position is 2.8
arc sec. from the center of the XRT error circle. The estimated magnitude is
16.27 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.08. 

Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180314A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22479
SUBJECT: GRB180314A: GROND detection of the afterglow
DATE:    18/03/14 01:17:19 GMT
FROM:    Jan Bolmer at MPE/Garching  <jan@bolmer.de>

J. Bolmer (ESO/MPE) reports:

I observed the field of GRB 180314A (Swift trigger 814129; P. D'Avanzo et al.,
GCN 22478) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 00:47 UT on March 14, 2018, 4 minutes after
the GRB trigger. They were performed at an average seeing of 1".1 and at
an average airmass of 1.03.

We clearly detect the NIR/optical transient of GRB 180314A at
the position reported by P. D'Avanzo et al. (GCN 22478).
Based on total exposure of 200 seconds in gâ€™râ€™i'z' at a midtime
of 00:50 UT, 7 minutes after the burst, we measure
the following preliminary magnitudes (AB magnitude
system):

g' = 17.87 +/- 0.01 mag,
r' = 17.57 +/- 0.02 mag,
i' = 17.36 +/- 0.03 mag,
z' = 17.25 +/- 0.03 mag

Magnitudes are calibrated against PanSTARRS field stars and are not
corrected for the Galactic foreground extinction corresponding to a
reddening of E_(B-V)= 0.07 mag in the direction of the burst (Schlegel et al. 1998).

Observations are continuing.


GRB_name: GRB180314A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22480
SUBJECT: GRB 180314A: Enhanced Swift-XRT position
DATE:    18/03/14 03:17:57 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1353 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 180314A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 99.26522, -24.49627 which is equivalent
to:

RA (J2000): 06h 37m 3.65s
Dec (J2000): -24d 29' 46.6"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180314A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22481
SUBJECT: GRB 180314A: MASTER-Net OT dtetction
DATE:    18/03/14 08:04:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov, D.Zimnukhov, V.Vladimirov, 
A.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.Chazov, D. Kuvshinov
(Lomonosov Moscow State University, SAI),

R. Rebolo, M. Serra-Ricart
(The Instituto de Astrofisica de Canarias),

R.Podesta, C.Lopez, F. Podesta
(Observatorio Astronomico Felix Aguilar (OAFA),National University of San Juan, Argentina),

H. Levato, C. Saffe
(Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina),

D.Buckley, S. Potter
(South African Astronomical Observatory),

O.Gres,  N.M.Budnev
(Irkutsk State University),

A. Tlatov, V.Senik, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory)

V.Yurkov, A.Gabovich, Yu.Sergienko
(Blagoveschensk Educational State University, Blagoveschensk),

MASTER-IAC and MASTER-OAFA automatically pointed to GRB 180314A (D'Avanzo et al. GCN 22478, Osborne et al. GCN 22480)
with optical transient detection by MASTER auto-detection system.
We confirm Swift and GROND OT (D'Avanzo et al. GCN 22478, Bolmer et al. GCN 22479).

There are also synchronous images from MASTER very wide field cameras (MASTER-VWFC).

MASTER-IAC  robotic telescope (MASTER-Net: http://observ.pereplet.ru ,Lipunov et al. Advances in Astronomy, 2010, 30L) 
located in Teyde observatory(Spain) was pointed to the  GRB180314.03 7 sec after notice time 
and 100 sec after trigger time at 2018-03-14 00:45:11 UT.
On our first (20s exposure)  set we  found 1 optical transient within SWIFT error-box 
(ra=99.275 dec=-24.4908 r=0.05) :


  T-Tmid      Date      Time       Expt.        Ra                Dec         Mag
---------|---------------------|-------|-----------------|-----------------|-------
      110   2018-03-14 00:45:11      20   (  6h 37m 03.7s , -24d 29m 45.8s)    15.36

The 5-sigma upper limit on the first 20s image is 17.2mag

The observations made on zenit distance = 83 degrees, galaxy latitude b = -13 degree.
The moon (12 % bright part) below the horizon (The altitude of the Moon is -59 degree ).
The sun  altitude  is -63.5 degree.



MASTER-OAFA robotic telescope located in Argentina was pointed to the  GRB180314A
17 sec after notice time and 110 sec after trigger time at 2018-03-14 00:45:21 UT.
On our first (20s exposure)  set we  found 1 optical transient within SWIFT error-box 
(ra=99.275 dec=-24.4908 r=0.05)


  T-Tmid      Date      Time       Expt.        Ra                Dec           Mag
---------|---------------------|-------|-----------------|-----------------|-------
      120   2018-03-14 00:45:21      20   (  6h 37m 03.7s , -24d 29m 45.8s)    15.60

The 5-sigma upper limit on first 20s image is 18.4 mag

The observations made on zenit distance = 15 degrees, galaxy latitude b = -13 degree.
The moon (12 % bright part) below the horizon (The altitude of the Moon is -37 degree ).
The sun  altitude  is -23.5 degree.

The message may be cited.


GRB_name: GRB180314A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22482
SUBJECT: GRB 180314A: REM optical/NIR observations
DATE:    18/03/14 09:49:07 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

A. Melandri, P. D'Avanzo, S. Covino, D. Fugazza (INAF/OAB) report on behalf of the REM team:

We observed the field of the GRB 180314A (D'Avanzo et al., GCN 22478) with the 60-cm robotic telescope REM located at the La Silla Observatory (Chile).  The observations started at 00:45:38 UT, about 2 min after the burst, and were carried out for the first hour in the JHK bands. Then observations continued in the g, r, i, z, J, H and K bands.

A preliminary analysis shows that the optical counterpart (D'Avanzo et al., GCN 22478; Bolmer, GCN 22479; Lipunov et al., GCN 22481) is well detected and at a mid time of 165 seconds after the burst it was:

H = 12.9 +/- 0.1 (Vega)

Magnitude is calibrated against the 2MASS catalog.


GRB_name: GRB180314A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22483
SUBJECT: GRB 180314A: Swift/UVOT Detection
DATE:    18/03/14 11:49:54 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (U.Warwick) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180314A
167 s after the BAT trigger (D'Avanzo et al., GCN Circ. 22478).
A source consistent with the XRT position
(Osborne et al. GCN Circ. 22480)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  06:37:03.68 =  99.26535 (deg.)
   Dec (J2000) = -24:29:46.0  = -24.49610 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white(FC)          167          317          147         16.28 +/- 0.03
white              606          626           19         17.86 +/- 0.15
v                  829          849           19         17.07 +/- 0.25
b                  755          774           19         18.09 +/- 0.28
u                  326          576          246         16.95 +/- 0.06
w1                 705         1131           39         17.98 +/- 0.33
m2                 680         1106           58         18.12 +/- 0.35
w2                 631         1578          117         18.75 +/- 0.30

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).







---------------------------------------------

Dr Samantha Oates

Leverhulme Early Career Fellow
Department of Physics
University of Warwick
Coventry
CV4, UK
Tel:  +44 (024) 765 23383
Email: s.oates@warwick.ac.uk<mailto:s.oates@warwick.ac.uk>
-----------------------------------------------


GRB_name: GRB180314A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22484
SUBJECT: GRB 180314A: VLT/X-shooter redshift
DATE:    18/03/14 12:27:27 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

B. Sbarufatti (INAF/Brera PSU), J. Bolmer (MPE), A. De Ugarte Postigo 
(IAA/CSIC and DARK/NBI), J. P. U. Fynbo (DAWN/NBI), J. Selsing 
(DARK/NBI), K. E. Heintz (Univ. Iceland and DAWN/NBI), D. Malesani 
(DAWN/NBI and DARK/NBI), N. R. Tanvir (Univ. Leicester), A. J. Levan 
(Univ. Warwick), A. Smette (ESO), K. Wiersema (Univ. Warwick), S. Covino 
(INAF/Brera), report on behalf of the Stargate collaboration:

We observed the optical counterpart of GRB 180314A (D'Avanzo et al., GCN 
22478; Bolmer, GCN 22479) with the ESO/VLT UT2 equipped with the 
X-shooter spectrograph. Observations started on Mar 14.067 UT (53.3 min 
after the GRB) and covered the wavelength range 3000-20000 AA. In our 
acquisition image, we measure for the afterglow r = 18.87 +- 0.05 AB, 
calibrated to the Pan-STARRS catalog. The afterglow position is RA = 
06:37:03.66, Dec = -24:29:46.2, consistent with the UVOT position 
(D'Avanzo et al., GCN 22478).

A high-S/N continuum is detected in all arms (reaching ~3100 AA in the 
blue end). We identify several absorption features, including Mg II, Zn 
II, Al II, Al III, Cr II, Fe II at a common redshift z = 1.445. We also 
detect at least one Fe II* fine-structure line at the same redshift, 
thus confirming the association of this system with GRB 180314A.

We acknowledge excellent support from the observing staff in Paranal, in 
particular Boris Haeussler and Zahed Wahhaj.


GRB_name: GRB180314A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22485
SUBJECT: GRB 180314A: Fermi GBM observation
DATE:    18/03/14 12:58:13 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico & INFN Bari) and O. Roberts (USRA)
report on behalf of the Fermi GBM Team:


"At 00:43:19.90 UT on 14 March 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180314A (trigger 542681004 / 180314030),
which was also detected by the Swift/BAT
(D'Avanzo et al. 2018, GCN 22478).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight
at the GBM trigger time is 99 degrees.

The GBM light curve consists of single emission episode
with a duration (T90) of about 28 s (50-300 keV).
The time-averaged spectrum from T0-1 s to T0+30 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.36 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 104 +/- 3 keV.

The event fluence (10-1000 keV) in this time interval is
(1.52 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux
measured starting from T0+15.3 s in the 10-1000 keV band
is 10.5 +/- 0.5 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180314A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22486
SUBJECT: GRB 180314A: Swift-XRT refined Analysis
DATE:    18/03/14 14:45:07 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S. J. LaPorte (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester),
P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), A. D'Ai
(INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU) and
P. D'Avanzo report on behalf of the Swift-XRT team:

We have analysed 8.7 ks of XRT data for GRB 180314A (D'Avanzo et al.
GCN Circ. 22478), from 165 s to 37.0 ks after the  BAT trigger. The
data comprise 181 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN Circ. 22480).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=2.60 (+0.04, -0.17). At T+328 s  the decay
steepens to an alpha of 5.8 (+2.2, -1.0) before breaking again at T+401
s to a final decay with index alpha=0.94 (+/-0.03).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.34 (+0.08, -0.04). The
best-fitting absorption column is  consistent with the Galactic value
of 1.5 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.77 (+/-0.07) and a best-fitting absorption column
consistent with the Galactic value. The counts to observed (unabsorbed)
0.3-10 keV flux conversion factor deduced from this spectrum  is 3.9 x
10^-11 (4.7 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 1.5 x 10^21 cm^-2
Intrinsic column:    1.5 (+0.8, -0.0) x 10^21 cm^-2 at z=1.445
Photon index:      1.77 (+/-0.07)

If the light curve continues to decay with a power-law decay index of
0.94, the count rate at T+24 hours will be 0.014 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.7 x
10^-13 (6.9 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00814129.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180314A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22487
SUBJECT: GRB 180314A: LCO Siding Springs observations
DATE:    18/03/14 17:03:19 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi, R. Martone (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell 
(U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a 
large collaboration report:

We observed the field of Swift GRB180314A (D'Avanzo et al. GCN 22478) on 
March 14, from 10:00 to 10:25 UT (mid time of 0.39 days post burst) with 
1-m and 2-m unit LCO telescopes in Siding Springs in the SDSS gri 
filters. We detect the optical afterglow (D'Avanzo et al.; Bolmer GCN 
22479; Lipunov et al. GCN 22481; Melandri et al. GCN 22482; Sbarufatti 
et al. GCN 22484) with the following magnitudes:

Mid time since GRB Exp Filter Magnitude
(days) (s)
-------------------------------------------------------------
0.39 5x120 SDSS-R 21.5 +- 0.15
0.40 5x120 SDSS-I 21.4 +- 0.2
-------------------------------------------------------------

as calibrated against nearby Pan-STARRS stars.


