# GCN_circulars

GRB_name: GRB110315A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11791
SUBJECT: GRB 110315A: MASTER early optical observations
DATE:    11/03/16 09:37:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina,
D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov,
D.Zimnukhov, M. Kornilov, A.V.Krylov, V.Shumkov, S.Shurpakov
Sternberg Astronomical Institute, Moscow State University


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


V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka

K.Ivanov, O.Chuvalaev, V.Poleschuk, E.Konstantinov, V.Lenok, O.Gres,
S.Yazev, N.M.Budnev,
Irkutsk State University


MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Kislovodsk was pointed to the GRB110315A (Melandri et al., GCN 
11790) 44 sec s 
after notice time and 89 sec after GRB time at 2011-03-15 23:58:33.212 UT.
On our first (20s exposure) set we haven't found optical transient  within 
SWIFT BAT error-box (ra=18 36 45 dec=+17 31 48 ).
The 3-sigma upper limit has been about 17.3 mag
The upper limit for 25 coadded images is 20.0 started 23:58:33.212 UT 
(mean time after trigger is 3240 sec ). 
The Galactic absroption in this direction is about 1 mag (Kalbela et al., 
2005, A&A,440,775).

The message may be cited.


mailto: lipunov@sai.msu.ru


GRB_name: GRB110315A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11792
SUBJECT: GRB 110315A: Enhanced Swift-XRT position
DATE:    11/03/16 12:21:48 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 8887 s of XRT Photon Counting mode data and 15 UVOT
images for GRB 110315A, 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 = 279.19531, +17.53899 which is equivalent
to:

RA (J2000): 18h 36m 46.87s
Dec (J2000): +17d 32' 20.4"

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: GRB110315A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11793
SUBJECT: GRB 110315A: Swift-BAT refined analysis
DATE:    11/03/16 13:47:11 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), C. B. Markwardt (GSFC),
A. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(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 110315A (trigger #449399)
(Melandri, et al., GCN Circ. 11790).  The BAT ground-calculated position is
RA, Dec = 279.205, 17.537 deg which is 
   RA(J2000)  =  18h 36m 49.2s 
   Dec(J2000) = +17d 32' 13.9" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 57%.
 
The mask-weighted light curve shows a multi-peak structure starting 
at ~T-70 sec, with several peaks of approximate equal brightness
at T-21, T-3, T+3, and T+17 sec, and then returning to background
at ~T+90 sec.  There is weak emission (~2 sigma) in the BAT 15-25 keV band
starting at ~T+440 out to ~T+580 sec.  This is likley associated with the flare
in the XRT lightcurve at ~T+500 sec.  T90 (15-350 keV) is 77 +- 12 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-66.8 to T+38.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.77 +- 0.08.  The fluence in the 15-150 keV band is 4.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+3.13 sec in the 15-150 keV band
is 1.7 +- 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/449399/BA/


GRB_name: GRB110315A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11794
SUBJECT: GRB 110315A: Swift-XRT refined Analysis
DATE:    11/03/16 15:26:41 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

A. Melandri, B. Sbarufatti, R. Margutti and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift-XRT team:

We have analysed 14 ks of XRT data for GRB 110315A (Melandri  et al.
GCN Circ. 11790), from 94 s to 34.8 ks after the  BAT trigger. The data
comprise 97 s in Windowed Timing (WT) mode (the first 8 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 11792).

The light curve can be modelled with an initial power-law decay with an
index of alpha=2.48 (+0.64, -0.53), followed by a break at T+150 s to
an alpha of 1.03 (+0.03, -0.03). Flaring activity is detected around
T+500 s.

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.14 (+0.26, -0.24). The
best-fitting absorption column is  2.5 (+0.8, -0.7) x 10^21 cm^-2, in
excess of the Galactic value of 1.8 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.19 (+0.15, -0.12)
and a best-fitting absorption column of 2.7 (+/-0.4) 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 (6.7 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.7 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 1.8 x 10^21 cm^-2
Excess significance: 10.0 sigma
Photon index:      2.19 (+0.15, -0.12)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00449399.

