# GCN_circulars

GRB_name: GRB161213A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20274
SUBJECT: GRB 161213A: POLAR Observation
DATE:    16/12/16 14:58:03 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

R. Marcinkowski, H. Xiao and W. Hajdas in the name of POLAR Collaboration
 

At 2016-12-13T07:05:02 during a routine on-ground search of data, POLAR detected the GRB 161213A, which was also observed by the FERMI/GBM (trigger #503305506) and Integral/SPIACS (2016-12-13T07:05:02.85). The POLAR light curve consists of two main peaks with total duration of 7s. The 1s maximum peak flux is 370 +/- 50 cts/s (background subtracted). The total number of counts is 1360 +/- 140 (background subtracted). The above measurements are preliminary and estimated energy range is about 80 keV to 500 keV.
 
LC_URL: http://polar.psi.ch/triggers/POLAR_GRB161213A.png


The incident angle in POLAR detector coordinate is:
theta:  46  [deg]
phi:    245 [deg]


This direction is computed using the best location from the FERMI/GBM, which is:
RA:   238 [deg]
Dec:   31 [deg]


The analysis results presented above are preliminary. The calibration work is ongoing. 
POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) on Sep 15, 2016.The energy detection range of POLAR is ~ 50-500 keV


GRB_name: GRB161214B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20275
SUBJECT: GRB 161214B: Mondy optical observations
DATE:    16/12/16 18:12:42 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of  GRB 161214B  (D'Avanzoet al., GCN 20257) with 
AZT-33IK telescope of Sayan observatory (Mondy) starting on December, 15 
(UT) 13:22:26. We obtained several images in R-filter.
The source previously reported (Malesani et al. GCN 20260; Marshall et 
al. GCN 20261) is clearly visible. Preliminary photometry of the source 
is following

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

2016-12-15 13:22:26  0.85579  R     120*30    18.69   0.03  21.9

The photometry includes a catalogued star SDSS J001524.26+072108.5 
already mentioned by Malesani et al. (GCN 20260) and Marshall et al. 
(GCN 20268). The R magnitude of the star obtained by Lupton 
transformations is 18.83 +/- 0.03.

Photometry is based on nearby SDSS-DR9 stars
SDSS-DR9_id            R(Lupton)
J001520.09+072300.5    17.01
J001517.29+072310.4    17.05
J001513.07+071914.3    17.28
J001511.86+071859.3    16.07
J001513.35+071841.1    15.26
J001525.83+072141.2    14.31
J001524.40+072156.0    17.79
J001530.21+072230.9    16.94


GRB_name: GRB161217A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20276
SUBJECT: GRB 161217A: Swift detection of a burst
DATE:    16/12/17 01:54:47 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

V. D'Elia (ASDC), J. A. Kennea (PSU), H. A. Krimm (CRESST/NSF/USRA),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL) and T. Sakamoto (AGU) report on behalf of the
Swift Team:

At 01:27:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 161217A (trigger=727167).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA, Dec 150.637, +52.389 which is 
   RA(J2000) = 10h 02m 33s
   Dec(J2000) = +52d 23' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a peak starting
around T+35s and lasting about 15 seconds.  (Because this was
an image trigger, the 'trigger time' is not tightly synchronized to
the time of the rate increase.)  The peak count rate
was ~600 counts/sec (15-350 keV), at ~35 sec after the trigger. 

The XRT began observing the field at 01:30:15.5 UT, 160.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 150.6517, 52.3592 which
is equivalent to:
   RA(J2000)  = 10h 02m 36.40s
   Dec(J2000) = +52d 21' 33.1"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 112 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 144 seconds with the White filter
starting 163 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 0.01. 

Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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: GRB161207A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20277
SUBJECT: GRB 161207A: POLAR observation
DATE:    16/12/17 04:32:48 GMT
FROM:    Yuanhao Wang at IHEP/CAS  <wangyuanhao@ihep.ac.cn>

Y. H. Wang (IHEP), Y. Zhao (IHEP), M. Z. Feng(IHEP), J. C. Sun (IHEP),
Z. H. Li (IHEP), H. C. Li (IHEP), S. L. Xiong (IHEP),T. Batsch(NCBJ),
T. Bernasconi (ISDC/UniGe),F. Cadoux (DPNC/UniGe), Y. W. Dong (IHEP),
M. Y. Ge (IHEP), W.Hajdas (PSI),Y. Huang (IHEP),Karol Jedrzejczak
(NCBJ), M. R. Kole (DPNC/UniGe), F. J. Lu (IHEP), R. Marcinkowski(PSI),
M. Pohl (DPNC/UniGe),N. Produit (ISDC/UniGe),A. Rutczynska (NCBJ),
D. Rybka (NCBJ),L. M. Song (IHEP),J. Szabelski (NCBJ), X. Wen (IHEP),
B. B. Wu (IHEP),X. Wu(DPNC/UniGe), H. L. Xiao (PSI), M. Xu (IHEP),
J. Zhang(IHEP),L. Y. Zhang (IHEP), P. Zhang (PSI), S. N. Zhang(IHEP),
Y. J. Zhang (IHEP), A. Zwolinska (NCBJ)
report for the POLAR collaboration:

At 2016-12-07T20:42:55 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 161207A, 
which was also detected by the CALET (GCN Circ #20246) and Fermi/GBM
(trigger 502836132/161207863).

The POLAR light curve consists of several peaks,
with a duration (T90) of 27.4 s measured from T0-2.87 s .
The 1s peak rate measured from T0+19.00 s is 350.4 cnts/s,
The total counts is about 4946 cnts.  The above measurements are
in the energy range of about 80-500 keV.

LC_URL:

http://polar.ihep.ac.cn/grb/2016/GRB161207A/lc/POLAR_lc_grb161207862.jpg

Using the best location from the Fermi/GBM, which is (J2000):
RA:    305.020     [deg]
Dec:   +20.700     [deg]
Err:     4.69      [deg]

the incident angle in POLAR coordinate at T0 is:
theta:  65.4  [deg]
phi:   -28.6  [deg]

The analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board
the Chinese space laboratory Tiangong-2 launched on Sep 15, 2016. More
information about POLAR can be found at http://polar.ihep.ac.cn/en/ ,
http://isdc.unige.ch/polar/ and http://polar.psi.ch/html/ .


GRB_name: GRB161217A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20278
SUBJECT: GRB 161217A: Enhanced Swift-XRT position
DATE:    16/12/17 05:27:58 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 1529 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 161217A, 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 = 150.65129, +52.35891 which is equivalent
to:

RA (J2000): 10h 02m 36.31s
Dec (J2000): +52d 21' 32.1"

with an uncertainty of 1.9 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: GRB161214B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20279
SUBJECT: GRB 161214B: AbAO and ISON/Terskol optical observations
DATE:    16/12/17 07:25:30 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), R. Inasaridze (AbAO),  A. Mokhnatkin (KIAM),  A. Pozanenko 
(IKI), A. Volnova (IKI),  V. Ayvazian  (AbAO), V. Zhuzhunadze,  (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 161214B  (D'Avanzoet al., GCN 20257) with 
AS-32 (0.7m) telescope of Abastumani Observatory  and with K-800 (0.8m) 
telescope  of ISON/Terskol   observatory  on December, 15.  We obtained 
several unfiltered images in each observatory. The source previously 
reported (Malesani et al. GCN 20260; Marshall et al. GCN 20261) is clearly 
visible. Preliminary photometry of the source is following

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

2016-12-15 15:31:49  0.97738   CR     85*60   18.79   0.05  22.2  AS-32
2016-12-15 18:07:05  1.06047   CR    142*30  18.76   0.13  21.4  K-800

Photometry is based on R-magnitudes the same stars used in (Mazaeva et al., 
GCN  20275) 


GRB_name: GRB161217A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20280
SUBJECT: GRB 161217A: Swift-XRT refined Analysis
DATE:    16/12/17 10:10:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

T.G.R. Roegiers (PSU), K.L. Page (U. Leicester), B. Mingo (U.
Leicester), A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A.
Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), L.M. McCauley (PSU), J.A.
Kennea (PSU) and V. D'Elia report on behalf of the Swift-XRT team:

We have analysed 6.5 ks of XRT data for GRB 161217A (D'Elia et al. GCN
Circ. 20276), from 171 s to 16.8 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Osborne et al. (GCN Circ. 20278).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.69 (+/-0.06).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.67 (+0.20, -0.11). The
best-fitting absorption column is  consistent with the Galactic value
of 7.7 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 3.9 x 10^-11 (3.9 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7 (+/-37) x 10^19 cm^-2
Galactic foreground: 7.7 x 10^19 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.67 (+0.20, -0.11)

If the light curve continues to decay with a power-law decay index of
0.69, the count rate at T+24 hours will be 7.9 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.0 x
10^-13 (3.1 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/00727167.

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


GRB_name: GRB161217A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20282
SUBJECT: GRB 161217A: Swift/UVOT Upper Limits
DATE:    16/12/17 17:26:54 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 161217A
163 s after the BAT trigger (D'Elia et al., GCN Circ. 20276).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al., GCN Circ. 20278)
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) exposures and subsequent exposures are:

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

white_FC           163          308          142         >21.0
u_FC               314          564          246         >21.0
white              163         1713          406         >21.2
v                  644         1589          117         >18.8
b                  576         1689          111         >19.8
u                  314         1664          343         >20.4
w1                 693         1639           97         >20.3

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: GRB161218A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20283
SUBJECT: GRB 161218A: Swift detection of a burst
DATE:    16/12/18 04:01:36 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. D'Ai (INAF-IASFPA), V. D'Elia (ASDC),
H. A. Krimm (CRESST/NSF/USRA), D. M. Palmer (LANL) and
M. H. Siegel (PSU) report on behalf of the Swift Team:

At 03:47:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 161218A (trigger=727288).  Swift could not slew to the burst
do to an observing constraint.  The BAT on-board calculated location is 
RA, Dec 245.257, -4.114 which is 
   RA(J2000) = 16h 21m 02s
   Dec(J2000) = -04d 06' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single complex
structure with a duration of about 10 sec.  The peak count rate
was ~20000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 15:54 UT on 2017 January 08. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.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: GRB161217A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20284
SUBJECT: GRB 161217A: Swift-BAT refined analysis
DATE:    16/12/18 04:08:49 GMT
FROM:    Hans Krimm at NASA-GSFC/NSF  <hans.krimm@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),  J. R. Cummings (CPI),
V. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA),
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+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 161217A (trigger #727167)
(D'Elia, et al., GCN Circ. 20276).  The BAT ground-calculated position is
RA, Dec = 150.658, 52.344 deg which is
   RA(J2000)  =  10h 02m 38.0s
   Dec(J2000) = +52d 20' 38.9"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows an initial soft, weak peak from T-20 to T+20
sec, followed by a stronger peak from T+32 to T+48 sec.   T90 (15-350 keV) is 1
8.2 +- 5.8 sec (estimated error including systematics).

The time-averaged spectrum from T+33.77 to T+53.86 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.70 +- 0.35.  The fluence in the 15-150 keV band is 1.9 +- 0.4 x 10^-7  erg/cm2.
The 1-sec peak photon flux measured from T+42.64 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/727167/BA/


GRB_name: GRB161217A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20285
SUBJECT: GRB 161217A: MITSuME Okayama upper limits
DATE:    16/12/18 15:22:08 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of MITSuME and OISTER collaboration:

We observed the field of GRB 161217A (D'Elia et al., GCNC 20276)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2016-12-17 12:40:15 UT (~11.2 h after
the burst). We did not find any new point source within the
Enhanced XRT circle (Osborne et al., GCNC 20278) in all the three
bands.

Three sigma upper limits of the OT are listed below.
We used SDSS-DR8 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc     Ic
-----------------------------------------------------
0.51298    13:46:16    5760.0   >19.1  >19.1  >18.4
0.76490    19:49:01    6180.0   >20.1  >19.9  >19.1
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB161218B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20286
SUBJECT: GRB 161218B: Fermi GBM detection
DATE:    16/12/18 18:19:00 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

R. Hamburg (UAH), C. Meegan (UAH), and H. Yu (MPE)
report on behalf of the Fermi GBM Team:

"At 08:32:40.65 UT on 18 December 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 161218B (trigger 503742764 / 161218356).

The on-ground calculated location, using the GBM trigger
data, is RA = 358.64, DEC = -16.95, with an uncertainty
of 1.00 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 80 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 26 s (50-300 keV).
The time-averaged spectrum from T0-2.0 s to T0+32.8 s is
best fit by a Band function with Epeak = 214.80 +/- 2.51 keV,
alpha = -0.51 +/- 0.01, and beta = -3.06 +/- 0.10.

The event fluence (10-1000 keV) in this time interval is
(8.91 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.7 s in the 10-1000 keV band
is 74.1 +/- 0.6 ph/s/cm^2.

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


GRB_name: GRB161218A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20287
SUBJECT: GRB 161218A: POLAR observation
DATE:    16/12/18 18:58:48 GMT
FROM:    Zhengheng Li at POLAR  <lizhengheng@ihep.ac.cn>

Z. H. Li (IHEP), Y. H. Wang (IHEP), S. L. Xiong (IHEP) 
report for the POLAR collaboration:

At 2016-12-18T03:47:34.634 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 161218A, 
which was also detected by the Swift/BAT (trigger #727288).

The POLAR light curve consists of a single peak,
with a duration (T90) of 6.76 s measured from T0+0.25 s .
The 0.25s peak rate measured from T0+1.25 s is 2660 cnts/s,
The total counts is about 6644 cnts.  The above measurements are
in the energy range of about 80-500 keV.

The preliminary estimation of minimum detectable polarization (MDP) 
is 32.5%[3-sigma, statistical only]. Follow-up observations are 
strongly encouraged.

LC_URL:
http://polar.ihep.ac.cn/grb/2016/GRB161218A/lc/POLAR_lc_grb161218158.png

Using the best location from the Fermi/GBM, which is (J2000):
RA:    245.257     [deg]
Dec:    -4.114     [deg]
Err:     3.00      [arcmin]

the incident angle in POLAR coordinate at T0 is:
theta:  24.327  [deg]
phi:   356.614  [deg]

The analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board 
the Chinese space laboratory Tiangong-2 launched on Sep 15, 2016. More 
information about POLAR can be found at http://polar.ihep.ac.cn/en/ , 
http://isdc.unige.ch/polar/ and http://polar.psi.ch/html/ .


GRB_name: GRB161218B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20288
SUBJECT: GRB 161218B: POLAR observation
DATE:    16/12/18 19:04:42 GMT
FROM:    Yuanhao Wang at IHEP/CAS  <wangyuanhao@ihep.ac.cn>

Y. H. Wang (IHEP), Z. H. Li (IHEP), S. L. Xiong (IHEP) 
report for the POLAR collaboration:

At 2016-12-18T08:32:41.341 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 161218B, which was also
detected by the Fermi/GBM (trigger 503742764/161218356).

The POLAR light curve consists of multiple peaks,
with a duration (T90) of 26.28 s measured from T0+1.0 s .
The 1s peak rate measured from T0+1.25 s is 9849 cnts/s,
The total counts is about 29340 cnts.The above measurements are
in the energy range of about 80-500 keV.

The preliminary estimation of minimum detectable polarization(MDP) 
is 36.8%[3-sigma, statistical only]. Follow-up observations are 
strongly encouraged.

LC_URL:
http://polar.ihep.ac.cn/grb/2016/GRB161218B/lc/POLAR_lc_grb161218356.png

Using the best location from the Fermi/GBM, which is (J2000):
RA:    358.640     [deg]
Dec:   -16.950     [deg]
Err:     1.00      [deg]

the incident angle in POLAR coordinate at T0 is:
theta:  77.7612  [deg]
phi:   252.239  [deg]

The analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board 
the Chinese space laboratory Tiangong-2 launched on Sep 15, 2016. More 
information about POLAR can be found at http://polar.ihep.ac.cn/en/, 
http://isdc.unige.ch/polar/ and http://polar.psi.ch/html/


GRB_name: GRB161217A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20289
SUBJECT: GRB 161217A: TAROT Calern observatory optical observations
DATE:    16/12/18 20:41:58 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 161217A detected by SWIFT
(trigger 727167) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 133.3s after the GRB trigger
(18.3s after the notice). The elevation of the field increased from
65 degrees above horizon and weather conditions
were good.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+133.3s to t0+193.3s : Rlim = 16.3

The second image is 30.0s exposure in tracking mode:
t0+208.6s to t0+238.6s : Rlim = 16.9

We co-added a series of exposures:
t0+208.6s to t0+611.7s : Rlim = 18.1

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.


GRB_name: GRB161218A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20290
SUBJECT: GRB 161218A: TAROT Calern observatory optical observations
DATE:    16/12/18 20:58:27 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP),
Boer, M., Laugier, R. (CNRS-ARTEMIS),
Gendre B. (UVI - Etelman Obs.) report:

We imaged the field of GRB 161218A detected by SWIFT
(trigger 727288) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 49 min after the GRB trigger
at the end of the night. The elevation of the field
increased from 3 degrees above horizon and weather
conditions were good.

We co-added a series of exposures.
We do not detect any OT with a limiting magnitude of:
t0+49 min to t0+68 min : Rlim = 17.3

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.


GRB_name: GRB161218A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20292
SUBJECT: Konus-Wind observation of GRB 161218A
DATE:    16/12/19 12:03:31 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 161218A (Swift-BAT detection: D'Ai et al., GCN 20283;
POLAR observation: Li et al., GCN 20287)
triggered Konus-Wind at T0=13651.970 s UT (03:47:31.970).

The burst light curve shows a single pulse with a total duration
of ~7 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(1.24 Â± 0.10)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+0.640, of (4.6 Â± 0.4)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+10.496 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 = -0.28 (-0.21,+0.25),
the high energy photon index beta = -3.40 (-1.17,+0.43),
the peak energy Ep = 128 (-8,+8) keV,
chi2 = 110/97 dof.

The spectrum near the peak count rate (measured from T0+0.256
to T0+2.304 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 = +0.08 (-0.26,+0.29),
the high energy photon index beta = -3.18 (-0.59,+0.31),
the peak energy Ep = 135 (-9,+10) keV,
chi2 = 84/74 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB161218_T13651/

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


GRB_name: GRB161218A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20293
SUBJECT: GRB 161218A: Swift-BAT refined analysis
DATE:    16/12/19 13:48:29 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
A. D'Ai (INAF-IASFPA), N. Gehrels (GSFC),H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), 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-352 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 161218A (trigger #727288)
(D'Ai, et al., GCN Circ. 20283).  The BAT ground-calculated position is
RA, Dec = 245.250, -4.113 deg which is
    RA(J2000)  =  16h 21m 00.1s
    Dec(J2000) = -04d 06' 46.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.

The mask-weighted light curve shows a bright FRED-like peak starting
from T-2 sec, peaking at T+1 sec and ending at T+14 sec.  A possible
extended emission is evident in the 10-sec binning light curve lasting
until T+80 sec.  T90 (15-350 keV) is 7.1 +- 0.6 sec (estimated error
including systematics).

The time-averaged spectrum from T-1.4 to T+14.5 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.56 +- 0.16,
and Epeak of 117 +- 13 keV (chi squared 38.16 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 6.7 +- 0.1 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+0.27 sec in the 15-150 keV band is
17.6 +- 0.5 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.29 +- 0.03 (chi squared 111.22 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/727288/BA/


GRB_name: GRB161218A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20294
SUBJECT: GRB 161218A: CALET Gamma-Ray Burst Monitor detection
DATE:    16/12/19 13:57:59 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

S. Torii (Waseda U), A. Yoshida, T. Sakamoto, Y. Kawakubo,
M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U),
S. Nakahira (JAXA), 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), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 161218A (D'Ai et al., GCN Circ. 20283) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 03:47:31.89 on 18 December 2016.
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 3:43 and 3:52.
The burst signal was seen by all CGBM instruments.

The light curve of the SGM shows a FRED-like structure starting at T+3 sec,
peaking at T+5 sec and ending at T+10 sec.  The T90 duration measured by
the SGM data is 5.1 +- 0.2 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1166067870/

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


GRB_name: GRB161219A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20295
SUBJECT: GRB 161219A: a long GRB detected by INTEGRAL
DATE:    16/12/19 17:24:41 GMT
FROM:    Diego Gotz at CEA  <diego.gotz@cea.fr>

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

a long gamma ray burst has been detected by IBAS in the IBIS/ISGRI data at
16:17:36 UT of 2016 December 19

Its refined coordinates (J2000) are:
R.A.= 188.437 deg
DEC.=  10.472 deg
with an uncertainty of 1.5 arc min (90% c.l.).

The burst lasts about 100 s and has peak flux of 1.2 photons/cmsq/s (20-200 keV, 1-s integration time) and fluence of 1.e-6 erg/cmsq (20-200 keV).

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


GRB_name: GRB161219B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20296
SUBJECT: GRB 161219B: Swift detection of a burst with an optical afterglow
DATE:    16/12/19 19:07:03 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. D'Ai (INAF-IASFPA), J. A. Kennea (PSU),
H. A. Krimm (CRESST/NSF/USRA), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and
M. H. Siegel (PSU) report on behalf of the Swift Team:

At 18:48:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 161219B (trigger=727541).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 91.717, -26.790 which is 
   RA(J2000) = 06h 06m 52s
   Dec(J2000) = -26d 47' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single triangle-
shaped structure with a duration of about 10 sec.  The peak count rate
was ~3900 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 18:50:27.5 UT, 108.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 91.7140, -26.7915 which
is equivalent to:
   RA(J2000)  = 06h 06m 51.35s
   Dec(J2000) = -26d 47' 29.4"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 11 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 (3.06 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 4
(+2.38/-1.96) x 10^21 cm^-2 (90% confidence). 

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)  = 06:06:51.41 = 91.71421
  DEC(J2000) = -26:47:29.2  = -26.79144
with a 90%-confidence error radius of about 0.5 arc sec. This position is 0.9
arc sec. from the center of the XRT error circle. The estimated magnitude is
16.10 with a 1-sigma error of about  0.03. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.03. 

Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.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.)

[GCN OPS NOTE(20dec16): Per author's request, the "-29:47:29.2"
in the 4th paragraph was changed to "-26:47:29.2".]


GRB_name: GRB161219B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20297
SUBJECT: GRB 161219B: Enhanced Swift-XRT position
DATE:    16/12/20 01:22:43 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 2622 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 161219B, 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 = 91.71401, -26.79163 which is equivalent
to:

RA (J2000): 06h 06m 51.36s
Dec (J2000): -26d 47' 29.9"

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: GRB161219B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20298
SUBJECT: GRB 161219B: Swift-XRT refined Analysis
DATE:    16/12/20 04:36:01 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 7.7 ks of XRT data for GRB 161219B (D'Ai et al. GCN
Circ. 20296), from 92 s to 22.7 ks after the  BAT trigger. The data
comprise 238 s in Windowed Timing (WT) mode (the first 9 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 Beardmore
et al. (GCN Circ. 20297).

The late-time light curve (from T0+4.7 ks) can be modelled with a
power-law decay with a decay index of alpha=0.75 (+/-0.07).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.05 (+/-0.08). The
best-fitting absorption column is  1.21 (+0.21, -0.20) x 10^21 cm^-2,
in excess of the Galactic value of 3.1 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.82 (+/-0.07) and a
best-fitting absorption column of 1.64 (+0.23, -0.22) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.9 x 10^-11 (4.8 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.64 (+0.23, -0.22) x 10^21 cm^-2
Galactic foreground: 3.1 x 10^20 cm^-2
Excess significance: 9.8 sigma
Photon index:      1.82 (+/-0.07)

If the light curve continues to decay with a power-law decay index of
0.75, the count rate at T+24 hours will be 0.22 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.3 x
10^-12 (1.0 x 10^-11) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00727541.

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


GRB_name: GRB161219B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20299
SUBJECT: GRB 161219B: GROND afterglow observations
DATE:    16/12/20 07:57:56 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T. Kruehler, P. Wiseman and J. Greiner (all MPE Garching) report on
behalf of the GROND team:

We observed the field of GRB 161219B (Swift trigger 727541; D'Ai,
GCN #20296) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO
La Silla Observatory (Chile).

Observations started at 01:33 UT on 2016-12-20, 6.7 hr after the GRB
trigger. They were performed at an average seeing of 1".1, and at an
average airmass of 1.3.

Based on combined images with 14.5 min of total exposures in g'r'i'z'
and 12.0 min in JHK at a mid-time of 01:42 UT on 2016-12-20,
we derive the following preliminary magnitudes (all in AB system)
for the optical/NIR afterglow (D'Ai et al., GCN 20296).

g' = 18.04 +- 0.05 mag
r' = 18.08 +- 0.05 mag
i' = 17.98 +- 0.05 mag
z' = 17.88 +- 0.05 mag
J = 17.68 +- 0.05 mag
H = 17.57 +- 0.07 mag
K = 17.54 +- 0.08 mag

Given magnitudes are calibrated against Pan-STARRS/2MASS field stars
and are not corrected for the expected Galactic foreground extinction
corresponding to a reddening of E_(B-V) = 0.028 mag in the direction of
the burst (Schlafly & Finkbeiner 2011).

We note the presence of a bright (r=21 mag) and visibly extended galaxy
in the Pan-STARRS data at the position of GRB 161219B. This is likely
the host galaxy of the GRB and would, if confirmed, indicate a
relatively low redshift.


GRB_name: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20300
SUBJECT: GRB 161219B: LCO Sutherland observations
DATE:    16/12/20 08:31:43 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

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

We observed Swift GRB 161219B (D'Ai et al. GCN 20296) on December 19, 
from 20:43 to 20:56 UT (1.9-2.1 hours since the GRB) with 1-m LCO 
telescope units in Sutherland with SDSS r and i filters. Within the 
enhanced enhanced XRT error circle (Beardmore et al. GCN 20297) we 
clearly detect the optical counterpart reported by UVOT (D'Ai et al.) 
with the following values:

Mid Time      Exposure       Filter       Magnitude
(hours)           (s)
-------------------------------------------------------
1.93              120         SDSS-R      17.38 +- 0.02
1.93              120         SDSS-I      16.72 +- 0.02
-------------------------------------------------------

as calibrated against nearby USNOB-1 source RA(J2000)=06:06:52.743, 
DEC(J2000)=-26:46:29.49 using nominal R2=15.12 mag, I=14.37 mag.
We however point out that the source is positionally coincident with a 
USNOB-1 source: 06:06:51.366, -26:47:29.80, which has nominal R2=20.14 
mag. This likely corresponds to the extended galaxy mentioned by 
Kruehler et al (GCN 20299) in Pan-STARRS data.


GRB_name: GRB161212A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20301
SUBJECT: GRB 161212A: POLAR Detection
DATE:    16/12/20 08:46:59 GMT
FROM:    Merlin Kole at U of Geneva/POLAR  <merlin.kole@unige.ch>

M. Kole (DPNC/UniGe) and R. Marcinkowski (PSI) report on behalf of the POLAR collaboration:

At 2016-12-12T15:38:59.0 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 161212A,
which was also observed by Fermi-GBM (trigger #503249943).

The POLAR light curve consists one peak with a duration (T90) of 1.0 +- 0.25 s measured from T0-0.0 s.
The 250-ms peak flux of the first peak, measured at T0+0.5 s, is 1376 cnts/sec.
The above measurements are in the preliminary calculated energy range of approximately 80 - 500 keV.

LC_URL: http://www.isdc.unige.ch/polar/lc/161212A/lcr.png

Using the best location from the Fermi/GBM, which is (J2000):

RA: 24.94  [deg]

Dec: 68.23  [deg]

Err: 8.5  [deg]

the incident angle in the POLAR coordinate at T0 is:

Alt: -2.2  [deg]

Theta:  46.11 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.

POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://isdc.unige.ch/polar/ and http://polar.ihep.ac.cn/en/.


This message is quotable in publications.


GRB_name: GRB161220A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20302
SUBJECT: GRB 161220A: Swift detection of a burst
DATE:    16/12/20 08:56:40 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB/PSU) and T. N. Ukwatta (LANL) report on behalf
of the Swift Team:

At 08:33:30 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 161220A (trigger=727610).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 350.817, -47.502 which is 
   RA(J2000) = 23h 23m 16s
   Dec(J2000) = -47d 30' 07"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a FRED-like 
structure with a duration of about 12 sec.  The peak count rate
was ~1285 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 08:34:39.2 UT, 69.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 350.84774,
-47.49773, which is equivalent to:
   RA(J2000)  = 23h 23m 23.46s
   Dec(J2000) = -47d 29' 51.8"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 76 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 1.19
x 10^20 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 1.94e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 78 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. Results from the list of sources
generated on-board are not available at this time. No correction has been made
for the expected extinction corresponding to E(B-V) of 0.01. 

Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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: GRB161218B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20303
SUBJECT: IPN Triangulation of GRB 161218B (long/very bright)
DATE:    16/12/20 09:25:37 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, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT 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

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

The long-duration, very bright GRB 161218B has been detected by Fermi
(GBM; Hamburg et al., GCN Circ. 20286), Konus-Wind, INTEGRAL (SPI-ACS),
Swift (BAT), and POLAR (Wang et al., GCN Circ. 20288), so far, at about 
30760 s UT (08:32:40). 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:
     0.888 (00h 03m 33s) -14.700 (-14d 42' 00")
  Corners:
     2.344 (00h 09m 23s) -18.473 (-18d 28' 23")
     3.138 (00h 12m 33s) -17.987 (-17d 59' 13")
   359.466 (23h 57m 52s) -10.927 (-10d 55' 37")
   358.690 (23h 54m 46s) -11.401 (-11d 24' 03")
  ---------------------------------------------
The error box area is 7.05 sq. deg, and its maximum
dimension is 8.0 deg (the minimum one is 53.5 arcmin).
The Sun distance was 87 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB161218_T30761/IPN

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


GRB_name: GRB161218B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20304
SUBJECT: Konus-Wind observation of GRB 161218B
DATE:    16/12/20 10:06:29 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 161218B (Fermi-GBM detection: Hamburg et al., GCN 20286;
POLAR observation: Wang et al., GCN 20288;
IPN triangulation: Svinkin et al., GCN 20303)
triggered Konus-Wind at T0=30761.134 s UT (08:32:41.134).

The light curve starts with a bright, short pulse followed by
a weaker emission; the total duration of the burst is ~30 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(8.6 Â± 0.4)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+1.344, of (2.7 Â± 0.2)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+34.560 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 = -0.42 (-0.08,+0.08),
the high energy photon index beta = -3.37 (-0.80,+0.31),
the peak energy Ep = 203 (-8,+8) keV,
chi2 = 106/97 dof.

The spectrum near the peak count rate (measured from T0+0.256
to T0+1.536 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 = -0.08 (-0.18,+0.21),
the high energy photon index beta = -2.71 (-0.24,+0.18),
the peak energy Ep = 203 (-15,+16) keV,
chi2 = 69/68 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB161218_T30761/

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


GRB_name: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20305
SUBJECT: GRB 161219B: Watcher optical observations
DATE:    16/12/20 14:15:30 GMT
FROM:    Antonio Martin-Carrillo at UCD,Space Science Group  <antonio.martin-carrillo@ucd.ie>

A. Martin-Carrillo (UCD), D. Murphy (UCD), L. Hanlon (UCD), H. J. van Heerden (UFS), B. van Soelen (UFS) and P. J. Meintjes (UFS)

We observed the field of GRB 161219B (D'Ai et al, GCN 20296) using the 40cm UCD Watcher telescope at Boyden Observatory in South Africa.

Due to bad weather, observations were delayed until December 20th at 00:30 UT (T0+5.67h) and were taken under poor seeing. Based on combined images in SDSS râ€™ filter, at a mid-time of 00:45 UT we derive a preliminary magnitude of r'=18.06 (AB system). This value is in agreement with the magnitude reported by Kruehler et al (GCN 20299) at 01:42 UT, one hour after our reported mid-time. In fact, our data shows no indication of fading between 00:30 UT to 02:00 UT when our observations stopped, indicating an optical plateau. 

Magnitudes were calibrated using several nearby APASS stars. No correction for Galactic extinction in the direction of the GRB has been applied.


GRB_name: GRB161219B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20306
SUBJECT: GRB 161219B: Swift/UVOT Detection
DATE:    16/12/20 17:08:41 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 161219B
112 s after the BAT trigger (D'Ai et al., GCN Circ. 20296).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 20297)
is detected in the initial UVOT exposures.

The source is detected in the first white exposure at the position:
  RA(J2000)  = 06:06:51.43 =  91.71428
  DEC(J2000) = -26:47:29.5  = -26.79152
with an uncertainty of 0.42" (90% confidence)

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are
in the table below. Fading is seen in all filters.
The detection in the w2 filter is consistent
with a  relatively low redshift as suggested by
Kruehler et al. (GCN Circ. 20299).

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag
white              112          261          147         16.1 +/- 0.1
v                  653          673           19         16.7 +/- 0.2
b                  579          599           20         16.9 +/- 0.1
u                  324          573          246         16.0 +/- 0.1
u                44962        45868          875         18.0 +/- 0.1 
w1                 702          722           20         15.6 +/- 0.1
m2                 677          697           19         15.7 +/- 0.2
w2                 629          649           20         15.9 +/- 0.2

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.


GRB_name: GRB161220A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20307
SUBJECT: GRB 161220A: Swift/UVOT Upper Limits
DATE:    16/12/20 17:10:33 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 161220A
78 s after the BAT trigger (D'Elia et al., GCN Circ. 20302).
No optical afterglow consistent with the XRT position
(D'Elia et al. GCN Circ. 20302)
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            78          228          147         >20.5
white               78         1012          295         >21.0

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: GRB161219B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20308
SUBJECT: GRB 161219B: Swift-BAT refined analysis
DATE:    16/12/20 18:22:59 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
A. D'Ai (INAF-IASFPA), N. Gehrels (GSFC), 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-240 to T+962 sec from the recent telemetry downlink, 
we report further analysis of BAT GRB 161219B (trigger #727541) 
(D'Ai, et al., GCN Circ. 20296). The BAT ground-calculated position is 
RA, Dec = 91.717, -26.801 deg which is  
  RA(J2000) = 06h 06m 52.0s 
  Dec(J2000) = -26d 48' 02.1â€ 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). 
The partial coding was 50%. 

 The mask-weighted light curve shows a soft, weak peak at around T-10 sec,then the
main peak starts at T-2 sec, peaks at T+2 sec and decays to background by T+8 sec.
T90 (15-350 keV) is 6.94 +- 0.79 sec (estimated error including systematics).