GRB_name: GRB180314A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22488
SUBJECT: GRB 180314A: TAROT La Silla observatory optical observations
DATE:    18/03/14 17:56:36 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Noysena K., Atteia J.L. (CNRS-OMP-IRAP),
Boer M., Eymar L. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 180314A detected by SWIFT
(trigger 814129) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 172.7s after the GRB trigger
(83.1s after the notice). The elevation of the field decreased from
77 degrees above horizon and weather conditions were good.

We detected the candidate couterpart mentioned by D'Avanzo et al.
(GCNC 22478), Bolmer (GCNC 22479), Lipunov et al. (GCNC 22481),
Melandri et al. (GCNC 22482) Sbarufatti et al. (GCNC 22484),
Guidorzi et al. (GCNC 22487). TAROT photometry is:

t1(h) t2(h) r(AB) 1sig
0.048 0.056 15.64 0.05
0.059 0.067 16.00 0.05
0.070 0.079 16.34 0.05
0.081 0.090 16.64 0.06
0.093 0.101 16.92 0.07
0.104 0.129 17.26 0.10
0.132 0.182 17.68 0.13
0.227 0.276 18.18 0.19
0.282 0.332 18.32 0.24
0.343 0.443 18.62 0.30

It shows clearly a decay -1.8 until 8 minutes after the trigger
and then a decay -0.92 later. So we suspect a strong reverse shock
during the 8 first minutes.

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.


GRB_name: GRB180314A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22490
SUBJECT: GRB 180314A: Swift-BAT refined analysis
DATE:    18/03/14 21:28:51 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), P. D'Avanzo (INAF-OAB),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
(i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180314A (trigger #814129)
(D'Avanzo et al., GCN Circ. 22478).  The BAT ground-calculated position is
RA, Dec = 99.208, -24.530 deg which is
  RA(J2000)  =  06h 36m 50.0s
  Dec(J2000) = -24d 31' 47.7"
with an uncertainty of 3.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 24%.

The mask-weighted light curve shows a few overlapping pulses that starts
at ~ T-12 s and ends at ~T+110 s. The main peak occurs at ~T+4 s. Note that
the burst location came in to the BAT FOV at ~T-32 s, and thus the burst
emission might start before it is in the BAT FOV. T90 (15-350 keV) is
51.2 +- 22.3 sec (estimated error including systematics).

The time-averaged spectrum from T-11.80 to T+109.75 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.83 +- 0.25,
and Epeak of 94.9 +- 17.8 keV (chi squared 47.72 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.1 +- 0.04 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T+3.05 sec in the 15-150 keV band is
7.9 +- 0.6 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.50 +- 0.05 (chi squared 72.57 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/814129/BA/


GRB_name: GRB180314B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22491
SUBJECT: GRB 180314B: Swift detection of a burst
DATE:    18/03/14 22:37:00 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

P. D'Avanzo (INAF-OAB), A. Deich (PSU), J.D. Gropp (PSU),
J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
B. Sbarufatti (PSU), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report
on behalf of the Neil Gehrels Swift Observatory Team:

At 22:23:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180314B (trigger=814305).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 297.866, +23.623 which is 
   RA(J2000) = 19h 51m 28s
   Dec(J2000) = +23d 37' 24"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 50 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 22:25:03.9 UT, 87.0 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 297.88663, 23.62434 which
is equivalent to:
   RA(J2000)  = 19h 51m 32.79s
   Dec(J2000) = +23d 37' 27.6"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 68 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 8.94
x 10^21 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 6.44e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 94 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. Because of the density of
catalogued stars, further analysis is required to report an upper limit for any
afterglow in the region. No correction has been made for the large, but
uncertain, extinction expected. 

Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180314B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22492
SUBJECT: GRB 180314B: Prompt enhanced Swift-XRT position
DATE:    18/03/14 23:20:59 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Using  promptly downlinked XRT event data for GRB 180314B, we find an
enhanced XRT position of the afterglow: RA, Dec: 297.8867, 23.6243
which is equivalent to:
   RA (J2000)  = 19 51 32.82
   Dec (J2000) = +23 37 27.4
with an uncertainty of 1.9 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/814305.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180313A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22493
SUBJECT: GRB 180313A: Fermi GBM detection
DATE:    18/03/15 00:52:55 GMT
FROM:    Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>

E. Bissaldi (Politecnico & INFN Bari), C. Meegan (UAH) and 
O.J. Roberts (USRA) report on behalf of the Fermi GBM Team:

"At 23:28:17.53 UT on 13 March 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180313A (trigger 542676502 / 180313978).
The on-ground calculated location, using the GBM trigger
data, is

RA, Dec = 317.51, -26.55 (J2000 degrees)

with an uncertainty of 5.7 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32]).

The trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the best location is 40 degrees.

The GBM light curve shows/consists of single peak
with a duration (T90) of about 0.1 s (50-300 keV).
The time-averaged spectrum from T0+0 s to T0+0.13 s is
best fit by a power-law function with an exponential
high-energy cutoff. The power law index is -0.26 +/- 0.21 and
the cutoff energy, parameterized as Epeak, is 287 +/- 44 keV

The event fluence (10-1000 keV) in this time interval is
(1.9 +/- 0.1)E-07 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+0 s in the 10-1000 keV band
is 16 +/- 1 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB180314B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22494
SUBJECT: GRB 180314B: Enhanced Swift-XRT position
DATE:    18/03/15 03:18:26 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2454 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 180314B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 297.88665, +23.62406 which is equivalent
to:

RA (J2000): 19h 51m 32.80s
Dec (J2000): +23d 37' 26.6"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180314B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22495
SUBJECT: GRB 180314B: Swift-XRT refined Analysis
DATE:    18/03/15 05:34:14 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), P.A. Evans (U. Leicester), S.L. Gibson (U.
Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), V.
D'Elia (ASDC), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU) and P.
D'Avanzo report on behalf of the Swift-XRT team:

We have analysed 6.4 ks of XRT data for GRB 180314B (D'Avanzo et al.
GCN Circ. 22491), from 102 s to 19.8 ks after the  BAT trigger. The
data are entirely in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Beardmore et al. (GCN Circ.
22492).

The light curve can be modelled with an initial power-law decay with an
index of alpha=0.08 (+0.09, -0.07), followed by a break at T+1503 s to
an alpha of 1.42 (+/-0.08).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.55 (+0.21, -0.20). The
best-fitting absorption column is  2.14 (+0.29, -0.27) x 10^22 cm^-2,
in excess of the Galactic value of 8.9 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.8 x 10^-11 (1.9 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.14 (+0.29, -0.27) x 10^22 cm^-2
Galactic foreground: 8.9 x 10^21 cm^-2
Excess significance: 7.6 sigma
Photon index:      2.55 (+0.21, -0.20)

If the light curve continues to decay with a power-law decay index of
1.42, the count rate at T+24 hours will be 5.5 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.7 x
10^-13 (1.1 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00814305.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180314B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22496
SUBJECT: GRB 180314B: Swift/UVOT Upper Limits
DATE:    18/03/15 16:38:44 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (U.Warwick) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180314B
94 s after the BAT trigger (D'Avanzo et al., GCN Circ. 22491).
No optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 22494)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            94          244          147         >19.6
u_FC               308          558          246         >19.3
white               94         7249          666         >19.7
v                  638         7660          607         >18.4
b                  563        11580          471         >19.3
u                  308         8274          834         >19.6
w1                 687         8070          588         >19.5
m2                 662         7865          607         >20.4
w2                 614         7455          607         >20.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 2.21 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180314B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22497
SUBJECT: GRB 180314B: Zeiss-1000/CrAO optical upper limit
DATE:    18/03/15 17:48:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI),  A. Novichonok (KIAM, PetrSU),  I. 
Nikolenko (CrAO), A. Volnova (IKI), I. Molotov (KIAM) report on behalf 
of larger GRB follow-up collaboration:

We observed the field of  Swift GRB 180314B (D'Avanzo et al., GCN 22491) 
with Zeiss-1000/Koshka (CrAO) telescope starting March 15 (UT) 01:55:39.
We obtained several  images in R-filter. We do not detect any source 
within enhanced Swift-XRT position (Beardmore et al., GCN 22494). 
Preliminary photometry of the field is following.

Date        UT start  t-T0      Filter Exp.   OT    Err.  UL
                       (mid, days)    (s)

2018-03-15  01:55:39  0.15459    R     7*180  n/d   n/d   22.2

The photometry is based on nearby USNO-B1.0 stars

USNO-B1_id   R1
1135-0426232 15.02
1135-0426125 15.64
1136-0433074 16.46


GRB_name: GRB180314B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22498
SUBJECT: GRB 180314B: Swift-BAT refined analysis
DATE:    18/03/15 20:11:42 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
P. D'Avanzo (INAF-OAB), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180314B (trigger #814305)
(D'Avanzo et al., GCN Circ. 22491).  The BAT ground-calculated position is
RA, Dec = 297.855, 23.634 deg which is
  RA(J2000)  =  19h 51m 25.3s
  Dec(J2000) = +23d 38' 04.1"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 66%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~ T-50 sec and ends at ~ T+35 s. The main peak occurs at ~ T0.
T90 (15-350 keV) is 73.0 +- 9.4 sec (estimated error including systematics).

The time-averaged spectrum from T-47.6 to T+34.4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.41 +- 0.25.  The fluence in the 15-150 keV band is 9.6 +- 1.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.57 sec in the 15-150 keV band
is 1.1 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/814305/BA/


GRB_name: GRB180314B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22499
SUBJECT: GRB 180314B: RATIR Optical Observations 
DATE:    18/03/15 23:01:36 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 180314B (D'Avanzo et al., GCN 22491) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2018/03 15.46 to 2018/03 15.52
UTC (12.55 to 13.99 hours after the BAT trigger), obtaining a total of
1.07 hours exposure in the r and i bands.

For a source within the Swift-XRT error circle, in comparison with the
USNO-B1 and 2MASS catalogs, we obtain the following 3-sigma upper
limits:

 r > 23.29
 i > 22.90

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180316A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22500
SUBJECT: GRB 180316A: Swift detection of a burst
DATE:    18/03/16 05:09:31 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Deich (PSU),
D. M. Palmer (LANL) and B. Sbarufatti (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 04:57:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180316A (trigger=814677).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 265.436, +0.737 which is 
   RA(J2000) = 17h 41m 45s
   Dec(J2000) = +00d 44' 11"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 20 sec.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 04:59:00.5 UT, 95.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 265.4290, 0.7497 which is equivalent to:
   RA(J2000)  = +17h 41m 42.96s
   Dec(J2000) = +00d 44' 58.9"
with an uncertainty of 6.1 arcseconds (radius, 90% containment). This
location is 52 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 104 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.27. 

Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180316A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22501
SUBJECT: GRB 180316A: Prompt enhanced Swift-XRT position
DATE:    18/03/16 05:31:08 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Using  promptly downlinked XRT event data for GRB 180316A, we find an
enhanced XRT position of the afterglow: RA, Dec: 265.4289, 0.7483 which
is equivalent to:
   RA (J2000)  = 17 41 42.94
   Dec (J2000) = +00 44 54.0
with an uncertainty of 2.1 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/814677.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180316A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22502
SUBJECT: GRB180316A: MASTER-IAC optical detection
DATE:    18/03/16 06:23:08 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, N.Tyurina, V.Kornilov, E.Gorbovskoy, P.Balanutsa, 
V.Vladimirov, A.Krylov, I.Gorbunov, A.Kuznetsov, V.Chazov, D. Kuvshinov, 
D.Zimnukhov
(Lomonosov Moscow State University, SAI),

R. Rebolo, M. Serra-Ricart
(The Instituto de Astrofisica de Canarias),


R.Podesta, C.Lopez, F. Podesta
(Observatorio Astronomico Felix Aguilar (OAFA),National University of San Juan, 
Argentina),

H. Levato, C. Saffe
(Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San 
Juan, Argentina),

D.Buckley, S. Potter
(South African Astronomical Observatory),


O.Gres,  N.M.Budnev
(Irkutsk State University),

A. Tlatov, V.Senik, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory)

V.Yurkov, A.Gabovich, Yu.Sergienko
(Blagoveschensk Educational State University, Blagoveschensk),


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in IAC was pointed to the  GRB180316A (Melandri et al GCN22500)
  15 sec after notice time 
and 44 sec after trigger time at 2018-03-16 04:58:09 UT.