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


GRB_name: GRB110315A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11795
SUBJECT: GRB 110315A: Swift/UVOT Upper Limits
DATE:    11/03/16 15:54:41 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) and A. Melandri (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110315A
113 s after the BAT trigger (Melandri et al., GCN Circ. 11790).
No optical afterglow consistent with the enhanced XRT position
(Beardmore et al., GCN Circ. 11792) is detected in the initial UVOT
exposures.  Preliminary 3-sigma upper limits using the UVOT photometric
system (Poole et al. 2008, MNRAS, 383, 627) for the first finding
chart (FC) exposure and subsequent exposures are:

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

white_FC           113          263          147         >20.5
u_FC               325          559          230         >19.7
white              113        12119         1275         >21.8

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.25 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110315A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11796
SUBJECT: GRB 110315A: RTT150 optical observations
DATE:    11/03/16 21:19:32 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

I. Bikmaev, R. Zhuchkov, N. Sakhibullin (Kazan University),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
Z. Eker, I. Khamitov (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)

report:

The field of GRB 110315A (Melandri et al., GCN 11790) was observed
with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK
National Observatory, Turkey) in March 16, 2011, during UT 01:05 -
03:15, i.e. starting approximately 1 hour after the burst. A serie of
21 exposures by 300 sec each in Rc filter was obtained.

We found no optical source within the 1.4'' enhanced XRT error circle
(Beardmore et al., GCN 11792) in our combined image at a limiting
magnitude of Rc =~ 23.6 mag.


GRB_name: GRB110318A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11798
SUBJECT: GRB 110318A: Swift detection of a burst
DATE:    11/03/18 13:21:49 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

B. Sbarufatti (INAF-OAB/IASFPA), S. D. Barthelmy (GSFC),
M. M. Chester (PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), C. Gronwall (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
R. Margutti (INAF-OAB), A. Melandri (INAF-OAB),
K. L. Page (U Leicester), P. Romano (INAF-IASFPA),
C. J. Saxton (UCL-MSSL), M. H. Siegel (PSU),
E. Sonbas (GSFC/USRA/Adiyaman Univ.) and C. A. Swenson (PSU) report on
behalf of the Swift Team:

At 13:14:19 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110318A (trigger=449542).  Swift did not slew to the burst
because of the Sun observing constraint. 
The BAT on-board calculated location is 
RA, Dec 338.274, -15.282, which is 
   RA(J2000)  =  22h 33m 06s
   Dec(J2000) = -15d 16' 55"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows two main peaks
with a duration of about 20 sec.  The peak count rate
was ~7000 counts/sec (15-350 keV), at ~2 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 05:00 UT on 2011 April 11. There will thus be no XRT or
UVOT data for this trigger before this time. 

Burst Advocate for this burst is B. Sbarufatti (boris.sbarufatti AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB110318B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11799
SUBJECT: GRB 110318B: Swift detection of a burst
DATE:    11/03/18 15:38:31 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

R. Margutti (INAF-OAB), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
S. Campana (INAF-OAB), P. D'Avanzo (INAF-OAB),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), C. Gronwall (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), O. M. Littlejohns (U Leicester),
V. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
P. T. O'Brien (U Leicester), J. P. Osborne (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.) and
C. A. Swenson (PSU) report on behalf of the Swift Team:

At 15:27:09 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110318B (trigger=449549).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 211.695, -51.559, which is 
   RA(J2000)  =  14h 06m 47s
   Dec(J2000) = -51d 33' 31"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a couple peaks
with a total duration of about 10 sec.  The peak count rate
was ~1100 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 15:28:22.5 UT, 72.8 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 211.67805, -51.57933 which
is equivalent to:
   RA(J2000)  = 14h 06m 42.73s
   Dec(J2000) = -51d 34' 45.6"
with an uncertainty of 3.8 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. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 2.42
x 10^21 cm^-2 (Kalberla et al. 2005). 

The UVOT processed images are delayed and will be analyzed as soon as
possible. 

Burst Advocate for this burst is R. Margutti (raffaella.margutti AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB110318B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11800
SUBJECT: GRB 110318B: Swift detection of a burst
DATE:    11/03/18 15:39:27 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

R. Margutti (INAF-OAB), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
S. Campana (INAF-OAB), P. D'Avanzo (INAF-OAB),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), C. Gronwall (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), O. M. Littlejohns (U Leicester),
V. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
P. T. O'Brien (U Leicester), J. P. Osborne (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.) and
C. A. Swenson (PSU) report on behalf of the Swift Team:

At 15:27:09 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110318B (trigger=449549).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 211.695, -51.559, which is 
   RA(J2000)  =  14h 06m 47s
   Dec(J2000) = -51d 33' 31"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a couple peaks
with a total duration of about 10 sec.  The peak count rate
was ~1100 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 15:28:22.5 UT, 72.8 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 211.67805, -51.57933 which
is equivalent to:
   RA(J2000)  = 14h 06m 42.73s
   Dec(J2000) = -51d 34' 45.6"
with an uncertainty of 3.8 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. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 2.42
x 10^21 cm^-2 (Kalberla et al. 2005). 