The time-averaged spectrum from T-0.54 to T+8.38 sec is best fit by a power law 
with an exponential cutoff. This fit gives a photon index 1.29 +- 0.35, 
 and Epeak of 61.9 +- 16.8 keV (chi squared 44.89 for 56 d.o.f.). For this 
model the total fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-6 erg/cm2 
and the 1-sec peak flux measured from T+1.56 sec in the 15-150 keV band is 
5.3 +- 0.4 ph/cm2/sec. A fit to a simple power law gives a photon index 
of 1.84 +- 0.08 (chi squared 53.05 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/727541/BA/


GRB_name: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20309
SUBJECT: GRB 161219B: ISON/Terskol optical observations
DATE:    16/12/20 21:25:52 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),   A. Mokhnatkin (KIAM),  A. Pozanenko (IKI), A. 
Volnova (IKI),   I. Molotov (KIAM)  report on behalf of  larger GRB 
follow-up collaboration:

We observed the field of GRB 161219B (Swift trigger 727541; D'Ai,
GCN 20296) with K-800 (0.8m) telescope  of ISON/Terskol   observatory 
starting  on December, 19 (UT) 18:57:51, i.e. about 9 minutes after GRB 
onset.  We obtained several unfiltered images of 30 s exposure. The 
optical afterglow (D'Ai et al., GCN 20296; Kruehler et al., GCN 20299; 
Guidorzi et al., GCN 20300; Martin-Carrillo et al., GCN 20305) is 
clearly visible in separate images. Preliminary light curve of the 
afterglow can be found in

http://grb.rssi.ru/GRB161219B/GRB161219B_161219_K800.png

Photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id     R2
0631-0120570    13.78
0632-0119151    14.86
0632-0119187    14.03
0632-0119198    15.05
0632-0119218    14.66
0631-0120752    14.81


GRB_name: GRB161217B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20310
SUBJECT: GRB 161217B: POLAR Observation
DATE:    16/12/21 00:31:23 GMT
FROM:    Jianchao Sun at IHEP  <sunjc@ihep.ac.cn>

J.C. Sun (IHEP/CAS), Y.H. Wang (IHEP/CAS), H.C. Li (IHEP/CAS) and

S.L. Xiong (IHEP/CAS) report on behalf of the POLAR collaboration:




At 2016-12-17T03:03:44.00 UT(T0), during a routine on-ground search

of data, POLAR detected the GRB 161217B, which was also observed

by Fermi-GBM (trigger #503636629).




The POLAR light curve consists of a single peak with a duration (T90)

of 5.317 s measured from T0-0.68 s. The 500-ms peak rate measured at

T0+0.25 s is 204.4 cnts/sec. The above measurements are in the energy

range between about 80 C 500 keV.




LC_URL:

http://polar.ihep.ac.cn/grb/2016/GRB161217B/lc/POLAR_lc_grb161217128.png




Using the best location from the Fermi/GBM, which is (J2000):

RA:   216.630   [deg]

Dec:  +51.980   [deg]

Err:  7.56      [deg]




the incident angle in POLAR coordinate at T0 is:

theta:  53.974  [deg]

phi:    30.943  [deg]




The analysis results presented above are preliminary. Calibration of the

instrument is ongoing.




POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched

on-board the Chinese space laboratory Tiangong-2 (TG-2) on Sep 15, 2016.

The energy detection range of POLAR is ~ 50-500 keV. More information

about POLAR can be found at http://polar.ihep.ac.cn/en/,

http://isdc.unige.ch/polar/ and http://polar.psi.ch/html/ .




This message is quotable in publications.


GRB_name: GRB161217C
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20311
SUBJECT: GRB 161217C: POLAR observation
DATE:    16/12/21 01:26:37 GMT
FROM:    Yuanhao Wang at IHEP/CAS  <wangyuanhao@ihep.ac.cn>

Y. H. Wang (IHEP/CAS), S. L. Xiong(IHEP/CAS)
report for the POLAR collaboration:

At 2016-12-17T03:53:15 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 161217C, 
which was also detected by the IPN-KW.

The POLAR light curve consists of two peaks,
with a duration (T90) of 6.409 s measured from T0-2.8525 s.
The 0.5s peak rate measured from T0+3.0s is 1733 cnts/s,
The total counts is about 4364 cnts.  The above measurements are
in the energy range of about 80-500 keV.

LC_URL:
http://polar.ihep.ac.cn/grb/2016/GRB161217C/lc/POLAR_lc_grb161217161.png

All the analysis results presented above are preliminary.
Calibration of the instrument is ongoing.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board 
the Chinese space laboratory Tiangong-2 launched on Sep 15, 2016. More 
information about POLAR can be found at http://polar.ihep.ac.cn/en/ , 
http://isdc.unige.ch/polar/ and http://polar.psi.ch/html/ .


GRB_name: GRB161220A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20312
SUBJECT: GRB 161220A: GROND Upper Limits
DATE:    16/12/21 01:58:47 GMT
FROM:    Philip Wiseman at MPE/Swift  <wiseman@mpe.mpg.de>

P. Wiseman, T. Kruehler, and J. Greiner (all MPE Garching) report on
behalf of the GROND team:

We observed the field of GRB 161220A (Swift trigger 727610; D'Elia et al.,
GCN #20302) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla
Observatory (Chile).

Observations started at 00:36 UT on 2016-12-21, 16 hrs after the GRB
trigger. They were performed at an average seeing of 0".9, and at an
average airmass of 1.2.

Similar to Marshall & D'Elia (GCN #20307), we detect no credible
optical/NIR afterglow consistent with the XRT position. Based on combined
images with 14.5 min of total exposures in g'r'i'z'
and 12.0 min in JHK at a mid-time of 00:45 UT on 2016-12-21,
we derive the following upper limits (all in AB system).

g' > 22.7 mag
r' > 22.7 mag
i' > 21.3 mag
z' > 21.8 mag
J > 20.8 mag
H > 20.4 mag
K > 17.2 mag

Given magnitudes are calibrated against USNO as well as 2MASS field stars
and are not corrected for the expected Galactic foreground extinction
corresponding to a reddening of E_(B-V) = 0.005 mag in the direction of
the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB161219B
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20313
SUBJECT: GRB 161219B: VLA Detection
DATE:    16/12/21 02:13:57 GMT
FROM:    Kate Alexander at Harvard  <kalexander@cfa.harvard.edu>

K. D. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), and E. Berger
(Harvard) report on behalf of a larger collaboration:

We observed the Swift GRB 161219B (Dâ€™Ai et al. GCN 20296) at multiple
frequencies with the Karl G. Jansky Very Large Array (VLA) beginning 2016
December 20.26 UT (11.4 hours after the burst). At a mean frequency of
14.75 GHz, we detect a radio source with a preliminary flux density of ~0.9
mJy at

RA (J2000) = 06:06:51.428 +/- 0.001
Dec (J2000) = -26:47:29.52 +/- 0.01

consistent with the position of the optical afterglow and the refined
Swift/XRT position (Beardmore et al. GCN 20297). Follow-up observations are
planned.

We thank the VLA staff for rapidly executing these observations.


GRB_name: GRB161219B
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20314
SUBJECT: GRB 161219B: MITSuME Akeno Optical Observation 
DATE:    16/12/21 05:31:31 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

T.Fujiwara, Y.Saito, Y. Tachibana, T. Yoshii,
Y.Ono, S.Harita, Y.Muraki, K.Morita, T.Ozawa, K.Saisho,Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 161219B (A. D'Ai et al., GCN
Circular #20296) 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 2016-12-20 11:49:20 UT (~17.0 hour after the burst) and
we detected the optical counterpart in g', Rc and Ic band.
The measured magnitudes were listed as follows.

We obtained following results for the magnitudes.

T0+[hour]    MID-UT      T-EXP[sec]         g'              Rc                      Ic
-------------------------------------------------------------------------------------------------------
~17.8        12:34:26            4920          18.83 +/- 0.11        18.23 +/- 0.09      18.14 +/- 0.11
-------------------------------------------------------------------------------------------------------

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


GRB_name: GRB161220A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20315
SUBJECT: GRB 161220A: LCO-FTS observations
DATE:    16/12/21 06:57:45 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

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

We observed Swift GRB 161220A (D'Elia et al. GCN 20302) on December 20, 
from 11:02 to 11:13 UT (2.5-2.7 hours since the GRB) with the 2-m LCO 
Faulkes Telescope South in Siding Springs with the SDSS i filter under 
poor sky transparency conditions. Within the XRT error circle we do not 
find any object brighter than i~20 mag (total exposure of 5x120s) as 
calibrated against nearby USNOB1 stars.


GRB_name: GRB161220A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20316
SUBJECT: GRB 161220A: Swift-XRT refined Analysis
DATE:    16/12/21 08:56:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 3.4 ks of XRT data for GRB 161220A (D'Elia et al. GCN
Circ. 20302), from 60 s to 58.3 ks after the  BAT trigger. The data
comprise 85 s in Windowed Timing (WT) mode (the first 7 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The refined XRT position is RA, Dec = 350.8479, -47.4978 which is
equivalent to:

RA (J2000): 23 23 23.49
Dec(J2000): -47 29 52.2

with an uncertainty of 3.6 arcsec (radius, 90% confidence).

The light curve can be modelled with a series of power-law decays. The
light curve initially rises, with an index alpha=-1.5 (+0.0, -2.0). At
T+71.0 s it breaks to an alpha of 4.75 (+0.51, -0.29) before breaking
again at T+217 s to a final decay with index alpha=0.82 (+0.13, -0.11).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.57 (+0.20, -0.19). The
best-fitting absorption column is  3.2 (+/-0.4) x 10^21 cm^-2, in
excess of the Galactic value of 1.2 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 2.1 x 10^-11 (9.9 x 10^-11) erg
cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      3.2 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 1.2 x 10^20 cm^-2
Excess significance: 12.4 sigma
Photon index:      3.57 (+0.20, -0.19)

If the light curve continues to decay with a power-law decay index of
0.82, 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 5.7 x
10^-14 (2.6 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/00727610.

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


GRB_name: GRB161129A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20317
SUBJECT: GRB 161129A: 15 GHz upper limits from AMI
DATE:    16/12/21 09:33:38 GMT
FROM:    Kunal Mooley at Oxford U  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender 
(Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. 
Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, 
P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)

The AMI Large Array robotically triggered on the Swift alert for GRB 
161129A (Kocevski et al., GCN 20210) as part of the 4pisky program, and 
subsequent follow up observations were obtained up to 10 days 
post-burst. Our observations at 15 GHz on 2016 Nov 29.50, Nov 30.72, Dec 
02.69 and Dec 06.68 (UT) do not reveal any radio source at the XRT 
location (Beardmore et al., GCN 20211), with 3sigma upper limits of 120 
uJy, 102 uJy, 90 uJy and 117 uJy respectively.

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/.


GRB_name: GRB161202A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20318
SUBJECT: GRB 161202A: 15 GHz upper limits from AMI
DATE:    16/12/21 09:35:10 GMT
FROM:    Kunal Mooley at Oxford U  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender 
(Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. 
Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, 
P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)

The AMI Large Array robotically triggered on the Swift alert for GRB 
161202A (Sbarufatti et al., GCN 20227) as part of the 4pisky program, 
and subsequent follow up observations were obtained up to 10 days 
post-burst. Although the data from the first epoch were lost due to 
technical problems, our observations at 15 GHz on 2016 Dec 03.93 and Dec 
05.77 (UT) do not reveal any radio source at the XRT location (Evans et 
al., GCN 20228), with 3sigma upper limits of 200 uJy and 121 uJy 
respectively.

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/.


GRB_name: GRB161214B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20319
SUBJECT: GRB 161214B: optical spectroscopy of the foreground SDSS object
DATE:    16/12/21 10:31:39 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI and DTU Space), J. P. U. Fynbo (DARK/NBI), B. 
Milvang-Jensen (DARK/NBI), N. R. Tanvir (Univ. Leicester), M. I. 
Andersen (DARK/NBI), H. Korhonen (DARK/NBI), D. A. Perley (DARK/NBI), T. 
Kruehler (MPE), D. Xu (NAOC/CAS), G. Fedorets (NOT and Univ. Helsinki), 
report on behalf of a larger collaboration:

We report on further analysis of our data (Malesani et al., GCN 20260) 
taken at the Nordic Optical Telescope for GRB 161214B (D'Avanzo et al., 
GCN 20257). The best-seeing images (~0.9") clearly reveal two blended 
objects within the XRT error circle, separated by <1 arcsec, with 
comparable brightness (at ~2.2 hr after the GRB). As first suggested in 
GCN 20260, the likely interpretation is the near-superposition of the 
afterglow of GRB 161214B and an unrelated, foreground object. 
Astrometric registration of our images with the SDSS frames shows that 
the afterglow is slightly south of the SDSS source.

A spectrum of the complex was secured using the AlFOSC spectrograph, 
covering both objects. Observations started on 2016 Dec 14.82 UT (2.42 
hr after the GRB) and consisted of 2x20 min exposures using grism #4, 
covering the wavelength range 3500-9400 AA. A few absorption lines are 
apparent, and there is a hint that their spatial extent on the trace is 
offset to the North (consistent with the SDSS source location). The two 
most prominent features can be identified as the Mg I b triplet and the 
Na I D doublet at redshift ~0, confirming that the SDSS object is a 
Galactic star (probably of K or early M type). One more feature is 
observed at ~4238 AA, whose identification is unclear. One possibility 
is the Ca I 4226 A resonant line at z = 0, sometimes observed in K 
stars, which would however require an offset of the wavelength 
calibration in the blue part of our spectrum.

No features which can be clearly attributed to the afterglow are 
detected in our spectrum. Marshall & D'Avanzo (GCN 20268) report 
detection of the afterglow in the UVOT UVW2 filter, at a flux level much 
brighter than the SDSS object (u ~ 22.5). This allows to set an upper 
limit to the redshift z <~ 1.2 from the absence of the Lyman limit dropout.


GRB_name: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20321
SUBJECT: GRB 161219B: VLT/X-shooter redshift
DATE:    16/12/21 14:25:47 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

N. R. Tanvir (U. Leicester), T. Kruehler (MPE), K. Wiersema (U. 
Leicester), D. Xu (NAOC/CAS), D. Malesani (DARK/NBI), B. Milvang-Jensen 
(DARK/NBI), and J. P. U. Fynbo (DARK/NBI) report on behalf of a larger 
collaboration:

We observed the optical counterpart of GRB 161219B (Swift trigger 
727541; D'Ai et al., GCN #20296) with the ESO Very Large Telescope UT 2 
(Kueyen) equipped with the X-shooter spectrograph, covering the 
wavelength range 3200-22000 AA. Observations started at 06:34 UT on 
2016-12-21, roughly 36 hr after the burst and consisted of 4 exposures 
of 600 s each. We measure r ~ 19.5 mag from the acquisition image.

Our spectrum exhibits absorption features from Mg II, Mg I, Ca H, Ca K, 
all at a common redshift of z = 0.1475. We also detect nebular lines 
from the Balmer series, [O II] and [O III] at a consistent redshift, 
which we conclude is the redshift of the GRB. The emission features are 
likely coming from the object visible in the PanSTARRS data, first 
noticed by Kruehler et al. (GCN 20299).

We acknowledge excellent support from the ESO observing staff in 
Paranal, in particular Julien Milli, Thomas Rivinius, and Dimitri Gadotti.


GRB_name: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20322
SUBJECT: GRB 161219B:  SALT observations
DATE:    16/12/21 17:29:49 GMT
FROM:    Soebur Razzaque at U of Johannesburg  <srazzaque@uj.ac.za>

D.A.H. Buckley (SAAO/SALT), A. Hamanowicz (Warsaw U.), A. Martin-Carrillo (UCD), S. Razzaque (U. Johannesburg), T. Garrigoux (North-West U.), L. Hanlon (UCD), M. M. Kotze (SAAO/SALT) and R. Kuhn (SAAO/SALT) report on behalf of a larger collaboration.

We observed the Swift GRB 161219B (Dâ€™Ai et al. GCN 20296) on December 20 using the Southern African Large Telescope (SALT) in Sutherland, South Africa, 24.73 h after the Swift GRB trigger. A 20 s r'-band image was obtained using SALTICAM at 19:32:30 UTC, just prior to the commencement of the spectroscopy, and the optical counterpart reported by D'Ai et al. (GCN 20296), Kruehler et al. (GCN 20299), Guidorzi et al. (GCN 20300), Martin-Carrillo et al. (GCN 20305), Mazaeva et a. (GCN 20309), Tanvir et al. (GCN 20321) was clearly visible in the SALT image.

From photometry of the source and six APASS reference stars in the field, we determined the brightness to be r' = 18.94 +/- 0.06. Spectroscopy with the Robert Stobie Spectrograph (RSS) started at 19:37:39 UTC and ran until 20:27:51 UTC during which two 1500 s spectra were obtained, nominally covering the spectral region from 340 to 1000 nm at a mean resolution of R = 350. The optical spectrum was characterised by a blue continuum and was heavily contaminated by sky emission lines above 850 nm. No obvious spectral faetures were seen in the combined spectrum.
________________________________

This email and all contents are subject to the following disclaimer:

http://disclaimer.uj.ac.za


GRB_name: GRB161219B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20323
SUBJECT: Konus-Wind observation of GRB 161219B
DATE:    16/12/21 17:31:16 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 161219A (Swift-BAT trigger #727541: D'Ai et al.,
GCN 20296; Palmer et al., GCN 20308; T0(BAT)=18:48:19.308 UT)
was detected by Konus-Wind (KW) in the waiting mode.

The light curve shows a single pulse with a duration of ~10 s.
Modeling the KW 3-channel time-integrated spectrum
(from T0(BAT)-0.134 s to T0(BAT)+8.698 s) by
a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.59 Â± 0.71 and Ep = 91 Â± 21 keV.
The corresponding 20-1000 keV energy fluence for this
time interval is (3.1 Â± 0.8)x10^-6 erg/cm2.

Assuming the redshift z=0.1475 (Tanvir et al., GCN 20321)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the burst isotropic energy release E_iso to ~1.6x10^50 erg
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, to ~104 keV.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB161219B/

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


GRB_name: GRB161218B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20324
SUBJECT: GRB 161218B: Astrosat CZTI detection
DATE:    16/12/21 18:20:09 GMT
FROM:    Vedant Kumar at Astrosat/CZTI/IUCAA  <vedant@iucaa.in>

V. Kumar, D. Bhattacharya and V. Bhalerao (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed clear detection of a long duration and bright GRB161218B (Fermi-GBM detection: Hamburg et al., GCN 20286) 
in the 40-200 keV energy range. The light curve shows multiple peak structure with at least 4 clear peaks and main peak at 08:32:42.0 UT followed
by a weaker emission, 1.35 secs after the Fermi- GBM trigger(consistent with GCN 20286). The measured peak count rate is 738.478 counts/sec above
the background in combined data of four quadrants, with a total of 6025.78 counts. The local mean background count rate was 328.52 counts/sec. 
Using cumulative rates, we measure a T90 of 29.0 sec.

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: GRB161220A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20325
SUBJECT: GRB 161220A: Swift-BAT refined analysis
DATE:    16/12/21 18:35:58 GMT
FROM:    Tilan Ukwatta at LANL  <tilan.ukwatta@gmail.com>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), V. D'Elia (ASDC),
N. Gehrels (GSFC), 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-61 to T+243 sec from the
recent telemetry downlink, we report further analysis
of BAT GRB 161220A (trigger #727610) (D'Elia, et al.,
GCN Circ. 20302).  The BAT ground-calculated position
is RA, Dec = 350.841, -47.480 deg which is
   RA(J2000)  =  23h 23m 21.7s
   Dec(J2000) = -47d 28' 47.3"
with an uncertainty of 2.0 arcmin, (radius, sys+stat,
90% containment). The partial coding was 100%.

The mask-weighted light curve shows a single episode
that starts around T-4 sec, peaks around T+3 sec and
ends at ~T+4 sec. T90 (15-350 keV) is 6 +- 1 sec
(estimated error including systematics).

The time-averaged spectrum from T-2.24 to T+4.66 sec
is best fit by a simple power-law model.  The power
law index of the time-averaged spectrum is 2.01 +- 0.25.
The fluence in the 15-150 keV band is
1.7 +- 0.3 x 10^-07 erg/cm2. The 1-sec peak photon flux
measured from T+2.42 sec in the 15-150 keV band
is 0.5 +- 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/727610/BA/


GRB_name: GRB161219B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20327
SUBJECT: Correction to GCN 20323 "Konus-Wind observation of GRB 161219B"
DATE:    16/12/21 21:34:19 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks reports on behalf of the Konus-WIND team:

The first line of GCN 20323 should read:
"The long GRB 161219B (Swift-BAT trigger #727541: D'Ai et al.,",
not " ... GRB 161219A ..."

We thank Sandro Mereghetti for pointing this out and we apologize
for any confusion this may have caused.


GRB_name: GRB161219B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20328
SUBJECT: GRB 161219B: Rapid ALMA Observations & Detection
DATE:    16/12/22 00:08:08 GMT
FROM:    Tanmoy Laskar at UC Berkeley  <tanmoylaskar@gmail.com>

T. Laskar (NRAO / UC Berkeley), K. D. Alexander (Harvard), and E. Berger
(Harvard) report on behalf of a larger collaboration:

We observed the Swift GRB 161219B (Dâ€™Ai et al. GCN 20296) at 3 mm with the
Atacama Large Millimeter/submillimeter Array (ALMA) beginning 2016 December
21.08 UT (1.30 days after the burst). At a mean frequency of 97 GHz, we
detect a radio source with a preliminary flux density of ~ 1 mJy at

RA (J2000) = 06:06:51.429 +/- 0.001
Dec (J2000) = -26:47:29.62 +/- 0.01

consistent with the position of the optical afterglow, the refined
Swift/XRT position (Beardmore et al. GCN 20297), and the radio afterglow
(Alexander et al. GCN 20313). Follow-up observations are planned.

We thank the JAO staff for rapidly executing these observations.


GRB_name: GRB161219B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20331
SUBJECT: GRB 161219B: POLAR Observation 
DATE:    16/12/22 10:38:13 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

Hualin Xiao (PSI), Wojtek Hajdas (PSI) and Radek Marcinkowski (PSI) report on behalf of the POLAR collaboration:

At 2016-12-19T18:48:39.0 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 161219B,
which was also observed by Swift BAT (trigger #727541).

The POLAR light curve consists of one peak with duration (T90) of 4.0 +- 0.5 s measured from T0.
The  0.5 s peak flux at T0+1.75 s  is equal to 248 +-44 cnts/sec.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB161219B.png
 and http://polar.psi.ch/pub/lc.php?event=GRB+161219B

Using the best location from the Swift BAT, which is (J2000):

RA: 91.717  [deg]
 
Dec: -26.790  [deg]

the incident angle in the POLAR coordinate at T0 is:

Theta: 96.6  [deg]

Phi:  201.2 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.

POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub , http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .


This message is quotable in publications.


GRB_name: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20332
SUBJECT: GRB 161219B: UKIRT near-IR afterglow detection
DATE:    16/12/22 23:40:43 GMT
FROM:    Wen-fai Fong at U of Arizona  <wfong@email.arizona.edu>

W. Fong and P. Milne (University of Arizona) report:

"We observed the field of the long-duration GRB 161219B (D'Ai et al., GCN
20296) with the Wide Field Camera (WFCAM) mounted on the 3.8-m United
Kingdom Infrared Telescope (UKIRT) on Mauna Kea beginning on 2016 Dec
22.368 UT (2.58 days post-burst). We obtained observations in the J-, H-
and K-bands in 0.72" seeing. Using the quick-look pipeline ORAC-DR, we
detect the near-IR afterglow in coincidence with the X-ray (Beardmore et
al., GCN 20297), optical (Kruehler et al., GCN 20299; Guidorzi et al., GCN
20300; Martin-Carrillo et al., GCN 20305; Marshall et al., GCN 20306;
Mazaeva et al., GCN 20309; Buckley et al., GCN 20322), and radio (Alexander
et al., GCN 20313; Laskar et al., GCN 20328) afterglows. Calibrated to
2MASS, we estimate a preliminary brightness of J(AB)=18.8 +/- 0.1 mag for
the near-IR afterglow of GRB 161219B. Further observations are planned.

We thank Watson Varricatt and Sam Benigni for their assistance in planning
and executing these observations."


GRB_name: GRB161224A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20337
SUBJECT: GRB 161224A: Swift-BAT refined analysis
DATE:    16/12/25 18:23:24 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), 
A. Cholden-Brown (PSU), J. R. Cummings (CPI),
N. Gehrels (GSFC), 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+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 161224A (trigger #728268)
(Cholden-Brown et al., GCN Circ. 20335).  The BAT ground-calculated position is
RA, Dec = 204.820, -18.028 deg which is 
   RA(J2000)  =  13h 39m 16.9s 
   Dec(J2000) = -18d 01' 41.7" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 48%.
 
The mask-weighted light curve shows a single pulse structure that starts at 
~ T+12 s, peaks at ~T+33 s, and ends at ~T+65 s. T90 (15-350 keV) is 
47.04 +- 12.12 sec (estimated error including systematics).
 
The time-averaged spectrum from T+12.46 to T+65.18 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index -0.21 +- 1.56, 
and Epeak of 34.5 +- 5.6 keV (chi squared 44.84 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is (8.2 +- 1.3) x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+32.88 sec in the 15-150 keV band is
0.8 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.21 +- 0.21 (chi squared 57.66 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/728268/BA/


GRB_name: GRB161224A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20338
SUBJECT: GRB 161224A: Swift-XRT refined Analysis
DATE:    16/12/26 06:15:37 GMT
FROM:    Aaron Cholden-Brown at PSU/Swift  <aaronb@swift.psu.edu>

A. Cholden-Brown (PSU) and P.A. Evans (U. Leicester) report on behalf
of the Swift-XRT team:

We have analysed 4.9 ks of XRT data for GRB 161224A, from 28.3 ks to
52.2 ks after the  BAT trigger. The data are entirely in Photon
Counting (PC) mode. A fading X-ray source is found in the BAT error
region. Using 617 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 = 204.81579, -18.02909
which is equivalent to:

RA (J2000): 13h 39m 15.79s
Dec(J2000): -18d 01' 44.7"

with an uncertainty of 4.1 arcsec (radius, 90% confidence).

The light curve can be modelled with a power-law decay with a decay
index of alpha=2.8 (+0.8, -2.1).

If the light curve continues to decay with a power-law decay index of
2.8, the count rate at T+24 hours will be 8.4 x 10^-4 count s^-1

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00728268.

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


GRB_name: GRB161224A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20339
SUBJECT: GRB 161224A: Swift/UVOT Upper limits
DATE:    16/12/26 12:12:17 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and A. Cholden-Brown (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 161224A
28.3ks after the BAT trigger after a Sun constraint (Cholden-Brown
et al., GCN Circ. 20335). At the position of the XRT source (Cholden-Brown
and
Evans, GCN Circ. 20338) no uv-optical source was found to the upper limits
below.

Preliminary 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
u       44266.0    44786.3     508      >19.99
v       28322.2    50899.7    1770      >19.90
uvw1    35223.6    41032.4     786      >19.91
uvw2    46285.0    46772.6     480      >19.88
uvm2    29234.3    35216.6    1198      >20.48

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.096 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB161224A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20340
SUBJECT: GRB 161224A: TSHAO optical observations
DATE:    16/12/26 13:04:31 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  I. Reva (Fesenkov Astrophysical Institute), A. 
Kusakin (Fesenkov Astrophysical Institute), A. Volnova (IKI), A. 
Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of GRB 161224A  (Swift trigger=728268, 
Cholden-Brownet al., GCN 20333) with Zeiss-1000 (East) 1-m telescope of 
Tien Shan Astronomical Observatory. We obtained several images in R 
filter starting on Dec. 25 (UT) 00:13:31 and Dec. 25 (UT) 23:45:12. We 
do not detect any evident variable source in the BAT ground-calculated 
position (Ukwatta  al., GCN 20337). Within enhanced XRT position 
(Cholden-Brownet al., GCN 20338) we not detected any source. Preliminary 
photometry of the field is following

Date       UT start   t-T0   Filter   Exp.   OT   Err.  UL
                       (mid, days)     (s)
2016-12-25 00:13:31   0.10201  R      16*180 n/d n/d   21.1
2016-12-25 23:45:12   1.07646  R      11*180 n/d n/d   20.7


Photometry is based on nearby USNO-B1.0 stars
0719-0341418 17.14
0720-0349085 17.50
0720-0348989 16.94
0719-0341338 15.94

A finding chart can be found in 
http://grb.rssi.ru/GRB161224A/GRB161224A_20161225_TSHAO_fc.png


GRB_name: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20342
SUBJECT: GRB 161219B: Spectroscopic detection of the associated SN with OSIRIS/GTC
DATE:    16/12/27 11:13:04 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), Z. Cano, L. Izzo, 
C. Thoene, R. Sanchez-Ramirez, K. Bensch (IAA-CSIC), D. A. Kann 
(IAA-CSIC, TLS), N. Tanvir (U. Leicester), S. Schulze, G. Leloudas 
(Weizmann Institute), S. Geier (IAC, GRANTECAN), A. Tejero 
(GRANTECAN) report on behalf of a larger collaboration:

We observed the optical counterpart of GRB 161219B (Dâ€™Ai et al. GCN 
20296) with OSIRIS at the 10.4m GTC telescope on La Palma (Spain). 
The observations consisted of 3 x 900 s spectra using grism R1000B, 
which covers the spectral region between 3700 and 7800 AA, plus g, r, i 
and z-band imaging. The point-like GRB counterpart is prominent on top 
of the elongated host galaxy.

The combined spectrum has mean UT epoch on 27.02 December (7.24 
days after the burst) and shows a strong continuum with clear broad 
features typical of a type Ic-BL supernova, implying that the supernova 
contribution is already significant. We also detect several emission 
features of the host galaxy (due to [OIII], [OII], [NII] and H) as well as CaII 
in absorption at the redshift of z = 0.1475 proposed for the GRB (Tanvir 
et al. GCN 20321).


GRB_name: GRB161214A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20343
SUBJECT: GRB 161214A: MASTER-IAC early optical observations
DATE:    16/12/27 16:40:44 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

D.Vlasenko, V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov,
O.Gress, P.Balanutsa, A.Kuznetsov, D.Kuvshinov
Lomonosov Moscow State University, Sternberg Astronomical Institute

R. Rebolo, M. Serra Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

R.Podesta, C.Lopez, F.Podesta
Observatorio Astronomico Felix Aguilar (OAFA), San Juan Univerdity,

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

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

O.Gres, K.Ivanov, J.Rabinovich, N.M.Budnev,
Irkutsk State University

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

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


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in IAC was pointed to the  GRB161214A  17 sec after notice time 
and 27 sec after trigger time at 2016-12-14 04:46:43 UT. On our first (10s 
exposure)  set we haven't found optical transient  within INTEGRAL 
error-box (ra=12 43 47 dec=+06 44 03 r=3.18) (Mereghetti et al., GCN 
20251). The 5-sigma upper limit set is about 16.2 mag(polaroid, 
unfiltered).

The observations made on zenit distance = 36 degrees, galaxy latitude b = 
69 degree.
The moon (99 % bright part) is 40 degrees above the horizon. The distance 
between  moon and  object is 102.6
The sun  altitude  is -39 degree.
The object can be observed till sunrise at 2016-12-14 07:46:48

Maximal coadded limit ~18.9 m. No OT found.

The message may be cited.


GRB_name: GRB161219B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20344
SUBJECT: GMRT radio detection of GRB 161219B
DATE:    16/12/27 16:44:35 GMT
FROM:    Nayana A J at NCRA-TIFR  <nayan89deva@gmail.com>

A. J. Nayana (NCRA-TIFR) and Poonam Chandra (NCRA-TIFR) reports:

We carried out Giant Metrewave Radio Telescope (GMRT) observations of
GRB 161219B (D'Ai et al. GCN Circ. 20296) in the 1390 MHz band on 2016 
Dec 26.68 UT. We
detect the  radio afterglow of the GRB in the Swift error circle 
(Beardmore et al. GCN
Circ. 20297). The 1390 MHz band flux density of the afterglow is 
397+/-55 uJy. Map rms is
40 uJy/beam.

Further observations are planned. We thank GMRT staff for making these
observations possible.


GRB_name: GRB161214B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20345
SUBJECT: GRB 161214B: MASTER-Kislovodsk early optical observations
DATE:    16/12/27 17:03:34 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

D.Vlasenko, V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov,
O.Gress, P.Balanutsa, A.Kuznetsov, D.Kuvshinov
Lomonosov Moscow State University, Sternberg Astronomical Institute

R. Rebolo, M. Serra Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

R.Podesta, C.Lopez, F.Podesta
Observatorio Astronomico Felix Aguilar (OAFA), San Juan Univerdity,

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

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

O.Gres, K.Ivanov, J.Rabinovich, N.M.Budnev,
Irkutsk State University

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

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


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Kislovodsk was pointed to the  GRB161214B  882 sec after notice 
time and 900.34 sec after trigger time at 2016-12-14 17:35:11 UT. On our 
first (180s exposure)  set we haven't found optical transient  within 
Swift error-box (ra=00 16 16 dec=+07 26 10 r=3.00) (D'Avanzo et al., GCN 
20257). The 5-sigma upper limit set is about 16.5 mag(polaroid, 
unfiltered).

The observations made on zenit distance = 49 degrees, galaxy latitude b = 
-54 degree.
The moon (98 % bright part) is 29.5 degrees above the horizon. The 
distance between  moon and  object is 87
The sun  altitude  is -40 degree.
The object can be observed till 2016-12-14 22:27:18

Maximal coadded limit ~18.7 m. No OT found.

The message may be cited.


GRB_name: GRB161219B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20346
SUBJECT: GRB161219B - Anticipated hyperluminal evidence
DATE:    16/12/29 07:49:28 GMT
FROM:    Arnon Dar at Technion-Israel Inst. of Tech  <arnon@physics.technion.ac.il>

S. Dado, A. Dar and A. De Rujula report:

High resolution VLA/VLBI follow-up observations of the radio
afterglow of GRB161219B [1,2] may provide direct measurements
of the hyperluminal motion and of the initial Lorentz factor of
the afterglow's source, relative to its parent supernova [3].