There is new changing OT at SWIFT XRT (Evans et al. GCN 22501) coordinates 
17 41 42.94 +00 44 54.0

The 5-sigma upper limit on the first 10s image is  17.06mag
The message may be cited.


====================================================================



The observations made on zenit distance = 42 degrees, galaxy latitude b = 
15 degree.
The moon ( 2 % bright part) below the horizon (The altitude of the Moon is 
-22 degree ).
The sun  altitude  is -30.4 degree.
The object can be observed till sunrise at 2018-03-16 07:14:55


GRB_name: GRB180316A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22503
SUBJECT: GRB180316A: MASTER-IAC OT light curve
DATE:    18/03/16 07:15:51 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, N.Tyurina, V.Kornilov, E.Gorbovskoy, P.Balanutsa, V.Vladimirov, 
A.Krylov, I.Gorbunov, A.Kuznetsov, V.Chazov, D. Kuvshinov, D.Zimnukhov
(Lomonosov Moscow State University, SAI),

R. Rebolo, M. Serra-Ricart
(The Instituto de Astrofisica de Canarias),


R.Podesta, C.Lopez, F. Podesta
(Observatorio Astronomico Felix Aguilar (OAFA),National University of San Juan, 
Argentina),

H. Levato, C. Saffe
(Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San 
Juan, Argentina),

D.Buckley, S. Potter
(South African Astronomical Observatory),


O.Gres,  N.M.Budnev
(Irkutsk State University),

A. Tlatov, V.Senik, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory)

V.Yurkov, A.Gabovich, Yu.Sergienko
(Blagoveschensk Educational State University, Blagoveschensk),


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in 
IAC was pointed to the  GRB180316A (Melandri et al GCN22500)
  15 sec after notice time and 44 sec after trigger time at 2018-03-16 04:58:09 
UT .

There is OT(GCN 22502)  as the GRB counterpart  coordinates
(17h 41m 42s.82, + 00d 44m 53s.6 ) 
error =+-0.5"

The automatical OT light curve available at
http://master.sai.msu.ru/static/OT/LC_GRB180316A.png

The message may be cited.


====================================================================



The observations made on zenit distance = 42 degrees, galaxy latitude b = 15 
degree.
The moon ( 2 % bright part) below the horizon (The altitude of the Moon is -22 
degree ).
The sun  altitude  is -30.4 degree.
The object can be observed till sunrise at 2018-03-16 07:14:55


GRB_name: GRB180316A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22504
SUBJECT: GROND observations of GRB 180316A
DATE:    18/03/16 10:40:27 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

P. Schady and S. Steinmassl (both MPE) report:

We observed the field of GRB 180316A (Swift trigger 814677; Melandri et
al., GCN #22500) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 06:46 UT on March 16, 1.8 hours after the GRB
trigger. They were performed at an average seeing of 1.5" and at an
average airmass of 1.5.

We clearly detect the NIR/optical transient of GRB 180316A within the
enhanced XRT position (Evans et al., GCN #22501), in agreement with the
optical transient detected with MASTER (Lipunov et al., GCN #22502,
#22503). Based on the first 4 minutes of exposure, we measure the
following magnitudes (all in AB system):

g' = 19.4 +/- 0.1 mag
r' = 19.0 +/- 0.1 mag
i' = 18.9 +/- 0.1 mag
z' = 18.8 +/- 0.1 mag
J = 18.2 +/- 0.1 mag
H = 18.0 +/- 0.1 mag
K = 17.8 +/- 0.2 mag

Given magnitudes are calibrated against GROND zeropoints in g'r'i'z' and
2MASS field stars in JHK, and are not corrected for the Galactic
foreground extinction corresponding to a reddening of E_(B-V)= 0.24 in the
direction of the burst (Schlafly & Finkbeiner 2011).

We acknowledge the excellent support from the TiO and the current observer
at the 2.2m in La Silla, Sam Kim and Charlotte Brand.


GRB_name: GRB180314A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22505
SUBJECT: GRB 180314A: MITSuME Okayama optical upper limits
DATE:    18/03/16 11:29:04 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. Shiraishi, R. Itoh, K. L. Murata, T. Yoshii, Y. Tachibana, S. Harita, K.
Morita, T. Ozawa, H. Mamiya, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 180314A (P. D'Avanzo  et
al., GCN Circular #22478) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of  Okayama Astrophysical
Observatory, Japan.

The observation started on 10:32:06 UT. We did not find any new point
source within enhanced XRT circle (J.P. Osborne et al., GCN Circular
#22480) in all three bands.
We obtained following limits for the magnitudes.


T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
------------------------------------------------------------
-------------------------------------------
9.99       12:03:20      7240     >19.3     >18.8     >18.6
------------------------------------------------------------
-------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB180316A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22507
SUBJECT: GRB 180316A: LCO Cerro Tololo observations
DATE:    18/03/16 12:10:56 GMT
FROM:    Renato Martone at Universita' di Ferrara  <mrtrnt@unife.it>

R. Martone, C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large collaboration report:

We observed the field of Swift GRB180316A (Melandri et al., GCN 22500) on March 16, from 07:38 to 07:59 UT (mid time of 0.12 days post burst) with a 1-m unit LCO telescope in Cerro Tololo in the SDSS râ€™ i' filters. We detect the optical afterglow (Lipunov et al., GCN 22502; Schady and Steinmassl, GCN 22504) with the following magnitudes:

Mid time since GRB     Exp        Filter         Magnitude
(days)                 (s)
-------------------------------------------------------------
0.11                   4x120      SDSS-R         19.04 +- 0.05
0.12                   4x120      SDSS-I         18.88 +- 0.05
-------------------------------------------------------------

as calibrated against nearby SDSS stars.


GRB_name: GRB180316A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22508
SUBJECT: GRB 180316A: Enhanced Swift-XRT position
DATE:    18/03/16 14:26:58 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 4963 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 180316A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 265.42854, +0.74813 which is equivalent
to:

RA (J2000): 17h 41m 42.85s
Dec (J2000): +00d 44' 53.3"

with an uncertainty of 1.4 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180316A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22509
SUBJECT: GRB 180316A: RATIR Optical Observations
DATE:    18/03/16 14:37:38 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 180316A (Melandri, et al., GCN 22500) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2018/03 16.39 to 2018/03 16.52 UTC (4.34 to
7.49 hours after the BAT trigger), obtaining a total of 2.29 hours exposure
in the r and i bands.

The afterglow is well-detected within the Swift-XRT error circle (Evans, et
al., GCN 22501).   In comparison with the USNO-B1 catalog, we obtain:

  r = 20.07 +/- 0.02
  i = 19.87 +/- 0.02

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The source appears so fade in flux
with time as t^(-1.4+/-0.1).

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180316A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22510
SUBJECT: GRB 180316A: Swift/UVOT Detection
DATE:    18/03/16 15:48:27 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and A. Melandri (INAF-OAB) report on behalf of 
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180316A 
105 s after the BAT trigger (Melandri et al., GCN Circ. 22500).
A fading source consistent with the enhanced XRT position (Evans et al. 
GCN Circ. 22508) and the optical transient reported by Lipunov et al. 
(GCN Circ. 22503), Shady & Steinmassl (GCN Circ. 22504) and Martone et 
al. (GCN Circ. 22507), Butler et al. (GCN Circ. 22509) is detected in 
the initial UVOT exposures.

The preliminary UVOT position is:
     RA  (J2000) =  17:41:42.87 = 265.42861 (deg.)
     Dec (J2000) = +00:44:53.7  =   0.74824 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT 
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for 
the finding chart (white_fc) and early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white_fc           105          254          147         16.27 Â± 0.03
white              596          616           20         17.40 Â± 0.11
v                  646          839           39         17.15 Â± 0.18
b                  572          592           20         17.40 Â± 0.15
u                  317          566          246         16.44 Â± 0.04
w1                 695        22410         1175        >20.4
m2               12527        12578           50        >19.2
w2                 622         6753          255        >19.5

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.28 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB180316A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22511
SUBJECT: GRB 180316A: Swift-XRT refined Analysis
DATE:    18/03/16 15:57:42 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A.
Tohuvavohu (PSU) and A. Melandri report on behalf of the Swift-XRT
team:

We have analysed 6.1 ks of XRT data for GRB 180316A (Melandri et al.
GCN Circ. 22500), from 101 s to 28.6 ks after the  BAT trigger. The
data comprise 534 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN Circ. 22501).

The late-time light curve (from T0+4.4 ks) can be modelled with an
initial power-law decay with an index of alpha=-0.0 (+/-0.6), followed
by a break at T+8729 s to an alpha of 2.1 (+/-0.3).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.94 (+0.07, -0.04). The
best-fitting absorption column is  2.038 (+0.286, -0.012) x 10^21
cm^-2, consistent with the Galactic value of 2.0 x 10^21 cm^-2
(Willingale et al. 2013). The PC mode spectrum has a photon index of
2.05 (+/-0.16) and a best-fitting absorption column of 3.3 (+/-0.7) x
10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 3.7 x 10^-11 (5.7 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.3 (+/-0.7) x 10^21 cm^-2
Galactic foreground: 2.0 x 10^21 cm^-2
Excess significance: 3.2 sigma
Photon index:      2.05 (+/-0.16)

If the light curve continues to decay with a power-law decay index of
2.1, the count rate at T+24 hours will be 2.9 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-13 (1.7 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00814677.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180316A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22512
SUBJECT: GRB 180316A: Swift-BAT refined analysis
DATE:    18/03/16 19:49:29 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

J. R. Cummings (CPI), S. D. Barthelmy (GSFC), 
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), A. Melandri (INAF-OAB),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180316A (trigger #814677)
(Melandri et al., GCN Circ. 22500).  The BAT ground-calculated position is
RA, Dec = 265.422, 0.737 deg which is 
  RA(J2000)  =  17h 41m 41.3s 
  Dec(J2000) = +00d 44' 14.3" 
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 29%.

The mask-weighted light curve shows a main structure with several overlapping 
pulses that starts at ~ T-15 s and ends at ~ T+30 s. The major peak occurs at
~ T+1 s. In addition, there are some weak emission before the main structure 
that starts at ~ T-80 s, and a weak tail afterward that lasts until ~ T+40 s.
T90 (15-350 keV) is 87.0 +- 20.6 sec (estimated error including systematics).

The time-averaged spectrum from T-79.73 to T+37.27 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.46 +- 0.12.  The fluence in the 15-150 keV band is 4.9 +- 0.4 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+1.27 sec in the 15-150 keV band
is 3.3 +- 0.5 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.


GRB_name: GRB180314A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22513
SUBJECT: Konus-Wind observation of GRB 180314A
DATE:    18/03/16 22:19:52 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 180314A
(Swift-BAT detection: D'Avanzo  et al., GCN 22478;
Ukwatta et al., GCN 22490;
Fermi GBM observation: Bissaldi & Roberts, GCN 22485)
triggered Konus-Wind at T0=2601.957 s UT (00:43:21.957).

The burst light curve shows a single emission episode with a total
duration of ~22 s.
The emission is seen up to ~1.5 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.47(-0.06,+0.06)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+0.490 s,
of 2.61(-1.05,+1.21)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+33.024 s)
is best fit in the 20 keV - 1.5 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.61(-0.16,+0.17),
and Ep = 111(-6,+6) keV (chi2 = 45/60 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -3.08 (chi2 = 45/59 dof).

The spectrum near the peak count rate
(measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 1.5 MeV range
by a power law with exponential cutoff model
with  alpha = -0.34(-0.57,+0.84),
and Ep = 303(-89,+161) keV (chi2 = 14/15 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.26 (chi2 = 14/14 dof).

Assuming the redshift z=1.445 (Sbarufatti et al., GCN 22484)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is 8.18(-0.34,+0.36)x10^52 erg,
the peak luminosity L_iso is 3.55(-1.42,+1.64)x10^52 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is 272(-14,+15) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180314_T02601/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180316A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22514
SUBJECT: GRB 180316A: RATIR Optical Observations, Possible Re-brightening
DATE:    18/03/17 15:19:48 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 180316A (Melandri,, et al., GCN 22500) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional
on Sierra San Pedro MÃ¡rtir from 2018/03 17.39 to 2018/03 17.52 UTC (28.35
to 31.55 hours after the BAT trigger), obtaining a total of 2.36 hours
exposure in the r and i bands.