The UVOT processed images are delayed and will be analyzed as soon as
possible. 

Burst Advocate for this burst is R. Margutti (raffaella.margutti AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB110318B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11801
SUBJECT: GRB 110318B: Swift/UVOT Non-Detection of an Afterglow
DATE:    11/03/18 16:00:34 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) &
R. Margutti (INAF-OAB)
report on behalf of the Swift/UVOT team:

     UVOT took a finding chart exposure of the field of GRB 110318B
(Margutti et al. 2011, GCNC 11800) of 150 seconds with the White
filter starting 77 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. No correction has been
made for the expected extinction corresponding to E(B-V) of 0.46.


GRB_name: GRB110318A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11802
SUBJECT: GRB 110318A: Swift-BAT refined analysis
DATE:    11/03/18 18:14:45 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), B. Sbarufatti (INAF-OAB/IASFPA),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-114 to T+595 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110318A (trigger #449542)
(Sbarufatti, et al., GCN Circ. 11798).  The BAT ground-calculated position is
RA, Dec = 338.292, -15.278 deg, which is 
   RA(J2000)  =  22h 33m 10.0s 
   Dec(J2000) = -15d 16' 40.9" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 27%.
 
The mask-weighted light curve shows a small precursor peak between T-8 and
T-2 sec.  The main peak starts at ~T-1 sec, peaks at ~T+1 sec, and ends
at ~T+15 sec.  T90 (15-350 keV) is 16.0 +- 1.7 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-13.0 to T+10.6 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.05 +- 0.23, 
and Epeak of 94.3 +- 23.7 keV (chi squared 43.1 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 4.9 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+1.95 sec in the 15-150 keV band is
8.0 +- 0.5 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.58 +- 0.05 (chi squared 59.4 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/449542/BA/


GRB_name: GRB110318B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11803
SUBJECT: GRB 110318B: Enhanced Swift-XRT position
DATE:    11/03/18 20:21:19 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 1818 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 110318B, 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 = 211.67808, -51.57883 which is equivalent
to:

RA (J2000): 14h 06m 42.74s
Dec (J2000): -51d 34' 43.8"

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: GRB110318B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11804
SUBJECT: GRB 110318B: Swift-BAT refined analysis
DATE:    11/03/18 21:01:05 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
R. Margutti (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110318B (trigger #449549)
(Margutti, et al., GCN Circ. 11799).  The BAT ground-calculated position is
RA, Dec = 211.691, -51.577 deg, which is 
   RA(J2000)  =  14h 06m 45.9s 
   Dec(J2000) = -51d 34' 35.7" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 85%.
 
The mask-weighted light curve shows a single peak starting at ~T-2 sec,
peaking at ~T+1 sec, and ending at ~T+5 sec.  T90 (15-350 keV) is
4.8 +- 0.6 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.7 to T+3.7 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.09 +- 0.17.  The fluence in the 15-150 keV band is 2.9 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.76 sec in the 15-150 keV band
is 0.7 +- 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/449549/BA/


GRB_name: GRB110318A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11805
SUBJECT: GRB 110318A: Fermi GBM detection
DATE:    11/03/18 22:15:54 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick@ucdconnect.ie>

G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team:


"At 13:14:16.70 UT on 18th March 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110318 (trigger 322146858 / 110318552),
which was also detected by the Swift/BAT (Sbarufatti et al. 2011,
GCN 11798). The GBM on-ground location is consistent with the Swift
position.


The angle from the Fermi LAT boresight is 70 degrees.


The GBM light curve consists of single peak
with a duration (T90) of about 12 s (50-300 keV).
The time-averaged spectrum from T0-1 s to T0+10 s is 
fit well with a power law function with an exponential
high-energy cutoff. The power law index is -0.86 +/- 0.04 and
the cutoff energy, parameterized as Epeak, is 114.70 +/- 3.72 keV


A Band function fits the spectrum equally well with Epeak= 107.00 +/- 5.18
keV, alpha =-0.80 +/- 0.05, and beta = -2.74 +/- 0.25.


The event fluence (10-1000 keV) in this time interval is
(8.05 +/- 0.15)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1 s in the 8-1000 keV band
is 10.97 +/- 0.29 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(19mar11): Per author's request, the citation
for GCN Circ 11798 was corrected.]