The small isotropic energy Eiso~1.6xE52 erg and the peak energy
E'p~104 keV of the relatively nearby GRB161219B measured by Konus-
Wind [4] indicate, in the cannonball model of GRBs, that this is
an ordinary GRB viewed far off-axis [5]. In this model ordinary
GRBs viewed on or near the axis of their relativistic ejecta
satisfy E'p~150 (Eiso/E52)^{1/2} keV. The Konus-Wind measurements
imply [5] a viewing angle @~3/Gamma and a linear polarization
P = 2 @^2 Gamma^2/(1+@^4 Gamma^4)~20% where Gamma is the bulk-motion
Lorentz factor of the jet which produced GRB161219B in a broad-line
Ic supernova explosion akin to that of  SN1998bw [3].

The bright radio afterglow of the relatively nearby GRB161219B [1,2]
at redshift z=0.1475 [6] provides an excellent opportunity to measure
the apparent superluminal speed V of its jet in the plane of the sky.
As long as @^2 x Gamma^2 >> 1, V=2c/(1+z)@ and a measurement of V yields
Gamma~3(1+z)V/2. If the jet decelerates in a constant density environment
and reaches  @^2 x Gamma^2 << 1 before its superluminal speed could be 
measured, then its late-time apparent superluminal speed in the plane of 
the sky, which is expected to decrease like t^{-1/2), if measured,
may be extrapolated to obtain an estimate of Gamma at early time [5].

[1] K. D. Alexander, et al.  GCN 20313 
[2] A. J. Nayana & and P. Chandra,  GCN 20344 
[3] A. de Ugarte Postigo, et al. GCN 20342
[4] D. Frederiks, T. Laskar, E. Berger, GCN 20323 
[5] S. Dado, A. Dar, A. De Rujula, arXiv:1610.01985
[6] N. R. Tanvir, et al. GCN 20321

[GCN OPS NOTE(29dec16): The suffix "B" was added to the GRB name
in the SUBJECT-line.]


GRB_name: GRB161228A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20347
SUBJECT: GRB 161228A: POLAR Observation
DATE:    16/12/30 11:51:57 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

Hualin Xiao (PSI), Wojtek Hajdas (PSI) and Radoslaw Marcinkowski (PSI) report on behalf of the POLAR collaboration:

At 2016-12-28T09:43:24.0 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 161228A,
which was also observed by Fermi GBM (trigger #504611009).

The POLAR light curve consists of one peak with duration (T90) of 3.5 +- 0.5 s measured from T0.
The  0.5 s peak flux at T0+1.75 s  is equal to 330 +-43 cnts/sec.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_161228A_raw.png
and http://polar.psi.ch/pub/lc.php?event=GRB+161228A
 

Using the best location from the Fermi-GBM, which is (J2000):

RA: 358.42  [deg]
 
Dec: -24.6  [deg]

Err:  5.63  [deg]

the incident angle in the POLAR coordinate at T0 is:

Theta: 70.47  [deg]

Phi:  171.332 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.

POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub , http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .


This message is quotable in publications.


GRB_name: GRB161228B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20348
SUBJECT: GRB 161228B: POLAR Observation
DATE:    16/12/30 11:53:28 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

Radoslaw Marcinkowski (PSI), Hualin Xiao (PSI) and Wojtek Hajdas (PSI) report on behalf of the POLAR collaboration:

At 2016-12-28T13:15:40.0 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 161228B,
which was also observed by Fermi GBM (trigger #504623745) and SPIACS (trigger: 2016-12-28T13-15-39.8537-31044-07056-0).

The POLAR light curve consists of one peak with duration (T90) of 8.5 +- 0.5 s measured from T0.
The  0.5 s peak flux at T0 + 3.25 s  is equal to 450 +- 40 cnts/sec.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_161228B_raw.png
and http://polar.psi.ch/pub/lc.php?event=GRB+161228B
 

Using the best location from the Fermi-GBM, which is (J2000):

RA: 129.290  [deg]
 
Dec: 43.670  [deg]

Err:  2.24   [deg]

the incident angle in the POLAR coordinate at T0 is:

Theta: 28.7  [deg]

Phi: 13.9  [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.

POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub , http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .


This message is quotable in publications.


GRB_name: GRB170101A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20349
SUBJECT: GRB 170101A: Swift detection of a burst
DATE:    17/01/01 02:47:02 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

A. Y. Lien (GSFC/UMBC), D. Malesani (DARK/NBI and DTU Space),
B. Mingo (U Leicester), K. L. Page (U Leicester) and
T. N. Ukwatta (LANL) report on behalf of the Swift Team:

At 02:26:01 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170101A (trigger=729293). 
The BAT on-board calculated location is 
RA, Dec 267.103, +11.654 which is 
   RA(J2000) = 17h 48m 25s
   Dec(J2000) = +11d 39' 15"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 5 sec.  The peak count rate
was ~28000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 23:58 UT on 2017 January 19. There will thus be no XRT
or UVOT data for this trigger before this time. 

The Swift team wishes the astronomical community a happy 2017. 

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: GRB170101B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20350
SUBJECT: GRB 170101B: Fermi GBM detection
DATE:    17/01/01 10:24:47 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 02:47:17.87 UT on 01 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170101B (trigger 504931642 / 170101116).

The on-ground calculated location, using the GBM trigger
data, is RA = 70.6, DEC = -1.6 (J2000 degrees,
equivalent to 04 h 43 m, -1 d 35 '), 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 65 degrees.

The GBM light curve shows/consists of two overlapping pulses
with a duration (T90) of about 12.8 s (50-300 keV).
The time-averaged spectrum from T0 to T0 + 15.7 s is
best fit by a Band function with Epeak = 213 +/- 13 keV,
alpha = -0.57 +/- 0.05, and beta = -2.29 +/- 0.12.

The event fluence (10-1000 keV) in this time interval is
(1.26 +/- 0.03)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0 + 6.1 s in the 10-1000 keV band
is 7.0 +/- 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: GRB170101B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20351
SUBJECT: GRB 170101B: Astrosat CZTI detection
DATE:    17/01/01 17:05:46 GMT
FROM:    Vedant Kumar at Astrosat/CZTI/IUCAA  <vedant@iucaa.in>

V. Kumar, D. Bhattacharya and V. Bhalerao (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:


Analysis of AstroSat CZTI data showed clear detection of GRB170101B (Fermi-GBM detection: Andreas von Kienlin et al., GCN 20350)
in the 40-200 keV energy range. The light curve shows dual peak structure with stronger peak at 02:47:25.870 UT, 8 secs after the Fermi- GBM trigger(consistent with GCN 20350). The measured peak count rate is 209.80 counts/sec above the background in combined data of four quadrants, with a total of 1751 counts. The local mean background count rate was 377 counts/sec. Using cumulative rates, we measure a T90 of 14.3 sec.


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: GRB170101A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20353
SUBJECT: GRB 170101A: Swift-BAT refined analysis
DATE:    17/01/02 02:07:41 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
N. Gehrels (GSFC), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
J. P. Norris (BSU), 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-119 to T+303 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170101A (trigger #729293)
(Lien et al., GCN Circ. 20349).  The BAT ground-calculated position is
RA, Dec = 267.089, 11.642 deg which is
   RA(J2000)  =  17h 48m 21.3s
   Dec(J2000) = +11d 38' 29.9"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 14%.
T90 (15-350 keV) is 2.43 +- 0.49 sec (estimated error including systematics).

The mask-weighted light curve shows a single FRED-like pulse that starts
at ~T-0.2 s, peaks at ~T0, and ends at ~T+3 s. In addition, there seems to
be some weak emission prior to the FRED-like pulse that starts at ~T-1.6 s,
and a weak tail afterwards that lasts till ~T+8 s. T90 (15-350 keV) is
3.2 +- 0.9 sec (estimated error including systematics).

The time-averaged spectrum from T-1.6 to T+8.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.87 +- 0.06.  The fluence in the 15-150 keV band is 6.0 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.22 sec in the 15-150 keV band
is 54.4 +- 2.0 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Using a 16-ms binned light curve, the lag analysis finds a lag of 39 +/- 8 ms for
the 100-350 keV to 25-50 keV, and  37 +/- 7 ms for the 50-100 keV to 15-25 keV
band, which is consistent with those of a long GRB.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/729293/BA/


GRB_name: GRB161229A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20354
SUBJECT: GRB 161229A: POLAR observation
DATE:    17/01/02 08:06:27 GMT
FROM:    Zhao Yi at POLAR  <yizhao@ihep.ac.cn>

Yi Zhao (IHEP), Jianchao Sun (IHEP) and Yuanhao Wang (IHEP)
report on behalf of the POLAR collaboration:


At 2016-12-29T21:03:49.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 161229A, 
which was also detected by the Fermi/GBM (trigger 504738232/161229877).


The POLAR light curve consists of multiple peaks,
with a duration (T90) of 35.77 s measured from T0+0.39 s.
The 1-s peak rate measured from T0+30.00 s is 2307.8 cnts/s,
The total counts is about 35134 cnts.The above measurements 
are in the energy range of about 80-500 keV.


LC_URL:
http://polar.ihep.ac.cn/grb/2016/GRB161229A/lc/POLAR_lc_grb161229877.jpg


Using the best location from the Fermi/GBM, which is (J2000):
RA:    81.030  [deg]
Dec:   +6.310  [deg]
Err:   1.00    [deg]


the incident angle in POLAR coordinate at T0 is:
theta:   87.6    [deg]
phi:     -103.7  [deg]


The Minimum Detectable Polarization (MDP) for this burst is estimated
to be ~46% [3-sigma, statistical only].


All analysis results presented above are preliminary.


POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board
the Chinese space laboratory Tiangong-2 launched on Sep 15,2016.
More information about POLAR can be found at http://polar.ihep.ac.cn/en/,
http://isdc.unige.ch/polar/and http://polar.psi.ch/pub/.


GRB_name: GRB170101A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20355
SUBJECT: GRB 170101A: POLAR observation
DATE:    17/01/02 13:57:14 GMT
FROM:    Hancheng Li at IHEP/POLAR  <lihc@ihep.ac.cn>

Hancheng Li (IHEP), Yuanhao Wang (IHEP), Zhengheng Li (IHEP)
report on the behalf of the POLAR collaboration:


At 2017-01-01T02:26:00.66 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170101A, which was also
detected by the Swift/BAT (trigger #729293).


The POLAR light curve consists of a single peak,
with a duration (T90) of 2.82 s measured from T0+0.00 s.
The 0.2-s peak rate measured from T0+0.20 s is 8836 cnts/s,
the total counts is about 5379 cnts.  The above measurements
are in the energy range of approximately 80-500 keV. 


LC_URL:
http://polar.ihep.ac.cn/grb/2017/01/GRB170101A/lc/GRB170101A.png


Using the best location from the Swfit/BAT, which is (J2000):
RA:    267.103     [deg]
Dec:   +11.654     [deg]
Err:     3.00      [arcmin]


the incident angle in POLAR coordinate at T0 is:
theta:  6.04  [deg]  
phi:   72.86  [deg] 


The Minimum Detectable Polarization(MDP) for this burst is
estimated to be ~6.0% [1-sigma, statistical only]. 
Follow-up observations are strongly encouraged.


All analysis results presented above are preliminary.


POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board 
the Chinese space laboratory Tiangong-2 launched on Sep 15, 2016. 
More information about POLAR can be found at:
http://polar.ihep.ac.cn/en/ , 
http://isdc.unige.ch/polar/ and http://polar.psi.ch/html/ .


GRB_name: GRB161228C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20357
SUBJECT: GRB 161228C: POLAR observation
DATE:    17/01/03 02:06:49 GMT
FROM:    Zhao Yi at POLAR  <yizhao@ihep.ac.cn>

Yi Zhao (IHEP), Yuanhao Wang (IHEP) and Zhengheng Li (IHEP)
report on behalf of the POLAR collaboration:

At 2016-12-28T00:46:20.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 161228C, 
which was also detected by the Fermi/GBM (trigger504578783/161228032).

The POLAR light curve consists of multiple peaks,
with a duration (T90) of 31.67 s measured from T0-6.29 s.
The 1-s peak rate measured from T0+16.00 s is 327.9 cnts/s.
The total counts is about 4408 cnts.The above measurements
arein the energy range of about 80-500 keV.

LC_URL:
http://polar.ihep.ac.cn/grb/2016/GRB161228C/lc/POLAR_lc_grb161228032.jpg

Using the best location from the Fermi/GBM, which is (J2000):
RA:   115.820  [deg]
Dec:  +25.760  [deg]
Err:  3.14     [deg]

The incident angle in POLAR coordinate at T0 is:
theta:  52.2   [deg]
phi:    -75.6  [deg]

All analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board
the Chinese space laboratory Tiangong-2 launched on Sep 15,2016.
More information about POLAR can be found at http://polar.ihep.ac.cn/en/ ,
http://isdc.unige.ch/polar/ and http://polar.psi.ch/pub/ .


GRB_name: GRB170101A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20359
SUBJECT: GRB 170101A: Lomonosov BDRG gamma ray discovery
DATE:    17/01/03 12:07:50 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V.V.Bogomolov, N.L.Dzhioeva, S.I.Svertilov,
A.M.Amelushkin, V.O.Barinova, M.I.Panasyuk, A.V.Bogomolov, A.F.Iyudin,
V.V.Kalegaev, D.Nguen,  V.L. Petrov, I.V.Yashin, P.S.Kazarian
Physics Department, Skobel'tsyn Institute of Nuclear Physics, Lomonosov 
Moscow
State University

V. Lipunov, E.S. Gorbovskoy, N.Tyurina, D.Kuvshinov
Lomonosov Moscow State University, Sternberg Astronomical Institute

I. Park, J. Lee, S. Jeong
Department of Physics, Sungkyunkwan University, Seobu-ro, Jangangu, 
Suwonsi,
Korea

A. J. Castro-Tirado
Instituto de Astrofisica de Andalucia (IAA-CSIC) and Universidad de 
Malaga, Spain


At 02:26:12 UT on 01 Jan 2017,
the Lomonosov BDRG  Gamma-ray Burst Monitor
(http://lomonosov.sinp.msu.ru/en/scientific-equipment-2/bdrg),
triggered GRB 170101A (A. Y. Lien (GSFC/UMBC), GCN 20349),
total duration ~3s,
the energy range 30-800 keV.
LC is available at:
https://downloader.sinp.msu.ru/static/grb_catalog/lc/grb_20170101_022612.png
More information is available at:
https://downloader.sinp.msu.ru/grb_catalog/
This Notice was ground-generated.

The message may be cited.


GRB_name: GRB170101B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20360
SUBJECT: GRB 170101B: Lomonosov BDRG gamma ray discovery 
DATE:    17/01/03 12:10:03 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

N.L.Dzhioeva,V.V.Bogomolov, S.I.Svertilov,
A.M.Amelushkin, V.O.Barinova, M.I.Panasyuk, A.V.Bogomolov, A.F.Iyudin,
V.V.Kalegaev, D.Nguen,  V.L. Petrov, I.V.Yashin, P.S.Kazarian
Physics Department, Skobel'tsyn Institute of Nuclear Physics, Lomonosov 
Moscow
State University

V. Lipunov, E.S. Gorbovskoy, N.Tyurina, D.Kuvshinov
Lomonosov Moscow State University, Sternberg Astronomical Institute

I. Park, J. Lee, S. Jeong
Department of Physics, Sungkyunkwan University, Seobu-ro, Jangangu, 
Suwonsi,
Korea

A. J. Castro-Tirado
Instituto de Astrofisica de Andalucia (IAA-CSIC) and Universidad de 
Malaga, Spain


At 02:47:22 UT on 01 Jan 2017,
the Lomonosov BDRG  Gamma-ray Burst Monitor
(http://lomonosov.sinp.msu.ru/en/scientific-equipment-2/bdrg),
triggered GRB 170101B (P Veres (UAH), GCN 20350),
total duration ~13s,
the energy range 30-300 keV.
LC is available at:
https://downloader.sinp.msu.ru/static/grb_catalog/lc/grb_20170101_024722.png
More information is available at:
https://downloader.sinp.msu.ru/grb_catalog/
This Notice was ground-generated.

The message may be cited.


GRB_name: GRB170101B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20361
SUBJECT: GRB 170101B: POLAR observation
DATE:    17/01/03 15:05:07 GMT
FROM:    Yuanhao Wang at IHEP/CAS  <wangyuanhao@ihep.ac.cn>

Hancheng Li (IHEP), Yuanhao Wang (IHEP), Zhengheng Li (IHEP)
report on the behalf of the POLAR collaboration:

At 2017-01-01T02:47:18.27 UT (T0), during a routine on-ground
search of data, POLAR detected the GRB 170101B, which was also
detected by the Fermi/GBM (trigger 504953918/170101374).

The POLAR light curve consists of multiple peaks,
with a duration (T90) of 11.2 s measured from T0+0.3 s.
The 0.2-s peak rate measured from T0+8.1 s is 968 cnts/s,
the total counts is about 5217 cnts. The above measurements
are in the energy range of approximately 80-500 keV.

LC_URL:
http://polar.ihep.ac.cn/grb/2017/01/GRB170101B/lc/GRB170101B.JPG

Using the best location from the Fermi/GBM, which is (J2000):
RA:    70.640[deg]
Dec:    -1.580[deg]
Err:     1.2[deg]

the incident angle in POLAR coordinate at T0 is:
theta:    63.43[deg]
phi:   -110.01[deg]

The Minimum Detectable Polarization(MDP) for this burst is
estimated to be ~23.5% [1-sigma, statistical only]. 

All analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV) on-board
the Chinese space laboratory Tiangong-2 launched on Sep 15, 2016. 
More information about POLAR can be found at:http://polar.ihep.ac.cn/en/, 
http://isdc.unige.ch/polar/and http://polar.psi.ch/html/.

[GCN OPS NOTE(03jan17):  Per operator, the SUBJECT-line  was corrected
from "170101A" to "170101B".]


GRB_name: GRB170101A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20362
SUBJECT: Konus-Wind observation of GRB 170101A
DATE:    17/01/03 19:54:15 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, intense GRB 170101A
(Swift-BAT trigger #729293: Lien  et al., GCN 20349;
Barthelmy et al., GCN 20353;
POLAR observation: Li et al., GCN 20355;
Lomonosov BDRG observation: Bogomolov et al., GCN 20359)
triggered Konus-Wind at T0=8757.802 s UT (02:25:57.802).

The burst light curve shows a single FRED-like pulse
with a total duration of ~4 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.35(-0.18,+0.20)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+0.264 s,
of 1.86(-0.23,+0.24)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+9.472 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 = -1.44(-0.13,+0.17),
the high energy photon index beta = -2.49(-0.65,+0.23),
the peak energy Ep = 123(-21,+23) keV,
chi2 = 101/97 dof.

The spectrum near the peak count rate
(measured from T0 to T0+1.280 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 = -1.07(-0.15,+0.17),
the high energy photon index beta = -2.48(-0.22,+0.14),
the peak energy Ep = 124(-15,+18) keV,
chi2 = 57/56 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170101_T08757/

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


GRB_name: GRB170102A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20363
SUBJECT: GRB 170102A: POLAR observation
DATE:    17/01/04 08:29:33 GMT
FROM:    Zhao Yi at POLAR  <yizhao@ihep.ac.cn>

Yi Zhao (IHEP), Hancheng Li (IHEP) and Minzi Feng (IHEP)
report on behalf of the POLAR collaboration:

At 2017-01-02T02:51:18.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170102A, 
which was also detected by the KONUS-Wind.

The POLAR light curve consists of multiple peaks,
with a duration (T90) of 40.03 s measured from T0-1.66 s.
The 1-s peak rate measured from T0+23.00 s is 335.7 cnts/s.
The total counts is about 4727 cnts. The above measurements
are in the energy range of about 80-500 keV.

LC_URL:
http://polar.ihep.ac.cn/grb/2017/01/GRB170102A/lc/POLAR_lc_grb170102A.jpg

All analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV)
on-board the Chinese space laboratory Tiangong-2 launched on
Sep 15,2016. More information about POLAR can be found at 
http://polar.ihep.ac.cn/en/, http://isdc.unige.ch/polar/
and http://polar.psi.ch/pub/.


GRB_name: GRB170102A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20368
SUBJECT: GRB 170102A: Astrosat CZTI detection
DATE:    17/01/05 10:51:34 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

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


Analysis of AstroSat CZTI data showed weak detection of GRB170102A (POLAR detection: Yi Zhao et al., GCN 20363) in the 40-200 keV energy range. 
The light curve shows multiple peak structure with stronger peak at 02:51:41 UT, 23 secs after POLAR trigger. The measured peak count rate is 
101.98 counts/sec above the background in combined data of four quadrants, with a total of 636.26 counts. The local mean background count rate
was 353 counts/sec.


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: GRB161219B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20380
SUBJECT: PESSTO follow-up of GRB 161219B/SN2016jca
DATE:    17/01/06 11:08:31 GMT
FROM:    Ting-Wan Chen at MPE  <jchen@mpe.mpg.de>

T.-W. Chen (MPE), J. Greiner (MPE), S. Klose (TLS), K. W. Smith (QUB), A. Cikota (ESO), M. Magee (QUB), C. Inserra (QUB), J. Lyman (Univ. of Warwick), E. Kankare (QUB), K. Maguire (QUB), S. J. Smartt (QUB), M. Sullivan (Southampton), S. Valenti (UC Davis), O. Yaron (Weizmann), D. Young (QUB), and I. Manulis (Weizmann) report:

We acquired spectroscopic followup of SN2016jca (de Ugarte Postigo et al., GCN 20342; Pian et al. on Transient Name Server <https://wis-tns.weizmann.ac.il/object/2016jca <https://wis-tns.weizmann.ac.il/object/2016jca>>), the SN associated with GRB 161219B (D'Ai et al. GCN 20296), using the ESO New Technology Telescope at La Silla at 04:48 UT on 2017-01-04 (15.4 days after the GRB trigger) with EFOSC2 and Grism 13 (3985-9315A, 18A resolution) in the framework of the PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Smartt et al. 2015, A&A, 579, 40 <http://www.pessto.org <http://www.pessto.org/>>).

The spectrum shows several broad emission features and a significant decrease in flux toward both the blue and red ends, as a broad-line Type Ic supernova around the maximum light. A good match is achieved with SN1998bw at +1.3d using GELATO (Harutyunyan et al., 2008,  A&A, 488, 383) and also with SN2002ap at -2d using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). 


GRB_name: GRB170105A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20387
SUBJECT: GRB 170105A: POLAR Observation
DATE:    17/01/07 06:44:37 GMT
FROM:    Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>

R. Marcinkowski (PSI), H. Xiao (PSI) and W. Hajdas (PSI) report on behalf
of the POLAR collaboration:

At 2017-01-05T06:14:07.0 UT(T0), during a routine on-ground search of
data, POLAR detected the GRB 170105A, which was also observed by SPIACS 
at 2017-01-05T06:14:06 and Konus-Wind at 22450.264s UT (06:14:10.264).

The POLAR light curve consists of 1 peak with duration (T90) of 
2.0 +/- 0.5 s measured from T0.
The 0.5 s peak flux at T0 + 0.8 s  is equal to 2490 +/- 90 counts/sec.
POLAR recorded 3600 +/- 160 events from the burst.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170105A_raw.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170105A

The analysis results presented above are preliminary. Calibration of the 
instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter 
which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2)
on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170105A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20389
SUBJECT: GRB 170105A: AstroSat CZTI  detection
DATE:    17/01/07 13:28:52 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma,  V. Bhalerao and 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 clear detection of GRB170105A (POLAR Observation: R. Marcinkowski et al., GCN Circ. 20387) in the 40-200 
keV energy range. The light curve shows a single peak structure with main peak at 06:14:06 UT in the quadrant A and B only,  ~1 sec before the 
POLAR trigger at 06:14:07 UT. The measured peak count rate is 305.46 counts/sec above the background in combined data of four quadrants, with a 
total of 762 counts. The local mean background count rate was 287.54 counts/sec. Using cumulative rates, we measure a T90 of 2.86 secs. 
 
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: GRB170105A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20406
SUBJECT: LIGO/Virgo G268556: IPN Triangulation of GRB 170105A (association with ATLAS17aeu)
DATE:    17/01/09 16:38:27 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

K. Hurley, on behalf of the IPN, 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, soft-spectrum GRB 170105A was detected by POLAR 
(Marcinkowski et al., GCN Circ. 20387), AstroSat (CZTI; Sharma et al., 
GCN Circ. 20389), Konus-Wind, and INTEGRAL (SPI-ACS) at about 22447 s UT 
(06:14:07).

We have triangulated this GRB to a Konus-INTEGRAL annulus centered at 
RA(2000)=129.749 deg (08h 38m 60s)  Dec(2000)=+27.904 deg (+27d 54' 
14"), whose radius is 34.255(-14.832,+1.812) deg (3 sigma).

This localization may be improved.

The distance between the annulus center line and the ATLAS17aeu optical 
transient reported by Tonry et al. (LVC Circ. 20382) is 0.57 degrees, 
strengthening the association of the transient with the GRB initially 
suggested by Kasliwal et al. (LVC Circ. 20393).

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB170105_T22450/IPN/.

As observed by Konus-Wind, the burst had a fluence of
2.56(-0.13,+0.18)x10^-6 erg/cm2,
and a 64-ms peak energy flux, measured from T0-0.204 s,
of 2.47(-0.30,+0.58)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170105_T22450/.


GRB_name: GRB170105A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20412
SUBJECT: GRB170105A: AstroSat CZTI localisation
DATE:    17/01/10 05:46:39 GMT
FROM:    Varun Bhalerao at IUCAA  <varunb@iucaa.in>

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

Detailed analysis of AstroSat CZTI data for GRB170105A (POLAR Observation: R. Marcinkowski et al., GCN Circ. 20387; CZTI detection: Sharma et al., GCN Circ. 20389) was carried out for localising the GRB. We modelled the counts in various quadrants using a raytracing code based on the instrument geometry. The GRB is localised to a 550 sq. deg. area, centred roughly on RA, Dec = 60, +80. While spectral fits are not possible at the current stage, the data indicate a rather soft spectrum, with strongest detection around 60-80 keV and almost no counts above 100 keV. Along with the T90 measurement in Sharma et al., GCN Circ. 20389, this suggests that GRB170501A was a long GRB.

A pdf showing the localisation region is available at:
http://www.iucaa.in/~astrosat/czti_grb/GRB170105A/heal/GRB170105A_localisation.pdf

A healpix map with the localisation region is available at: http://www.iucaa.in/~astrosat/czti_grb/GRB170105A/heal/GRB170105A_localisation.fits

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: GRB170105A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20413
SUBJECT: LIGO/Virgo G268556: ATLAS17aeu position is consistent with GRB170105A
DATE:    17/01/10 06:15:41 GMT
FROM:    Varun Bhalerao at IUCAA  <varunb@iucaa.in>

Varun Bhalerao (IUCAA), Sujay Mate (IUCAA), Dipankar Bhattacharya (IUCAA), Sukanta Bose (IUCAA), Gulab Chand Dewangan (IUCAA), Ranjeev Misra (IUCAA), Sanjit Mitra (IUCAA), A R Rao (TIFR), Tarun Souradeep (IUCAA), Santosh Vadawale (PRL), on behalf of the Astrosat CZTI team report:

Bhalerao et al. (GCN Circ. 20412) have used AstroSat CZTI to infer that GRB170105A is a long GRB, and have localised it to a  ~550 square degree region (1-sigma). This region includes 3.9% probability of containing the LIGO trigger G268556, based on the revised LALInference sky map (Greco et al,  20385). The overlap with the IPN triangulation (Svikin et al., GCN Circ. 20406) is about 50 square degrees.

The position of ATLAS17aeu (Tonry et al., GCN Circ. 20382) is marginally outside the AstroSat CZTI error region, consistent at better than 1.1 sigma. This further indicates that ATLAS17aeu is the afterglow of GRB170105A (Kasliwal et al., GCN Circ. 20393).


GRB_name: GRB170105A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20415
SUBJECT: LIGO/Virgo G268556: Swift-XRT confirms that ATLAS17aeu is fading in X-rays
DATE:    17/01/10 09:45:26 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), J.A. Kennea (PSU), S.D. Barthelmy
(NASA/GSFC), A.P. Beardmore (U. Leicester), A.A. Breeveld (UCL-MSSL),
D.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC), G.
Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB),
V.D'Elia (ASDC), N. Gehrels (NASA/GSFC), P. Giommi (ASI), C. Gronwall
(PSU), H.A. Krimm (CRESST/GSFC/USRA), N.P.M. Kuin (UCL-MSSL), A.Y. Lien
(GSFC/UMBC), D. Malesani (DARK/NBI), F.E. Marshall (NASA/GSFC), A.
Melandri (INAF-OAB), B. Mingo (U. Leicester),  J.A. Nousek (PSU), S.R.
Oates (U. Warwick), P.T. O'Brien (U. Leicester), J.P. Osborne (U.
Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester), D.M.
Palmer (LANL), M. Perri (ASDC), J.L. Racusin (NASA/GSFC), B. Sbarufatti
(INAF-OAB/PSU), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), E. Troja
(NASA/GSFC/UMCP) report on behalf of the Swift team:

Swift has continued to observed ATLAS17aeu (Tonry et al., LVC Circ.
20382), gathering a total of 21.3 ks of data, from T0+222 ks to T0+470
ks (where T0 is the GW trigger time). The X-ray counterpart (Evans et
al., LVC Circ. 20390) is now confirmed to be fading.

Assuming the trigger time from the GW event (LVC Circ. 20364) the light
curve is decaying with a power-law index of 2.2 (+1.1, -1.2). If instead
we take T0 from GRB 170105A (Marcinkowski et al., GCN Circ. 20387), the
decay index is 1.7 (+1.1, -0.9). At the mid-point of the latest 
observation, GW_T0+453 ks (=GRB_T0+381 ks) the 0.3-10 keV XRT count-rate
was 0.0017 (+/- 0.0006) ct/sec.

A spectrum compiled from the data can be fitted with an absorbed
power-law, with NH consistent with the Galactic value of 4.6e20 cm^-2
(Willingale et al. 2013) and photon index Gamma=1.60 (+0.4, -0.3).

Using this spectrum the count-rate above corresponds to an observed
(unabsorbed) 0.3-10 keV flux of (6.7+/-2.4)e-14  ( [7.2+/-2.6]e-14) erg
cm^-2 s^-1.

The spectral and temporal indices are consistent with the values
typically seen for X-ray GRB afterglows (e.g. the Swift-XRT GRB
catalogue: http://www.swift.ac.uk/xrt_live_cat/; Evans et al. 2009).

This circular is an official product of the Swift GW follow up team.


GRB_name: GRB170105A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20417
SUBJECT: LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394
DATE:    17/01/10 15:22:53 GMT
FROM:    Jinzhong Liu at Xinjiang Astronomical Observatory  <liujinzh@xao.ac.cn>

D. Xu (NAOC/CAS), J.Z. Liu, H.B. Niu, Y. Zhang, X. Zhang, G.X. Pu, S.G.
Ma, T.Z. Yang, F.F. Song (XAO), X. Zhou, T.M. Zhang (NAOC/CAS), H.B.
Zhao, B. Li, G.T. Zhaori (PMO), J.M. Bai, J.R. Mao (YNAO) report on
behalf of a Chinese Gravitational Wave collaboration:

We have performed tiled observations of LIGO/Virgo G268556 (LVC, GCN
20364) using the Nanshan One-meter Wide field Telescope (NOWT),
Xinjiang, China, the 0.6/0.9-m Schmidt telescope at Xinglong, Hebei,
China, and the 1-m telescope at Xuyi, Jiangsu, China.

The Nanshan 1-m has a FOV of 1.3x1.3 deg^2, and covered the position of
ATLAS17aeu (Tonry et al. GCN 20382), the potential optical afterglow of
GRB 170105A (e.g., Marcinkowski et al., GCN 20387; Sharma et al., GCN
20389; Kasliwal, et al., GCN 20393), in a single night. We obtained an
upper limit of m(V)>20.0 mag (3 sigma) at 14:55 UT on 2017-01-07.

The 0.6/0.9-m Schmidt telescope has a FOV of  1.5x1.5 deg^2, and covered
the position of ATLAS17aeu also in a single night. We obtained an upper
limit of m(White)>18.8 mag (5 sigma) at 18:26 UT on 2017-01-08.

The Xuyi 1-m has a FOV of 3.0x3.0 deg^2, and covered the position of
ATLAS17aeu in a single night. We obtained an upper limit of m(r)>14 mag
(3 sigma) at  14:32 UT on 2017-01-09.

In addition, we note that the two sources, dubbed EWE001 and EWE002, in
GCN 20394, are obviously known sources in several surveys such as DSS II
and SDSS.





--
N: Jinzhong Liu, Dr.
O: Main building, 213
P: 150, Science 1-Street, Urumqi, Xinjiang 830011, China
T: 86 991 3689027
D: 2012-07-14
E: optics@xao.ac.cn


GRB_name: GRB170109A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20418
SUBJECT: GRB 170109A: POLAR Observation
DATE:    17/01/10 15:30:24 GMT
FROM:    Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>

R. Marcinkowski (PSI), H. Xiao (PSI) and W. Hajdas (PSI) report on behalf 
of the POLAR collaboration:

At 2017-01-09 03:17:35 UT(T0), during a routine on-ground search of data, 
POLAR detected the GRB 170109A, which was also observed by Fermi GBM 
(trigger # 505624660). Significant detection was recorded in 5 of 25 
POLAR detection modules.

The POLAR light curve consists of multipeak structure compatible with Fermi 
GBM with duration (T90) of 9.0 +/- 1.0 s measured from T0. The 1.0 s peak 
flux at T0 + 4.5 s  is equal to 530 +/- 60 counts/sec. POLAR (5 modules) 
recorded 3140 +/- 140 events from the burst.

Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170109A_raw_5of25.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170109A

Using the best location from the Fermi GBM, which is (J2000):

RA : 114.4  [deg]
Dec:  -6.8  [deg]
Err:   2.85 [deg]

the incident angle in the POLAR coordinate at T0 is:
Theta: 81.0 [deg]
Phi:  114.3 [deg]

The analysis results presented above are preliminary. Calibration of the 
instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter 
which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) 
on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub , 
http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170105A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20421
SUBJECT: LIGO/Virgo G268556: Lijiang Observatory GMG Telescope Upper Limit on ATLAS17aeu
DATE:    17/01/10 23:03:21 GMT
FROM:    Mansi M. Kasliwal at Caltech  <mansi@astro.caltech.edu>

A.K.H. Kong (NTHU/Oxford), J. Mao, X. Hou, J. Wang, and J.-M. Bai  (YNAO)

We observed the field of the optical transient ATLAS17aeu (Tonry et al.,
LVC GCN 20382; Kasliwal et al., GCN 20398) that is within the error region
of LIGO/Virgo G268556 (LVC, GCN 20364) with the 2.4-m GMG telescope at the
Lijiang Observatory in Yunnan, China. We obtained an R-band image with the
Yunnan Faint Object Spectrograph and Camera (YFOSC) on 2017-01-07 14:55:35
UT. ATLAS17aeu was not detected with a 3-sigma limit of about R~23 mag.