The optical afterglow (e.g., Lipunov, et al., GCN 22502) is again cleanly
detected.  In comparison with the USNO-B1 catalog, we obtain:

  r = 20.23 +/- 0.02
  i = 19.93 +/- 0.01

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  These magnitudes are comparable to
those reported for RATIR for 2018/03.16 (Butler, et al., GCN 22509).
During that observation, the afterglow was fading strongly.  We again
observe the afterglow to be fading, as t^(-0.7+/-0.3), and we infer that
the afterglow may have brightened between our epochs, at a time around 1
day after the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180314A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22515
SUBJECT: GRB 180314A: AstroSat CZTI detection
DATE:    18/03/17 21:15:29 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a bright GRB 180314A, which was also detected by Swift (D'Avanzo P. et al., GCN 22478) and Fermi-GBM (Bissaldi E. et al., GCN 22485).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 00:43:20.5 UT. The measured peak count rate is 339.5 cts/s above the background in combined data of four quadrants, with a total of 5127 cts. The local mean background count rate was 586.5 cts/s. Using cumulative rates, we measure a T90 of 37.3 s. 

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180316A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22516
SUBJECT: GRB 180316A: TSHAO optical observations
DATE:    18/03/18 18:33:32 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), A. Kusakin (FAPHI), A. Pozanenko (IKI), I. Reva 
(FAPHI),  E. Mazaeva (IKI), M. Krugov (FAPHI) report on behalf of larger 
GRB follow-up collaboration:

We observed the field of GRB GRB 180316A (Melandri et al., GCN 22500) 
with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory 
starting on Mar. 17 (UT) 23:19:40. We obtained several images in 
R-filter.  The optical afterglow (Lipunov et al., GCN 22502; Schady  et 
al. GCN  22504; Martone  et al. GCN  22507; Butler et al., GCN 22509; 
Breeveld et al. GCN  22510) is marginally detected in a stacked image. 
Preliminary photometry of the field is following.

Date        UT start t-T0     Filter Exp.    OT    Err.  UL
                      (mid, days)     (s)

2018-03-17  23:19:40 1.78280  R      36*60   21.5  0.5   21.0

The photometry is based on several nearby USNO-B1.0 stars.


GRB_name: GRB180316A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22517
SUBJECT: GRB 180316A: MITSuME Okayama optical upper limits
DATE:    18/03/19 07:23:59 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. L. Murata, R. Itoh, T. Yoshii, Y. Tachibana, S. Harita, K. Morita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 180316A (A. Melandri  et
al., GCN Circular #22500) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of  Okayama Astrophysical
Observatory, Japan.

The observation started on 16:19:04 UT. We did not find any new point
source within enhanced XRT circle (P.A. Evans et al., GCN Circular #22508)
in all three bands.
We obtained following limits for the magnitudes.


T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
------------------------------------------------------------
-------------------------------------------
12.22       19:44:32      1980     >17.3     >17.4     >17.4
------------------------------------------------------------
-------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB180316A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22518
SUBJECT: GRB 180316A: MITSuME Akeno optical upper limits
DATE:    18/03/19 07:26:57 GMT
FROM:    Katsuhiro L. Murata at Nagoya U  <murata@u.phys.nagoya-u.ac.jp>

K. L. Murata, R. Itoh, T. Yoshii, Y. Tachibana, S. Harita, K. Morita, T.
Ozawa, H. Mamiya, K. Shiraishi, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 180316A (A. Melandri  et
al., GCN Circular #22500) with the optical three color (g', Rc, and Ic) CCD
cameras attached to the MITSuME 50 cm telescope of Akeno Observatory,
Yamanashi, Japan.

The observation started on 16:39:08 UT. We did not find any new point
source within enhanced XRT circle (P.A. Evans et al., GCN Circular #22508)
in all three bands.
We obtained following limits for the magnitudes.


T0+[hour]    MID-UT      T-EXP[sec]    g'       Rc        Ic
------------------------------------------------------------
-------------------------------------------
11.71       18:28:36      11620     >20.6     >19.7     >18.9
------------------------------------------------------------
-------------------------------------------

T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB180316A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22519
SUBJECT: GRB 180316A: RATIR Optical Observations 
DATE:    18/03/19 14:38:20 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and
Vicki Toy (UMD) report:

We observed the field of GRB 180316A (Melandri et al., GCN 22500) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2018/03 19.38 to 2018/03 19.52
UTC (76.23 to 79.44 hours after the BAT trigger), obtaining a total of
2.44 hours exposure in the r and i bands.

For a source within the Swift-XRT error circle, in comparison with the
USNO-B1 and 2MASS catalogs, we obtain the following 3-sigma upper
limits:

 r > 23.72
 i > 23.59

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180317A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22521
SUBJECT: IPN Triangulation of GRB 180317A (short/hard)
DATE:    18/03/20 13:03:52 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D.Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report:

The short-duration GRB 180317A has been detected by
Konus-Wind, INTEGRAL(SPI-ACS), and Swift(BAT) at about 61285 s UT 
(17:01:25). The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    92.196 (06h 08m 47s) +23.164 (+23d 09' 50")
  Corners:
    92.178 (06h 08m 43s) +21.042 (+21d 02' 32")
    92.100 (06h 08m 24s) +23.291 (+23d 17' 27")
    92.237 (06h 08m 57s) +25.258 (+25d 15' 28")
    92.293 (06h 09m 10s) +23.037 (+23d 02' 13")
  ---------------------------------------------
The error box area is 1373 sq. arcmin, and its maximum
dimension is 4.22 deg (the minimum one is 10.2 arcmin).
The Sun distance was 94 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180317_T61287/IPN

The time history and spectrum will be given in forthcoming
GCN Circulars.


GRB_name: GRB180318A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22522
SUBJECT: IPN Triangulation of GRB 180318A (long)
DATE:    18/03/20 13:08:59 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 180318A has been detected by Konus-Wind,
Swift (BAT), and Mars-Odyssey (HEND), so far, at about 84000 s UT
(23:20:00).

We have triangulated it to a preliminary, 3 sigma error box whose
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   180.343 (12h 01m 22s) +33.936 (+33d 56' 09")
  Corners:
   179.707 (11h 58m 50s) +32.043 (+32d 02' 35")
   181.324 (12h 05m 18s) +35.706 (+35d 42' 23")
   180.991 (12h 03m 58s) +35.829 (+35d 49' 46")
   179.386 (11h 57m 33s) +32.164 (+32d 09' 49")
  ---------------------------------------------
The error box area is 1.16 sq. deg, and its maximum
dimension is 3.93 deg (the minimum one is 17.8 arcmin).
The Sun distance was 144 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180318_T84002/IPN

The time history and spectrum will be given in forthcoming
GCN Circulars.


GRB_name: GRB180324A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22524
SUBJECT: GRB 180324A: Swift detection of a burst
DATE:    18/03/24 04:50:01 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

E. Sonbas (Adiyaman Univ.), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), M. H. Siegel (PSU) and
A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 04:37:09 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180324A (trigger=817345).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 76.585, +56.725 which is 
   RA(J2000) = 05h 06m 20s
   Dec(J2000) = +56d 43' 29"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a small 
precursor about 5 seconds before the main, short, peak for a 
total duration of about 6 sec.  The peak count rate
was ~8000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 04:38:17.4 UT, 67.8 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 76.52896, 56.71298 which is equivalent
to:
   RA(J2000)  = 05h 06m 06.95s
   Dec(J2000) = +56d 42' 46.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 118 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.  We cannot determine whether the source is
fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.81 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 7.1
(+6.82/-5.48) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 71 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.90. 

Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180324A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22525
SUBJECT: GRB 180324A: Prompt enhanced Swift-XRT position
DATE:    18/03/24 05:18:47 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Using  promptly downlinked XRT event data for GRB 180324A, we find an
enhanced XRT position of the afterglow: RA, Dec: 76.5270, 56.7137 which
is equivalent to:
   RA (J2000)  = 05 06 06.49
   Dec (J2000) = +56 42 49.2
with an uncertainty of 2.0 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/817345.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180324A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22526
SUBJECT: Plans for GRB 180324A and ToOs
DATE:    18/03/24 05:21:22 GMT
FROM:    Aaron Cholden-Brown at PSU/Swift  <aaronb@swift.psu.edu>

The GRB will run for a few orbits.

At the 08:46 UT Malindi pass we will upload a 1ks observation of
ASASSN-18gb.

The following targets in the PPST were lost due to the AT (merit 76)
AT observed: 2018-083-09:46:00 - 2018-083-10:04:00 for 1140 secs

Merit  TargID Seg Name                           Lost(s) Remain(s)
72      34934 114 OJ 287                           1080         0
72      10556 14  SN2018pv                           60      2040

Cheers,
Aaron


GRB_name: GRB180324A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22527
SUBJECT: GRB 180324A: KAIT Optical Upper Limit
DATE:    18/03/24 06:07:20 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on
behalf of the KAIT GRB team:

The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 180324A (Sonbas et al.,
GCN 22524) starting at 04:54:12 UT, ~17 minutes after the burst,
and lasted ~10 minutes before it reached the physical limit of the
telescope.
Observations were performed with an automatic sequence in the
clear (roughly R), and I filters, and the exposure time was 20 s
per image. We do not detect any optical afterglow candidate within
the enhanced XRT position error circle (Evans et al., GCN 22525).
The typical limiting magnitude of our single clear image is about
19.0 mag calibrated to the APASS catalog.


GRB_name: GRB180324A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22528
SUBJECT: GRB 180324A: RATIR Optical Observations and Possible Afterglow Detection
DATE:    18/03/24 07:16:36 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora
Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), JesÃºs
GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey Moseley (GSFC), John
Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:

We observed the field of GRB 180324A (Sonbas, et al., GCN 22524) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico Nacional on
Sierra San Pedro MÃ¡rtir from 2018/03 24.19 to 2018/03 24.23 UTC (2.4
minutes to 0.92 hours after the BAT trigger), obtaining a total of 0.66
hours exposure in the r and i bands.

We detect a weak source within the Swift-XRT error circle (Evans, et al.,
GCN 22525) in our first 80 s exposure, i-band image only.  In comparison
with the USNO-B1 catalog, we find i=20.15+/-0.37.

The source is not on the frame in the subsequent image and is not detected
in the next possible frame 3.5 minutes later.  In our full 0.66 hour
exposure time, the source is not detected with the following upper limits
(3-sigma):

  r > 22.08
  i > 22.04

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  If the detection in the first
frame is due to the afterglow, then the afterglow faded rapidly.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180324A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22529
SUBJECT: GRB 180324A: Enhanced Swift-XRT position
DATE:    18/03/24 09:18:29 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2334 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 180324A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 76.52652, +56.71430 which is equivalent
to:

RA (J2000): 05h 06m 6.37s
Dec (J2000): +56d 42' 51.5"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180324A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22530
SUBJECT: GRB 180324A: Swift-XRT refined Analysis
DATE:    18/03/24 10:19:31 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia
(ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows
(PSU), A. Tohuvavohu (PSU), S. J. LaPorte (PSU), A.P. Beardmore (U.
Leicester) and E. Sonbas report on behalf of the Swift-XRT team:

We have analysed 7.1 ks of XRT data for GRB 180324A (Sonbas et al. GCN
Circ. 22524), from 80 s to 13.9 ks after the  BAT trigger. The data are
entirely in Photon Counting (PC) mode. The enhanced XRT position for
this burst was given by Goad et al. (GCN Circ. 22525).

The late-time light curve (from T0+5.7 ks) can be modelled with a
power-law decay with a decay index of alpha=1.07 (+/-0.16).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.36 (+0.13, -0.12). The
best-fitting absorption column is  9.0 (+1.6, -1.4) x 10^21 cm^-2, in
excess of the Galactic value of 3.8 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 6.7 x 10^-11 (8.7 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.0 (+1.6, -1.4) x 10^21 cm^-2
Galactic foreground: 3.8 x 10^21 cm^-2
Excess significance: 5.9 sigma
Photon index:      1.36 (+0.13, -0.12)

If the light curve continues to decay with a power-law decay index of
1.07, the count rate at T+24 hours will be 0.032 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.2 x
10^-12 (2.8 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00817345.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180324A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22531
SUBJECT: GRB 180324A: Swift/UVOT Upper Limits
DATE:    18/03/24 23:27:32 GMT
FROM:    Sam LaPorte at PSU  <sjl5346@psu.edu>

GRB 180324A: Swift/UVOT Upper Limits

S. J. Laporte (PSU) and E. Sonbas (Adiyaman Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180324A
72 s after the BAT trigger (Sonbas et al., GCN Circ. 22524).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 22529) or RATIR position (Butler et al. GCN Circ. 22528)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            72          221          147         >19.8
u_FC               284          534          246         >19.3
white               72        12383         1552         >21.3
v                  614        13894         1172         >19.5
b                  539         8158          549         >20.9
u                  284         7992          814         >20.3
w1                 664         7787          471         >20.2
w2                6970        13290         1082         >21.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.90 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180325A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22532
SUBJECT: GRB 180325A: Swift detection of a burst with an optical counterpart
DATE:    18/03/25 02:04:12 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

E. Troja (NASA/GSFC/UMCP), A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC),
J. A. Kennea (PSU), S. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU)
and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 01:53:02 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180325A (trigger=817564).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 157.432, +24.439 which is 
   RA(J2000) = 10h 29m 44s
   Dec(J2000) = +24d 26' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a ~10 second
FRED peak (~3000 counts/s) which is followed by brighter peak
which reaches a maximum of ~11000 counts/sec (15-350 keV), at ~81
after the trigger, for a total duration of ~120 seconds. 

The XRT began observing the field at 01:54:16.2 UT, 73.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 157.4281, 24.4627 which is equivalent to:
   RA(J2000)  = +10h 29m 42.74s
   Dec(J2000) = +24d 27' 45.7"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 86 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 82 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 10:29:42.59 = 157.42746
  DEC(J2000) = +24:27:48.5  =  24.46347
with a 90%-confidence error radius of about 0.76 arc sec. This position is 3.5
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.45 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.02. 

We note that the second peak seen by BAT occurs during the 
early UVOT and XRT images, so these sample the prompt GRB
emission. 

Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180324A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22533
SUBJECT: GRB 180324A, Swift-BAT refined analysis
DATE:    18/03/25 02:06:18 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), J. P. Norris (BSU),
D. M. Palmer (LANL), T. Sakamoto (AGU),
E. Sonbas (Adiyaman Univ.), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180324A (trigger #817345)
(Sonbas et al., GCN Circ. 22524).  The BAT ground-calculated position is
RA, Dec = 76.581, 56.744 deg which is
  RA(J2000)  =  05h 06m 19.4s
  Dec(J2000) = +56d 44' 36.8"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%.

The mask-weighted light curve shows a small precursor at ~T-5 s, followed
by the main pulse that starts at ~T-0.2, peaks at ~T+0.3 s, and ends at ~T+1 s.
There is also some weak emission that lasts till ~T+4 s. T90 (15-350 keV)
is 7.2 +- 1.3 sec (estimated error including systematics).

The lag analysis for the main pulse finds a lag of 48 +- 18 ms for the
100-350 keV to 25-100 keV band. This value is consistent with that of a
long GRB. In addition, no extended emission is found after ~T+4 s.

The time-averaged spectrum from T-5.4 to T+3.7 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.45 +- 0.14.  The fluence in the 15-150 keV band is 5.6 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.13 sec in the 15-150 keV band
is 4.4 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/817345/BA/


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22534
SUBJECT: GRB 180325A: prompt LT observations
DATE:    18/03/25 03:05:01 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), 
A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large 
collaboration report:

The 2-m Liverpool Telescope automatically began observing Swift GRB 
180325A (Troja et al. GCN 22532) on March 25, 01:55:25 UT (143 seconds 
since the GRB trigger time) with the RINGO3 polarimeter and the IO:O 
camera in the SDSS-R filter. We clearly detect the optical afterglow 
(Troja et al.) with the following magnitude:

Mid Time from GRB  Exposure       Filter       Magnitude (AB)
(min)              (s)
-------------------------------------------------------------
35.1               6x10           SDSS-R       19.02 +- 0.05
-------------------------------------------------------------

as calibrated against nearby SDSS objects.


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22535
SUBJECT: GRB 180325A: NOT redshift
DATE:    18/03/25 03:33:36 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

K. E. Heintz (Univ. Iceland and DAWN/NBI), J. P. U. Fynbo (DAWN/NBI), D. 
Malesani (DAWN/NBI and DARK/NBI), report on behalf of a larger 
collaboration:

We observed the optical counterpart of GRB 180325A (Troja et al., GCN 
22532; Guidorzi et al., GCN 22534) with the 2.5-m Nordic Optical 
Telescope (NOT) equipped with ALFOSC, starting at 02:02:30 UT on 25 
March 2018. We obtained 3x100 s in the r-band and measure a magnitude of 
m(r) = 18.61 +/- 0.03 mag at a mean post-explosion epoch of 11 minutes. 
The calibration was performed using local Pan-STARRS stars in the GRB 
field. This apparent magnitude is not corrected for foreground extinction.

We subsequently obtained spectroscopy for a total of 3x600 s, using 
grism #4 and covering the wavelength range 3650-9450 AA. In our 
low-resolution spectrum we identify several absorption features, 
including Mg II, Fe II, Al II, C IV, Si II at a common redshift of z = 
2.25. The 2175 AA bump is clearly visible at this redshift. We also note 
the presence of a strong intervening system at z = 2.04, as revealed by 
Mg II and Fe II absorption features.

Further observations are in progress.


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22536
SUBJECT: GRB 180325A: prompt REM optical/NIR detection
DATE:    18/03/25 03:50:18 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, A. Melandri, S. Covino, D. Fugazza (INAF/OAB) report on behalf of the REM team:

We observed the field of the GRB 180325A (Troja et al., GCN 22532) with the 60-cm robotic telescope REM located at the La Silla Observatory (Chile).  
The observations started on 25-03-2018 at 01:53:52 UT, 50s after the burst, and were carried in the g, r, i, z, J, H and K bands.

A preliminary analysis shows that the optical counterpart (Troja et al., GCN 22532; Guidorzi et al. GCN 22534; Heintz et al. GCN 22535) is well detected 
and at a mid time of 123 seconds after the burst it was:

r = 17.2 +/- 0.2 (AB)
H = 12.7 +/- 0.1 (Vega)

Magnitudes are calibrated against the SDSS (optical) and 2MASS (NIR) catalogues.


GRB_name: GRB180325A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22537
SUBJECT: GRB 180325A: RATIR Optical Observations 
DATE:    18/03/25 06:01:31 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 180325A (Troja et al., GCN 22532) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2018/03 25.12 to 2018/03 25.23
UTC (1.02 to 3.67 hours after the BAT trigger), obtaining a total of
1.47 hours exposure in the r and i bands and hours exposure in the Z, Y,
J, and H bands.

For a source within the Swift-XRT error circle, in comparison with the
SDSS DR9 catalog, we obtain the following detections:

  r = 19.79 +/- 0.02
  i = 19.38 +/- 0.01

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180325A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22538
SUBJECT: GRB 180325A: Optical Photometry with SLKT
DATE:    18/03/25 06:42:44 GMT
FROM:    Peter Garnavich at U of Notre Dame  <pgarnavi@nd.edu>

C. Littlefield and P. Garnavich (Notre Dame) report:

We observed the field of GRB 180325A (GCN 22532)  with the
0.8-m Sarah L. Krizmanich Telescope at the University of
Notre Dame. Unfiltered CCD images were obtained
under hazy conditions beginning 1.5 hours after the
burst. We calibrated the afterglow in SDSS-r using a
nearby star in the Pan-STARRS catalog and constructed
the following light curve:

DateAge     SDSS-r err
(UT)          (hours)
March 25.1403  1.483    19.29  0.14
March 25.1626  2.018    19.52  0.18
March 25.227    3.564    20.1   0.3

Based on SDSS-r magnitudes reported by Heintz et al.
(GCN 22535) and Guidorzi et al. (GCN 22534), we obtain
a rather shallow power-law decay index of 0.31+/-0.05
between 0.5 hours and 2 hours after the burst.


GRB_name: GRB180325A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22539
SUBJECT: GRB 180325A: Enhanced Swift-XRT position
DATE:    18/03/25 07:43:32 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2783 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 180325A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 157.42735, +24.46361 which is equivalent
to:

RA (J2000): 10h 29m 42.56s
Dec (J2000): +24d 27' 49.0"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180325A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22540
SUBJECT: GRB 180325A: Swift-XRT refined Analysis
DATE:    18/03/25 12:09:56 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K.L. Page (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), A. Tohuvavohu (PSU), S. J. LaPorte
(PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U.
Leicester) and E. Troja report on behalf of the Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 180325A (Troja et al. GCN
Circ. 22532), from 61 s to 29.3 ks after the  BAT trigger. The data
comprise 329 s in Windowed Timing (WT) mode (the first 10 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Osborne et
al. (GCN Circ. 22539).

The late-time light curve (from T0+4.8 ks) can be modelled with a
power-law decay with a decay index of alpha=2.02 (+0.09, -0.08).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.60 (+/-0.09). The
best-fitting absorption column is  1.7 (+0.6, -0.5) x 10^22 cm^-2, at a
redshift of 2.25, in addition to the Galactic value of 1.3 x 10^20
cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index
of 1.85 (+/-0.09) and a best-fitting absorption column of 1.3 (+/-0.4)
x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 3.6 x 10^-11 (4.2 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 1.3 x 10^20 cm^-2
Intrinsic column:    1.3 (+/-0.4) x 10^22 cm^-2 at z=2.25
Photon index:      1.85 (+/-0.09)

If the light curve continues to decay with a power-law decay index of
2.02, the count rate at T+24 hours will be 7.0 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.5 x
10^-13 (2.9 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00817564.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22541
SUBJECT: GRB 180325A: D50 early optical follow-up
DATE:    18/03/25 13:20:11 GMT
FROM:    Martin Jelinek at Astro.Inst-AVCR,Ondrejov  <martin.jelinek@asu.cas.cz>

Jan Strobl, Martin Jelinek and Rene Hudec (ASU CAS Ondrejov)

report

We observed the field of the Swift GRB 180325A (Troja et al., GCNC 22532)
with the 0.5m telescope D50 in Ondrejov (Czech Republic), starting at
01:53:47.1 UT, i.e. 44.3s after the trigger.

The observation consisted of a series of 10 s unfiltered exposures,
covering the peak of the optical emission at mag ~16.3. The maximum seems
to be somewhat delayed with respect to the bright peak in gamma-rays.

This message can be cited.


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22542
SUBJECT: GRB 180325A: TAROT Calern observatory optical observations
DATE:    18/03/25 14:36:31 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Noysena K., Atteia J.L. (CNRS-OMP-IRAP),
Boer M., Eymar L. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 180325A detected by SWIFT
(trigger 817564) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 26s after the GRB trigger
(14s after the notice). The elevation of the field decreased
from 37 degrees above horizon and weather conditions
were excellents.

We detect clearly the optical transcient (OT) reported by
Troja et al. (GCN 22532), Guidorzi et al. (GCN 22534),
Heintz et al. GCN 22535), D'Avanzo et al. (GCNC 22536),
Watson  et al. (GCNC 22537), Garnavich  et al. (GCNC 22538),
Strobl et al. (GCNC 22541).

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We detect the OT at a magnitude of:
t0+26s to t0+86s : r(AB) = 17.2 +/- 0.3

It is important to notice that a bright gamma flash in
Swift-BAT data occured between 70 and 92 seconds. We
do not detect any significant optical flux increase
during the range 70 to 86 seconds of the first TAROT
exposure.

After an overhead time of 13 seconds the second image
of 30s exposure in tracking mode started 99 seconds
after the trigger. In this image the OT has brightened
by about 1 magnitude. The third image shows a rapid
decrease of 1 magnitude compatible with a decay index
of about 3 followed by a mean decay of 0.45 until
1.7 hour after the trigger confirming the small decay
value published by Littlefield and Garnavich (GCNC 22538).