ATLAS17aeu was detected with i=21.9 mag on 2017-01-07 08:05:33 UT (Kasliwal
et al., GCN 20398) and was proposed to be the afterglow of GRB 170105A. Our
observation indicates that the source is fainter than the suggested
power-law decay. However, due to the use of different filters in ATLAS,
Palomar, and Lijiang, the lightcurve should be treated with caution.


GRB_name: GRB170111A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20423
SUBJECT: GRB 170111A: Swift detection of a burst
DATE:    17/01/11 00:53:54 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. P. Beardmore (U Leicester), D. N. Burrows (PSU), C. Gronwall (PSU),
J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL) and
M. H. Siegel (PSU) report on behalf of the Swift Team:

At 00:33:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170111A (trigger=731887).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 20.717, -32.540 which is 
   RA(J2000) = 01h 22m 52s
   Dec(J2000) = -32d 32' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
structure with a duration of about 40 sec.  The peak count rate
was ~700 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 00:35:14.8 UT, 106.7 seconds after
the BAT trigger. Using promptly downlinked data we find a variable, uncatalogued
X-ray source with an enhanced position: RA, Dec 20.6981, -32.5653 which
is equivalent to:
   RA(J2000)  = 01h 22m 47.56s
   Dec(J2000) = -32d 33' 55.1"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 107 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 (3.10 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 4.1
(+2.60/-2.25) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 112 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  approximately 70% 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 0.03. 

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: GRB170111A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20424
SUBJECT: GRB 170111A: Enhanced Swift-XRT position
DATE:    17/01/11 04:24:27 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 564 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 170111A, 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 = 20.69735, -32.56485 which is equivalent
to:

RA (J2000): 01h 22m 47.36s
Dec (J2000): -32d 33' 53.5"

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: GRB170105A
Detection_method: AMI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20425
SUBJECT: LIGO/Virgo G268556: AMI 15 GHz detection of ATLAS17aeu
DATE:    17/01/11 12:58:07 GMT
FROM:    Kunal Mooley at U of Oxford  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley, R. P. Fender (Oxford), A. Horesh (HUJI) report on behalf 
of a larger collaboration

We observed the optical transient ATLAS17aeu (Tonry et al., LVC GCN 
20382) located in the error region of LIGO/Virgo G268556 (LVC GCN 20364) 
with the AMI Large Array on 2017 Jan 07.04 UT. At 15.5 GHz, the flux 
density of the source is 336+/-20 uJy. We are currently monitoring this 
source.

We thank the AMI staff for scheduling this observation. Since this 
source is likely the afterglow of GRB 170105A (e.g. Kasliwal et al., LVC 
GCN 20393; Chambers et al., LVC GCN 20407), we will be updating the 
AMI-GRB database (http://4pisky.org/ami-grb/) with the measurements.


GRB_name: GRB170111A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20427
SUBJECT: GRB 170111A: MASTER-OAFA (Argentina) prompt OT observations
DATE:    17/01/11 14:51:27 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

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

V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina,
A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University

V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk

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

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

MASTER-OAFA  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in OAFA (Argentina) was pointed to the  GRB170111.02 17 sec after 
notice time 
and 63 sec after trigger time at 2017-01-11 00:34:31 UT. On our first (10s 
exposure)  set we haven't found optical transient  within SWIFT error-box 
(ra=20.7167 dec=-32.54 r=0.05).
The 5-sigma upper limit has been about 17.5 mag
The observations made on zenit distance = 25 degrees, galaxy latitude b = 
-81 degree.
The moon (97 % bright part) is 26 degrees above the horizon. The distance 
between  moon and  object is 84
Observations started at twilight.
The sun  altitude  is -9.8 degree.
The object can be observed till 2017-01-11 06:13:03.

  The 
message may be cited.


GRB_name: GRB161230A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20429
SUBJECT: GRB 161230A: POLAR Observation
DATE:    17/01/11 15:46:08 GMT
FROM:    Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>

R. Marcinkowski (PSI), H. Xiao (PSI) and W. Hajdas (PSI) report on behalf 
of the POLAR collaboration:

At 2016-12-30T12:16:07 UT(T0), during a routine on-ground search of data, 
POLAR detected the GRB 161230A, which was also observed by Fermi GBM 
(trigger # 504792972).

The POLAR light curve consists of 1 peak with duration (T90) of 
3.5 +/- 0.2 s measured from T0. The 0.2 s peak flux at T0 + 2.6 s 
is equal to 390 +/- 60 counts/sec. POLAR recorded 990 +/- 90 events from 
the burst.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_161230A_raw.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+161230A

Using the best location from the Fermi GBM, which is (J2000):
RA : 324.1 [deg]
Dec:  -9.0 [deg]
Err:   3.0 [deg]

the incident angle in the POLAR coordinate at T0 is:
Theta: 47.5 [deg]
Phi:  159.0 [deg]

The analysis results presented above are preliminary. Calibration of the 
instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter 
which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) 
on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub , 
http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170111A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20431
SUBJECT: GRB 170111A: Swift-XRT refined Analysis
DATE:    17/01/11 17:52:10 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.
Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU),
T.G.R. Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U.
Leicester) and report on behalf of the Swift-XRT team: report on
behalf of the Swift-XRT team:

We have analysed 6.2 ks of XRT data for GRB 170111A, from 96 s to 42.0
ks after the  BAT trigger. The data comprise 17 s in Windowed Timing
(WT) mode (the first 4 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The late-time light curve (from T0+5.1 ks) can be modelled with a
power-law decay with a decay index of alpha=0.72 (+/-0.18).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.68 (+0.17, -0.16). The
best-fitting absorption column is  3.6 (+0.9, -0.8) x 10^21 cm^-2, in
excess of the Galactic value of 3.1 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 4.6 x 10^-11 (6.1 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.6 (+0.9, -0.8) x 10^21 cm^-2
Galactic foreground: 3.1 x 10^20 cm^-2
Excess significance: 6.6 sigma
Photon index:      1.68 (+0.17, -0.16)

If the light curve continues to decay with a power-law decay index of
0.72, the count rate at T+24 hours will be 0.020 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.5 x
10^-13 (1.2 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/00731887.

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


GRB_name: GRB170111A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20432
SUBJECT: GRB 170111A: SMARTS optical/IR observations
DATE:    17/01/11 20:41:35 GMT
FROM:    Bethany Cobb at GWU  <bcobb@gwu.edu>

B. E. Cobb (GWU) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 170111A
(GCN 20423, Beardmore et al.) with a mid-exposure time of about
1 hour post-burst (2017-01-11 01:36 UT). Total summed exposure
times amounted to 36 minutes in I and 30 minutes in J.

No source is detected at the position of the X-ray
afterglow (GCN 20424, Evans et al.) in either I or J,
to an approximate 3-sigma limiting magnitude of I > 21.9
(calibrated using USNO-B1.0 stars).


GRB_name: GRB170111A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20433
SUBJECT: GRB 170111A: Swift-BAT refined analysis
DATE:    17/01/11 21:41:56 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester),

J. R. Cummings (CPI), N. Gehrels (GSFC), 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+739 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170111A (trigger #731887) (Beardmore, et al., GCN Circ. 20423). The BAT ground-calculated position is RA, Dec = 20.688, -32.541 deg which is RA(J2000) = 01h 22m 45.2s Dec(J2000) = -32d 32' 28.4" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%. The mask-weighted light curve shows a single, triangular shaped peak beginning at

T-20 sec, peaking at T+0 sec and ending at about T+10 sec. T90 (15-350 keV) is

29.9 +- 9.4 sec (estimated error including systematics).


The time-averaged spectrum from T-13.59 to T+25.32 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.64 +- 0.21.  The fluence in the 15-150 keV band is 8.1 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+2.09 sec in the 15-150 keV band
is 0.9 +- 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/731887/BA/


GRB_name: GRB170105A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20434
SUBJECT: LIGO/Virgo G268556: Early SWASP limits of ATLAS17aeu
DATE:    17/01/11 22:56:15 GMT
FROM:    Danny Steeghs at U of Warwick/GOTO  <D.T.H.Steeghs@warwick.ac.uk>

D.Steeghs, D.Pollacco, K.Ulaczyk, R.Cutter, R.West, A.Levan (U. Warwick), D.K. Galloway, E.Rol, E.Thrane (Monash U.), V.Dhillon, M.Dyer, S.Littlefair, E.Daw, J.Maund, J.Mullaney (U. Sheffield), G.Ramsay (Armagh O.), P.O'Brien, R.Starling (U. Leicester)

On behalf of the GOTO collaboration:

We have analysed our SWASP imaging related to G268556 (GCN #20364, spanning MJD 57758.043-57758.210) for evidence of ATLAS17aeu. Our first imaging window following G268556 spans 9-5 hours before the reported detections in Tonry et al. (GCN #20382) and end 1 hour before GRB170105A (GCN #20387). We do not find any evidence for an optical source at the ATLAS17aeu position. We combined 3 sets of images not affected by clouds and achieve the following 5-sigma upper limits:

MJD (mid):              g limit:    r limit:
57758.05948013   >17.7       >17.0
57758.09198558   >17.6       >16.9
57758.20992235   >17.0       >16.3

These photometric limits were derived by crossmatching field stars with the APASS survey. Considering the reported optical flux evolution of ATLAS17aeu (GCN #20382, #20393, #20397, #20407, #20416) and extrapolating to earlier times, we would have expected to detect ATLAS17aeu if its peak optical flux preceded GRB170105A. Our non-detections thus further corroborate associating ATLAS17aeu with the optical afterglow of GRB170105A.


GRB_name: GRB170111A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20435
SUBJECT: GRB170111A: REM optical/NIR observations
DATE:    17/01/11 23:19:54 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, D. Fugazza, S. Covino, A. Melandri (INAF/OAB) report on behalf of the REM team:

We observed the field of GRB 170111A (Beardmore et al., GCN 20423) with the 60-cm robotic 
telescope REM located at the La Silla Observatory (Chile). The observations started at 00:34:41 UT, 
73 seconds after the burst, and were carried out simultaneously in the g, r, i, z and H bands.

A preliminary photometry indicates that no source is detected at the X-ray afterglow position 
(Evans et al. GCN 20424) down to the following 3sigma limiting magnitudes:

r > 16.3 at T-T0 =  78s
H > 15.9 at T-T0 =  86s
r > 18.9 at T-T0 = 706s
H > 17.7 at T-T0 = 785s


Magnitudes are in the AB system and have been calibrated with respect to the 2MASS (H-band) 
and APASS (r-band) catalogues.


GRB_name: GRB170112A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20436
SUBJECT: GRB 170112A: Swift detection of a short burst
DATE:    17/01/12 02:17:42 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

B. Mingo (U Leicester), D. N. Burrows (PSU), C. Gronwall (PSU),
J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 02:02:00 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170112A (trigger=732188).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 15.231, -17.190 which is 
   RA(J2000) = 01h 00m 56s
   Dec(J2000) = -17d 11' 24"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 0.1 sec.  The peak count rate
was ~4000 counts/sec (15-350 keV), at ~0.1 sec after the trigger. 

The XRT began observing the field at 02:03:02.4 UT, 62.3 seconds after
the BAT trigger. No source was detected in 368 s of promptly downlinked
data. We are waiting for the full dataset to detect and localise the
XRT counterpart. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 66 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 25% of
the BAT 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
BAT 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
0.02. 

Burst Advocate for this burst is B. Mingo (bm188 AT 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: GRB170112A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20438
SUBJECT: GRB 170112A: REM optical/NIR observations
DATE:    17/01/12 12:23:09 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, D. Fugazza, S. Covino, A. Melandri (INAF/OAB) report on behalf of the REM team:

We observed the field of the short GRB 170112A (Mingo et al., GCN 20436) with the 60-cm robotic 
telescope REM located at the La Silla Observatory (Chile). The observations started at 02:02:55 UT, 
55 seconds after the burst, and were carried out simultaneously in the g, r, i, z and H bands.

A preliminary photometry of the first co-added images indicates that no obvious afterglow candidate 
is detected within the Swift/BAT error circle (Mingo et al. GCN 20436) down to the following 3sigma 
limiting magnitudes:

r > 18.8 at T-T0 = 763s
H > 18.0 at T-T0 = 730s


Magnitudes are in the AB system and have been calibrated with respect to the 2MASS (H-band) 
and APASS (r-band) catalogues.


GRB_name: GRB170112A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20439
SUBJECT: GRB 170112A: MASTER-OAFA (Argentina) early  optical observations
DATE:    17/01/12 13:50:39 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

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

V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, 
A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov 
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
O. Ershova
Irkutsk State University

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

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

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

MASTER   robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in OAFA was pointed to the  GRB170112A 18 sec after notice time 
and 25 sec after trigger time at 2017-01-12 02:02:31 UT. On our first (10s 
exposure)  set we haven't found optical transient  within SWIFT 
BAT error-box (Mingo et al., GCN 20436).
The 5-sigma upper limit has been about 16.04mag
The message may be cited.

The observations made on zenit distance = 54 degrees, galaxy latitude b = 
-79 degree.
The moon (100 % bright part) is 30 degrees above the horizon. The distance 
between  moon and  object is 97
The sun  altitude  is -23.9 degree.
The object can be observed till 2017-01-12 04:57:47

  The message may be cited.


GRB_name: GRB170112A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20440
SUBJECT: GRB 170112A: Swift-XRT observations
DATE:    17/01/12 14:12:03 GMT
FROM:    Beatriz Mingo at U of Leicester,XRT  <bm188@le.ac.uk>

A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB),
D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU), S.L.
Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester)  reports on behalf of the Swift-XRT team:

We have analysed 5.7 ks of Photon Counting (PC) mode XRT data for the
Swift/BAT-detected burst GRB 170112A, collected between T0+73 s and
T0+13.3 ks. 

No X-ray sources have been detected consistent with being within 296
arcsec of the Swift/BAT position. The 3-sigma upper limit in the field
ranges from ~0.002 to ~0.003 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 7.8e-14 to 1.1e-13 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).

Six uncatalogued sources were detected too far from the GRB position to
be likely afterglow candidates.

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/00732188.

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


GRB_name: GRB170111A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20441
SUBJECT: GRB 170111A: Swift/UVOT Upper Limits
DATE:    17/01/12 14:21:19 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M.H. Siegel (PSU) and A. P. Beardmore (U Leicester) 
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170111A
111 s after the BAT trigger (Beardmore et al., GCN Circ. 20423).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 20424)
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           111          261          147         >20.6
white              111          570          167         >20.7
v                  601          621           19         >18.0
b                  525          545           19         >19.6
u                  676          696           19         >19.3

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: GRB161219B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20442
SUBJECT: GRB 161219B: afterglow and SN2016jca optical observations
DATE:    17/01/12 17:57:30 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of GRB 161219B (Swift trigger 727541; D'Ai,GCN 20296) 
with AZT-33IK (Mondy), ZTSh (CrAO), AS-32 (AbAO) and Zeiss-1000 (SAO RAS) 
telescopes.  We obtained  unfiltered images (AbAO) and images in R-filter 
(other observatories). The optical source associated with the afterglow 
(D'Ai et al., GCN 20296; Kruehler et al., GCN 20299; Guidorzi et al., GCN 
20300; Martin-Carrillo et al., GCN 20305) and SN2016jca  (de Ugarte Postigo 
et al., GCN 20342; Chen et al., GCN 20380) is clearly visible in all our 
observations.

Preliminary light curve of the afterglow and  SN2016jca  can be found at
http://grb.rssi.ru/GRB161219B/GRB161219B_LC.png
Photometry is based on nearby USNO-B1.0 stars (R2) common for all images. 
Late time photometry is contaminated by  Pan-STARRS galaxy previously 
reported by Kruehler et al. (GCN 20299), and  also presented in USNO-B1.0. 
Apparent maximum brightness of the SN2016jca was observed at about 11 days 
after burst onset (R = 19.2 at 2016-12-30 (UT) 20:04:59) and actual SN peak 
could be slighter later,  between 11 and 14 days after burst.


GRB_name: GRB170112A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20443
SUBJECT: GRB 170112A: Swift-BAT refined analysis
DATE:    17/01/12 23:33:12 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), N. Gehrels (GSFC),
H. A. Krimm (NSF/USRA), C. B. Markwardt (GSFC),
J. P. Norris (BSU), 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 170112A (trigger #732188)
(Mingo, et al., GCN Circ. 20436).  The BAT ground-calculated position is
RA, Dec = 15.232, -17.233 deg which is
   RA(J2000)  =  01h 00m 55.7s
   Dec(J2000) = -17d 13' 57.9"
with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a single-peaked structure that starts
and peaks at ~T0, and ends at ~T+0.06 s. T90 (15-350 keV) is 0.06 +- 0.02 sec
(estimated error including systematics).

The time-averaged spectrum from T-0.00 to T+0.06 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.17 +- 0.34.  The fluence in the 15-150 keV band is 1.3 +- 0.4 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.47 sec in the 15-150 keV band
is 0.3 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

Using a 16-ms binned light curve, the lag analysis finds a lag of 19 (-17, +36) ms for
the 100-350 keV to 25-50 keV, -7 (-12, +14) ms for the 50-100 keV to 15-25 keV
band, and 0 (-7, +7) ms for the 50-100 keV to 25-50 keV. These values are
consistent with those of a short GRB. Moreover, no extended emission are found.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/732188/BA/


GRB_name: GRB170112A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20444
SUBJECT: GRB 170112A: RATIR Optical and NIR Observations
DATE:    17/01/12 23:48:48 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), Neil Gehrels (GSFC),
Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU),
and Vicki Toy (UMD) report:

We observed the field of the short GRB 170112A (Mingo, et al., GCN 20436)
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 2017/01 12.15 to 2017/01 12.21 UTC (1.58 to
2.95 hours after the BAT trigger), obtaining a total of 0.76 hours
exposure in the r and i bands and 0.32 hours exposure in the Z and Y bands.

Comparison to the DSS reveals no obvious new source brighter than about
magnitude 19. However our data are deeper and we cannot yet exclude a 
fainter
counterpart.

Further observations to check for variability are planned.

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


GRB_name: GRB170113A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20446
SUBJECT: GRB 170113A: Swift detection of a burst with an optical counterpart
DATE:    17/01/13 10:15:42 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

P.A. Evans (U Leicester), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), H. A. Krimm (CRESST/NSF/USRA),
B. Mingo (U Leicester), P. T. O'Brien (U Leicester),
B. Sbarufatti (INAF-OAB/PSU), R. L. C. Starling (U Leicester) and
E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift Team:

At 10:04:05 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170113A (trigger=732526).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 61.648, -71.925, which is 
   RA(J2000)  =  04h 06m 36s
   Dec(J2000) = -71d 55' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multiple peaks
with a duration of about 30 sec.  The peak count rate
was ~2100 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 10:05:04.2 UT, 58.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 61.73063, -71.94326 which
is equivalent to:
   RA(J2000)  = 04h 06m 55.35s
   Dec(J2000) = -71d 56' 35.7"
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This
location is 113 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 1.01e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 67 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 04:06:55.85 =  61.73272
  DEC(J2000) = -71:56:34.5  = -71.94293
with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.7
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.39 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.11. 

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: GRB161217A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20447
SUBJECT: GRB 161217A: 15 GHz upper limits from AMI
DATE:    17/01/13 12:17:33 GMT
FROM:    Kunal Mooley at Oxford U  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson 
(Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. 
Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. 
Grainge, A. Scaife (Manchester)

The AMI Large Array triggered on the Swift alert for GRB 161217A (D'Elia 
et al., GCN 20276) as part of the 4pisky program, and follow up 
observations were obtained up to 10 days post-burst. Our observations at 
15 GHz on 2016 Dec 23.16, Dec 24.15 and Dec 27.17 (UT) do not reveal any 
radio source at the XRT location (Osborne et al., GCN 20278), with 
3sigma upper limits of 84 uJy, 66 uJy and 77 uJy respectively.

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/.


GRB_name: GRB170113A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20448
SUBJECT: GRB 170113A: LCO Sutherland observations
DATE:    17/01/13 12:18:14 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

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

We observed Swift GRB 170113A (Evans et al. GCN 20446) on January 13, 
from 10:53:32 UT (50 minutes since the GRB) with 1-m LCO telescope units 
in Sutherland with SDSS r and i filters. We clearly detect the 
Swift-UVOT optical counterpart with the following values:

Mid Time      Exposure       Filter       Magnitude (AB)
(hours)           (s)
-------------------------------------------------------
0.89             5x60         SDSS-R      19.06 +- 0.11
0.89             5x60         SDSS-I      18.84 +- 0.08
-------------------------------------------------------

as calibrated against nearby USNO-UCAC4 sources.


GRB_name: GRB170101A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20449
SUBJECT: GRB 170101A: 15 GHz upper limits from AMI
DATE:    17/01/13 12:19:27 GMT
FROM:    Kunal Mooley at Oxford U  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender 
(Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. 
Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, 
P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester)

The AMI Large Array triggered on the Swift alert for GRB 170101A (Lien 
et al., GCN 20349) as part of the 4pisky program, and follow up 
observations were obtained up to 10 days post-burst. Our observations at 
15 GHz on 2016 Jan 03.33, Jan 04.45, Jan 05.46 and Jan 07.45 (UT) do not 
reveal any radio source in the BAT error circle (Barthelmy et al., GCN 
20353), with 3sigma upper limits of 105 uJy, 132 uJy, 78 uJy and 120 uJy 
respectively.

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/.


GRB_name: GRB170113A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20450
SUBJECT: GRB 170113A: Enhanced Swift-XRT position
DATE:    17/01/13 15:27:03 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 1363 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 170113A, 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 = 61.73332, -71.94279 which is equivalent
to:

RA (J2000): 04h 06m 56.00s
Dec (J2000): -71d 56' 34.0"

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: GRB170112A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20451
SUBJECT: GRB 170112A: Swift/UVOT Upper Limits
DATE:    17/01/13 16:17:42 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) and B. Mingo (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170112A
279 s after the BAT trigger (Mingo et al., GCN Circ. 20436).
No optical afterglow consistent with the BAT position
(Lien et al., GCN Circ. 20443) 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           856         1006          147         >20.5
u_FC               279          529          246         >19.9
white              856         6361          344         >21.0
v                 5136         6771          393         >19.2
b                 5956         6156          197         >20.0
u                  279         7338          593         >20.4
w1                5546         7180          393         >19.9
m2                5341         6975          393         >20.2
w2                6366         6566          197         >20.0

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: GRB170113A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20452
SUBJECT: GRB 170113A: Fermi GBM observations
DATE:    17/01/13 18:39:20 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 10:04:10.11 UT on 13 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170113A (trigger 505994655 / 170113420).
which was also detected by the Swift/BAT (Evans et al., GCN 20446).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger
time is 145 degrees.

The GBM light curve shows a single pulse
with a duration (T90) of about 49 s (50-300 keV).
The time-averaged spectrum from T0-10 s to T0+47 s is
adequately fit by a simple power law function with
index -2.05 +/- 0.08.

The event fluence (10-1000 keV) in this time interval is
(3.8 +/- 0.4)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+4.5 s in the 10-1000 keV band
is 2.9 +/- 0.4 ph/s/cm^2.

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


GRB_name: GRB161214B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20453
SUBJECT: GRB 161214B: 15 GHz upper limits from AMI
DATE:    17/01/13 18:59:15 GMT
FROM:    Kunal Mooley at Oxford U  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson 
(Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. 
Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. 
Grainge, A. Scaife (Manchester)

The AMI Large Array robotically triggered on the Swift alert for GRB 
161214B (D'Avanzo et al., GCN 20257) as part of the 4pisky program, and 
subsequent follow up observations were obtained up to 10 days 
post-burst. Our observations at 15 GHz on 2016 Dec 14.76, Dec 16.76, Dec 
18.75 and Dec 21.74 (UT) do not reveal any radio source at the XRT 
location (Goad et al., GCN 20264), with 3sigma upper limits of 96 uJy, 
87 uJy, 85 uJy and 104 uJy respectively.

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/.


GRB_name: GRB170113A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20454
SUBJECT: GRB 170113A: Swift-XRT refined Analysis
DATE:    17/01/13 19:00:37 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 8.0 ks of XRT data for GRB 170113A, from 50 s to 19.1
ks after the  BAT trigger. The data comprise 243 s in Windowed Timing
(WT) mode (the first 7 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The late-time light curve (from T0+5.2 ks) can be modelled with a
power-law decay with a decay index of alpha=1.14 (+/-0.10).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.88 (+/-0.07). The
best-fitting absorption column is  1.82 (+0.26, -0.24) x 10^21 cm^-2,
in excess of the Galactic value of 1.1 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.77 (+/-0.08) and a
best-fitting absorption column of 1.43 (+0.26, -0.25) x 10^21 cm^-2.
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:
Total column:      1.43 (+0.26, -0.25) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: 2.3 sigma
Photon index:      1.77 (+/-0.08)

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 0.030 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-12 (1.4 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/00732526.

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


GRB_name: GRB170113A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20455
SUBJECT: GRB 170113A: Swift/UVOT Observations
DATE:    17/01/13 20:40:06 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) 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 170113A
68 s after the BAT trigger (Evans et al., GCN Circ. 20446).
A fading source consistent with the XRT position
(Goad et al. GCN Circ. 20450)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  04:06:55.86 =  61.73276 (deg.)
   Dec (J2000) = -71:56:34.9  = -71.94302 (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 (fc)          68          217          147         18.27+-0.06
white              560         1009          186         19.56+-0.11
white             1163         1875           97         19.65+-0.17
white             6392         6592          196         20.64+-0.26
v                  609         1751          136         19.09+-0.36
v                 5367         7002          393         >19.49
b                  535         1850          136         19.33+-0.19
b                 6188         6388          196         >20.39
u (fc)             280          530          245         18.76+-0.13
u                  683         1825          116         19.33+-0.27
u                 5983         7615          390         >20.44
uvw1               659         1801          136         >19.38
uvm2               634         1776          136         >19.12
uvw2               585         1727          136         >19.42

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.11 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB170113A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20456
SUBJECT: GRB 170113A: Swift-BAT refined analysis
DATE:    17/01/14 03:03:42 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), N. Gehrels (GSFC),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
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 170113A (trigger #732526)
(Evans et al., GCN Circ. 20446).  The BAT ground-calculated position is
RA, Dec = 61.735, -71.933 deg which is
   RA(J2000)  =  04h 06m 56.5s
   Dec(J2000) = -71d 55' 58.0"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T0 and ends at ~T+25 s. The main peak occurs at ~T+2 s. T90 (15-350 keV)
is 20.66 +- 4.44 sec (estimated error including systematics).

The time-averaged spectrum from T-0.61 to T+23.84 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.75 +- 0.59,
and Epeak of 73.3 +- 33.6 keV (chi squared 72.24 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 6.7 +- 0.7 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+1.63 sec in the 15-150 keV band is
1.1 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.57 +- 0.13 (chi squared 79.06 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/732526/BA/


GRB_name: GRB170113A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20457
SUBJECT: GRB 170113A: GROND afterglow observations
DATE:    17/01/14 08:00:28 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T. Kruehler (MPE Garching) reports:

I observed the field of GRB 170113A (Swift trigger 732526; Evans
et al. GCN #20446) simultaneously in g'r'i'z'JHK with GROND
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG
telescope at the ESO La Silla Observatory (Chile).

Observations started at 01:34 UT on 2017-01-14, 15.5 hr after the GRB
trigger. Based on combined images with 22 min of total exposure time
in g'r'i'z' and 18 min in JHK at a mid-time of 01:50 UT on 2017-01-14,
I derive the following preliminary magnitudes and upper limits
(all in the AB system) for the optical/NIR afterglow (Evans et al.,
GCN 20446, Guidorzi et al., GCN 20448, Siegel et al., GCN 20455):

g' = 22.3 +- 0.1 mag
r' = 22.0 +- 0.1 mag
i' = 21.8 +- 0.1 mag
z' = 21.6 +- 0.1 mag
J = 20.9 +- 0.2 mag
H = 20.8 +- 0.3 mag
K > 19.0 mag

Given magnitudes are calibrated against GROND zeropoints and 2MASS
field stars and are not corrected for the expected Galactic
foreground extinction corresponding to a reddening of
E_(B-V)=0.099 mag in the direction of the burst (Schlafly &
Finkbeiner 2011).

I acknowledge excellent help in obtaining these data from the
supporting astronomer on La Silla, Regis Lachaume.


GRB_name: GRB170113A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20458
SUBJECT: GRB 170113A: VLT/X-shooter redshift
DATE:    17/01/14 17:33:08 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu (NAOC/CAS), K. E. Heintz (Univ. Iceland and DARK/NBI), D. 
Malesani, J. P. U. Fynbo (DARK/NBI) report on behalf of a larger 
collaboration:

We observed the optical afterglow of GRB 170113A (Evans et al. GCN 
20446; Veres et al., GCN 20452; Guidorzi et al., GCN 20448) with the ESO 
Very Large Telescope UT 2 (Kueyen) equipped with the X-shooter 
spectrograph, covering the wavelength range 3500-20000 AA. Spectroscopy 
started at 01:17:53 UT on 2017-01-14 (i.e., 15.23 hr after the GRB) and 
consisted of 4 exposures of 1200 s each.

 From the acquisition image prior to the spectroscopy, the afterglow has 
m(r)~21.7 mag, calibrated with nearby USNO B1 stars.

The spectrum exhibits several absorption features such as Si II, Fe II, 
Mg II, as well as emission features such as [O II] doublet, Hbeta, 
[OIII] doublet, all at a common redshift of z=1.968. We conclude this is 
the redshift of the GRB.

We acknowledge the excellent support from the ESO staff, particularly 
Luca Sbordone, Laura Magrini, Cedric Ledoux, and Elizabeth (Liz) 
Bartlett, in obtaining these observations.


GRB_name: GRB170112B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20460
SUBJECT: GRB 170112B: POLAR observation
DATE:    17/01/15 06:28:51 GMT
FROM:    Wen Xing at POLAR  <wenxing@ihep.ac.cn>

Xing Wen (IHEP), Yi Zhao (IHEP) and Hancheng Li (IHEP)
report on behalf of the POLAR collaboration:

At 2017-01-12T23:16:09.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170112B, 
which was also detected by the 
Fermi/GBM (trigger 505955774/170112970).

The POLAR light curve consists of a single peak,
with a duration (T90) of 13.54 s measured from T0-0.06 s.
The 1-s peak rate measured from T0+0.00 s is 509.0 cnts/s.
The total counts is about 1970 cnts. The above measurements
are in the energy range of about 80-500 keV.

LC_URL:
http://polar.ihep.ac.cn/grb/2017/01/GRB170112B/lc/POLAR_lc_grb170112B.jpg

All analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV)
on-board the Chinese space laboratory Tiangong-2 launched on
Sep 15,2016. More information about POLAR can be found at 
http://polar.ihep.ac.cn/en/ , http://isdc.unige.ch/polar/
and http://polar.psi.ch/pub/.


GRB_name: GRB170114A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20461
SUBJECT: GRB 170114A: Fermi GBM detection
DATE:    17/01/15 16:21:45 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

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

"At 22:01:09.50 UT on 14 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170114A (trigger 506124074 / 170114917).


The on-ground calculated location, using the GBM trigger
data, is RA = 12.08, DEC = -12.55 (J2000 degrees,
equivalent to 0 h 48 m, -12 d 33 '), with an uncertainty
of 1 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 80 degrees.

The GBM light curve shows a single pulse
with a duration (T90) of about 14.6 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+17.9 s is
best fit by a Band function with Epeak = 237 +/- 19 keV,
alpha = -0.84 +/- 0.04, and beta = -1.99 +/- 0.06.

The event fluence (10-1000 keV) in this time interval is
(1.93 +/- 0.03)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.7 s in the 10-1000 keV band
is 25.0 +/- 0.4 ph/s/cm^2.


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


GRB_name: GRB170115A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20462
SUBJECT: GRB 170115A: Swift detection of a burst
DATE:    17/01/15 21:15:39 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

K. L. Page (U Leicester), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
A. Cholden-Brown (PSU), C. Gronwall (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/NSF/USRA), F. E. Marshall (NASA/GSFC) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 20:50:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170115A (trigger=733103).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 332.154, +13.781 which is 
   RA(J2000) = 22h 08m 37s
   Dec(J2000) = +13d 46' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve is only immediately
available until T+8 seconds due to a telemetry gap, showing a
rise to a maximum rate of ~800 counts/s at the end of that period. 

The XRT began observing the field at 20:51:39.5 UT, 91.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 332.1390, 13.7283 which is equivalent to:
   RA(J2000)  = +22h 08m 33.36s
   Dec(J2000) = +13d 43' 41.9"
with an uncertainty of 6.3 arcseconds (radius, 90% containment). This
location is 196 arcseconds from the BAT onboard position, outside the
BAT error circle. 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 5.14e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 99 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
0.07. 

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: GRB170115B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20463
SUBJECT: GRB 170115B: Fermi GBM detection
DATE:    17/01/16 00:02:09 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

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

"At 17:49:14.03 UT on 15 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170115B (trigger 506195359 / 170115743).

The on-ground calculated location, using the GBM trigger
data, is RA = 189.03, DEC = -51.55, with an uncertainty
of 1.43 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 32 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 44 s (50-300 keV).
The time-averaged spectrum from T0-0.6 s to T0+42.4 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.89 +/- 0.01 and
the cutoff energy, parameterized as Epeak, is 1656 +/- 81 keV.
A Band function fits the spectrum equally well
with Epeak= 1563 +/- 106 keV, alpha = -0.88 +/- 0.01
and beta = -2.47 +/- 0.36.

The event fluence (10-1000 keV) in this time interval is
(5.98 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.77 s in the 10-1000 keV band
is 15.1 +/- 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: GRB170115B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20464
SUBJECT: GRB 170115B: Fermi-LAT detection
DATE:    17/01/16 00:33:21 GMT
FROM:    Julie McEnery at NASA/GSFC  <julie.e.mcenery@nasa.gov>

J.E. McEnery, J. Racusin (NASA/GSFC) and E. Bissaldi (Politecnico & INFN 
Bari)
report on behalf of the Fermi-LAT team:

At 17:49:14.03 on January 15, 2017 Fermi-LAT detected high-energy
emission from GRB 170115B, which was also detected by
Fermi-GBM (GCNC 20463).