The photometric analysis of the TAROT images are given:

t1(h)  t2(h)  r(AB) 1sig
0.0277 0.0361 16.24 0.09
0.0391 0.0474 17.22 0.20
0.0504 0.0815 17.68 0.19
0.0843 0.1093 18.02 0.30
0.2062 0.2872 18.56 0.30
0.2951 0.4364 18.78 0.39
0.4392 1.1843 18.94 0.22
1.2400 1.6746 19.26 0.36

Magnitudes were estimated with the nearby star
NOMAD-1 1144-0181799 R=14.440 (V-R)=0.65, converted into
r(AB) system and are not corrected for galactic dust extinction.

Note that the TAROT light curve is compatible with an
optical flash occuring with a lag of 20 +/- 10 seconds
after the bright gamma emission peak as mentioned
by Strobl et al. (GCNC 22541).


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22543
SUBJECT: GRB 180325A: Global MASTER-Net OT prompt observations 
DATE:    18/03/25 15:05:51 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov, D.Zimnukhov, V.Vladimirov, 
A.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.Chazov, D. Kuvshinov
(Lomonosov Moscow State University, SAI),

R.Podesta, C.Lopez, F. Podesta
(Observatorio Astronomico Felix Aguilar (OAFA),National University of San 
Juan, Argentina),

H. Levato, C. Saffe
(Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), 
San Juan, Argentina),

R. Rebolo, M. Serra-Ricart, G.Israelyan
(The Instituto de Astrofisica de Canarias),

D.Buckley, S. Potter
(South African Astronomical Observatory),

O.Gres,  N.M.Budnev
(Irkutsk State University),

A. Tlatov, V.Senik, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory)

V.Yurkov, A.Gabovich, Yu.Sergienko
(Blagoveschensk Educational State University, Blagoveschensk),

MASTER-OAFA and MASTER-IAC automatically pointed to GRB 180314A (Eleonora 
Troja et al. GCN 22532) with optical transient detection by MASTER 
auto-detection system.
We confirm Swift, LT, NOT, REM,  RATIR, SLKT, D50  GROND OT (GCN 22532, 
22534, 22535, 22536, 22537, 22538, 22541) but observed before.


MASTER-OAFA  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in OAFA (Argentina,http://oafa.master.sai.msu.ru:49001/) was 
pointed to the  GRB180325.08 38 sec after 
trigger time at 2018-03-25 01:53:40 UT. On our second
(20s exposure)  set robot automaticaly  found 1 optical transient within 
SWIFT error-box (ra=157.429 dec=24.4389 r=0.05) brighter then 16.7 .


  T-Ttrig  Date      Time       Expt.        Ra              Dec        Mag
-------|-------------------|-------|-----------------|---------------|-------
    88   2018-03-25 01:54:31    20    ( 10h 29m 42.7s , +24d 27m 49.3s)  16

The 5-sigma upper limit has been about 17.3mag

====================================================================



The observations made on zenit distance = 58 degrees, galaxy latitude b =
59 degree. The moon (55 % bright part) is 25 degrees above the horizon. 
The distance between  moon and  object is 53
The sun  altitude  is -40.3 degree.
The object can be observed till 2018-03-25 07:53:41 UT.




MASTER-IAC  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in IAC (Tenerife, Tejde Observatory) was pointed to the 
GRB180325.08 63 sec after trigger time 
at 2018-03-25 01:54:09 UT. On our second 
(20s exposure)  set robot automaticaly  found 1 optical transient within 
SWIFT error-box (ra=157.429 dec=24.4386 r=0.05) brighter then 17.0.


  T-Ttrig     Date   Time       Expt.        Ra                Dec         Mag
-------|-------------------|-------|-----------------|-----------------|-------
   119   2018-03-25 01:55:01    20     ( 10h 29m 42.6s , +24d 27m 48.3s)  16.50

The 5-sigma upper limit has been about 17.5 mag
The message may be cited.


====================================================================


The observations made on zenit distance = 34 degrees, galaxy latitude b = 
59 degree.
The moon (55 % bright part) is  6 degrees above the horizon. The distance 
between  moon and  object is 53
The sun  altitude  is -58.3 degree.
The object can be observed till 2018-03-25 06:24:39 with good limit.


This message can be cited.


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22544
SUBJECT: GRB 180325A: GROND observations
DATE:    18/03/25 17:51:03 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

T. Schweyer (MPE), and D. A. Kann (HETH/IAA-CSIC) report:

We observed the field of GRB 180325A (Swift trigger 817564; E. Troja et 
al., GCN #22532) simultaneously in g'r'i'z'JHK with GROND (Greiner et 
al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La 
Silla Observatory (Chile).

Observations started at 02:53 UTC on March 25, 1.0 hours after the GRB 
trigger. They were performed at an average seeing of 1".5 and at an 
average airmass of 1.7.

We clearly detect the NIR/optical transient of GRB 180325A within the 
enhanced XRT position (J. P. Osborne et al., GCN #22539), in agreement 
with the optical transient detected by UVOT (E. Troja et al., GCN 
#22532).
Based on 7 minutes of exposure centered around 03:30 UTC, we measure the 
following magnitudes (all in AB system).

g' = 20.45 +/- 0.03 mag
r' = 19.57 +/- 0.02 mag
i' = 19.18 +/- 0.02 mag
z' = 18.30 +/- 0.02 mag
J = 17.42 +/- 0.02 mag
H = 16.85 +/- 0.02 mag
K = 16.34 +/ 0.03 mag

Given magnitudes are calibrated against SDSS in g'r'i'z' and 2MASS field 
stars in JHK, and are not corrected for the Galactic foreground 
extinction corresponding to a reddening of E_(B-V)= 0.015 in the
direction of the burst (Schlafly & Finkbeiner 2011).

We acknowledge the excellent support from the TiO and the current 
observer at the 2.2m in La Silla, Angela Hempel and Victor Marian.


GRB_name: GRB180325A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22545
SUBJECT: GRB 180325A, Swift-BAT refined analysis
DATE:    18/03/25 22:01:01 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/UMCP), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+500 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180325A (trigger #817564)
(Troja et al., GCN Circ. 22532).  The BAT ground-calculated position is
RA, Dec = 157.416, 24.461 deg which is
  RA(J2000)  =  10h 29m 39.9s
  Dec(J2000) = +24d 27' 39.7"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.

The mask-weighted light curve shows two separate pulses. The first pulse
starts and peaks at ~T0, and ends at ~T+10 s. The second brighter pulse
starts at ~T+70 s, peaks at ~T+80 s, and ends at ~T+110 s. T90 (15-350 keV)
is 94.1 +- 1.5 sec (estimated error including systematics).

The time-averaged spectrum from T-0.0 to T+107.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.18 +- 0.05.  The fluence in the 15-150 keV band is 6.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+80.75 sec in the 15-150 keV band
is 9.4 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/817564/BA/


GRB_name: GRB180325A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22546
SUBJECT: Konus-Wind observation of GRB 180325A
DATE:    18/03/26 09:41:07 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, M. Ulanov, D. Svinkin,
A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 180325A (Swift-BAT trigger 817564:
Troja et al., GCN 22532; Lien et al., GCN 22545)
triggered Konus-Wind at T0=6866.876 s UT (01:54:26.876)

The burst light curve shows a single pulse,
which started at ~T0-1 s and peaked at ~T0+1.7 s.
The total duration of the burst is ~10 s.
The emission is seen up to ~7 MeV.

As observed by Konus-Wind, the burst had a fluence of
(1.9 Â± 0.3)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+1.728, of (8.2 Â± 1.3)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+7.424 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.50 (-0.19,+0.21),
the high energy photon index beta = -2.65 (-1.06,+0.31),
the peak energy Ep = 306 (-39,+50) keV,
chi2 = 99/92 dof.

Assuming the redshift z=2.25 (Heintz et al., GCN 22535)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.3, and Omega_Lambda = 0.7,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~2.3x10^53 erg,
the peak luminosity L_iso is ~3.2x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,z, is ~995 keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180325_T06866/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB180324A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22547
SUBJECT: Konus-Wind observation of GRB 180324A
DATE:    18/03/26 13:27:09 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, M. Ulanov, D. Svinkin,
A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:

GRB 180324A (Swift-BAT trigger 817345:
Sonbas et al., GCN 22524; Krimm et al., GCN 22533)
triggered Konus-Wind at T0=16629.939 s UT (04:37:09.939)

The burst light curve shows a weak pulse,
which started at ~T0-0.4 s and peaked at ~T0 s.
The total duration of the burst is ~0.7 s.
The emission is seen up to ~0.5 MeV.

As observed by Konus-Wind, the burst had a fluence of
(7.4 Â± 2.1)x10^-7 erg/cm2 and a 64-ms peak energy flux,
measured from T0, of (1.8 Â± 0.5)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The burst spectrum (measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.56(-0.71,+1.16),
and the peak energy Ep = 154(-38,+77) keV,
chi2 = 22/19 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and an upper limit on beta of ~-2.2

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180324_T16629/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB180316A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22548
SUBJECT: Konus-Wind observation of GRB 180316A
DATE:    18/03/26 15:10:45 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

A. Tsvetkova, S. Golenetskii, R.Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Lysenko, A. Kozlova and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 180316A
(Swift detection of a burst: Melandri et al., GCN 22500;
Cummings et al., GCN 22512)
triggered Konus-Wind at T0=17845.869 s UT (04:57:25.869).

The burst light curve shows a single emission episode
which starts at ~T0-13 s and has a total duration of ~29 s.
The emission is seen up to ~1.2 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.43(-0.21,+0.38)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+2.976 s,
of 2.77(-1.16,+1.49)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 1.2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.23(-0.23,+0.27),
and Ep = 439(-139,+424) keV (chi2 = 74/60 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -1.87 (chi2 = 74/59 dof).

The spectrum near the peak count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model
with  alpha = -1.19(-0.22,+0.26),
and Ep = 498(-165,+498) keV (chi2 = 54/61 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -1.75 (chi2 = 53/60 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180316_T17845/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180325A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22549
SUBJECT: GRB 180325A: Swift/UVOT Detection
DATE:    18/03/26 17:07:59 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180325A
82 s after the BAT trigger (Troja et al., GCN Circ. 22532).
A fading source consistent with the enhanced XRT position
(Osborne et al. GCN Circ. 22539)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  10:29:42.59 = 157.42744 (deg.)
    Dec (J2000) = +24:27:48.6  =  24.46349 (deg.)
with an estimated uncertainty of 0.44 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               82          232          147         18.48 +/- 0.05
white             5039         5239          197         20.75 +/- 0.23
v                 5450         5650          197        >18.8
b                 4834         6385          309        >20.1
u                  295         6265          353        >20.0
w1                5860         6060          197        >20.1
m2                5654         5854          197        >19.4
w2                5245        12343          980        >20.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180326A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22550
SUBJECT: IPN Triangulation of GRB 180326A (long)
DATE:    18/03/26 18:13:59 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:

The long-duration GRB 180326A has been detected by Konus-Wind,
INTEGRAL (SPI-ACS), and Mars-Odyssey (HEND), so far, at about 12367 s UT 
(03:26:07).

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   291.728 (19h 26m 55s) -13.553 (-13d 33' 10")
  Corners:
   291.335 (19h 25m 20s) -13.809 (-13d 48' 34")
   291.286 (19h 25m 09s) -12.172 (-12d 10' 20")
   292.121 (19h 28m 29s) -13.297 (-13d 17' 48")
   292.210 (19h 28m 50s) -15.184 (-15d 11' 04")
  ---------------------------------------------
The error box area is 1.37 sq. deg, and its maximum
dimension is 3.14 deg (the minimum one is 46.9 arcmin).
The Sun distance was 74 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB180326_T12367/IPN

The time history and spectrum will be given in forthcoming
GCN Circulars.


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22551
SUBJECT: GRB 180325A: further NOT observations
DATE:    18/03/26 23:43:36 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

Daniele Malesani (DAWN/NBI and DARK/NBI) and Johan P.U. Fynbo (DAWN/NBI) report on behalf of a larger collaboration:

We observed the optical afterglow of GRB 180325A (Troja et al., GCN 22532) using the Nordic Optical Telescope (NOT) equipped with the AlFOSC imaging camera. The seeing in our observations was not good, around 2". 4 and 2 exposures by 600 s were obtained in the R and I filters, respectively.

The afterglow was not detected in R, and marginally (if at all) in I. The following magnitudes were computed with respect to nearby Pan-STARRS reference stars, and are therefore in the AB system.

Time (UT)    Time since GRB (hr) Filter  Magnitude
-----------------------------------------------------
Mar 25.856   18.65                r       >22.6
Mar 25.871   18.92                i       22.9 +- 0.3

These values are significantly fainter than the extrapolation based on the earlier measurements (Guidorzi et al., GCN 22534; Heintz et al., GCN 22535; D'Avanzo et al., GCN 22536; Watson et al., GCN 22536; Littlefield & Garnavich, GCN 22538; Strobl et al., GCN 22541; Klotz et al., GCN 22542; Lipunov et al., GCN 22543; Schweyer & Kann, GCN 22544) and indicate a break in the afterglow light curve.


GRB_name: GRB180317A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22552
SUBJECT: Konus-Wind observation of GRB 180317A
DATE:    18/03/27 11:31:50 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov,
A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The short-duration, hard-spectrum GRB 180317A
(IPN triangulation: Svinkin et al., GCN 22521)
triggered Konus-Wind at T0=61287.097 s UT (17:01:27.097).

The burst light curve shows a single pulse
which starts at T0-34 ms and has a total duration of ~74 ms.

As observed by Konus-Wind, the burst
had a fluence of 9.47(-2.14,+6.93)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0-0.024 s,
of 2.69(-0.71,+2.00)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the most intense part of the burst was detected before
the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modeling the KW 3-channel time-integrated spectrum
(from T0-0.034 s to T0+0.040 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.74(-0.36,+0.51), and Ep = 757(-253,+1050) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180317_T61287/

The burst is not seen in the waiting mode data.

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180326A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22553
SUBJECT: Konus-Wind observation of GRB 180326A
DATE:    18/03/27 14:23:52 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 180326A
(IPN Triangulation: Hurley et al., GCN 22550)
triggered Konus-Wind at T0=12367.064 s UT (03:26:07.064).

The burst light curve shows a multipeaked structure
which starts at ~T0-0.2 s and has a total duration of ~20.6 s.
The emission is seen up to ~6 MeV.

As observed by Konus-Wind, the burst
had a fluence of 2.19(-0.30,+0.36)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.336 s,
of 9.16(-2.36,+2.52)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+16.640 s)
is best fit in the 20 keV - 6 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.55(-0.20,+0.24)
and Ep = 767(-142,+200) keV (chi2 = 80/80 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.0
(chi2 = 80/79 dof)

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+8.448 s)
is best fit in the 20 keV - 6 MeV range
by a power law with exponential cutoff model
with alpha = -0.61(-0.20,+0.23)
and Ep = 806(-151,+208) keV (chi2 = 85/80 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.6
(chi2 = 85/79 dof)

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180326_T12367/
We note the MAXI J1820+070 activity seen in the waiting mode data.

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180318A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22554
SUBJECT: Konus-Wind observation of GRB 180318A
DATE:    18/03/27 16:06:20 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

A. Tsvetkova, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 180318A
(IPN Triangulation: Hurley et al., GCN 22522)
triggered Konus-Wind at T0=84002.795 s UT (23:20:02.795).

The burst light curve shows two emission episodes with multipeaked 
structure,
which start at ~T0-53 s and have a total duration of ~280.0 s.
The main episode lasts from ~T0-53 s to ~T0+30 s,
the second episode lasts from ~T0+150 s to ~T0+200 s.
The emission is seen up to 1.2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180318_T84002/

As observed by Konus-Wind, the burst
had a fluence of 1.13(-0.24,+0.23)x10^-4 erg/cm2,
and a 64-ms peak energy flux, measured from T0+18.560 s,
of 4.89(-1.04,+1.11)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+205.056 s)
is best fit in the 20 keV - 1.2 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.89(-0.24,+0.31),
the high energy photon index beta = -2.12(-0.48,+0.18),
the peak energy Ep = 195(-45,+69) keV,
chi2 = 83/59 dof.

The spectrum near the maximum count rate
(measured from T0+16.640 to T0+24.832 s)
is best fit in the 20 keV - 1.2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.98(-0.19,+0.22)
and Ep = 251(-40,+63) keV (chi2 = 63/60 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and  beta < -2.13 (chi2 = 62/59 dof)

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB180325A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22555
SUBJECT: GRB 180325A: VLT/X-shooter spectroscopic observations
DATE:    18/03/27 21:30:43 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. Dâ€™Avanzo (INAF-OAB), J. Bolmer (ESO/MPE), V. Dâ€™Elia (ASI-SSDC), J. P. U. Fynbo (DAWN/NBI), K. E. Heintz (U. Iceland, DAWN/NBI), L. Izzo (HETH/IAA-CSIC), J. Japelj (API, U. Amsterdam), D. A. Kann  (HETH/IAA-CSIC), D. Malesani (DAWN/NBI and DARK/NBI), J. Selsing (DARK/NBI), N. R. Tanvir (Univ. Leicester), T. Zafar (AAO), S. Campana (INAF-OAB), A. de Ugarte Postigo (HETH/IAA-CSIC and DARK/NBI), J. Hjorth (DARK/NBI), L. Kaper (Univ. Amsterdam), A. Melandri (INAF-OAB), A. Smette (ESO), report on behalf of the Stargate Consortium:

We observed the optical afterglow of GRB 180325A (Troja et al. GCN 22532) with the ESO VLT/X-shooter spectrograph, covering the wavelength range 3000-25000 AA. Spectroscopy started at 03:20:45 UT on 2018-03-25 (i.e., ~1.5 hr after the GRB) and consisted of 8 exposures of 600 s.

The spectrum exhibits a red continuum with several absorption features, including Ly-alpha and different metal and fine-structure lines, together with [OII], [OIII] and Halpha emission lines, all at a common redshift of z=2.248. At the same redshift, we also note the presence of a clear continuum depression corresponding to the 2175 AA bump. Finally, the spectrum shows the presence of a strong double intervening system at z = 2.041/2.043. 

The above results are in agreement with the findings of Heintz et al. (GCN 22535). 


We acknowledge the excellent support from the ESO staff, particularly Luca Sbordone, Jose Velasquez and Zahed Wahhaj in obtaining these observations.


GRB_name: GRB180329A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22556
SUBJECT: Swift Trigger 819301: possible GRB 180329A
DATE:    18/03/29 01:17:44 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. L. Racusin (NASA/GSFC), A. Deich (PSU), J. A. Kennea (PSU),
H. A. Krimm (NSF/USRA), K. L. Page (U Leicester), D. M. Palmer (LANL)
and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 00:58:00 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a marginal-significance (6.9 sigma) image peak that may be 
GRB 180329A (trigger=819301).  Swift could not slew to the location 
due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 329.298, -15.071 which is 
   RA(J2000) = 21h 57m 11s
   Dec(J2000) = -15d 04' 14"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows some variation
consistent with a ~8 second long GRB, however this variation
is also consistent with the presence of the currently-active black hole
transient MAXI J1820+070 in the FOV.  The peak count rate
was ~1400 counts/sec (15-350 keV), at ~5 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 23:07 UT on 2018 April 02. There will thus be no XRT or
UVOT data for this trigger before this time. 

Due to the low significance of this detection, the presence of
a bright variable X-ray source in the BAT Field of View, and the lack
of follow-up observations from the XRT and UVOT, we cannot determine
whether this is a GRB at this time.  Further analysis of the
full downlinked data will be required to decide if this is a
GRB or a statistical fluctuation in the image plane. 

Burst Advocate for this burst is J. L. Racusin (judith.racusin AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180325A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22557
SUBJECT: GRB180325A: AstroSat CZTI detection
DATE:    18/03/29 10:36:12 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 180325A, which was also detected by Swift (Troja E. et al., GCN 22532), Swift-BAT (Lien A. Y. et al., GCN 22454), Swift-XRT (Page K.L. et al., GCN 22540) and Konus-Wind (Frederiks D. et al., GCN 22546).

The source was clearly detected in the 40-200 keV energy range. The light curve shows single peak of emission at 01:54:23.0 UT, ~81 s after Swift-BAT trigger time. The measured peak count rate is 1093.8 cts/s above the background in combined data of four quadrants, with a total of 5294 cts. The local mean background count rate was 510.2 cts/s. Using cumulative rates, we measure a T90 of 15.7 s. In Preliminary analysis, we find that 495.2 compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB180329B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22558
SUBJECT: GRB 180329B: Swift detection of a burst with an optical afterglow
DATE:    18/03/29 14:21:48 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. L. Racusin (NASA/GSFC), A. Deich (PSU), J.D. Gropp (PSU),
J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (PSU) and
A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 14:08:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180329B (trigger=819490).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 82.916, -23.708 which is 
   RA(J2000) = 05h 31m 40s
   Dec(J2000) = -23d 42' 27"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a small complex
peak from T-10 to T+20 s (peak of 800 counts/s) with a stronger peak
from T+140 to T+160 (the limit of currently available data).  
The peak count rate was ~1400 counts/sec (15-350 keV), at ~147 sec 
after the trigger. 

The XRT began observing the field at 14:10:07.5 UT, 103.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 82.9031, -23.6889 which is equivalent to:
   RA(J2000)  = +05h 31m 36.74s
   Dec(J2000) = -23d 41' 20.0"
with an uncertainty of 6.5 arcseconds (radius, 90% containment). This
location is 80 arcseconds from the BAT onboard position, within the BAT
error circle. 

The initial flux in the 2.5 s image was 4.57e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 111 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 05:31:36.90 =  82.90376
  DEC(J2000) = -23:41:25.9  = -23.69052
with a 90%-confidence error radius of about 0.62 arc sec. This position is 6.2
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.65 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.04. 

The brighter, second, peak of this GRB occurs during the time that
XRT and UVOT were taking data, so the early observations sample
the prompt burst emission. 

Burst Advocate for this burst is J. L. Racusin (judith.racusin AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180329B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22559
SUBJECT: GRB 180329B: Enhanced Swift-XRT position
DATE:    18/03/29 19:45:14 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3233 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 180329B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 82.90376, -23.69085 which is equivalent
to:

RA (J2000): 05h 31m 36.90s
Dec (J2000): -23d 41' 27.1"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180329B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22560
SUBJECT: GRB 180329B: Swift-XRT refined Analysis
DATE:    18/03/29 21:14:48 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), S. J.
LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), A.P.
Beardmore (U. Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U.
Leicester) and J.L. Racusin report on behalf of the Swift-XRT team:

We have analysed 7.4 ks of XRT data for GRB 180329B (Racusin et al. GCN
Circ. 22558), from 109 s to 17.7 ks after the  BAT trigger. The data
comprise 260 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Beardmore et al. (GCN Circ. 22559).

The late-time light curve (from T0+4.6 ks) can be modelled with a
power-law decay with a decay index of alpha=1.14 (+/-0.12).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.54 (+/-0.04). The
best-fitting absorption column is  7.5 (+1.4, -1.3) x 10^20 cm^-2, in
excess of the Galactic value of 2.5 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.86 (+/-0.11) and a
best-fitting absorption column of 6.5 (+2.8, -2.6) x 10^20 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.5 x 10^-11 (4.0 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      6.5 (+2.8, -2.6) x 10^20 cm^-2
Galactic foreground: 2.5 x 10^20 cm^-2
Excess significance: 2.6 sigma
Photon index:      1.86 (+/-0.11)

If the light curve continues to decay with a power-law decay index of
1.14, the count rate at T+24 hours will be 0.012 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.4 x
10^-13 (5.0 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00819490.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180329A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22561
SUBJECT: GRB 180329A: Swift-BAT refined analysis
DATE:    18/03/29 22:26:04 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180329A (trigger #819301)
(Racusin et al., GCN Circ. 22556).  The BAT ground-calculated position is
RA, Dec = 329.314, -15.043 deg which is
  RA(J2000)  =  21h 57m 15.3s
  Dec(J2000) = -15d 02' 36.0"
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 80%.