The best LAT on-ground location is found to be

RA, Dec = 189.12, -46.85 (J2000)
with an error radius of 0.26 deg (90 % containment, statistical error 
only).

This was ~40 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 and temporally correlated with the trigger with high 
significance.

A Swift ToO has been requested for this burst.

The Fermi-LAT point of contact for this burst is
Elisabetta Bissaldi (elisabetta.bissaldi@ba.infn.it).

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: GRB170115A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20465
SUBJECT: GRB 170115A: Enhanced Swift-XRT position
DATE:    17/01/16 03:35:10 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 615 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 170115A, 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 = 332.13844, +13.72836 which is equivalent
to:

RA (J2000): 22h 08m 33.23s
Dec (J2000): +13d 43' 42.1"

with an uncertainty of 3.7 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: GRB170115B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20466
SUBJECT: GRB 170115B:  AstroSat  CZTI (Veto)  detection
DATE:    17/01/16 07:35:52 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

V. Sharma, V. Bhalerao and 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 clear detection of GRB170115B (Fermi detection: R. Hamburg et al., GCN Circ. 20463) in the 40-200 keV energy range. The light curve shows multiple peaks structure with main peak at 17:49:14.03 UT, coincident with Fermi trigger. The measured peak count rate is 618.7 counts/sec above the background in combined data of four quadrants, with a total of 4196.9 counts. The local mean background count rate was 372.3 counts/sec. Using cumulative rates, we measure a T90 of 15.3 secs.

It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection 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: GRB170115B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20467
SUBJECT: GRB 170115B: Tiled Swift observations
DATE:    17/01/16 09:04:15 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 series of observations, tiled on the sky, of the
Fermi/LAT GRB 170115B. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00062

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: GRB170114A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20468
SUBJECT: GRB 170114A: POLAR Observation
DATE:    17/01/16 09:35:44 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

H.L. Xiao (PSI) , W. Hajdas (PSI) and R. Marcinkowski (PSI)   report on behalf of the POLAR collaboration:
At 2017-01-14 22:01:10.0 UT(T0), during a routine on-ground search of data, POLAR detected GRB 170114A,
which was also observed by Fermi GBM (trigger #506124074) .

The POLAR light curve consists of one peak with duration (T90) of 8.0 +/- 0.5 s measured from T0.
The 0.5 s peak flux at T0 + 2.8 s  is equal to 7660 +/- 120 counts/sec.
POLAR recorded 26800 events from the burst.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170114A_raw.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170114A

Using the best location from Fermi GBM, which is (J2000):
RA : 12.1 [deg]
Dec: -12.6 [deg]
the incident angle in the POLAR coordinate at T0 is:
Theta: 26.4 [deg]
Phi: 4.9 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.
POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
 http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170114B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20469
SUBJECT: GRB 170114B: POLAR Observation
DATE:    17/01/16 09:45:23 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

H.L. Xiao (PSI) , W. Hajdas (PSI) and R. Marcinkowski (PSI) report on behalf of the POLAR collaboration:
At 2017-01-14 19:59:12.0 UT(T0), during a routine on-ground search of data, POLAR detected GRB 170114B,
which was also observed by  Fermi GBM (trigger #506116757) and Konus-Wind at 71956.53s UT (19:59:16.53).


The POLAR light curve consists of one peak with duration (T90) of 12.0 +/- 1.0 s measured from T0.
Ten of 25 modules of POLAR recorded 5240 events from the burst.
The 1.0 s peak flux at T0 + 3.5 s  is equal to 750 +/- 60 counts/sec.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170114B_10of25.png
     or raw LC: http://polar.psi.ch/pub/lc.php?event=GRB+170114B

Using the best location from Fermi GBM, which is (J2000):
RA : 137.9 [deg]
Dec: -28.5 [deg]
the incident angle in the POLAR coordinate at T0 is:
Theta: 102.0 [deg]
Phi: 140.6 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.
POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
 http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170115A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20470
SUBJECT: GRB 170115A: Swift-XRT refined Analysis
DATE:    17/01/16 15:12:26 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

We have analysed 3.9 ks of XRT data for GRB 170115A, from 82 s to 40.4
ks after the  BAT trigger. The data comprise 224 s in Windowed Timing
(WT) mode (the first 7 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.54 (+0.06, -0.05).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.22 (+0.17, -0.16). The
best-fitting absorption column is  1.3 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 6.1 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 2.9 x 10^-11 (4.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      1.3 (+0.5, -0.4) x 10^21 cm^-2
Galactic foreground: 6.1 x 10^20 cm^-2
Excess significance: 2.6 sigma
Photon index:      2.22 (+0.17, -0.16)

If the light curve continues to decay with a power-law decay index of
1.54, the count rate at T+24 hours will be 4.1 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-14 (1.7 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/00733103.

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


GRB_name: GRB170115A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20471
SUBJECT: GRB 170115A: Swift-BAT refined analysis
DATE:    17/01/16 19:22:36 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),

N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), K. L. Page (U Leicester),  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+450 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170115A (trigger #733103) (Page, et al., GCN Circ. 20462). The BAT ground-calculated position is RA, Dec = 332.145, 13.750 deg which is RA(J2000) = 22h 08m 34.9s Dec(J2000) = +13d 45' 01.6" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single FRED-shaped peak, starting at T+0,

peaking at around T+10 sec and decaying to background by around T+50 sec.  The

spacecraft entered the SAA at around T+400 seconds, so there is no data after

this time. T90 (15-350 keV) is 48.0 +- 22.6 sec (estimated error including

systematics).

The time-averaged spectrum from T-7.6 to T+40.4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.45 +- 0.25.  The fluence in the 15-150 keV band is 4.7 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+15.94 sec in the 15-150 keV band
is 0.2 +- 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/733103/BA/


GRB_name: GRB170112A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20472
SUBJECT: GRB 170112A : AbAO optical observations
DATE:    17/01/16 19:35:42 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI), R. Inasaridze (AbAO), A. Volnova 
(IKI),  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 short GRB 170112A (Mingo  et al., GCN 20436) 
with AS-32 (0.7m) telescope of Abastumani Observatory  on Jan., 12 (UT) 
15:35:30. We obtained several unfiltered images of the field. Within BAT 
error circle (Mingo  et al., GCN 2043) we found the source which is 
absent in USNO-B1.0 at coordinates (J2000) 01:00:49.80  -17:10:17.5 with 
uncertainty of 0.9 arcsec in both coordinates.
Finding chart can be found at 
http://grb.rssi.ru/GRB170112A/GRB170112A_AAO_170112.png
The source is  barely visible in DSS2 (R). Preliminary photometry  of 
the source is following

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

2017-01-12  15:35:30   0.61446   CR     47*60  17.50 0.25  17.7

Photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id  R2
0727-0016063 14.46
0728-0016765 15.73
0728-0016759 12.78
0728-0016802 14.33

The source above does not match any source of XRT observation (D'Ai   et 
al., GCN 20440), see also http://www.swift.ac.uk/ToO_GRBs/00732188/


GRB_name: GRB170115B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20474
SUBJECT: GRB 170115B: AGILE detection
DATE:    17/01/16 22:48:39 GMT
FROM:    Francesco Verrecchia at ASDC  <francesco.verrecchia@asdc.asi.it>

F. Verrecchia (ASDC and INAF/OAR), A. Ursi (INAF/IAPS), F. Lucarelli (ASDC
and INAF/OAR), F. Longo (Univ. Trieste and INFN Trieste), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata) report:

AGILE detected the long GRB 170115B, reported by Fermi-GBM (Hamburg et al.
GCN #20463) and Fermi-LAT (McEnery et al. GCN #20464), at favourable
off-axis angles between 0 and 30 deg. The AGILE-GRID detected the burst at
about 4-sigma above 30 MeV with an extended gamma-ray emission lasting
about 60 sec.

The AGILE MiniCaLorimeter (MCAL), sensitive in the energy range from 400 keV
to 100 MeV, detected this burst that triggered the on-board sub-millisecond
timescale logic. The MCAL light curve shows multiple peaks, from T0 until
the end of the acquisition at T0 + 10.5 s. Three main peaks are evident
during the first 2.5 sec following T0. During this time interval, the total
number of counts is ~5500 for a background rate of 580 counts/s.

This measurement was obtained with AGILE observing a large portion of the
sky in spinning mode.


GRB_name: GRB170115B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20475
SUBJECT: IPN Triangulation of GRB  170115B
DATE:    17/01/17 08:43:56 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 170115B (Fermi GBM detection: Hamburg et al.,
GCN 20463) has been detected by Fermi(GBM), Konus-Wind, INTEGRAL
(SPI-ACS), and Mars-Odyssey(HEND), so far, at about 64154 s UT (17:49:14).

We have triangulated it to a Konus-HEND annulus centered at
RA(2000)=171.562 deg (11h 26m 15s)  Dec(2000)=+4.317 deg (+4d 19' 01"),
whose radius is 53.310 +/- 0.093 deg (3 sigma).

This annulus intersects the Fermi-LAT 90% CL error circle
(McEnery et al., GCN Circ. 20464) to form an error box
whose area is about 2 times smaller than that of the LAT
error circle, and whose corners are:
-----------------------------------------------
   RA(2000), deg       Dec(2000), deg
-----------------------------------------------
    Corners:
    189.426           -46.696
    189.079           -46.592
    188.888           -46.644
    188.743           -46.884
-----------------------------------------------
The box area is about 260 sq. arcmin.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB170115_T64155/IPN/

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


GRB_name: GRB170115B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20476
SUBJECT: Konus-Wind observation of GRB 170115B
DATE:    17/01/17 09:01:14 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 170115B (Fermi-GBM detection: Hamburg & Meegan, GCN 20463;
Fermi-LAT detection: McEnery et al., GCN 20464;
AstroSat CZTI observation: Sharma et al., GCN 20466;
POLAR observation: Xiao et al., GCN 20469;
AGILE detection:  Verrecchia et al., GCN 20474;
IPN triangulation: Hurley et al., GCN 20475)
triggered Konus-Wind at T0=64155.241 s UT (17:49:15.241).

The light curve shows a bright, hard, multi-peaked pulse
followed by a weaker emission; the total duration of the burst is ~50 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst had a fluence of
(1.26 Â± 0.12)x10^-4 erg/cm2 and a 64-ms peak energy flux,
measured from T0+0.512, of (3.1 Â± 0.2)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+38.144 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 = -0.86 (-0.06,+0.06),
the high energy photon index beta = -2.49 (-0.90,+0.31),
the peak energy Ep = 1114 (-156,+180) keV,
chi2 = 94/97 dof.

The spectrum near the peak count rate (measured from T0 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 = -0.61 (-0.08,+0.08),
the high energy photon index beta = -2.59 (-1.30,+0.32),
the peak energy Ep = 1278 (-175,+223) keV,
chi2 = 94/97 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170115_T64155/

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


GRB_name: GRB170115B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20477
SUBJECT: GRB 170115B: Swift-XRT observations
DATE:    17/01/17 09:15:10 GMT
FROM:    Sarah Gibson at U.of Leicester  <slg44@leicester.ac.uk>

P. D'Avanzo (INAF-OAB), S. J. LaPorte (PSU), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), K.L. Page (U. Leicester), B. Mingo (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 170115B in a series of observations tiled
on the sky. The total exposure time is 4.7 ks, distributed over 5
tiles; the maximum exposure at a single sky location was 3.3 ks. The
data were collected between T0+54.5 ks and T0+66.3 ks, and are entirely
in Photon Counting (PC) mode. 

One uncatalogued X-ray source has been detected, 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):  189.0597  =  12:36:14.34
  Dec (J2000): -46.8311  =  -46:49:52.1
  Error: 6.5 arcsec (radius, 90% conf.)
  Count-rate: 0.0117 +/- 0.0029 ct s^-1   
  Distance: 163 arcsec from Fermi/LAT position.

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00062.

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


GRB_name: GRB170115A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20478
SUBJECT: GRB 170115A: Swift/UVOT Upper Limits
DATE:    17/01/17 16:39:49 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) 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 170115A
100 s after the BAT trigger (Page et al., GCN Circ. 20462).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al. GCN Circ. 20465) 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)         100          250          147         >20.40
white             4804         6335          291         >20.66
v                 5214        35195          816         >19.67
b                 4599        40415          838         >20.68
u (fc)             260          328           67         >18.98
u                 5829         6029          196         >19.65
uvw1              5624         5824          196         >19.32
uvm2              5419         5619          196         >19.37
uvw2              5009        11435          992         >20.69

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.07 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB170115A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20479
SUBJECT: GRB 170115A : AbAO optical upper limit
DATE:    17/01/17 17:16:40 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI), R. Inasaridze (AbAO), A. Volnova 
(IKI),  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 the GRB 170115A (Page et al., GCN Circ. 20462) 
with AS-32 (0.7m) telescope of Abastumani Observatory  on Jan., 16 (UT) 
14:57:24. We obtained several unfiltered images of the field. No source 
is found within enhanced XRT position (Osborne et al. GCN Circ. 20465).
Preliminary photometry  of the field is following

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

2017-01-16  14:57:24   0.78450   CR     49*60  n/d   n/d 22.5

Photometry is based on nearby SDSS_DR9 stars
SDSS_DR9_id R(Lupton)
J220832.66+134330.8 18.50
J220831.22+134259.5 18.59
J220831.94+134225.7 18.57
J220847.68+134539.9 16.60
J220833.30+133952.6 16.32
J220835.19+134539.0 17.66
J220837.56+134537.8 15.86


GRB_name: GRB170117A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20480
SUBJECT: Swift Trigger #733426: possible detection of a burst or transient
DATE:    17/01/17 23:14:38 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

Swift Trigger #733426: possible detection of a burst or transient

D. M. Palmer (LANL) 
reports on behalf of the Swift team:

At 2017-01-17 03:37:48 UT, the Swift Burst Alert Telescope (BAT)
took a series of waiting mode images that showed peaks of marginal
significance, recognized in further ground analysis as a possible
unknown source or GRB (Triggers #733426-#733430, GRB 170117A).
The most significant image showed a peak at a BAT on-board calculated 
location RA, Dec 61.589, +21.743 which is 
  RA(J2000) = 04h 06m 21s
  Dec(J2000) = +21d 44' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The onboard images show a maximum flux
level over the T+240 s to T+304 s time interval, while the maximum
significance is found over the T+0 s to T+672 s image covering
the entire pointing interval.

Due to the marginal significance (maximum 6.5 sigma) of the
image peak detection, the reality of this detection is uncertain.
Its several-minute or longer duration is longer than usual for a GRB,
but its distance from the Galactic plane (l,b ~ 172,-22) would
be unusual for a Galactic transient.  Therefore, both the
reality and category of this source are uncertain.

A Swift Target of Opportunity follow-up has been requested. 


GRB_name: GRB170117A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20481
SUBJECT: GRB 170117A: Swift ToO observations
DATE:    17/01/18 02:56:18 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 170117A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020728

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: GRB170117A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20482
SUBJECT: GRB 170117A: Swift-XRT observations
DATE:    17/01/18 21:43:57 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), B.
Mingo (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC),
A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) 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 170117A, collecting 2.9 ks of Photon
Counting (PC) mode data between T0+86.3 ks and T0+116.0 ks. 

No X-ray sources have been detected consistent with being within 296
arcsec of the Swift/BAT position. The 3-sigma upper limit in the field
ranges from ~0.003 to ~0.004 ct s^-1, corresponding to a 0.3-10 keV
observed flux of 1.3e-13 to 1.8e-13 erg cm^-2 s^-1 (assuming a typical
GRB spectrum).

An uncatalogued was detected, however this was too far from the GRB
position to be the afterglow.

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/00020728.

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


GRB_name: GRB170115B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20483
SUBJECT: GRB 170115B: CALET Gamma-Ray Burst Monitor detection
DATE:    17/01/19 04:50:32 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, Y. Kawakubo,
M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
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), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 170115B (Hamburg et al., GCN Circ. 20463; McEnery et al.,
GCN Circ. 20464; Sharma et al., GCN Circ. 20466; Xiao et al., GCN Circ. 20469;
Verrecchia et al., GCN Circ. 20474; Frederiks et al., GCN Circ. 20476) triggered
the CALET Gamma-ray Burst Monitor (CGBM) at 17:49:12.63 on 15 January 2017.
The burst signal was only seen by the SGM instrument.

The light curve of the SGM shows several overlapping pulses starting at T0,
peaking at T+3 sec and ending at T+15 sec.  The T90 duration measured by
the SGM data is 12.0 +- 0.9 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight/1168537525/

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


GRB_name: GRB170117A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20484
SUBJECT: GRB 170117A: Swift/UVOT Upper Limits
DATE:    17/01/19 12:38:02 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 170117A
86251 s after the BAT trigger (Palmer, GCN Circ. 20480).
No optical afterglow consistent with the BAT position given in that 
circular is detected in the initial UVOT exposures.
The preliminary 3-sigma upper limit using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial summed 
exposures is:

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

white            86251       116034         2654         >22.0

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.35 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB170120A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20500
SUBJECT: GRB 170120A: POLAR Observation
DATE:    17/01/22 22:09:02 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

H.L. Xiao (PSI) , W. Hajdas (PSI) and R. Marcinkowski (PSI) report on behalf of the POLAR collaboration:

At 2017-01-20 11:18:30.0 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 170120A,
which was also observed by Fermi GBM (trigger # 506603916).

The POLAR light curve consists of multiple peaks with duration (T90) of 16.0 +/- 1.0 s measured from T0.
The 1.0 s peak flux at T0 + 7.5 s  is equal to 600 +/- 70 counts/sec.
POLAR recorded 4970 events from the burst.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170120A_raw.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170120A

Using the best location from Fermi GBM, which is (J2000):
RA : 262.83 [deg]
Dec: 12.57 [deg]
the incident angle in the POLAR coordinate at T0 is:
Theta: 60.7 [deg]
Phi: 201.9 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.
POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
 http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170121A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20501
SUBJECT: GRB 170121A: POLAR Observation
DATE:    17/01/22 22:11:04 GMT
FROM:    Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>

H.L. Xiao (PSI) , W. Hajdas (PSI) and R. Marcinkowski (PSI) report on behalf of the POLAR collaboration:

At 2017-01-21 01:36:55.20 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 170121A,
which was also observed by Fermi GBM (trigger #506655418) .

The POLAR light curve consists of one peak with duration (T90) of 3.25 +/- 0.25 s measured from T0.
The 0.25 s peak flux at T0 + 0.75 s  is equal to 3000 +/- 100 counts/sec.
POLAR recorded 4290 events from the burst.
Above measurements are in the energy range of about 80 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170121A_raw.png
     or raw LC: http://polar.psi.ch/pub/lc.php?event=GRB+170121A

Using the best location from Fermi GBM, which is (J2000):
RA : 3.0 [deg]
Dec: -75.62 [deg]
the incident angle in POLAR coordinate at T0 is:
Theta: 37.5 [deg]
Phi: 290.8 [deg]

The analysis results presented above are preliminary. Calibration of the instrument is ongoing.
POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space
laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
 http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170121B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20504
SUBJECT: GRB 170121B: Swift ToO observations
DATE:    17/01/23 00:49:18 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/GBM GRB 170121B. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020729

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/GBM 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: GRB170121B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20505
SUBJECT: GRB 170121B: Fermi GBM detection
DATE:    17/01/23 01:04:55 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

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

"At 14:44:22.41 UT on 21 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170121B (trigger
506702667 / 170121614).

It may be noted that this burst is distinct from GRB 170121A
(trigger 506655418 / 170121067), which was also detected by POLAR
(H.L. Xiao et al. 2017, GCN 20501).

A potential optical counterpart to GRB 170121B was detected
by MASTER, although it was referenced as GRB 170121A
(V. Lipunov et al. 2017, GCN 20502).

The on-ground calculated location, using the GBM trigger
data, is RA = 72.84, DEC = -12.65, with an uncertainty
of 1.78 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 74
degrees.

The GBM light curve shows two main peaks
with a duration (T90) of about 46 s (50-300 keV).
The time-averaged spectrum from T0-2.05 s to T0+43.01 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.00 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 455.90 +/- 27.70 keV.

The event fluence (10-1000 keV) in this time interval is
(2.97 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+24.6 s in the 10-1000 keV band
is 9.4 +/- 0.3 ph/s/cm^2.

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

[GCN OPS NOTE(23jan17), Per author's request, the Subject and first sentence
were changed from "160121B" to "170121B".]


GRB_name: GRB170105A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20507
SUBJECT: LIGO/Virgo G268556/GW170104: MAXI/GSC observations
DATE:    17/01/23 02:51:51 GMT
FROM:    Motoko Serino at RIKEN/MAXI  <motoko@crab.riken.jp>

M. Serino (RIKEN), N. Kawai, S.Sugita (Tokyo Tech), H. Negoro (Nihon U.), 
S. Ueno, H. Tomida, S. Nakahira, M. Ishikawa, Y. Sugawara (JAXA), 
Y. E. Nakagawa (JAMSTEC),
T. Mihara, M. Sugizaki, W. Iwakiri, M. Shidatsu, J. Sugimoto, T.  Takagi, M. Matsuoka (RIKEN), 
N.Isobe, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara, S. Harita, Y. Muraki (Tokyo Tech), 
A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka (AGU), 
H. Tsunemi, R. Shomura (Osaka U.), 
M. Nakajima, K. Tanaka, T. Masumitsu, T. Kawase (Nihon U.), 
Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto, S. Oda (Kyoto U.), 
Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.), 
M. Yamauchi, K. Furuya (Miyazaki U.), 
K. Yamaoka (Nagoya U.)
report on behalf of the MAXI team:

We examined the MAXI/GSC all-sky X-ray images (2-20 keV) obtained
in the orbit and the day after the LVC trigger
G268556/GW170104 at 2017-01-04 10:11:58.599 UTC (GCN 20364).

In the 92-min orbit, MAXI/GSC scanned more than 80% 
of the whole sky, which includes 89.3% of the 
90% regions in the bayestar skymap.
One day image covers 95.2% of the 90% regions 
in the bayestar skymap.
No significant new source was found in these images.

The upper limits for the X-ray flux are different depending 
on the part of the sky.
For instance, typical 2-20 keV 1-sigma (3-sigma) upper limits obtained 
from the one-orbit and oneday images are  
19 (56) mCrab and 5 (16) mCrab, respectively.

MAXI/GSC also observed the position of GRB 170105A 
(GCN Circ. 20377, 20390, 20406). The first scan after the burst
was at 2017-01-05T06:47 (UT). No significant emission was observed
at the position at the scan. The 1-sigma (3-sigma) upper limits in 2-20 keV 
are 18 (54) mCrab.


GRB_name: GRB170121B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20508
SUBJECT: GRB 170121B: LCO FTN observations
DATE:    17/01/23 08:41:54 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

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

We observed Fermi GRB 170121B (Hamburg et al. GCN 20505) on January 23, 
07:21 UT (1.7 days since the GRB) with the 2-m LCO Faulkes Telescope 
North in Hawaii with SDSS r and i filters. We do not detect the MASTER 
optical counterpart (Lipunov et al. GCN 20502) down to the following limits:

Mid Time      Exposure       Filter       Magnitude (AB)
(days)           (s)
-------------------------------------------------------
1.69            2x120        SDSS-R        > 21.0
1.69            2x120        SDSS-I        > 19.5
-------------------------------------------------------

as calibrated against nearby USNO-URAT1 sources.


GRB_name: GRB170121B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20510
SUBJECT: GRB 170121B: Swift-XRT and UVOT observations
DATE:    17/01/23 14:53:39 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A.P. Beardmore (U.
Leicester), S.L. Gibson (U. Leicester), A. D'Ai (INAF-IASFPA), A.
Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU),
P.A. Evans (U. Leicester) and A.A. Breeveld (UCL-MSSL) report on behalf
of the Swift team:

Swift-XRT has performed follow-up observations of the optical transient
reported by Lipunov et al. (GCN Circ. 20502) as a possible candidate
afterglow of the Fermi/GBM-detected burst GRB 170121B (Hamburg et al.
GCN Circ. 20505), collecting 4.5 ks of Photon Counting (PC) mode data
between T0+124.0 ks and T0+147.4 ks. 

No X-ray sources have been detected at the position of the optical
transient reported by Lipunov et al. (GCN Circ. 20502). 

An uncatalogued X-ray source is detected within the XRT field of view
at the position RA, Dec 72.6361, -9.2424 which is equivalent to:
   RA(J2000)  = 04h 50m 32.66s
   Dec(J2000) = -09d 14' 32.5"
with an uncertainty of 2.7 arcseconds (radius, 90% containment). The
source has a 0.3-10 keV count rate of about 9e-3 ct/sec. We cannot
determine fading at this time.

The 3-sigma upper limit in the field ranges from ~2e-3 to ~3e-3 ct
s^-1, corresponding to a 0.3-10 keV observed flux of 6.5e-14 to 1.0e-13
erg cm^-2 s^-1 (assuming a typical GRB spectrum).

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/00020729.


The Swift/UVOT began settled observations 124 ks after the trigger
(Hamburg et al, GCN Circ. 20505). Summing up the early white data at
the position of the OT found by Lipunov et al. (GCN Circ. 20502) we do
not find any source to an upper limit of 22.2 mags in 3430s.
At the position of the new uncatalogued XRT source described above we
do see a source already listed in the USNO-B1.0 catalogue and it is not
fading.


This circular is an official product of the Swift team.


GRB_name: GRB170121B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20511
SUBJECT: GRB 170121B:  AstroSat CZTI detection
DATE:    17/01/23 17:18:36 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

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

Analysis of AstroSat CZTI data showed clear detection of GRB170121B (Fermi GBM detection: R.Hamburg et al., GCN Circ. 20505) in the 40-200 keV energy range. The light curve shows two peaks structure with brightest peak at 14:44:31.41 UT, 9 seconds after the Fermi trigger. The measured peak count rate is 320.2 counts/sec above the background in combined data of four quadrants, with a total of 4185.9 counts. The local mean background count rate was 344.2 counts/sec. Using cumulative rates, we measure a T90 of 28.3 secs.

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: GRB170121B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20514
SUBJECT: GRB 170121B:  MASTER early optical observations of the Swift possible XT
DATE:    17/01/24 14:05:20 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, E.Popova, N.Tyurina, V.Kornilov, D.Kuvshinov, 
N.Tyurina, A.V.Krylov, I.Gorbunov, P.Balanutsa,
A.Kuznetsov, V.V.Chazov, D.Vlasenko
Lomonosov Moscow State
University, Sternberg Astronomical Institut of MSU

V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
O. Ershova
Irkutsk State University

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

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, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in 
Blagoveschensk was pointed to the  Fermi trigger Number 506702667 
(Hamburg et al., 20505)  72 sec 
after notice time and 171 sec after trigger time at 2017-01-21 14:47:14 UT.

MASTER-Amur auto-detection system discovered MASTER OT J045017.73-091602.0
with unfiltered magnitude is 14.9m (limit 16.0 m) (Lipunov et al., GCN 20502).

We do not see any optical source at Swift XRT position (Sbarufatti et 
al., GCN 20510) with next limits:

  Date         UT        Exp        Type        Limit
             start

2017-01-21 14:50:48  60 Alert (FERMI) 16.6

2017-01-21 14:49:21     60 Alert (FERMI) 16.1

2017-01-21 14:48:11     40 Alert (FERMI) 16.4

2017-01-21 14:47:14     30 Alert (FERMI) 16.0

2017-01-21 14:46:28     20 Alert (FERMI) 16.0


The message may be cited.


GRB_name: GRB170121B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20516
SUBJECT: GRB 170121B:  AbAO optical observations
DATE:    17/01/24 17:41:03 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI), R. Inasaridze (AbAO), A. Volnova 
(IKI),  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 optical transient reported by Lipunov et al. (GCN 
20502) as a possible candidate of the Fermi/GBM GRB 170121B (Hamburg et al. 
GCN Circ. 20505) and XRT  afterglow  candidate reported by Sbarufatti  et 
al. (GCN  20510) with AS-32 (0.7m) telescope of Abastumani Observatory 
starting on Jan., 23 (UT)  16:14:49. We obtained several unfiltered images 
of the field.  We do not find any source at coordinates of the optical 
transient (Lipunov et al., GCN  20502). Within XRT error circle  (Sbarufatti 
et al., GCN  20510) we find the source which is also presented in DSS2 and 
USNO-B1.0 as the star USNO-B1.0 0807-0048671 (magnitudes R1 = 17.94, R2 = 
17.07). Preliminary photometry  of the source and the field of  the optical 
transient (Lipunov et al., GCN  20502) is following

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

2017-01-23 16:14:49.   2.09866   CR     60*60  17.76  0.07  22.9

Photometry is based on nearby USNO-B1.0 stars (R2 magnitudes)
USNO-B.1_id    R2
0807-0048576 16.37
0806-0049543 18.47
0807-0048525 17.28
0807-0048536 17.23
0806-0049637 15.57
0807-0048826 15.71
0807-0048833 15.41
0807-0048816 17.22


GRB_name: GRB170115B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20525
SUBJECT: GRB 170115B: AGILE/SuperAGILE localisation
DATE:    17/01/25 15:51:18 GMT
FROM:    Ettore Del Monte at IASF/INAF  <sa.grb@iaps.inaf.it>

Y. Evangelista, L. Pacciani, E. Del Monte and I. Donnarumma  
(INAF/IAPS), A. Trois (INAF/OAC) on behalf of the AGILE Team, report:

SuperAGILE localised the long-duration GRB 170115B (Hamburg et al.,  
GCN 20463; McEnery et al., GCN  20464; Sharma et al., GCN 20466; Xiao  
et al., GCN 20469; Verrecchia et al., GCN 20474; Frederiks et al., GCN  
20476, Shimizu et al., GCN 20483) on 15 January 2017, at 17:49:14 UT.

The event had a duration of about 50.0 s in the 18-60 keV energy  
range, with a multi-peaked structure. The burst position was  
reconstructed as:

RA(J2000):       189.011 deg (12h 36m 02.64s)

DEC(J2000):      -46.796 deg (-46d 47' 45.58")

with an uncertainty of 5' (radius). The uncertainty accounts for both  
the statistical and systematic errors.

The SuperAGILE error box is completely contained in the FERMI-LAT  
error box (McEnery et al., GCN  20464) and partially intersects the  
IPN annulus (Hurley et al., GCN 20475). The Swift-XRT afterglow  
candidate (D'Avanzo et al., GNC 20477) is also contained in the  
SuperAGILE error box.

Due to telemetry downlink restrictions, the SuperAGILE experiment has  
been kept on but with no telemetry download since late 2012. The full  
telemetry link for the AGILE mission has now been restored and the  
data of SuperAGILE are again routinely downloaded.

This message may be cited.


GRB_name: GRB170115A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20529
SUBJECT: GRB 170115A: 15 GHz upper limits from AMI
DATE:    17/01/26 11:30:40 GMT
FROM:    Kunal Mooley at Oxford U  <kunal.mooley@physics.ox.ac.uk>

K. P. Mooley, T. D. Staley, R. P. Fender (Oxford), G. E. Anderson 
(Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. 
Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. 
Grainge, A. Scaife (Manchester)

The AMI Large Array robotically triggered on the Swift alert for GRB 
170115A (Page et al., GCN 20462) as part of the 4pisky program, and 
subsequent follow up observations were obtained up to 10 days 
post-burst. Our observations at 15 GHz on 2016 Jan 16.42, Jan 17.59, Jan 
18.67 and Jan 23.51 (UT) do not reveal any radio source at the XRT 
location (Osborne et al., GCN 20465), with 3sigma upper limits of 300 
uJy, 78 uJy, 72 uJy and 81 uJy respectively.

We thank the AMI staff for scheduling these observations. The AMI-GRB 
database is a log of all GRB follow up observations with the AMI, and is 
available at http://4pisky.org/ami-grb/.


GRB_name: GRB170126A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20530
SUBJECT: GRB 170126A: Swift detection of a burst with an optical counterpart
DATE:    17/01/26 11:44:29 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

D. Kocevski (NASA/MSFC), S. D. Barthelmy (GSFC),
A. A. Breeveld (UCL-MSSL), D. N. Burrows (PSU), A. D'Ai (INAF-IASFPA),
S. W. K Emery (UCL-MSSL), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC) and M. H. Siegel (PSU) report on behalf of
the Swift Team:

At 11:30:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170126A (trigger=735188).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 263.579, -64.757 which is 
   RA(J2000)  =  17h 34m 19s
   Dec(J2000) = -64d 45' 26"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single FRED-like peak
structure with a duration of about 15 sec.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 11:32:09.4 UT, 87.1 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 263.63341, -64.76046 which is
equivalent to:
   RA(J2000)  = 17h 34m 32.02s
   Dec(J2000) = -64d 45' 37.7"
with an uncertainty of 4.2 arcseconds (radius, 90% containment). This
location is 84 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 131 seconds with the White filter
starting 90 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 17:34:31.95 = 263.63311
  DEC(J2000) = -64:45:37.0  = -64.76027
with a 90%-confidence error radius of about 0.62 arc sec. This position is 0.9
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.12 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.10. 

Burst Advocate for this burst is D. Kocevski (dankocevski 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: GRB170126A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20531
SUBJECT: GRB 170126A: Enhanced Swift-XRT position
DATE:    17/01/26 16:19:27 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 2613 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 170126A, 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 = 263.63308, -64.76064 which is equivalent
to:

RA (J2000): 17h 34m 31.94s
Dec (J2000): -64d 45' 38.3"

with an uncertainty of 1.9 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: GRB170126A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20533
SUBJECT: GRB 170126A: Fermi GBM observation
DATE:    17/01/26 19:00:13 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

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


"At 11:30:41.54 UT on 26 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170126A (trigger 507123046 / 170126480),
which was also detected by the Swift/BAT (Kocevski et al. 2017, GCN 20530).
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 BAT location is 46 degrees.

The GBM light curve consists of a single peak
with a duration (T90) of about 14 s (50-300 keV).
The time-averaged spectrum from T0 to T0+14 s is
adequately fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.13 +/- 0.04 and
the cutoff energy, parameterized as Epeak, is 260 +/- 21 keV.
A Band function fits the spectrum equally well
with Epeak = 187 +/- 23 keV, alpha = -1.02 +/- 0.06 and
beta = -2.08 +/- 0.11.

The event fluence (10-1000 keV) in this time interval is
(9.5 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1 s in the 10-1000 keV band
is 12.3 +/- 0.4 ph/s/cm^2.


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


GRB_name: GRB170126A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20534
SUBJECT: GRB 170126A: Swift/UVOT Detection of a Fading Afterglow
DATE:    17/01/26 22:12:19 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and D. Kocevski (NASA/MSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170126A
91 s after the BAT trigger (Kocevski et al., GCN Circ. 20530).
A fading source consistent with the enhanced XRT position
(Beardmore et al. GCN Circ. 20531)
is detected in the initial UVOT exposure.

The preliminary UVOT position is:
    RA  (J2000) =  17:34:31.97 = 263.63319 (deg.)
    Dec (J2000) = -64:45:37.3  = -64.76035 (deg.)
with an estimated uncertainty of 0.45 arc sec. (radius, 90% confidence).

Preliminary detection 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               91          222          129         18.10 +/- 0.05
white            11432        12036          590        >19.7
v                 1907         2273           58        >17.7
b                 1832         6164          132        >20.1
u                 1807         6084          255        >19.3
w1                1783         5879          255        >19.8
m2                1931         2297           58        >20.0
w2                1882         2248           58        >19.4

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: GRB170126A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20535
SUBJECT: GRB 170126A: Swift-XRT refined Analysis
DATE:    17/01/27 04:49:22 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 7.0 ks of XRT data for GRB 170126A, from 73 s to 40.7
ks after the  BAT trigger. The data comprise 68 s in Windowed Timing
(WT) mode (the first 7 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.30 (+0.06, -0.05).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.52 (+0.33, -0.28). The
best-fitting absorption column is  2.0 (+2.5, -1.3) x 10^21 cm^-2,
consistent with the Galactic value of 7.0 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 4.5 x 10^-11 (5.3 x
10^-11) erg cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      2.0 (+2.5, -1.3) x 10^21 cm^-2
Galactic foreground: 7.0 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.52 (+0.33, -0.28)

If the light curve continues to decay with a power-law decay index of
1.30, 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 4.2 x
10^-14 (4.9 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/00735188.

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


GRB_name: GRB170126A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20537
SUBJECT: GRB 170126A: AstroSat CZTI detection
DATE:    17/01/27 11:23:28 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

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

Analysis of AstroSat CZTI data showed clear detection of GRB170126A (Swift detection: D. Kocevski et al., GCN Circ. 20530) in quadrant C and D in the 40-200 keV energy range. The light curve shows single peak structure with main peak at 11:30:42 UT, coincident with Swift trigger. The measured peak count rate is 185.7 counts/sec above the background in combined data of four quadrants, with a total 1008.2 counts. The local mean background count rate was 336.3 counts/sec. Using cumulative rates, we measure a T90 of 26.9 secs.

It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection 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: GRB170127A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20538
SUBJECT: GRB 170127A: Swift detection of a burst
DATE:    17/01/27 14:33:09 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. B. Markwardt (NASA/GSFC), S. D. Barthelmy (GSFC),
S. B. Cenko (GSFC), A. Cholden-Brown (PSU), A. D'Ai (INAF-IASFPA),
V. D'Elia (ASDC), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 14:21:15 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170127A (trigger=735326).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 174.336, -45.852, which is 
   RA(J2000)  =  11h 37m 21s
   Dec(J2000) = -45d 51' 05"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a couple weak peaks
with a duration of about 35 sec.  The peak count rate
was ~900 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 14:22:51.5 UT, 95.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 174.35974, -45.83603 which
is equivalent to:
   RA(J2000)  = 11h 37m 26.34s
   Dec(J2000) = -45d 50' 09.7"
with an uncertainty of 4.1 arcseconds (radius, 90% containment). This
location is 82 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 7.10e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
101 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 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.07. 

Burst Advocate for this burst is C. B. Markwardt (Craig.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: GRB170127A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20539
SUBJECT: GRB 170127A: Prompt enhanced Swift-XRT position
DATE:    17/01/27 14:57:53 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 170127A, we find an
enhanced XRT position of the afterglow: RA, Dec: 174.3600, -45.8358
which is equivalent to:
   RA (J2000)  = 11 37 26.41
   Dec (J2000) = -45 50 08.7
with an uncertainty of 2.2 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/735326.

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: GRB170127B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20540
SUBJECT: GRB 170127B: Swift detection of a short burst
DATE:    17/01/27 15:25:04 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

J. K. Cannizzo (NASA/UMBC), S. D. Barthelmy (GSFC),
S. B. Cenko (GSFC), A. Cholden-Brown (PSU), A. D'Ai (INAF-IASFPA),
V. D'Elia (ASDC), P.A. Evans (U Leicester), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 15:13:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170127B (trigger=735331).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 19.944, -30.338, which is 
   RA(J2000)  =  01h 19m 47s
   Dec(J2000) = -30d 20' 14"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
structure with a duration of about 0.2 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 15:14:43.3 UT, 74.7 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 19.9766, -30.3588 which
is equivalent to:
   RA(J2000)  = 01h 19m 54.37s
   Dec(J2000) = -30d 21' 31.6"
with an uncertainty of 2.9 arcseconds (radius, 90% containment). This
location is 125 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 2.01
x 10^20 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 113 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 0.02. 

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: GRB170127B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20541
SUBJECT: GRB 170127B: MASTER-Kislovodsk early optical observations
DATE:    17/01/27 16:05:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

E. Gorbovskoy, V. Lipunov,  V.Kornilov, D.Kuvshinov, N.Tyurina, 
P.Balanutsa, A.Kuznetsov, V.V.Chazov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

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

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

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk, O. 
Ershova
Irkutsk State University

R. Podesta, Claudio Mallamaci, Carlos Lopez and Federico Podesta
Observatorio Astronomico Felix Aguilar (OAFA)

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Kislovodsk was pointed to the  GRB170127B 37 sec after notice 
time and 52 sec after trigger time at 2017-01-27 15:14:21 UT in two 
polarization. On our first 
(10s exposure)  set we haven't found optical transient  within SWIFT 
error-box (Cannizzo et al GCN 20540).
The 5-sigma upper limit has been about 17.0 mag on single (10 s) and 19.5 
on  coadd (total exposure 540 s) images.
The message may be cited.

====================================================================

The observations made on zenit distance = 76 degrees, galaxy latitude b =  -83 degree.
The moon ( 0 % bright part) below the horizon (The altitude of the Moon is 
-14 degree ).
Observations started at twilight.
The sun  altitude  is -11.4 degree.


GRB_name: GRB170127C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20543
SUBJECT: GRB 170127C: Fermi GBM detection
DATE:    17/01/27 16:56:33 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

E. Bissaldi (Politecnico & INFN Bari), B. Mailyan and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:


"At 01:35:47.79 UT on 27 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170127C (trigger 507173752 / 170127067).
The on-ground calculated location, using the GBM trigger data, is

RA, Dec = 336.380, -63.400

(J2000 degrees, equivalent to 22 h 25 m, -63 d 24 '), with an uncertainty
of 1.95 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 140 degrees.

The GBM light curve consists of single peak
with a duration (T90) of about 0.210 s (50-300 keV).
The time-averaged spectrum from T0-0.064 s to T0+0.192 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is 0.27 +/- 0.09 and
the cutoff energy, parameterized as Epeak, is 859 +/- 34 keV.

The event fluence (10-1000 keV) in this time interval is
(7.4 +/- 0.2)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0 in the 10-1000 keV band
is 84 +/- 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: GRB170127C
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20544
SUBJECT: GRB 170127C: Fermi-LAT detection
DATE:    17/01/27 17:11:28 GMT
FROM:    Magnus Axelsson at Stockholm U.  <magaxe@kth.se>

E. Moretti (MPP), G. Vianello (Stanford Univ.), E. Bissaldi (INFN and Politecnico Bari), J. Racusin (NASA/GSFC) and M. Axelsson (Stockholm Univ. and KTH Stockholm) report on behalf of the Fermi-LAT team:

On January, 27, 2017 Fermi-LAT detected high-energy emission from GRB 170127C, which was also detected by Fermi-GBM starting at T0 = 01:35:47.79 (trigger 507173752 / 170127067; Bissaldi et al. GCN 20543).


The best LAT on-ground location is found to be

RA, Dec =  339.3, -63.9 (J2000)

with an error radius of 0.4 deg (90 % containment, statistical error only).

The location was outside the LAT field-of-view at the time of the trigger. The event triggered an autonomous repoint of the spacecraft, causing the location to enter the field-of-view around 300s later.

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 500 MeV event which is observed 2890 seconds after the GBM trigger. A total of 5 photons above 100 MeV were detected up to 4000s after the trigger.

A Swift ToO has been requested for this burst.


The Fermi-LAT point of contact for this burst is Elena Moretti (moretti@mpp.mpg.de<mailto:moretti@mpp.mpg.de>).


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: GRB170127C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20545
SUBJECT: GRB 170127C (Fermi/GBM trigger 507173752): AGILE analysis
DATE:    17/01/27 17:15:24 GMT
FROM:    Francesco Verrecchia at ASDC  <francesco.verrecchia@asdc.asi.it>

AGILE analysis of GRB 170127C (Fermi/GBM trigger 507173752)

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

We performed an analysis of AGILE data of the GRB 170127C (Fermi/GBM
trigger num 507173752; GCN #20543), which occurred at 2017-01-27
01:35:47.79 UTC.

The Mini-CALorimeter (MCAL), sensitive in the energy range from 400 keV
to 100 MeV, detected a short burst at T0 = 2017-01-27 01:35:47.9294 UTC,
that triggered both the on-board 16 ms and 64 ms timescale hardware logic
system. The MCAL light curve shows a sharp single peak, that lasted about
0.13 s and released a total number of ~980 counts above 400 keV in the
detector, above an average background rate of 590 counts/s.

The time-integrated spectrum measured between T0 and T0+0.13 s can be fit
in the energy range 0.5 - 20 MeV with a power law with high-energy
cut-off at 1.63 MeV, with photon index -1.64Â±0.19 and reduced chi-squared
1.08 (18 d.o.f.). As observed by MCAL, the burst fluence in the same
energy range and time interval is 1.20Â±0.01e-6 erg cm-2. All quoted
errors are at 90% confidence levels.

SuperAGILE, sensitive in the energy range 18 to 60 keV, also clearly
detected the burst with its ratemeters.


GRB_name: GRB170127C
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20546
SUBJECT: GRB 170127C: Tiled Swift observations
DATE:    17/01/27 18:35:17 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 170127C. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00063

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: GRB170126A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20547
SUBJECT: Konus-Wind observation of GRB 170126A
DATE:    17/01/27 18:44:30 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-duration GRB 170126A
(Swift-BAT detection: Kocevski et al., GCN 20530;
Fermi-GBM observation: Bissaldi, GCN 20533;
AstroSat CZTI detection: Sharma et al., GCN 20537)
triggered Konus-Wind at T0=41440.253 s UT (11:30:40.253).

The burst light curve shows a single pulse
started at ~T0-0.5 s with a total duration of ~28 s.
The emission is seen up to 2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170126_T41440/

As observed by Konus-Wind, the burst
had a fluence of 8.25(-0.81,+0.94)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+0.992 s,
of 2.87(-0.85,+0.87)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 - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.98(-0.22,+0.24)
and Ep = 188(-27,+40) keV (chi2 = 54/59 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 = 54/58 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 - 2 MeV range
by a power law with exponential cutoff model
with  alpha = -1.03(-0.17,+0.18)
and Ep = 206(-27,+37) keV (chi2 = 40/58 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.4
(chi2 = 40/57 dof)

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


GRB_name: GRB170127A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20548
SUBJECT: GRB 170127A: Enhanced Swift-XRT position
DATE:    17/01/27 19:24:11 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 1366 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 170127A, 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 = 174.35970, -45.83565 which is equivalent
to:

RA (J2000): 11h 37m 26.33s
Dec (J2000): -45d 50' 08.3"

with an uncertainty of 2.4 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: GRB170127B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20549
SUBJECT: GRB 170127B: NOT r-band upper limits
DATE:    17/01/27 21:08:30 GMT
FROM:    Zach Cano at U of Iceland  <zewcano@gmail.com>

â€‹Z. Cano (IAA-CSIC), K. E. Heintz (Univ. Iceland & DARK/NBI), D. Malesani
(â€‹DARK/NBI and DTU Spaceâ€‹)â€‹ & R. Tronsgaard (NOT) report on behalf of a
larger collaboration:

We observed the field of short-duration GRB 170127B (Cannizzo et al.; GCN
Circ. 20540) with the 2.5-m Nordic Optical Telescope equipped with ALFOSC,
starting at 19:48:56 UT on 27 January 2017 (4.59 hrs from detection).  We
obtained 3x300 s in the r-band.  In our co-added image no new object is
detected in the XRT error circle to the following limit:

Filter    t-t0 (hr)     magnitude (AB)
-------------------------------------------
  r        4.73           >23.4

The r-band upper limit is for an isolated point source in the GRB field,
which is calibrated to local Pan-STARRS standards in the field.  This upper
limit is not corrected for foreground extinction (E(B-V) = 0.02 mag,
Schlegel et al. 1998).


GRB_name: GRB170127B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20550
SUBJECT: GRB 170127B: Enhanced Swift-XRT position
DATE:    17/01/27 22:16:33 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 1434 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 170127B, 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 = 19.97709, -30.35807 which is equivalent
to:

RA (J2000): 01h 19m 54.50s
Dec (J2000): -30d 21' 29.1"

with an uncertainty of 2.0 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: GRB170127B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20551
SUBJECT: GRB 170127B: Fermi GBM observation
DATE:    17/01/27 22:28:58 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

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

"At 15:13:28.77 UT on 27 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170127B (trigger 507222813 / 170127634)
which was also detected by the Swift/BAT (Cannizzo et al., GCN 20540).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 44 degrees.

The GBM light curve shows two overlapping pulses
with a duration (T90) of about 1.7 s (50-300 keV).
The time-averaged spectrum from T0-0.1 s to T0+0.4 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.67 +/- 0.16 and
the cutoff energy, parameterized as Epeak, is 688 +/- 195 keV.


The event fluence (10-1000 keV) in this time interval is
(7.6 +/- 0.6)E-7 erg/cm^2. The 64 ms peak photon flux measured
starting from T0-64 ms in the 10-1000 keV band
is 8.4 +/- 1.2 ph/s/cm^2.


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


GRB_name: GRB170127A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20552
SUBJECT: GRB 170127A: Swift/UVOT Upper Limits
DATE:    17/01/27 22:44:14 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and C. B. Markwardt (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170127A
102 s after the BAT trigger (Markwardt et al., GCN Circ. 20538).
No optical afterglow consistent with the enhanced XRT position
(Evans et al. GCN Circ. 20548)
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

u_FC               102          351          246         >20.5
v                  409         1533          136         >18.7
b                  359         1632          175         >20.4
u                  102         1607          529         >20.7
w1                 458         1583          136         >19.4
m2                 434         1558          136         >20.0
w2                 385         1658          175         >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.07 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB170127B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20554
SUBJECT: GRB 170127B: Swift/UVOT Upper Limits
DATE:    17/01/28 02:36:04 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) 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 170127B
114 s after the BAT trigger (Cannizzo et al., GCN Circ. 20540).
No optical afterglow consistent with the enhanced XRT position
(Goad et al. GCN Circ. 20550)
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) exposures and subsequent exposures are:

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

white_FC           114          264          147         >21.2
u_FC               327          576          246         >19.9
white              114         1377          373         >21.0
v                  656         1427           97         >19.4
u                  327          576          246         >19.9

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: GRB170124A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20556
SUBJECT: GRB 170124A: CALET Gamma-Ray Burst Monitor detection
DATE:    17/01/28 04:30:56 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>

W. Ishizaki (ICRR), A. Yoshida, T. Sakamoto, Y. Kawakubo, M. Moriyama,
Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 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), P. S. Marrocchesi (U of Siena)
and the CALET collaboration:

The long-duration GRB 170124A (Fermi-GBM trigger #506984291; Konus-Wind trigger
time on 20:58:06.428 UT) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
20:58:04.58 on 24 January 2017.  The burst signal was seen by all CGBM instruments.

The light curve of the SGM shows two peaks.  The first peak starts at T0,
peaks at T+8 sec and ends at T+15 sec.  The second peak starts at T+15 sec,
peaks at T+23 sec and ends at T+30 sec.  The T90 duration measured by
the SGM data is 20.9 +- 1.3 sec (40-1000 keV).

The light curve is available at

http://cgbm.calet.jp/cgbm_trigger/flight//1169326441/index.html

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


GRB_name: GRB170126A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20557
SUBJECT: GRB 170126A, Swift-BAT refined analysis
DATE:    17/01/28 05:03:02 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), N. Gehrels (GSFC),
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-240 to T+200 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170126A (trigger #735188)
(Kocevski, et al., GCN Circ. 20530).  The BAT ground-calculated position is
RA, Dec = 263.623, -64.755 deg which is
   RA(J2000)  =  17h 34m 29.4s
   Dec(J2000) = -64d 45' 18.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 4%.

The mask-weighted light curve shows a single-peaked structure that starts
at ~T-1 s, peaks at ~T+1 s, and ends at ~T+11 s. T90 (15-350 keV) is
9.5 +- 1.6 sec (estimated error including systematics).

The time-averaged spectrum from T-0.8 to T+10.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.54 +- 0.14.  The fluence in the 15-150 keV band is 2.8 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.31 sec in the 15-150 keV band
is 7.3 +- 1.1 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/735188/BA/


GRB_name: GRB170127A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20558
SUBJECT: GRB 170127A: Swift-XRT refined Analysis
DATE:    17/01/28 11:12:10 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), S. J. LaPorte
(PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), B. Mingo (U.
Leicester) and report on behalf of the Swift-XRT team: report on
behalf of the Swift-XRT team:

We have analysed 6.2 ks of XRT data for GRB 170127A, from 86 s to 58.8
ks after the  BAT trigger. The data comprise 168 s in Windowed Timing
(WT) mode (the first 7 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The light curve can be modelled with an initial power-law decay with an
index of alpha=1.28 (+/-0.15), followed by a break at T+329 s to an
alpha of 8.0 (+0.0, -1.1).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.49 (+/-0.10). The
best-fitting absorption column is  1.3 (+/-0.4) x 10^21 cm^-2, in
excess of the Galactic value of 8.5 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 4.5 x 10^-11 (5.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      1.3 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 8.5 x 10^20 cm^-2
Excess significance: 2.0 sigma
Photon index:      1.49 (+/-0.10)

If the light curve continues to decay with a power-law decay index of
5.19, the count rate at T+24 hours will be 2.0 x 10^-13 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.9 x
10^-24 (10.0 x 10^-24) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00735326.

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


GRB_name: GRB170124A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20559
SUBJECT: GRB 170124A: POLAR Observation
DATE:    17/01/28 12:40:29 GMT
FROM:    Zhao Yi at POLAR  <yizhao@ihep.ac.cn>

Yi Zhao (IHEP), R. Marcinkowski (PSI), Xing Wen (IHEP),
H. Xiao (PSI), Minzi Feng (IHEP) and W. Hajdas (PSI)
report on behalf of the POLAR collaboration:

At 2017-01-24T20:58:06.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170124A, 
which was also detected by the 
Fermi/GBM (trigger 506984291/170124873), Konus-Wind and 
the CALET Gamma-ray BurstMonitor (Circ 20556).

The POLAR light curve consists of multiple peaks,
with a duration (T90) of 22.38 s measured from T0+2.26 s.
The 1-s peak rate measured from T0+8.00 s is 514.8 cnts/s.
The total counts is about 7657 cnts. The above measurements
are in the energy range of about 80-500 keV.

LC_URL:
http://polar.ihep.ac.cn/grb/2017/01/GRB170124A/lc/POLAR_lc_grb170124A.png

Using the best location from the Fermi/GBM, which is (J2000):
RA:     282.040  [deg]
Dec:    -75.510  [deg]
Err:    1.00     [deg]

the incident angle in POLAR coordinate at T0 is:
theta:  111.4    [deg]
phi:    -143.2   [deg]

All analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV)
on-board the Chinese space laboratory Tiangong-2 launched on
Sep 15,2016. More information about POLAR can be found at 
http://polar.ihep.ac.cn/en/ , http://isdc.unige.ch/polar/
and http://polar.psi.ch/pub/.


GRB_name: GRB170127B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20560
SUBJECT: GRB 170127B: Swift-XRT refined Analysis
DATE:    17/01/28 15:25:05 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), J.A. Kennea (PSU), B. Sbarufatti
(INAF-OAB/PSU), D.N. Burrows (PSU), B. Mingo (U. Leicester), A.P.
Beardmore (U. Leicester) and  report on behalf of the Swift-XRT team:
report on behalf of the Swift-XRT team:

We have analysed 2.8 ks of XRT data for GRB 170127B, from 60 s to 10.6
ks after the  BAT trigger. The data comprise 7 s in Windowed Timing
(WT) mode (taken while Swift was slewing), with the remainder in Photon
Counting (PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.7 (+0.5, -0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.57 (+0.27, -0.23). The
best-fitting absorption column is  consistent with the Galactic value
of 2.0 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 4.1 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.0 (+/-4.2) x 10^20 cm^-2
Galactic foreground: 2.0 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.57 (+0.27, -0.23)

If the light curve continues to decay with a power-law decay index of
1.7, the count rate at T+24 hours will be 6.7 x 10^-6 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.7 x
10^-16 (2.8 x 10^-16) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00735331.

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


GRB_name: GRB170127C
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20561
SUBJECT: GRB 170127C: AstroSat CZTI detection
DATE:    17/01/28 17:45:19 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

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

Analysis of AstroSat CZTI data showed clear detection of GRB170127C (Fermi detection: E. Bissaldi et al., GCN Circ. 20543) in the 40-200 keV energy range. The light curve shows single peak structure with main peak at 01:35:47.79 UT, coincident with Fermi trigger. The measured peak count rate is 895.2 counts/sec above the background in combined data of four quadrants, with a total 904.3 counts. The local mean background count rate was 416.8 counts/sec. Using cumulative rates, we measure a T90 of 0.91 secs.

It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection 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: GRB170127A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20562
SUBJECT: GRB 170127A: GROND Upper limits
DATE:    17/01/28 17:52:34 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

P. Schady, P. Wiseman and J. Greiner (all at MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 170127A (Swift trigger 735326; Markwardt et al., GCN #20538) 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 05:23 UT on 2017-01-27, 15 hrs after the GRB trigger. They were performed at high seeing that varied between 1.5 and 2" and at an average airmass of 1.4.

In combined images with 36 min of total exposures in gr'i'z' and 30 min in JHK at a mid-time of 05:40 UT on 2017-01-28, we do not detect a source within the Swift-XRT error circle reported by Evans et al. (GCN #20548) down to the following 3 sigma upper limits (all in AB system)

g' > 24.0 mag
r' > 23.7 mag
i' > 23.1 mag
z' > 23.0 mag
J > 20.7 mag
H > 20.3 mag
K > 17.7 mag

Given magnitudes are calibrated against GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.06 in the direction of the burst (Schlafly & Finkbeiner 2011).


GRB_name: GRB170127C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20563
SUBJECT: GRB 170127C: POLAR Observation
DATE:    17/01/29 07:32:35 GMT
FROM:    Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>

R. Marcinkowski (PSI), H.L. Xiao (PSI), W. Hajdas (PSI), Yi Zhao (IHEP), 
M. Kole (DPNC) and S.L. Xiong (IHEP) report on behalf of the POLAR 
collaboration:

At 2017-01-27 01:35:48.7 UT(T0), during a routine on-ground search of data,
POLAR detected GRB 170127C, which was also observed by Fermi GBM
(trigger # 507173752) and reported by Fermi GBM (Bissaldi et al. GCN 20543),
Fermi-LAT (E. Moretti et al. GCN 20544), Agile (A. Ursi et al. GCN 20545)
and AstroSat (V. Sharma et al. GCN 20561).

The POLAR light curve consists of 1 short (~0.15 s), strong peak followed by
longer and weaker multi peak structure with duration (T90) of 22.0 +/- 0.2 s
measured from T0. The light curve is compatible with the one from
Fermi-GBM. The 0.2 s peak flux at T0 + 0.2 s  is equal to
13000 +/- 140 counts/sec. POLAR recorded 3600 +/- 140 events from the burst.
Above measurements are in the energy range of about 20 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170127C_raw.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170127C

Using the best location from Fermi LAT (E. Moretti et al. GCN 20544),
which is:
RA : 339.3 [deg]
Dec: -63.9 [deg]
Err:   0.4 [deg]

the incident angle in the POLAR coordinate at T0 is:
Theta: 41.8 [deg]
Phi: 157.6 [deg]

The analysis results presented above are preliminary. Calibration of the
instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter which
was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) on
Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
 http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170127C
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20564
SUBJECT: GRB 170127C: Swift-XRT observations
DATE:    17/01/29 12:05:26 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

V. DElia (ASDC) reports on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 170127C (Bissaldi et al., GCN Circ 20543, Moretti et al., GCN Circ 20544)  in a series of observations tiled on the sky. The total exposure time is 5 ks, distributed over 7 tiles; the maximum exposure at a single sky location was 1.4 ks. The data were collected between T0+61.2 and T0+77.4 ks and are entirely in Photon Counting (PC) mode. 

No new source is detected in the XRT field of view, at a count rate limit in the range 0.005-0.01 cts/s.

The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, areavailable at http://www.swift.ac.uk/xrt_products/TILED_GRB00063.

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


GRB_name: GRB170127A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20565
SUBJECT: GRB 170127A: Swift-BAT refined analysis
DATE:    17/01/29 16:00:54 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), N. Gehrels (GSFC),
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-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170127A (trigger #735326)
(Markwardt et al., GCN Circ. 20538).  The BAT ground-calculated position is
RA, Dec = 174.382, -45.827 deg which is
   RA(J2000)  =  11h 37m 31.6s
   Dec(J2000) = -45d 49' 38.6"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 97%.

The mask-weighted light curve shows some weak overlapping pulses that
starts at ~T-5 s and ends at ~T+65 s. T90 (15-350 keV) is
62.26 +- 10.39 sec (estimated error including systematics).

The time-averaged spectrum from T-4.65 to T+64.51 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.10 +- 0.30.  The fluence in the 15-150 keV band is 5.2 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+7.31 sec in the 15-150 keV band
is 0.3 +- 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/735326/BA/


GRB_name: GRB170127B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20566
SUBJECT: GRB 170127B: Swift-BAT refined analysis
DATE:    17/01/29 16:03:01 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. K. Cannizzo (NASA/UMBC), J. R. Cummings (CPI),
N. Gehrels (GSFC), H. A. Krimm (NSF/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
J. P. Norris (BSU), 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 170127B (trigger #735331)
(Cannizzo et al., GCN Circ. 20540).  The BAT ground-calculated position is
RA, Dec = 19.997, -30.340 deg which is
   RA(J2000)  =  01h 19m 59.2s
   Dec(J2000) = -30d 20' 25.2"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.

The mask-weighted light curve shows a single-peaked structure that starts
and peaks at ~T0, and ends at ~T+0.6 s. T90 (15-350 keV) is 0.51 +- 0.14 sec
(estimated error including systematics).

The time-averaged spectrum from T+0.05 to T+0.64 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.89 +- 0.25.  The fluence in the 15-150 keV band is 1.0 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.16 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.

Using a 8-ms binned light curve, the lag analysis finds a lag of -4 (-17, +8) ms
for the 100-350 keV to 25-50 keV, and -12 (-8, +8) ms for the 50-100 keV to
15-25 keV band. These values are consistent with those of a short GRB. Moreover,
no extended emission are found.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/735331/BA/


GRB_name: GRB170127C
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20567
SUBJECT: Konus-Wind observation of GRB 170127C (short/hard GRB with extended emission)
DATE:    17/01/29 16:15:14 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 short/hard GRB 170127C (Fermi-GBM detection: Bissaldi et al.,
GCN 20543; Fermi-LAT detection: Moretti et al., GCN 20544;
AGILE analysis: Ursi et al., GCN 20545;
AstroSat CZTI Sharma:  Verrecchia et al., GCN 20561;
POLAR observation: Marcinkowski et al., GCN 20563)
triggered Konus-Wind at T0=5744.660 s UT (01:35:44.660).

The light curve shows a bright, hard initial pulse with a
duration of ~0.170 ms, followed, after a short period of quiescence,
by a weaker and softer emission episode lasing for ~16 s.
Even more weaker and softer emission is traced in the KW light curve
up to ~T0+90 s.
The emission in the initial pulse is seen up to ~5 MeV.

As observed by Konus-Wind, the burst had a total fluence of
1.62(-0.25, +0.49)x10^-5 erg/cm2 and a 16-ms peak energy flux,
measured from T0, of (1.1 Â± 0.1)x10^-4 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the initial pulse
(measured from T0 to T0+0.192 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.01 (-0.14,+0.16), Ep = 887 (-88,+90) keV,
chi2 = 46/55 dof.

The time-averaged spectrum of the extended emission
(measured from T0+0.256 to T0+16.640 s)
is best fit in the 20 keV - 15 MeV range
by the CPL model with alpha = -1.19 (-0.29,+0.35),
Ep = 307 (-98,+342) keV, chi2 = 91/98 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170127_T05744/

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


GRB_name: GRB170130A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20568
SUBJECT: GRB 170130A: POLAR Observation
DATE:    17/02/01 08:43:20 GMT
FROM:    Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>

R. Marcinkowski (PSI), H.L. Xiao (PSI) and W. Hajdas (PSI) report on behalf 
of the POLAR collaboration:

At 2017-01-30 07:14:45 UT(T0), during a routine on-ground search of data, 
POLAR detected GRB 170130A, which was also observed by Fermi GBM 
(trigger # 507453289). Significant detection was recorded in 9 of 25 POLAR 
modules.

The POLAR light curve consists of multi peak structure with duration (T90) 
of 35.0 +/- 1.0 s measured from T0 and is compatible with Fermi GBM light curve. 
The 1.0 s peak flux at T0 + 30.5 s is equal to 480 +/- 80 counts/sec. POLAR 
recorded about 5300 events from the burst.

Above measurements are in the energy range of about 20 - 500 keV and bases 
on data from 9 modules.

LC_URL: http://polar.psi.ch/triggers/GRB_170130A_raw_9of25.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170130A

Using the best location from Fermi GBM, which is (J2000):
RA : 271.1 [deg]
Dec: -29.1 [deg]
Err:   5.5 [deg]

the incident angle in the POLAR coordinate at T0 is:
Theta: 56.2 [deg]
Phi:  230.9 [deg]

The analysis results presented above are preliminary. Calibration of the 
instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter 
which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) 
on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub , 
http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170131A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20570
SUBJECT: GRB 170131A detected in Swift/BAT ground processing
DATE:    17/02/01 19:19:04 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

GRB 170131A detected in Swift/BAT ground processing

David Palmer (LANL), on behalf of the Swift team, reports:

At 23:15:13 UT on 2017-01-31, the Swift Burst Alert Telescope (BAT) 
detected a marginal peak in a rate-triggered image (Swift Trigger #736107).
Because it was below the image significance threshold, it did not yield a GRB 
follow-up.  However, ground analysis shows that it is at the same location 
as a Fermi/GBM trigger (#507597304).  KONUS/WIND also reported a trigger
at the same time.

The BAT on-board calculated location is 
RA, Dec 341.447, 64.006, which is 
 RA(J2000)  =  22h 45m 55s
 Dec(J2000) = +64d 00' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a ~30 s long
FRED structure starting at ~T-20 (consistent with the Fermi/GBM
trigger time) superimposed with a ~5 second peak near the BAT
trigger time.  The peak count rate was ~3000 counts/sec (15-350 keV),
at ~3 sec after the BAT trigger. 

A Swift ToO observation has been scheduled.


GRB_name: GRB170131A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20571
SUBJECT: GRB 170131A: Swift ToO observations
DATE:    17/02/01 20:34:18 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 170131A. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020738

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: GRB170131A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20572
SUBJECT: GRB 170131A: Fermi GBM observation
DATE:    17/02/01 23:24:55 GMT
FROM:    Bagrat Mailyan at UAH  <bm0054@uah.edu>

B. Mailyan (UAH) and O.J Roberts (NASA-MSFC/USRA) report on
behalf of the Fermi GBM Team:

"At 23:14:59.36 UT on January 31st 2017, the Fermi Gamma-Ray
Burst Monitor triggered and located GRB 170131A
(trigger 507597304 /170131969) which was also detected by
the Swift/BAT (Palmer, GCN 20570). The GBM on-ground location
is consistent with the Swift-BAT position.

The angle from the Fermi LAT boresight at the GBM trigger
time using the Swift-BAT position is 18 degrees.

The GBM light curve shows a FRED-like burst with overlapping
pulses with a duration (T90) of about 23 s (50-300 keV).
The time-averaged spectrum from T0-1.0 s to T0+18.4 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.37+/-0.06
and the cutoff energy, parameterized as Epeak, is 209 +/- 34 keV.

The event fluence (10-1000 keV) in this time interval is
(4.56 +/- 0.27)E-06 erg/cm^2. The 1 s peak photon flux measured
starting from T0+15.4 s in the 10-1000 keV band is
4.9 +/- 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: GRB170131A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20573
SUBJECT: GRB 170131A: Swift-XRT observations
DATE:    17/02/02 08:41:10 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), B.
Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Cholden-Brown (PSU),
B. Mingo (U. Leicester), A.P. Beardmore (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
Swift/BAT-detected burst GRB 170131A (David Palmer et al. GCN Circ.
20570), collecting 4.9 ks of Photon Counting (PC) mode data between
T0+78.4 ks and T0+96.6 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):  341.3994  =  22:45:35.85
  Dec (J2000): +64.0090  =  +64:00:32.6
  Error: 5.8 arcsec (radius, 90% conf.)
  Count-rate: (2.19 [+0.93, -0.75])e-3 ct s^-1  
  Distance: 75 arcsec from Swift/BAT position.
  Flux: (6.2 [+2.6, -2.1])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)

A uncatalogued source was also detected, however this was too far from
the GRB position to be the afterglow.

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/00020738.