The mask-weighted light curve shows a weak pulse that starts at ~T0, peaks
at ~T+1 s, and ends at ~T+10 s. T90 (15-350 keV) is 9.1 +- 1.8 sec (estimated
error including systematics).

The time-averaged spectrum from T-0.30 to T+9.69 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.39 +- 0.31.  The fluence in the 15-150 keV band is 2.3 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.14 sec in the 15-150 keV band
is 0.5 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Due to an observing constraint, there are no observations of this source with the
Swift XRT or UVOT, and hence no confirmation of the nature of the source.
However, because the image significance from the ground analysis of the BAT
data is ~ 9 sigma, and the temporal and spectral properties are consistent with
those from a BAT GRB, we conclude that this source is likely a real GRB.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/819301/BA/


GRB_name: GRB180329B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22562
SUBJECT: GRB 180329B: NOT optical afterglow detection
DATE:    18/03/29 23:19:12 GMT
FROM:    Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>

D. A. Perley (LJMU), K. E. Heintz (Univ. of Iceland and DAWN/NBI), and
D. Malesani (DAWN/NBI and DARK/NBI) report:

We observed the location of GRB 180329B (Racusin et al., GCN 22558)
using the Nordic Optical Telescope (NOT) equipped with the AlFOSC
imaging camera.  Three exposures of 300 s each were obtained in the SDSS
r filter.  Observations were taken during twilight at low elevation, and
the field was partially vignetted due to the dome shutter.

A weak source is detected in each exposure at a position coincident with
the Swift UVOT and XRT error circles. We estimate a magnitude of m(r) =
19.4 +/- 0.2 mag at the time of our observations (midpoint UT 20:27:14),
corresponding to 6.32 hr after trigger.

The position of the afterglow (J2000) is:
RA =  05:31:36.90
Dec = -23:41:26.3
    (+/- 0.4")

We thank the NOT staff (J. Telting) and the observer (L. Siltala) for
acquiring these observations.











________________________________
Important Notice: the information in this email and any attachments is for the sole use of the intended recipient(s). If you are not an intended recipient, or a person responsible for delivering it to an intended recipient, you should delete it from your system immediately without disclosing its contents elsewhere and advise the sender by returning the email or by telephoning a number contained in the body of the email. No responsibility is accepted for loss or damage arising from viruses or changes made to this message after it was sent. The views contained in this email are those of the author and not necessarily those of Liverpool John Moores University.


GRB_name: GRB180329B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22564
SUBJECT: GRB 180329B: RATIR Optical Observations
DATE:    18/03/30 06:41:22 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC),
William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J.
Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), JesÃºs GonzÃ¡lez (UNAM), Carlos RomÃ¡n-ZÃºÃ±iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki
Toy (UMD) report:

We observed the field of GRB 180329B (Racusin et al., GCN 22558) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio AstronÃ³mico
Nacional on Sierra San Pedro MÃ¡rtir from 2018/03 30.13 to 2018/03 30.18
UTC (12.92 to 14.22 hours after the BAT trigger), obtaining a total of
0.96 hours exposure in the r and i bands.

For a source within the Swift-XRT error circle, in comparison with the
USNO-B1 catalog, we obtain the following detections:

 r = 20.29 +/- 0.09
 i = 20.32 +/- 0.10

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

The source has faded in r at the 4-sigma level when compared to the
earlier NOT observation of Perley et al. (GCN 22562).

We thank the staff of the Observatorio AstronÃ³mico Nacional in San Pedro
MÃ¡rtir.


GRB_name: GRB180329B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22565
SUBJECT: GRB 180329B: Swift/UVOT Detection
DATE:    18/03/30 11:38:14 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) and J. L. Racusin (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180329B
113 s after the BAT trigger (Racusin et al., GCN Circ. 22558).
A fading source consistent with the XRT position
(Beardmore et al. GCN Circ. 22559) also detected by the
NOT (Perley et al. GCN Circ. 22562) and RATIR (Watson et al. GCN Circ. 22564)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  05:31:36.91 =  82.90381 (deg.)
    Dec (J2000) = -23:41:25.8  = -23.69051 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              113          263          147         17.69 +/- 0.04
white              550         6892          599         17.64 +/- 0.03
v                  601         5867          274         17.25 +/- 0.07
b                  526         6687          452         17.94 +/- 0.05
u                  271         6482          697         17.00 +/- 0.04
u                16039        39219         1961         18.74 +/- 0.07
w1                 650         6277          452         18.72 +/- 0.14
m2                 626         6073          274        >19.8
w2                 577         7017          390        >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180329B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22566
SUBJECT: GRB 180329B: Swift-BAT refined analysis
DATE:    18/03/30 13:57:48 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 180329B (trigger #819490)
(Racusin et al., GCN Circ. 22558).  The BAT ground-calculated position is
RA, Dec = 82.905, -23.694 deg which is
  RA(J2000)  =  05h 31m 37.2s
  Dec(J2000) = -23d 41' 39.8"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 15%.

The mask-weighted light curve shows a triple-peaked structure, with the first peak
running from T-10 to T+40 sec, and the second peak from T+130 to T+160 sec.
This is followed by a much weaker, softer peak from T+160 to T+280 sec.
T90 (15-350 keV) is 210.0 +- 44.0 sec (estimated error including systematics).

The time-averaged spectrum from T-9.91 to T+230.39 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.97 +- 0.56,
and Epeak of 48.6 +- 9.1 keV (chi squared 54.64 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.3 +- 0.3 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+1.56 sec in the 15-150 keV band is
1.4 +- 0.4 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.93 +- 0.12 (chi squared 65.32 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/819490/BA/


GRB_name: GRB180329B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22567
SUBJECT: GRB 180329B: VLT/X-shooter spectroscopic observations
DATE:    18/03/30 14:21:00 GMT
FROM:    Luca Izzo at IAA-CSIC  <Luca.Izzo@ICRA.it>

L. Izzo (HETH/IAA-CSIC), K. E. Heintz (Univ. Iceland and DAWN/NBI), D. Malesani (DAWN/NBI and DARK/NBI), B. Milvang-Jensen (DAWN/NBI), N.R. Tanvir (Univ. Leicester), D.A. Perley (LJMU), A. de Ugarte Postigo (HETH/IAA-CSIC and DARK/NBI), J.P.U. Fynbo (DAWN/NBI), D.A. Kann (HETH/IAA-CSIC) report on behalf of the Stargate Consortium:

We observed the optical afterglow of GRB 180329B (Racusin et al. GCN 22558, Perley et al. GCN 22562) with the ESO VLT/X-shooter spectrograph, covering the wavelength range 3000-21000 AA. Spectroscopy started at 00:10:12 UT on 2018-03-30 (~10 hours after the GRB trigger) and consisted of 2 exposures of 600 s.

Preliminary analysis of the spectrum reveals absorption lines of O I 1302, C IV 1548/50, Al II 1670, Fe II 2344, 2374, 2382, 2586, 2600, Mg II 2796/2803 and Mg I 2853 at a common redshift of z=1.998.  This is consistent with a broad absorption seen in the UVB arm spectrum at ~3635 AA, due to a damped Lyman-alpha feature. We therefore propose this to be the redshift of the GRB. 

We acknowledge the excellent support from the ESO staff, particularly Marcela Espinoza, Luca Sbordone, Eleonora Sani and Pascale Hibon in obtaining these observations.


GRB_name: GRB180331A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22568
SUBJECT: GRB 180331A: Swift detection of a burst
DATE:    18/03/31 04:43:56 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

C. B. Markwardt (GSFC), A. Deich (PSU), A. Y. Lien (GSFC/UMBC), 
K. L. Page (U Leicester) and A. Tohuvavohu (PSU) report on behalf 
of the Neil Gehrels Swift Observatory Team:

At 04:14:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180331A (trigger=820347).  Swift slewed immediately to the burst.
The BAT on-board calculated location is 
RA, Dec 66.017, +13.398 which is 
   RA(J2000) = 04h 24m 04s
   Dec(J2000) = +13d 23' 52"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 50 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~7 sec after the trigger.

The XRT began observing the field at 04:16:48.0 UT, 112.3 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 66.0242,
13.3979 which is equivalent to:
   RA(J2000)  = 04h 24m 05.81s
   Dec(J2000) = +13d 23' 52.5"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 25 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.85 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 3
(+3.23/-2.75) x 10^21 cm^-2 (90% confidence).

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 115 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.60.

Burst Advocate for this burst is C. B. Markwardt (craig.b.markwardt AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB180331A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22569
SUBJECT: GRB 180331A: Enhanced Swift-XRT position
DATE:    18/03/31 06:21:42 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1180 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 180331A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 66.02468, +13.39893 which is equivalent
to:

RA (J2000): 04h 24m 5.92s
Dec (J2000): +13d 23' 56.1"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB180331A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22570
SUBJECT: GRB 180331A: Swift/UVOT Upper Limits
DATE:    18/03/31 11:26:21 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and C. B. Markwardt (GSFC) report
on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB
180331A 116 s after the BAT trigger (Markwardt et al., GCN Circ.
22568).  No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 22569) is detected in the initial UVOT
exposures.
Preliminary 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the
first finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           116          266          147         >20.2
u_FC               274          524          246         >19.9
white              116         1373          371         >20.4
v                  604         1250           78         >18.6
b                  530         1350           78         >19.4
u                  274          524          246         >19.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.60 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB180329B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22571
SUBJECT: GRB 180329B: LCO FTS observations
DATE:    18/03/31 11:57:19 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi, R. Martone (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell 
(U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a 
large collaboration report:

The LCO 2-m unit Faulkes Telescope South in Siding Springs began 
observing Swift GRB 180329B (Racusin et al. GCN 22558) on March 30, 
08:56 UT (0.78 days since the GRB) with the SDSS-R filter. We detect the 
optical afterglow (Racusin et al.; Perley et al. GCN 22562) with the 
following magnitude:

Mid Time from GRB  Exposure       Filter       Magnitude (AB)
(days)             (s)
-------------------------------------------------------------
0.79               5x120          SDSS-R       20.14 +- 0.21
-------------------------------------------------------------

as calibrated against nearby Pan-STARRS objects.


GRB_name: GRB180331A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22572
SUBJECT: GRB 180331A: Swift-XRT refined Analysis
DATE:    18/03/31 13:46:11 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester) and C. B. Markwardt (GSFC) report on behalf
of the Swift-XRT team:

We have analysed 4.2 ks of XRT data for GRB 180331A (Markwardt et al.
GCN Circ. 22568), from 115 s to 23.0 ks after the  BAT trigger. The
data comprise 70 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN Circ. 22569).

The light curve can be modelled with an initial power-law decay with an
index of alpha=0.64 (+0.21, -0.19), followed by a break at T+368 s to
an alpha of 3.47 (+0.30, -0.25); it then breaks again at T+1.2 ks to a 
decay of alpha=1.2 (+0.5, -2.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.35 (+0.21, -0.20). The
best-fitting absorption column is  4.9 (+1.7, -1.5) x 10^21 cm^-2, in
excess of the Galactic value of 2.9 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 6.0 x 10^-11 (7.3 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.9 (+1.7, -1.5) x 10^21 cm^-2
Galactic foreground: 2.9 x 10^21 cm^-2
Excess significance: 2.3 sigma
Photon index:      1.35 (+0.21, -0.20)

If the light curve continues to decay with a power-law decay index of
1.2, the count rate at T+24 hours will be 3.3e-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x
2.0^-14 (2.4 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00820347.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB180331B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  22573
SUBJECT: GRB 180331B: Swift detection of a burst
DATE:    18/03/31 15:58:51 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), A. Deich (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU), K. L. Page (U Leicester) and
A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 15:38:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180331B (trigger=820513).  Swift executed a delayed slewed
due to an observing constraint.  The BAT on-board calculated location is 
RA, Dec 196.820, +61.725, which is 
   RA(J2000)  =  13h 07m 17s
   Dec(J2000) = +61d 43' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
with a duration of about 8 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 15:49:43.0 UT, 663.7 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 196.7829, 61.7271 which
is equivalent to:
   RA(J2000)  = 13h 07m 07.91s
   Dec(J2000) = +61d 43' 37.5"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 63 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 667 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.01. 

Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