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


GRB_name: GRB170131A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20574
SUBJECT: GRB 170131A: Swift/UVOT Upper Limits
DATE:    17/02/02 14:21:17 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL), M. Stamatikos (OSU) and F. E. Marshall 
(NASA/GSFC) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170131A 
78368 s after the BAT trigger (Palmer, GCN Circ. 20570) using the UVW2 
filter only.
No optical afterglow consistent with the XRT source 1 position (Melandri 
et al., GCN Circ. 20573) is detected in the initial UVOT exposures. 
However, there is a USNO-B1.0 source at this position (USNO-B1.0 
1540-029147), but it is not detected in the UVW2 filter.
The preliminary 3-sigma upper limit using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial 
exposures is:

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

w2               78368        96539         4888         >21.2

The magnitude in the table is not corrected for the large, but uncertain 
Galactic extinction due to the reddening of E(B-V) = 1.19 in the 
direction of the burst (Schlegel et al. 1998).


GRB_name: GRB170202A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20575
SUBJECT: GRB 170202A: Swift detection of a burst with an optical afterglow
DATE:    17/02/02 18:53:46 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

J. L. Racusin (NASA/GSFC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC),
A. Cholden-Brown (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/NSF/USRA), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 18:28:02 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170202A (trigger=736407).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 152.529, +5.002 which is 
   RA(J2000)  =  10h 10m 07s
   Dec(J2000) = +05d 00' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows 4 main peaks
with a total duration of about 40 sec.  The peak count rate
was ~4800 counts/sec (15-350 keV), at ~16 sec after the trigger. 

The XRT began observing the field at 18:29:14.8 UT, 72.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 152.51422, 5.01213 which
is equivalent to:
   RA(J2000)  = 10h 10m 03.41s
   Dec(J2000) = +05d 00' 43.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 64 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 2.21e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 83 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 10:10:03.49 = 152.51455
  DEC(J2000) = +05:00:41.8  = 5.01161
with a 90%-confidence error radius of about 0.75 arc sec. This position is 0.5
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.46 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. 

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: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20576
SUBJECT: GRB 170202A : Xinglong TNT optical observation
DATE:    17/02/02 20:09:09 GMT
FROM:    L.P. Xin at NAOC  <xlp@nao.cas.cn>

L. P. Xin,   W. X, Li,  J. Y. Wei,  Y. L. Qiu,  J. S. Deng, 
J. Wang,  X. H. Han, C. Wu and H. L. Li report:

We  observed  GRB 170202A  (Racusin et al. GCN 20575)  with 
Xinglong  0.8-m TNT telescope at 18:29:00 UT, 58 sec after the burst.

The optical afterglow (Racusin et al. GCN 20575 ) was  detected 
in our white and R-band images, with a coordinate of 
RA=10:10:03.48
DEC=05:00:42.29
Epoch=J2000
Which is consistent with report by UVOT detection ( Racusin et al. GCN 20575).

The brightness of the optical afterglow is about 18.9 mag 
at the mid time  of 69 sec afer the burst,  
calibrated by the USNO B1.0 star (RA=10:10:03.29  DEC=04:59:37.4  R2=14.95mag).

The observations are continuous.

The message may be cited.


GRB_name: GRB170202A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20577
SUBJECT: GRB 170202A: Mini-MegaTORTORA upper limits
DATE:    17/02/02 20:42:54 GMT
FROM:    Sergey Karpov at SAO RAS  <karpov@sao.ru>

S.Karpov, G.Beskin (SAO RAS and Kazan Federal University, Russia), S.Bondar,
E.Ivanov, E.Katkova, N.Orekhova, A.Perkov (OJS RPC PSI, Russia), A.Biryukov
(SAI MSU and Kazan Federal University, Russia), V.Sasyuk (Kazan Federal
University, Russia)

Mini-MegaTORTORA nine-channel wide-field monitoring system  with high
temporal resolution responded to the BAT trigger and observed the position
of GRB 170702A (Racusin et al. GCN 20575) since 2017-02-02 18:28:50 UT
(T+47.8 s) and until 2017-02-02 18:39:04 UT (T + 662.0 s). The system
acquired a series of 5 s exposure frames with all 9 channels pointed to the
object location in white light, with and without polarimetric filters
installed. No transient object is detected over this interval, with
detection limit on a single frame V=13.0 mag. Co-adding 9 simultaneous
frames improves the detection limit to V=14.0 mag at the mid-time of first
exposure (Tmid = T+50.3 s, 5 s exposure).

Mini-MegaTORTORA belongs to Kazan Federal University and is located at
Special Astrophysical Observatory near Russian 6-m telescope.

The message may be cited.


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20578
SUBJECT: GRB 170202A: MASTGlobal ER-Net bright OT nonmonotonic light curve
DATE:    17/02/02 21:28:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, N.Tyurina, E. Gorbovskoy, V.V.Kornilov, 
D.Kuvshinov, P.Balanutsa,  A.Kuznetsov, V.V.Chazo, A.V.Krylov, I.Gorbunov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

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

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

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk, O. Ershova
Irkutsk State University

R. Podesta, Carlos Lopez and Federico Podesta
Observatorio Astronomico Felix Aguilar (OAFA)

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB170202.77 37 sec after 
notice time and 49 sec after trigger time at 2017-02-02 18:28:58 UT. On 
our first (10s exposure)  set we  found 1 optical transient within SWIFT 
error-box (ra=152.525 dec=5.00139 r=0.05) brighter then 16.5

RA, DEC = 10h 10m 03s.5 , + 5d 0m 41s.8
Mag = 16.2

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka was pointed to the  GRB170202.77 69 sec after notice time 
and 85 sec after trigger time at 2017-02-02 18:29:33 UT. On our first (20s 
exposure)  set we  found  optical transient within SWIFT error-box 
(ra=152.525 dec=5.00111 r=0.05) brighter then 17.8.

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was pointed to the  GRB170202.77 4070 sec after notice 
time and 4082 sec after trigger time at 2017-02-02 19:36:11 UT. On our 
18-th (180s exposure)  set we  found  optical transient within SWIFT 
error-box (ra=152.525 dec=5.00111 r=0.05) brighter then 17.00.

MASTER-Amur light curve   is 
available at http://master.sai.msu.ru/static/OT/MASTERGRB170202A.jpg


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20579
SUBJECT: GRB 170202A: LCO Sutherland observations
DATE:    17/02/02 22:32:33 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

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

We observed Swift GRB 170202A (Racusin et al. GCN 20575) on February 02, 
from 21:19 UT (2.8 hours since the GRB) with 1-m LCO telescope units in 
Sutherland with SDSS r and i filters. We detect the optical afterglow 
(Racusin et al. GCN 20575; Xi et al. GCN 20576; Lipunov et al. GCN 
20578) at the Swift-UVOT position with the following values:

Mid Time      Exposure       Filter       Magnitude (AB)
(hours)           (s)
-------------------------------------------------------
2.9             4x120         SDSS-R      19.65 +- 0.15
3.0             4x120         SDSS-I      19.32 +- 0.18
-------------------------------------------------------

as calibrated against nearby SDSS sources.


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20580
SUBJECT: GRB 170202A: Zadko observatory - Gingin optical observations
DATE:    17/02/02 22:55:17 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

A. Klotz, D. Turpin (IRAP-CNRS-OMP),
D. Macpherson (UWA/ICRAR), D. Coward (UWA),
M. Boer, R. Laugier (UNS-CNRS-OCA),
Gendre B. (UVI - Etelman Obs.),
A. Williams (PO-UWA), R. Martin (PO-UWA)
report:

We imaged the field of GRB 170202A detected by SWIFT
(trigger 736407) with the Zadko robotic telescope (D=100cm)
located at the observatory - Gingin, Australia.

The observations started 58s after the GRB trigger
(42s after the notice). The elevation of the field decreased from
51 degrees above horizon and weather conditions
were very good.

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 optical transcient described by Racusin et
al. (GCNC 20575), Xin et al. (GCNC 20576) and Lipunov et
al. (GCNC 20578). We calibrated magnitudes using the same
reference star than Xin et al. (GCNC 20576).

The afterglow increases slowly and continuously from 73s
(i.e. the limiting magnitude R~19) until 400s (R=16.5).
After 550s the flux start to decrease with a standard
temporal decay alpha=-1 until 5000s (R=19).

Extrapolation with this rate gives R=22.3 at t0+1day.
So we encourage to perform spectrometry.

N.B. Zadko Magnitudes are not corrected for galactic dust extinction.


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20581
SUBJECT: GRB 170202A: Kanata optical and infrared observations
DATE:    17/02/02 23:12:08 GMT
FROM:    Michitoshi Yoshida at HASC,Hiroshima U  <yoshidam@hiroshima-u.ac.jp>

Mori, H., Nakaoka, T., Kawabata, M., Hirochi, J., Kawahara, N.,
Yoshida, M., Kawabata, K. and Uemura, M. (Hiroshima Univ.) on
behalf of the OISTER collaboration

We performed R-band and Ks-band imaging observations around the
error circle of GRB 170202A (Racusin et al., GCN 20575) with the
optical imager HOWPol and opt-NIR imager HONIR attached to Kanata
telescope of Hiroshima University. The observations took place at
2017-02-02 18:33:37 UT (mid time of the observation). We detected
the optical transient reported by Xin et al.(GCN 20576), Lipunov
et al. (GCN 20578) and Guidorzi et al. (GCN 20579) in our R-band
and Ks-band images. The detected magnitude of the OT and five
sigma upper limit (in Vega magnitude) of the observations are
listed below.

# T0+   MID-UT     T-EXP    R mag.   R err   R limit
-----------------------------------------------------
  335    18:33:37      30    16.35    0.3     18.0
-----------------------------------------------------

# T0+   MID-UT     T-EXP    Ks mag.  Ks err  Ks limit
-----------------------------------------------------
  3208   19:21:30    1320    17.1     0.4     18.6
-----------------------------------------------------
T0+ : Elapsed time after the burst [sec]
T-EXP: Total Exposure time [sec]


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20582
SUBJECT: GRB 170202A: NOT afterglow observations
DATE:    17/02/02 23:31:00 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T. Kruehler (MPE Garching), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI),
and Pasi J. Hakala (FINCA) report on behalf of the Nordic GRB
collaboration:

We observed the field of GRB 170202A (Racusin et al. GCN 20575)
with the NOT equipped with ALFOSC. Photometry in the r and i-band
filter started at 22:46 UTC on 2017-02-02, 4.3 hr after the GRB
trigger.

Calibrating our images against magnitudes of field stars from the
SDSS catalog, we measure a preliminary brightness of the optical
afterglow (Racusin et al. GCN 20575, Xin et al. GCN 20576,
Lipunov et al. GCN 20578, Guidorzi et al. GCN 20579, Klotz et al.
GCN 20580, Mori et al. GCN 20581) of

r = 20.1 +- 0.1 mag.

This magnitude is not corrected for the expected foreground
extinction corresponding to a reddening of E_B-V = 0.02 mag
(Schlafly & Finkbeiner 2011).


GRB_name: GRB170203A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20583
SUBJECT: GRB 170203A: Swift detection of a burst
DATE:    17/02/03 00:13:29 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. L. Racusin (NASA/GSFC), A. Cholden-Brown (PSU),
K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of
the Swift Team:

At 00:03:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170203A (trigger=736432).  Swift could not slew to the burst
due to the Sun observing constraint. 
The BAT on-board calculated location is 
RA, Dec 332.860, +25.173 which is 
   RA(J2000) = 22h 11m 26s
   Dec(J2000) = +25d 10' 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 40 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~4 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 01:25 UT on 2017 April 10. There will thus be no XRT or
UVOT data for this trigger before this time. 

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: GRB170202A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20584
SUBJECT: GRB 170202A: Redshift from OSIRIS/GTC
DATE:    17/02/03 00:22:15 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), L. Izzo (IAA-CSIC), 
C. Thoene (IAA-CSIC), D.A. Kann (IAA-CSIC, TLS), P. Pessev 
(GRANTECAN, IAC, ULL), A. Perez (GRANTECAN) report on 
behalf of a larger collaboration:

We observed the afterglow of GRB 170202A (Racusin et al. 
GCN 20575) using OSIRIS at the 10.4m GTC telescope at the 
Roque de los Muchachos observatory (La Palma, Spain). The 
observation started at 23:22 UT (4.91 hr after the burst) and 
included observations with grisms R1000B and R1000R covering
 the ranges 3700 - 7800 AA and 5100 - 9300 AA respectively.

The blue spectra shows a strong signal with multiple features being 
especially significant Lyman-alpha (both in absorption and emission), 
the full Ly-forest, NV, SII, SiII, SiII*, OI, CII, SiIV, CIV and AlII at a 
common redshift of 3.645, which we identify as the redshift of the 
GRB.


GRB_name: GRB170202A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20585
SUBJECT: GRB 170202A: MITSuME Akeno Optical Observation
DATE:    17/02/03 00:47:37 GMT
FROM:    Yutaro Tachibana at Tokyo Tech  <tachibana@hp.phys.titech.ac.jp>

Y. Saito, R. Itoh, Y. Tachibana, K. Morita, Y. T. Yoshii, H. Ohuchi, Y. Yano, Y. Ono, T. Fujiwara, S. Harita, Y. Muraki,  K. Saisho, Y. Ozawa, Y. Yatsu, and N. Kawai
(Tokyo Tech)
report on behalf of the MITSuME collaboration:

We searched for the optical counterpart of GRB 1710202A (J. L. Racusin et
al., GCN Circular #20575) 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 2017-02-02 18:28:41 UT (39 sec after the burst).
We detected the optical counterpart (J. L. Racusin et al., GCN Circular #20575
) in g', Rc and Ic band.
The measured magnitudes were listed as follows.

T0+[sec]    MID-UT    T-EXP[sec]            g'                          Rc                          Ic    
-------------------------------------------------------------------------------------------------------
     54      18:28:56         30                >18.4                      >17.7                   >17.0
     92      18:29:34         30                >19.1                 17.01 +/- 0.12       17.08 +/- 0.25 
    131     18:30:13         30            17.61 +/- 0.13       16.38 +/- 0.09       15.89 +/- 0.12     
-------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.


GRB_name: GRB170202A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20586
SUBJECT: GRB 170202A: Enhanced Swift-XRT position
DATE:    17/02/03 04:26:17 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 2000 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 170202A, 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 = 152.51441, +5.01136 which is equivalent
to:

RA (J2000): 10h 10m 3.46s
Dec (J2000): +05d 00' 40.9"

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: GRB170202A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20587
SUBJECT: GRB 170202A: Swift/UVOT Detection
DATE:    17/02/03 05:18:40 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (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 170202A
84 s after the BAT trigger (Racusin et al., GCN Circ. 20575). A source
consistent with the enhanced XRT position (Osborne et al., GCN 20586)
and is detected in the initial UVOT exposures. No detection in the U and
UV filters is consistent with the reported redshift (de Ugarte Postigo et
al,
GCN Circ. 20584).

The preliminary UVOT position is:
    RA  (J2000) =  10:10:03.49 = 152.51454 (deg.)
    Dec (J2000) = +05:00:41.8  =   5.01161 (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               84          233          147         18.31 +/- 0.05
v                  625         1419           97         18.27 +/- 0.20
b                  551         1345           78         19.18 +/- 0.19
u                  295         1837          363        >21.1
w1                 675         1812          136        >19.6
w2                1030         1050           19        >19.0

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: GRB170202A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20588
SUBJECT: GRB 170202A: Xinglong 2.16m photometry and spectroscopic redshift
DATE:    17/02/03 07:31:00 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu (NAOC), Y. Qin (Geneva Observatory), Y.D. Hu (IAA-CSIC), H.J. 
Wang, H. Wu, M. He, H.X. Feng, Z.P. Zhu (NAOC) report:

We observed the optical afterglow of GRB 170202A (Racusin et al., GCN 
20575) using the 2.16-m telescope at Xinglong, Hebei, China, equipped 
with the BFOSC camera. The observation started at 18:59:32 UT on 
2017-02-02  (i.e., 31.5 mins after the BAT trigger), 4x120s R-band 
photometry was obtained, followed by 1x3600s spectroscopy using the 
G4+385LP grism setting, covering the wavelength of ~3600 - 8500 AA.

The optical afterglow has m(R)~18.0 mag from the first R-band exposure, 
calibrated with the nearby SDSS stars.

Preliminary analysis shows that the spectrum is featured by a prominent 
Lyman_alpha trough, a Lyman forest blue to the trough, together with Si 
IV, C IV and other potential absorption lines red to the trough, all at 
a common redshift of z = 3.65. This redshift value is consistent with 
measurement in de Ugarte Postigo et al. (GCN 20584).


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20589
SUBJECT: GRB 170202A VLT/X-shooter redshift
DATE:    17/02/03 09:49:18 GMT
FROM:    Jesse Palmerio at IAP  <palmerio@iap.fr>

J. Palmerio (Univ. Paris VI, IAP), T. Kruehler (MPE Garching), D.
Malesani, J. P. U. Fynbo (DARK/NBI) report on behalf of a larger
collaboration:

We observed the optical afterglow of GRB 170202A
(Racusin et al. GCN 20575) with the ESO
Very Large Telescope UT 2 (Kueyen) equipped with the X-shooter
spectrograph, covering the wavelength range 3500-20000 AA.
Spectroscopy started at 04:10:05 UT on 2017-02-03 (i.e., 9.7 hr after the
GRB)
 and consisted of 4 exposures of 600 s each.

The spectrum exhibits several absorption features such as Lya, CIV,
SiIV, FeII, SiII, MgII as well as the [OIII]5007 emission line,
 all at a common redshift of z=3.645, consistent with
A. de Ugarte Postigo et al. (GCN 20584) and D. Xu et al. (GCN 20588).
We conclude this is the redshift of the GRB.

We acknowledge the excellent support from the ESO staff, particularly
Fernando J. Selman, A. Mehner in obtaining these observations.


GRB_name: GRB170202A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20590
SUBJECT: GRB 170202A VLT/X-shooter redshift [minor correction]
DATE:    17/02/03 09:55:04 GMT
FROM:    Jesse Palmerio at IAP  <palmerio@iap.fr>

J. Palmerio (Univ. Paris VI, IAP), T. Kruehler (MPE Garching),
D. Xu (NAOC,CAS), D. Malesani, J. P. U. Fynbo (DARK/NBI)
report on behalf of a larger collaboration:

We observed the optical afterglow of GRB 170202A
(Racusin et al. GCN 20575) with the ESO
Very Large Telescope UT 2 (Kueyen) equipped with the X-shooter
spectrograph, covering the wavelength range 3500-25000 AA.
Spectroscopy started at 04:10:05 UT on 2017-02-03 (i.e., 9.7 hr after the
GRB)
 and consisted of 4 exposures of 600 s each.

The spectrum exhibits several absorption features such as Lya, CIV,
SiIV, FeII, SiII, MgII as well as the [OIII]5007 emission line,
 all at a common redshift of z=3.645, consistent with
A. de Ugarte Postigo et al. (GCN 20584) and D. Xu et al. (GCN 20588).
We conclude this is the redshift of the GRB.

We acknowledge the excellent support from the ESO staff, particularly
Fernando J. Selman, A. Mehner in obtaining these observations.


GRB_name: GRB170202A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20591
SUBJECT: GRB 170202A: T100 observations
DATE:    17/02/03 10:29:03 GMT
FROM:    Eda Sonbas at NASA/GSFC  <edasonbas@gmail.com>

E. Sonbas (Adiyaman Univ.), T. Guver, M. De Pasquale (Istanbul Univ.), E.
Gogus (Sabanci Univ.), O. Erece, M. Kocak, H. Kirbiyik, H. Esenoglu (TUG)
report on behalf of a larger collaboration


We observed the field of Swift GRB 170202A (Racusin et al., GCN#20575) with
the 1.0 meter T100 telescope (Bakirlitepe, TUBITAK National Observatory,
Turkey), starting February, 2, 20:12:45.56 UT (~ 1.7 hours after the
trigger). Observations were carried out in the R filter. The afterglow is
detected in the R band images with an exposure time of 300 s.


Using USNO-B1 stars USNO-B1 0950-0184329 (R.A.=152.492, Dec=+5.028) and
USNO-B1 0949-0181744 (R.A.=152.514, Dec=+4.993) in the field, the magnitude
of the OT was estimated as follows;


t-t0 (hr) exp.(s) filt mag err (+/-)

1.75 300 R 18.98 0.07


Analysis of further observations with the same filter is ongoing.


We thank to TUBITAK National Observatory for a partial support in using
T100 telescope with project number 10CT100-95 and technical support.


GRB_name: GRB170202A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20592
SUBJECT: GRB 170202A: Swift-XRT refined Analysis
DATE:    17/02/03 11:12:09 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU), A.
Cholden-Brown (PSU), S. J. LaPorte (PSU), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), A.
D'Ai (INAF-IASFPA) and J.L. Racusin report on behalf of the Swift-XRT
team:

We have analysed 6.7 ks of XRT data for GRB 170202A (Racusin et al. GCN
Circ. 20575), from 64 s to 40.8 ks after the  BAT trigger. The data
comprise 131 s in Windowed Timing (WT) mode (the first 7 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. 20586).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=2.9 (+3.3, -0.6). At T+84.5 s  the decay
flattens to an alpha of -1.5 (+0.0, -2.0). The light curve breaks again
at T+95.5 s to a decay with alpha=3.15 (+0.19, -0.17), and  again at
T+314 s s to alpha=0.01 (+0.17, -0.18),  before a final break at T+2223
s s after which the decay index is 1.08 (+0.12, -0.17).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.94 (+0.09, -0.08). The
best-fitting absorption column is  3.7 (+6.4, -3.7) x 10^21 cm^-2, at a
redshift of 3.645, in addition to the Galactic value of 2.0 x 10^20
cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index
of 2.00 (+0.13, -0.12) and a best-fitting absorption column of 5.2
(+8.8, -5.2) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10
keV flux conversion factor deduced from this spectrum  is 3.2 x 10^-11
(3.5 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 2.0 x 10^20 cm^-2
Intrinsic column:    5.2 (+8.8, -5.2) x 10^21 cm^-2 at z=3.645
Photon index:      2.00 (+0.13, -0.12)

If the light curve continues to decay with a power-law decay index of
1.08, the count rate at T+24 hours will be 0.018 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.9 x
10^-13 (6.4 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/00736407.

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


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20593
SUBJECT: GRB 170202A: LCO FTN observations
DATE:    17/02/03 11:36:23 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

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

We observed Swift GRB 170202A (Racusin et al. GCN 20575) on February 03, 
from 10:30 to 10:40 UT (16 hours since the GRB) with the 2-m LCO FTN in 
Hawaii with SDSS r and i filters. We detect the optical afterglow with 
the following values:

Mid Time      Exposure       Filter       Magnitude (AB)
(hours)           (s)
-------------------------------------------------------
16.1            2x120         SDSS-R      21.10 +- 0.15
16.2            2x120         SDSS-I      20.94 +- 0.19
-------------------------------------------------------

as calibrated against nearby SDSS sources.


GRB_name: GRB170202A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20594
SUBJECT: GRB 170202A: SQUEAN Observation
DATE:    17/02/03 13:25:13 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Yongjung Kim, & Joonho Kim (CEOU/SNU)

We observed the field of GRB 170202A (Racusin et al., GCN 20575) using
the SQUEAN instrument on the 2.1m Otto Struve telescope at the McDonald
Observatory, Texas. The observation started at 2017-02-03 10:26:26 UT,
â€‹ â€‹
or about 16 hours after the BAT alert.

We identify the afterglow at the location of the reported GRB position,
with the following preliminary results based on the photometry calibration
using SDSS stars in the vicinity.

 Filter    Mag (AB)  Mag_err   Exp.time  Start-time (UT)
â€‹    r            21.1       0.08         180s x 3    10:26:26.6â€‹
    i            20.6        0.06         180s x 3    10:36:20.7
    z           20.5        0.10         180s x 3    10:47:15.6

 Further observations are planned.


GRB_name: GRB170202A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20595
SUBJECT: GRB 170202A: RATIR Optical and NIR Observations
DATE:    17/02/03 16:56:06 GMT
FROM:    Nat Butler at UC berkeley  <natxbutler@gmail.com>

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), Neil Gehrels (GSFC), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy
(UMD) report:

We observed the field of GRB 170202A (Racusin, et al., GCN 20575) 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 2017/02 3.18 to 2017/02 3.57 UTC (9.92 to
19.17 hours after the BAT trigger), obtaining a total of 3.98 hours
exposure in the r and i bands and 1.68 hours exposure in the Z and Y bands.

For a source within the Swift-XRT error circle (Osborne, et al., GCN
20586), in comparison with the SDSS DR9 and 2MASS catalogs, we obtain the
following detections:

r = 20.68 +/- 0.01
i = 20.83 +/- 0.02
Z = 20.84 +/- 0.07
Y = 20.50 +/- 0.06

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: GRB170202A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20596
SUBJECT: GRB 170202A: Swift-BAT refined analysis
DATE:    17/02/03 17:28:41 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

S. D. Barthelmy (GSFC), J. R. Cummings (CPI), N. Gehrels (GSFC),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
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+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170202A (trigger #736407)  (Racusin, et al.,
GCN Circ. 20575). The BAT ground-calculated position is RA, Dec = 152.526, 5.021 deg
which is RA(J2000) = 10h 10m 06.3s Dec(J2000) = +05d 01' 15.7" with an uncertainty
of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%.

The mask-weighted light curve shows a multi-peaked structure.  The first peak
starts at T+0 sec, peaks at T+3 sec and decays to near background by T+15 sec,
at which time the second, larger peak begins.  This structure peaks at T+17 sec,
and the third overlapping peak has a maximum at T+21 sec, and decays to
near background by T+50 sec, with some low-level emission extending out to
T+80 sec. T90 (15-350 keV) is 46.2 +- 11.5 sec (estimated error including systematics).

The time-averaged spectrum from T+0.25 to T+76.46 sec is best fit by
a simple power-law model. The power law index of the time-averaged
spectrum is 1.68 +- 0.07. The fluence in the 15-150 keV band is
3.3 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from
T+16.04 sec in the 15-150 keV band is 4.7 +- 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/736407/BA/


GRB_name: GRB170203A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20597
SUBJECT: GRB 170203A: Swift-BAT refined analysis
DATE:    17/02/03 17:29:04 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

J. R. Cummings (CPI), S. D. Barthelmy (GSFC),  N. Gehrels (GSFC),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
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+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170203A (trigger #736432)
(Racusin, et al., GCN Circ. 20583).  The BAT ground-calculated position is
RA, Dec = 332.861, 25.186 deg which is
  RA(J2000)  =  22h 11m 26.6s
  Dec(J2000) = +25d 11' 08.4"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 67%.

The mask-weighted light curve shows a single main peak, which starts at T+0 sec,
peaks at T+5 sec and decays to background by T+30 sec.  There is a much
weaker peak from T+25 to T+50 sec. T90 (15-350 keV) is 45.2 +- 6.4 sec
(estimated error including systematics).

The time-averaged spectrum from T-0.04 to T+48.43 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.53 +- 0.29.  The fluence in the 15-150 keV band is 6.2 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+3.70 sec in the 15-150 keV band
is 0.8 +- 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/736432/BA/


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20598
SUBJECT: GRB 170202A: Etelman Observatory optical observations
DATE:    17/02/03 22:24:51 GMT
FROM:    Bruce Gendre at ASDC  <bruce.gendre@gmail.com>

B. Gendre (UVI), N. Orange (OrangeWave Innovative Science, LLC), D. 
Morris (UVI), A. Cucchiara (UVI), D. Drost (UVI), T. Giblin (USAF
Academy), J. Hakkila (College of Charleston), A. Klotz (IRAP), J. Neff 
(NSF), D. Smith (UVI), J. Staff (UVI), P. Thierry (Auragne Observatory), 
R. Watlington (UVI), and L. Wentlent (UVI) report:

We observed the field of GRB 170202A (Racusin et al. GCN 20575) with the 
0.5m Virgin Island Robotic Telescope (VIRT) on February the 3rd,
starting at 3:16 UT (8.8 hours after the trigger), until 10:30 UT. We 
performed a series of exposures in the clear filter. The weather 
conditions were variable with a typical estimated seeing of 2".

We detected the afterglow observed by UVOT (Racusin et al., GCN 20575) 
on a combined image (spanning times from 10h to 11.92h after the 
trigger). Its magnitude, estimated by comparison to nearby USNO-B1 
stars, was R = 20.8 +/- 0.3.

Further analysis is in progress.

Magnitudes have not been corrected for Galactic extinction. The VIRT is 
still in its commissioning phase.

This message can be cited.


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20599
SUBJECT: GRB 170202A: Zadko observatory - Gingin optical observations
DATE:    17/02/03 22:58:08 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

A. Klotz, D. Turpin (IRAP-CNRS-OMP),
D. Macpherson (UWA/ICRAR), D. Coward (UWA),
M. Boer, R. Laugier (UNS-CNRS-OCA),
Gendre B. (UVI - Etelman Obs.),
A. Williams (PO-UWA), R. Martin (PO-UWA)
report:

We continue to image the field of GRB 170202A
with the Zadko robotic telescope (D=100cm)
located at the observatory - Gingin, Australia
(see Klotz et al. GCNC 20580 for early measures).

The observations started 19.56h after the GRB trigger
and were stopped at t0+22.99h. We stacked 25 images
of 180s with no filter.

We detect the optical transcient described by Racusin et
al. (GCNC 20575), Xin et al. (GCNC 20576) and Lipunov et
al. (GCNC 20578). We calibrated magnitudes using the same
reference star than Xin et al. (GCNC 20576):

t0+19.56h t0+22.99h R=21.8 +/-0.4

Magnitudes are not corrected for galactic dust extinction.


GRB_name: GRB170131A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20600
SUBJECT: GRB 170131A: POLAR Observation
DATE:    17/02/04 03:20:19 GMT
FROM:    Zhao Yi at POLAR  <yizhao@ihep.ac.cn>

Yi Zhao (IHEP), Xing Wen (IHEP), Yuanhao Wang (IHEP)
report on behalf of the POLAR collaboration:


At 2017-01-31T23:14:59.00 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170131A, 
which was also detected by the 
Fermi/GBM (trigger 507597304/170131969, Circ 20572),
Swift (Circ 20570) and Konus-Wind.


The POLAR light curve consists of multiple peaks,
with a duration (T90) of 21.88 s measured from T0-1.21 s.
The 1-s peak rate measured from T0+16.00 s is 888.4 cnts/s.
The total counts is about 7085 cnts. The above measurements
are in the energy range of about 20-500 keV.


LC_URL:
http://polar.ihep.ac.cn/grb/2017/01/GRB170131A/lc/POLAR_lc_grb170131A.png


Using the best location from the Swift/BAT, which is (J2000):
RA:     341.447  [deg]
Dec:    +64.006  [deg]
Err:    3.00     [arcmin]


the incident angle in POLAR coordinate at T0 is:
theta:  76.5     [deg]
phi:    22.2     [deg]


All analysis results presented above are preliminary.


POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV)
on-board the Chinese space laboratory Tiangong-2 launched on
Sep 15,2016. More information about POLAR can be found at 
http://polar.ihep.ac.cn/en/ , http://isdc.unige.ch/polar/
and http://polar.psi.ch/pub/.


GRB_name: GRB170202A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20601
SUBJECT: GRB 170202A: SQUEAN Observation (2nd night)
DATE:    17/02/04 11:15:37 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Yongjung Kim, & Joonho Kim (CEOU/SNU)

We continued the observation of the GRB 170202A afterglow with the SQUEAN
instrument on the 2.1m Otto Struve telescope at the McDonald Observatory,
Texas. The 2nd night observation started at 2017-02-04 09:45:52 UT,
â€‹ â€‹or
about 39.3 hours after the BAT alert.

The afterglow shows the following preliminary magnitude based on the
photometry calibration using SDSS stars in the vicinity.

 Filter    Mag (AB)  Mag_err   Exp.time  Start-time (UT)

r             21.8         0.15      180s x 10    09:45:52â€‹


GRB_name: GRB170202B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20602
SUBJECT: GRB 170202B POLAR Observation
DATE:    17/02/05 07:52:11 GMT
FROM:    Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>

R. Marcinkowski (PSI), H.L. Xiao (PSI) and W. Hajdas (PSI) report on behalf
of the POLAR collaboration:

At 2017-02-02 07:19:54 UT(T0), during a routine on-ground search of data, 
POLAR detected long GRB 170202B, which was also observed by Konus at 
07:19:54.107 UT.

The POLAR light curve consists of multi peak structure with duration 
(T90) of 23.0 +/- 0.5 s measured from T0. The 0.5 s peak flux at 
T0 + 4.8 s  is equal to 5000 +/- 120 counts/sec. POLAR recorded about
29700 events from the burst.
Above measurements are in the energy range of about 20 - 500 keV.

LC_URL: http://polar.psi.ch/triggers/GRB_170202B_raw.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170202B

The analysis results presented above are preliminary. Calibration of the
instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter which
was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) on
Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
 http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170205A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20603
SUBJECT: GRB 170205A: Swift detection of a burst with an optical counterpart
DATE:    17/02/05 12:58:40 GMT
FROM:    David Burrows at PSU/Swift  <burrows@astro.psu.edu>

E. Troja (NASA/GSFC/UMCP), D. N. Burrows (PSU),
A. Cholden-Brown (PSU), H. A. Krimm (CRESST/NSF/USRA),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC) and
K. L. Page (U Leicester) report on behalf of the Swift Team:

At 12:39:09 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170205A (trigger=736843).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 262.151, -0.053 which is 
   RA(J2000) = 17h 28m 36s
   Dec(J2000) = -00d 03' 08"
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 25 sec.  The peak count rate
was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 12:40:10.9 UT, 61.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
262.1696, -0.0626 which is equivalent to:
   RA(J2000)  = 17h 28m 40.70s
   Dec(J2000) = -00d 03' 45.3"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 75 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 (1.97 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 6.4
(+5.93/-4.46) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 7.05e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 314 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 17:28:40.69 = 262.16953
  DEC(J2000) = -00:03:47.3  =  -0.06313
with a 90%-confidence error radius of about 0.62 arc sec. This position is 1.9
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.62 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.35. 

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: GRB170202A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20604
SUBJECT: Konus-Wind observation of GRB 170202A
DATE:    17/02/05 14:32:27 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 170202A (Swift-BAT trigger #736407: Racusin et al.,
GCN 20575; Barthelmy et al., GCN 20596; T0(BAT)=18:28:02.373 UT)
was detected by Konus-Wind (KW) in the waiting mode.

The light curve shows a double-peaked with a duration of ~30 s.
Modeling the KW 3-channel time-integrated spectrum
(from T0(BAT)+0.907 s to T0(BAT)+30.347 s) by
a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.16(-0.34,+0.59) and Ep = 247(-86,+166) keV.
The energy fluence (20 keV-10 MeV) for this time interval
is (5.9 Â± 1.4)x10^-6 erg/cm2.

Assuming the redshift z=3.645 (de Ugarte Postigo et al., GCN 20584)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the burst isotropic energy release E_iso to ~1.7x10^53 erg
and the rest-frame peak energy of the time-integrated spectrum,
Ep,z, to ~1150 keV.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB170202A/

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


GRB_name: GRB170205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20605
SUBJECT: GRB 170205A: LCO FTN observations
DATE:    17/02/05 16:16:18 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

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

We observed Swift GRB 170205A (Troja et al. GCN 20603) on February 05, 
from 14:40 UT (2.0 hours since the GRB) with the 2-m LCO FTN in Hawaii 
with SDSS r and i filters. We detect the optical afterglow at the 
Swift-UVOT position with the following values:

Mid Time      Exposure       Filter       Magnitude (AB)
(hours)           (s)
-------------------------------------------------------
2.0             2x120         SDSS-R        20.3 +- 0.1
2.1             2x120         SDSS-I        20.0 +- 0.1
-------------------------------------------------------

as calibrated against nearby SDSS sources.


GRB_name: GRB170202A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20606
SUBJECT: GRB 170202A: SMARTS optical/IR afterglow observations
DATE:    17/02/05 16:55:09 GMT
FROM:    Bethany Cobb at GWU  <bcobb@gwu.edu>

B. E. Cobb (GWU) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 170202A
(GCN 20575, Racusin et al.) at three different epochs: 0.41671
[2017-02-03 04:28 UT], 0.53096 [2017-02-03 07:13 UT] and 2.39175
[2017-02-05 03:52 UT] days post-burst. At each epoch, total summed
exposure times amounted to 36 minutes in I and 30 minutes in J.

The afterglow of GRB 170202A (e.g. GCN 20575, Racusin et al.;
GCN 20576, Xin et al.; GCN 20578, Lipunov et al.) is detected
in our early images, with the preliminary magnitudes (and 3-sigma
limits) listed below. Note that the optical photometry is calibrated
against USNO-B1.0 stars in the field, so suffers from a large
photometric calibration error of about +/-0.3 magnitudes, which has
not been included in the errors quoted below. The IR photometry
is calibrated against the single 2MASS star in our field-of-view,
so similarly may include a large (but unknown) calibration error.

mid-exposure time
(days post-burst)  I mag             J mag
0.41671                20.1+/-0.1      18.9+/-0.1
0.53096                20.6+/-0.1      >18.5
2.39175                >21.0             >18.6


GRB_name: GRB170205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20609
SUBJECT: GRB 170205A: RATIR Optical and NIR Observations
DATE:    17/02/05 19:35:56 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), Neil Gehrels (GSFC), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and Vicki Toy
(UMD) report:

We observed the field of GRB 170205A (Troja, et al., GCN 20603) 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 2017/02 5.53 to 2017/02 5.58 UTC (2.3 minutes
to 1.25 hours after the BAT trigger), obtaining a total of 0.61 hours
exposure in the r and i bands and 0.29 hours exposure in the Z and Y bands.

In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following
detections for the optical afterglow (see, also, Guidorzi, et al., GCN
20605):

r = 18.31 +/- 0.01
i = 17.90 +/- 0.01
Z = 18.06 +/- 0.01
Y = 19.26 +/- 0.07

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The source fades (from i~16 mag)
as t^(-1.6) until ~15 minutes after the GRB, after which the fade flattens
to t^(-1.1).

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


GRB_name: GRB170205A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20610
SUBJECT: GRB 170205A: Enhanced Swift-XRT position
DATE:    17/02/05 21:51:08 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 2830 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 170205A, 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 = 262.16934, -0.06320 which is equivalent
to:

RA (J2000): 17h 28m 40.64s
Dec (J2000): -00d 03' 47.5"

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: GRB170205A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20611
SUBJECT: GRB 170205A: Swift-XRT refined Analysis
DATE:    17/02/06 05:18:00 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

We have analysed 10 ks of XRT data for GRB 170205A (Troja et al. GCN
Circ. 20603), from 271 s to 34.9 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Beardmore et al. (GCN Circ. 20610).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.89 (+0.03, -0.04).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.87 (+0.14, -0.13). The
best-fitting absorption column is  3.4 (+0.7, -0.6) x 10^21 cm^-2, in
excess of the Galactic value of 2.0 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 4.1 x 10^-11 (5.7 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.4 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 2.0 x 10^21 cm^-2
Excess significance: 3.8 sigma
Photon index:      1.87 (+0.14, -0.13)

If the light curve continues to decay with a power-law decay index of
0.89, the count rate at T+24 hours will be 0.021 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.5 x
10^-13 (1.2 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/00736843.

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


GRB_name: GRB170205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20612
SUBJECT: GRB 170205A: NOT afterglow observations
DATE:    17/02/06 11:00:35 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T. Kruehler (MPE Garching), D. Xu (NAOC,CAS), K. E. Heintz (Univ.
Iceland & DARK/NBI) and G. Fedorets (NOT) report on behalf of the
Nordic GRB collaboration:

We observed the field of GRB 170205A (Troja et al. GCN 20603)
with the NOT equipped with ALFOSC. Photometry in the r and i-band
started at 05:49 UTC on 2017-02-06, 17.2 hr after the GRB trigger,
and was obtained under adverse atmospheric conditions (seeing
around 2.5").

Calibrating our images against magnitudes of field stars from the
SDSS catalog, we measure preliminary brightnesses of the optical
afterglow (Troja et al. GCN 20603, Guidorzi et al. GCN 20605, Butler
et al. GCN 20609) of

r = 22.2 +- 0.2 mag and
i = 22.0 +- 0.2 mag.

These magnitudes are not corrected for the expected foreground
extinction corresponding to a reddening of E_B-V = 0.30 mag
(Schlafly & Finkbeiner 2011).


GRB_name: GRB170205A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20613
SUBJECT: GRB 170205A: Swift-BAT refined analysis
DATE:    17/02/06 14:52:41 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), 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-10 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170205A (trigger #736843)
(Troja, et al., GCN Circ. 20603).  The BAT ground-calculated position is
RA, Dec = 262.157, -0.058 deg which is
  RA(J2000)  =  17h 28m 37.8s
  Dec(J2000) = -00d 03' 30.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 91%.

The mask-weighted light curve shows that the burst consisted of two peaks of
roughly equal peak counts, the first from T-2 sec to T+12 sec and the second
from T+12 sec to T+30 sec.  T90 (15-350 keV) is 26.1 +- 3.2 sec (estimated
error including systematics). It is possible that the burst is longer than this since
there was no data before T-10 seconds, following the re-enabling of data collection
after an SAA passage.

The time-averaged spectrum from T-1.42 to T+46.40 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.85 +- 0.06.  The fluence in the 15-150 keV band is 3.8 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.30 sec in the 15-150 keV band
is 4.3 +- 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/736843/BA/


GRB_name: GRB170205A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20614
SUBJECT: Konus-Wind observation of GRB 170205A
DATE:    17/02/06 16:19:11 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 170205A
(Swift-BAT detection: Troja et al., GCN Circ. 20603),
triggered Konus-Wind at T0=45549.824 s UT (12:39:09.824).

The burst light curve shows a double-peaked structure which
started at ~T0-32 s and had a total duration of ~56 s.
The emission is seen up to ~1 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170205_T45549/

As observed by Konus-Wind, the burst
had a fluence of 1.22(-0.20,+0.24)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0-0.220 s,
of 3.29(-1.62,+1.99)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+24.832 s)
is best fit in the 20 keV - 10 MeV range
by a power law with spectral index = -2.19(-0.12,+0.13)
(chi2 = 58/69 dof).
Fitting this spectrum by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields
alpha = -1.75 (-0.24,+0.62) and
an upper limit on Ep of 75 keV (chi2 = 56/68 dof).
For the CPL model, the burst fluence is
6.2(-0.8,+1.4)x10^-6 erg/cm2,
and the 64-ms peak flux is 1.8(-0.8,+2.8)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

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


GRB_name: GRB170205A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20615
SUBJECT: GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
DATE:    17/02/06 16:33:17 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (UCL-MSSL), E. Troja (NASA/GSFC/UMCP) and A.A. Breeveld (UCL-MSSL)  
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170205A
314 s after the BAT trigger (Troja et al., GCN Circ. 20603).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 20610) and also detected by
Guidorzi et al. GCN 20605, Butler et al. GCN 20609 and Kruehler et al. GCN 20612
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  17:28:40.69 = 262.16955 (deg.)
    Dec (J2000) = -00:03:47.3  =  -0.06313 (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(FC)       314             464           147        17.52 +/- 0.04
u(FC)                520             540             19        17.30 +/- 0.22
white             4361           4561          197         20.84 +/- 0.33
v                         619        17292        1101        >20.3
b                         545             565             19         17.79 +/- 0.24
u                      3951        12169          785         20.65 +/- 0.33
w1                     496        10592          924        >20.6
m2                  6287        17909          741        >20.6
w2                  4567        16378        1082        >21.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.35 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB170206A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20616
SUBJECT: GRB 170206A: Fermi GBM observation
DATE:    17/02/06 18:04:50 GMT
FROM:    Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>

A. von Kienlin (MPE) and O.J. Roberts (USRA/NASA-MSFC) report 
on behalf of the Fermi GBM Team:

"At 10:51:57.70 UT on February 6th 2017, the Fermi Gamma-Ray
Burst Monitor triggered and located GRB 170206A
(trigger 508071122 /170206453). The on-ground calculated 
location, using the GBM trigger data, 

is RA = 211.80, DEC = +13.06, (J2000 degrees, equivalent to 
J2000 14h 07m, +/- 13d 03')

with an uncertainty of 1.14 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 67 degrees.

The GBM light curve shows a short, bright burst with a duration 
(T90) of about 1.2 s (50-300 keV). The time-averaged spectrum 
from T0+0.1s to T0+1.3 s is best fit by a BAND function, with 
alpha=  -0.28 +/- 0.04, beta= -2.55 +/- 0.12 and Epeak, 
is 341 +/- 13 keV.

The event fluence (10-1000 keV) in this time interval is
(1.34 +/- 0.02) E-05 erg/cm^2. The 64 ms peak photon flux 
measured starting from T0+0.6 s in the 10-1000 keV band is
57.0 +/- 2.1 ph/s/cm^2.

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


GRB_name: GRB170206A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20617
SUBJECT: GRB 170206A: Fermi-LAT detection
DATE:    17/02/06 20:02:31 GMT
FROM:    Donggeun Tak at UMCP/GSFC  <donggeun.tak@nasa.gov>

GRB 170206A: Fermi-LAT detection

F. Fana Dirirsa (U. Johannesburg ), D.Tak (UMD/NASA-GSFC), G. Vianello (Stanford Univ.), J. Racusin (NASA/GSFC), D. Kocevski (NASA/MSFC)  report on behalf of the Fermi-LAT team:

At 10:51:57.70 on February, 06, 2017 Fermi-LAT detected high-energy emission from GRB 170206A which was also detected by Fermi-GBM starting at 10:51:57.70 UT (trigger 508071122 /170206453; Oliver J Roberts et al. GCN 20616).  

The best LAT on-ground location is found to be

RA, Dec = 212.79,  14.48 (J2000)

with an error radius of 0.85 deg (90 % containment, statistical error only). 

This was 67 deg from the LAT boresight at the time of the trigger.

The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance. 

The highest-energy photon is a 811 MeV event which is observed 5.17 seconds after the GBM trigger.

The Fermi-LAT point of contact for this burst is Feraol Fana Dirirsa (fdirirsa@uj.ac.za <mailto: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: GRB170206B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20618
SUBJECT: GRB 170206B: Swift detection of a burst
DATE:    17/02/06 22:29:11 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
A. Cholden-Brown (PSU), J. A. Kennea (PSU),
F. E. Marshall (NASA/GSFC), B. Mingo (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-OAB),
B. Sbarufatti (INAF-OAB/PSU) and E. Troja (NASA/GSFC/UMCP) report on
behalf of the Swift Team:

At 21:57:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170206B (trigger=737125).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 271.786, +11.223, which is 
  RA(J2000) = 18h 07m 09s
  Dec(J2000) = +11d 13' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  Due to a processing outage, the real-time light curve
is not available at this time. 

Using promptly downlinked data we find an uncatalogued X-ray source
with an enhanced position: RA, Dec 271.7708, 11.1943 which is
equivalent to:
   RA(J2000)  = 18h 07m 04.98s
   Dec(J2000) = +11d 11' 39.4"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). 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 (1.13 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.8
(+2.82/-2.42) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 250 seconds with the U filter. 
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 18.0 mag. No correction has been made 
for the expected extinction of E(B-V) = 0.146. 

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: GRB170206B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20619
SUBJECT: GRB 170206B: Enhanced Swift-XRT position
DATE:    17/02/07 08:35:07 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 1338 s of XRT Photon Counting mode data and 1 UVOT  image, 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 = 271.77061, 11.19366 which is equivalent to:

RA (J2000):  18 07 04.95
Dec (J2000): +11 11 37.2

with an uncertainty of 1.9 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 is an official product of the Swift-XRT team.


GRB_name: GRB170206B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20620
SUBJECT: GRB 170206B: Swift-XRT refined Analysis
DATE:    17/02/07 09:46:41 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),
S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo
(INAF-OAB) and A.Y. Lien report on behalf of the Swift-XRT team:

We have analysed 7.4 ks of XRT data for GRB 170206B (Lien et al. GCN
Circ. 20618), from 88 s to 24.5 ks after the  BAT trigger. The data
comprise 7 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. Using 2057 s
of PC mode data and 3 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 = 271.77062, +11.19383 which is equivalent
to:

RA (J2000): 18h 07m 04.95s
Dec(J2000): +11d 11' 37.8"

with an uncertainty of 1.6 arcsec (radius, 90% confidence).

The light curve can be modelled with a power-law decay with a decay
index of alpha=2.48 (+0.19, -0.20).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.46 (+0.18, -0.17). The
best-fitting absorption column is  4.9 (+0.8, -0.7) x 10^21 cm^-2, in
excess of the Galactic value of 1.1 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 3.1 x 10^-11 (6.9 x 10^-11) erg
cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      4.9 (+0.8, -0.7) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: 8.5 sigma
Photon index:      2.46 (+0.18, -0.17)

If the light curve continues to decay with a power-law decay index of
2.48, the count rate at T+24 hours will be 2.5 x 10^-7 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.8 x
10^-18 (1.8 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/00737125.

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


GRB_name: GRB170206B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20622
SUBJECT: GRB 170206B: Swift-BAT refined analysis
DATE:    17/02/07 13:47:54 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), N. Gehrels (GSFC),
H. A. Krimm (NSF/USRA), 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+359 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170206B (trigger #737125)
(Lien et al., GCN Circ. 20618).  The BAT ground-calculated position is
RA, Dec = 271.784, 11.175 deg which is
   RA(J2000)  =  18h 07m 08.2s
   Dec(J2000) = +11d 10' 28.3"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%.

The mask-weighted light curve shows a weak pulse that starts at ~T0 and
ends at ~T+15 s. T90 (15-350 keV) is 13.36 +- 2.67 sec (estimated error
including systematics).

The time-averaged spectrum from T-0.33 to T+15.53 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.42 +- 0.27.  The fluence in the 15-150 keV band is 3.2 +- 0.6 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.32 sec in the 15-150 keV band
is 0.4 +- 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/737125/BA/


GRB_name: GRB170206A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20623
SUBJECT: IPN Triangulation of GRB 170206A (short/hard)
DATE:    17/02/07 21:01:15 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,

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 short-duration, hard-spectrum GRB 170206A
(Fermi-GBM detection: von Kienlin and Roberts, GCN Circ. 20616;
Fermi-LAT detection: Fana Dirirsa et al., GCN Circ. 20617)
was detected by Fermi (GBM), Konus-Wind, INTEGRAL (SPI-ACS),
and Mars-Odyssey (HEND) at about 39118 s UT (10:51:58).

We have triangulated it to a preliminary, 3 sigma error box whose
coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   212.633 (14h 10m 32s) +14.238 (+14d 14' 17")
  Corners:
   212.341 (14h 09m 22s) +14.997 (+14d 59' 50")
   212.901 (14h 11m 36s) +14.095 (+14d 05' 41")
   212.915 (14h 11m 40s) +13.455 (+13d 27' 20")
   212.365 (14h 09m 28s) +14.378 (+14d 22' 41")
  ---------------------------------------------
The error box area is 1156 sq. arcmin, and its maximum
dimension is 1.64 deg (the minimum one is 18.2 arcmin).
The Sun distance was 110 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB170206_T39121/IPN/

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


GRB_name: GRB170206A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20624
SUBJECT: GRB 170206A: POLAR observation
DATE:    17/02/07 21:13:46 GMT
FROM:    Yuanhao Wang at IHEP/CAS  <wangyuanhao@ihep.ac.cn>

Yuanhao Wang (IHEP), Shaolin Xiong (IHEP), Yi Zhao (IHEP)
report on behalf of the POLAR collaboration:

At 2017-02-06T10:51:57.70 UT (T0), during a routine on-ground 
search of data, POLAR detected the GRB 170206A, which was 
also detected by Fermi/GBM
(trigger 508071122/170206453; A. von Kienlin et al. GCN 20616), 
Fermi/LAT(F. Fana Dirirsa et al. GCN 20617) and 
INTEGRAL/SPIACS(trigger_num 7680).

The POLAR light curve consists of multiple peaks,
with a duration (T90) of 1.194 s measured from T0+0.147 s.
The 0.1s peak rate measured from T0+0.4s is 16145.2 cnts/s.
The total counts is about 12918 cnts.
LC_URL:
http://polar.ihep.ac.cn/grb/2017/02/GRB170206A/lc/POLAR_lc_grb170206A.png

The above result is not dead time corrected. The above 
measurements are in the energy range of about 20-500 keV.

Using the best location from the Fermi/LAT, which is (J2000):
RA:   212.79 [deg]
Dec:  +14.48 [deg]
Err:  0.85  [deg] (90% containment, statistical error only)

the incident angle in POLAR coordinate at T0 is:
theta: 19.5   [deg]
phi:   148.70 [deg]

The Minimum Detectable Polarization(MDP) for this burst is
estimated to be ~5.7% [1-sigma, statistical only]. 
Follow-up observations are strongly encouraged.

All analysis results presented above are preliminary.

POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV)
on-board the Chinese space laboratory Tiangong-2 launched on
Sep 15,2016. More information about POLAR can be found at 
http://polar.ihep.ac.cn/en/ , http://isdc.unige.ch/polar/
and http://polar.psi.ch/pub/ .


GRB_name: GRB170206A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20625
SUBJECT: Konus-Wind observation of GRB 170206A
DATE:    17/02/07 21:17:17 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 short-duration, hard-spectrum, bright GRB 170206A
(Fermi-GBM detection: von Kienlin and Roberts, GCN Circ. 20616;
Fermi-LAT detection: Fana Dirirsa et al., GCN Circ. 20617;
IPN triangulation: Hurley et al., GCN Circ. 20623)
triggered Konus-Wind at T0=39121.226 s UT (10:52:01.226).

The burst light curve shows a multipeaked structure
started at ~T0-0.2 s with a total duration of ~1.5 s.
The emission is seen up to ~15 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170206_T39121/

As observed by Konus-Wind, the burst
had a fluence of 1.49(-0.15,+0.16)x10^-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.306 s,
of 3.30(-0.64,+0.66)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+1.280 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 = 0.00(-0.20,+0.24),
the high energy photon index beta = -2.28(-0.18,+0.13),
the peak energy Ep = 260(-29,+33) keV
(chi2 = 58/61 dof)

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


GRB_name: GRB170206B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20626
SUBJECT: GRB 170206B: Swift/UVOT Upper Limits
DATE:    17/02/07 21:35:31 GMT
FROM:    Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>

S.W.K. Emery (UCL-MSSL) 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 170206B
106 s after the BAT trigger (Lien et al., GCN Circ. 20618).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 20619)
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           106          255          147         >20.3
u_FC               264          513          246         >19.6
white              106         1534          392         >20.7
v                  594         1411           97         >18.2
b                  519         1510           97         >19.1
u                  226         1484          343         >19.7
w1                 643         1460           97         >18.6
w2                 569         1386           97         >19.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.146 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB170207A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20628
SUBJECT: IPN Triangulation of GRB 170207A (long/very bright)
DATE:    17/02/08 15:27:25 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,

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

and

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team, report:

The long-duration, very bright GRB 170207A has been
detected by Fermi (GBM trigger 508196708), Konus-Wind, INTEGRAL 
(SPI-ACS), and Swift (BAT), so far, at about 78304 s UT (21:45:04).
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:
   315.704 (21h 02m 49s) +55.690 (+55d 41' 25")
  Corners:
   307.259 (20h 29m 02s) +52.583 (+52d 35' 00")
   325.165 (21h 40m 40s) +58.232 (+58d 13' 54")
   324.653 (21h 38m 37s) +57.713 (+57d 42' 46")
   306.905 (20h 27m 37s) +51.893 (+51d 53' 34")
  ---------------------------------------------
The error box area is 4.66 sq. deg, and its maximum
dimension is 12.17 deg (the minimum one is 24.0 arcmin).
The Sun distance was 70 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB170207_T78301/IPN/

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


GRB_name: GRB170207A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20629
SUBJECT: Konus-Wind observation of GRB 170207A
DATE:    17/02/08 17:11:32 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, very bright GRB 170207A
(IPN triangulation: Svinkin et al, GCN Circ. 20628)
triggered Konus-Wind at T0=78301.73 s UT (21:45:01.730).

The burst light curve shows three multipeaked emission episodes
which started at ~T0-0.3 s and had a total duration of ~42 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/GRB170207_T78301/

As observed by Konus-Wind, the burst
had a fluence of 7.84(-0.96,+0.85)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+18.016 s,
of 1.50(-0.21,+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+41.984 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 = -0.86(-0.06,+0.06),
the high energy photon index beta = -2.63(-0.84,+0.26),
the peak energy Ep = 394(-33,+42) keV
(chi2 = 106/97 dof)

The spectrum near the maximum count rate
(measured from T0+13.824 to T0+18.944 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 = -0.63(-0.08,+0.08),
the high energy photon index beta = -3.60(-6.40,+0.83),
the peak energy Ep = 524(-46,+56) keV
(chi2 = 107/82 dof)

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


GRB_name: GRB170207A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20630
SUBJECT: GRB 170207A: Fermi GBM observation
DATE:    17/02/08 18:17:45 GMT
FROM:    Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>

O.J. Roberts (USRA/NASA), B. Mailyan (UAH) and C. Meegan (UAH) 
report on behalf of the Fermi GBM Team:

"At 21:45:03.67 UT on February 7th 2017, the Fermi Gamma-Ray
Burst Monitor triggered and located GRB 170207A
(trigger 508196708 /170207906). This event was also detected 
by Konus Wind (Svinkin et al, GCN 20629) and localized by the 
IPN (Svinkin et al, GCN 20628). The on-ground calculated location 
using the GBM trigger data is,

RA = 325.87, DEC = +50.05 (J2000 degrees), equivalent to
J2000 21h 43m, +50d 03',

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 initial angle from the Fermi-LAT boresight to the GBM
ground-location is 94 degrees.

The GBM light curve shows a long burst with multiple
episodes of bright emission over a duration (T90) of about 
39 s (50-300 keV). The time-averaged spectrum from T0+0 s to 
T0+39 s is best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.92 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 499.4 +/- 19.5 keV.

A Band function fits the spectrum equally well, with
alpha= -0.91 +/- 0.02, beta= -2.68 +/- 0.28 and Epeak
is 478.8 +/- 23.1 keV.

The event fluence (10-1000 keV) in this time interval is
(5.86 +/- 0.07) E-05 erg/cm^2. The 1s peak photon flux
measured starting from T0+20.5 s in the 10-1000 keV band is
25.4 +/- 0.4 ph/s/cm^2.

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


GRB_name: GRB170208A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20631
SUBJECT: GRB 170208A: Swift detection of a burst
DATE:    17/02/08 18:27:27 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

A. Cholden-Brown (PSU), D. N. Burrows (PSU), J. A. Kennea (PSU),
A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester),
B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf
of the Swift Team:

At 18:11:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170208A (trigger=737438).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 166.563, -46.779 which is 
   RA(J2000) = 11h 06m 15s
   Dec(J2000) = -46d 46' 43"
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 10 sec.  The peak count rate
was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 18:13:16.4 UT, 120.2 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 166.5643,
-46.7674 which is equivalent to:
   RA(J2000)  = 11h 06m 15.44s
   Dec(J2000) = -46d 46' 02.6"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 41 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 (1.25 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 2.4
(+2.01/-1.79) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 124 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 BAT 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 0.13. 

Burst Advocate for this burst is A. Cholden-Brown (aaronb AT swift.psu.edu). 
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: GRB170208B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20632
SUBJECT: GRB 170208B: Swift detection of a burst
DATE:    17/02/08 22:50:18 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

M. H. Siegel (PSU), S. D. Barthelmy (GSFC), A. Cholden-Brown (PSU),
J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC)
and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:

At 22:33:38 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 170208B (trigger=737463).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 127.155, -9.027 which is 
   RA(J2000)  =  08h 28m 37s
   Dec(J2000) = -09d 01' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several overlapping peaks
with a total duration of about 40 sec.  The peak count rate
was ~14,500 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 22:34:40.6 UT, 61.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 127.14389,
-9.02979 which is equivalent to:
   RA(J2000)  = 08h 28m 34.53s
   Dec(J2000) = -09d 01' 47.2"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 40 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 (5.32 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.9
(+2.27/-2.01) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 7.16e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
126 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 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.05. 

Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 
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: GRB170208A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20633
SUBJECT: GRB 170208A: Fermi GBM Detection
DATE:    17/02/09 00:05:14 GMT
FROM:    Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>

O.J. Roberts (USRA/NASA) and C. Meegan (UAH) report on 
behalf of the Fermi GBM Team:

"At 18:11:16.40 UT on the 8th of February 2017, the Fermi
Gamma-Ray Burst Monitor triggered and located GRB 170208A
(trigger 508270281 / 170208758), which was also detected by 
Swift (A. Cholden-Brown et al. 2017, GCN 20631). The GBM 
on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger
time using the Swift-XRT position is 117 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of a long GRB with several
episodes of bright emission over a duration (T90) of about
7 s (50-300 keV). The time-averaged spectrum from T0+0 s
to T0+7.2 s is best fit by a power law function with an 
exponential high-energy cutoff.  The power law index is 
-0.92 +/- 0.09 and the cutoff energy, parameterized as Epeak 
is 246.9 +/- 30.5 keV

The event fluence (10-1000 keV) in this time interval is 
(3.10 +/- 0.19)E-06 erg/cm^2. The 1-sec peak photon flux
measured starting from T0-0.13 s in the 10-1000 keV band
is 8.1 +/- 0.4 ph/s/cm^2.

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


GRB_name: GRB170208A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20634
SUBJECT: GRB 170208A: Enhanced Swift-XRT position
DATE:    17/02/09 01:36:34 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 1316 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 170208A, 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 = 166.56468, -46.76827 which is equivalent
to:

RA (J2000): 11h 06m 15.52s
Dec (J2000): -46d 46' 05.8"

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: GRB170208B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20635
SUBJECT: GRB 170208B: Enhanced Swift-XRT position
DATE:    17/02/09 02:43:34 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 1870 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 170208B, 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 = 127.14385, -9.03002 which is equivalent
to:

RA (J2000): 08h 28m 34.52s
Dec (J2000): -09d 01' 48.1"

with an uncertainty of 2.2 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: GRB170208B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20636
SUBJECT: GRB 170208B: Etelman observatory optical observations
DATE:    17/02/09 05:22:46 GMT
FROM:    Bruce Gendre at ASDC  <bruce.gendre@gmail.com>

B. Gendre (UVI), N. Orange (OrangeWave Innovative Science, LLC), D.
Morris (UVI), A. Cucchiara (UVI), D. Drost (UVI), T. Giblin (USAF
Academy), J. Hakkila (College of Charleston), A. Klotz (IRAP), J. Neff
(NSF), D. Smith (UVI), J. Staff (UVI), P. Thierry (Auragne Observatory), 
R. Watlington (UVI), and L. Wentlent (UVI) report:

We observed the field of GRB 170208B (Siegel et al., GCN 20632) with the 
0.5m Virgin Island Robotic Telescope (VIRT) on February the 9th,
starting at 3:10 UT (4.7 hours after the trigger). We
performed a series of exposures in the clear filter. The weather
conditions were good during the  first hour of observation.

We co-added the exposures taken between 3h10UT and 4h17UT. At the 
position of the X-ray afterglow reported by Goad et al. (GCN 20635), we 
do not detect any optical emission, with an upper limit of R ~ 19 
(estimated from nearby USNO-B1 stars).

Magnitudes have not been corrected for Galactic extinction. The VIRT is
still in its commissioning phase.

This message can be cited.


GRB_name: GRB170208B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20637
SUBJECT: GRB 170208B: Swift-XRT refined Analysis
DATE:    17/02/09 09:00:40 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), B. Mingo (U. Leicester), A.
Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N.
Burrows (PSU) and M.H. Siegel report on behalf of the Swift-XRT team:

We have analysed 6.4 ks of XRT data for GRB 170208B (Siegel et al. GCN
Circ. 20632), from 50 s to 24.0 ks after the  BAT trigger. The data
comprise 260 s in Windowed Timing (WT) mode (the first 9 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 Goad et al.
(GCN Circ. 20635).

The late-time light curve (from T0+5.4 ks) can be modelled with a
power-law decay with a decay index of alpha=0.81 (+0.19, -0.20).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.46 (+/-0.05). The
best-fitting absorption column is  4.34 (+/-0.21) x 10^21 cm^-2, in
excess of the Galactic value of 5.3 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.07 (+0.15, -0.14)
and a best-fitting absorption column of 3.7 (+0.7, -0.6) 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 (5.9 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.7 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 5.3 x 10^20 cm^-2
Excess significance: 8.5 sigma
Photon index:      2.07 (+0.15, -0.14)

If the light curve continues to decay with a power-law decay index of
0.81, the count rate at T+24 hours will be 0.020 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.6 x
10^-13 (1.2 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/00737463.

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


GRB_name: GRB170208B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20638
SUBJECT: GRB 170208B: NOT upper limits
DATE:    17/02/09 11:33:49 GMT
FROM:    Kasper Elm Heintz at Univ. of Iceland and DARK/NBI  <heintz@dark-cosmology.dk>

K. E. Heintz (Univ. Iceland and DARK/NBI), D. Malesani (DARK/NBI and DTU Space), N. R. Tanvir (Univ. Leicester), A. de Ugarte Postigo (IAA-CSIC and DARK/NBI), A. J. Korn (Uppsala Univ.) and I. R. Losada (NOT, NORDITA, and Stockholm Univ.) report on behalf of a larger collaboration:

We observed the field of GRB 170208B (Siegel et al., GCN 20632) using the ALFOSC instrument equipped at the 2.56-m Nordic Optical Telescope (NOT). Observations started at 23:24:13.1 UT on 2017-02-08 (i.e., 50.5 min after the trigger). We obtained SDSS r- and z-band images with 3x300 s and 4x200 s exposures, respectively. The weather conditions were good with a measured seeing of 1.6 and 1.3 arcsec in the r- and z-band, respectively.

In the stacked r- and z-bands no optical afterglow of the burst is detected within the XRT error circle (Goad et al., 20635) at limiting magnitudes of m(r) < 22.5 and m(z) < 22.2 (all AB) mag, calibrated with nearby stars from the Pan-STARRS survey.


GRB_name: GRB170206C
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20639
SUBJECT: GRB 170206C: POLAR Observation
DATE:    17/02/09 13:49:21 GMT
FROM:    Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>

R. Marcinkowski (PSI), H. Xiao (PSI) and W. Hajdas (PSI) report on behalf
of the POLAR collaboration:

At 2017-02-06 11:40:10 UT(T0), during a routine on-ground search of data,
POLAR detected GRB 170206C, which was also marginally observed by
Integral/SPIACS (trigger 2017-02-06T11:40:10).

The POLAR light curve consists of 2 peaks with duration (T90) of
16.0 +/- 0.5 s measured from T0. The 0.5 s peak flux at T0 + 3.2 s is
equal to 1400 +/- 100 counts/sec. POLAR recorded about 9700 events
from the burst.
Above measurements are in the energy range of about 20 - 500 keV,
presented light curve is not deadtime corrected.

LC_URL: http://polar.psi.ch/triggers/GRB_170206C_raw.png
     or http://polar.psi.ch/pub/lc.php?event=GRB+170206C

The analysis results presented above are preliminary. Calibration of the
instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter
which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2)
on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.
More information about POLAR can be found at http://polar.psi.ch/pub ,
http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .

This message is quotable in publications.


GRB_name: GRB170208B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  20640
SUBJECT: GRB 170208B: GROND observations
DATE:    17/02/09 14:08:32 GMT
FROM:    Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>

T. Kruehler (MPE Garching) reports:

I observed the field of GRB 170208B (Swift trigger 737463; Siegel
et al. GCN 20632) simultaneously in g'r'i'z'JHK with GROND
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG
telescope at the ESO La Silla Observatory (Chile).

Observations started at 01:22 UT on 2017-02-09, 2.8 hr after the
GRB trigger and reveal a faint optical source centered at:

RA (J2000): 08:28:34.55
Dec (J2000): -09:01:38.1

which is 2.0" away from the center of the XRT error circle
(Goad et al. GCN 20635, current 90% error radius of 1.6").

Based on combined images with 66 min of total exposures in g'r'i'z'
and 60.0 min in JHK at a mid-time of 02:39 UT on 2017-02-09, this
source has the following preliminary magnitudes and upper limits
(all in the AB system):

g' = 24.5 +- 0.4 mag
r' = 24.4 +- 0.3 mag
i' = 23.4 +- 0.2 mag
z' = 23.1 +- 0.2 mag
J > 21.3 mag
H > 21.0 mag
K > 19.0 mag

Given magnitudes are calibrated against Pan-STARRS and 2MASS field
stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=0.042 mag in the
direction of the burst (Schlafly & Finkbeiner 2011).

This source is marginally detected already in the archival Pan-STARRS
imaging of the field, so it is not the GRB 170208B afterglow. It is,
however, a possible host galaxy candidate (the chance coincidence
probability of finding a similarly bright object at 2" from the XRT
position is around 6%).

I acknowledge excellent help in obtaining these data from the
supporting astronomers on La Silla, Sam Kim and Simon Steinmassl.