GRB_name: GRB110318B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11806
SUBJECT: GRB 110318B: Swift-XRT refined Analysis
DATE:    11/03/18 23:46:59 GMT
FROM:    Raffaella Margutti at U. di Milano Bicocca  <raffaella.margutti@brera.inaf.it>

R. Margutti, B. Sbarufatti, A. Melandri (INAF-OAB) report on behalf of
the Swift-XRT team:

We have analysed 4.9 ks of XRT data for GRB 110318B (Margutti  et al.
GCN Circ. 11799), from 83 s to 13.4 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Evans et al. (GCN. Circ 11803).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.10 (+0.10, -0.09).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.3 (+/-0.3). The
best-fitting absorption column is  5.2 (+1.5, -1.3) x 10^21 cm^-2, in
excess of the Galactic value of 2.4 x 10^21 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.3 x 10^-11 (9.8 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.2 (+1.5, -1.3) x 10^21 cm^-2
Galactic foreground: 2.4 x 10^21 cm^-2
Excess significance: 6.5 sigma
Photon index:      2.3 (+/-0.3)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00449549.

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


GRB_name: GRB110319A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11807
SUBJECT: GRB 110319A: Swift detection of a burst
DATE:    11/03/19 02:31:37 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), P. D'Avanzo (INAF-OAB),
J. M. Gelbord (PSU), C. Gronwall (PSU),
S. T. Holland (CRESST/USRA/GSFC), N. P. M. Kuin (UCL-MSSL),
R. Margutti (INAF-OAB), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
B. Sbarufatti (INAF-OAB/IASFPA) and M. H. Siegel (PSU) report on
behalf of the Swift Team:

At 02:16:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110319A (trigger=449578).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA, Dec 356.401, -66.017 which is 
   RA(J2000) = 23h 45m 36s
   Dec(J2000) = -66d 01' 01"
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 ~30 sec.  The peak count rate
was ~3800 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 02:17:37.5 UT, 55.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
356.5017, -66.0114 which is equivalent to:
   RA(J2000)  = 23h 46m 0.40s
   Dec(J2000) = -66d 00' 40.9"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 148 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 2.62
x 10^20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 1.10e-09 erg cm^-2 s^-1 (0.2-10
keV). 

     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' x 2.7' sub-image covers 100% of the XRT error circle.  The typical
3-sigma upper limit has been about 19.6 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. Melandri (andrea.melandri AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB110319A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11808
SUBJECT: GRB 110319A: Enhanced Swift-XRT position
DATE:    11/03/19 07:59:32 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 285 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110319A, 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 = 356.50181, -66.01113 which is equivalent
to:

RA (J2000): 23h 46m 0.43s
Dec (J2000): -66d 00' 40.1"

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

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

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


GRB_name: GRB110318B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11809
SUBJECT: GRB 110318B: GROND upper limits
DATE:    11/03/19 09:10:25 GMT
FROM:    Thomas Kruehler at MPE/MPI  <kruehler@mpe.mpg.de>

T. Kruehler, J. Greiner, F. Schrey (all MPE Garching), and S. Klose (TLS
Tautenburg) report on behalf of the GROND team.

We observed the field of GRB 110318B (Swift trigger 449549; Margutti et
al., GCN #11800 simultaneously in g'r'i'z' with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla
Observatory (Chile).

Observation started at 07:40 UT, which is 16.2 h after the trigger, and
were obtained under clear skies with an airmass of around 1.1 and seeing
of 1"

In stacked images with a total integration time of 25 min, we do not
detect a source in the refined XRT error circle (Evans et al., GCN #11803)
to the following upper limits (AB system):

g' > 23.7
r' > 23.6
i' > 23.6
z' > 23.4

Given magnitudes are calibrated against GROND zeropoints and are not
corrected for the expected Galactic foreground extinction corresponding to
a reddening of E_(B-V)=0.46 mag in the direction of the burst (Schlegel et
al. 1998).

GROND is currently undergoing hardware maintenance, and hence no NIR data
are available for this burst.


GRB_name: GRB110319A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11810
SUBJECT: GRB 110319A: Swift-XRT refined Analysis
DATE:    11/03/19 13:59:42 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

A. Melandri, B. Sbarufatti and R. Margutti (INAF-OAB) reports on behalf
of the Swift-XRT team:

We have analysed 9.9 ks of XRT data for GRB 110319A (Melandri  et al.
GCN Circ. 11807), from 47 s to 23.4 ks after the  BAT trigger. The data
comprise 33 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 Goad et al.
(GCN. Circ 11808).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=3.7 (+0.6, -0.3). At T+151 s  the decay
flattens to an alpha of -0.63 (+0.07, -0.65). The light curve breaks
again at T+4335 s to a decay with alpha=0.98(+0.11, -0.10).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.4 (+0.4, -0.3). The
best-fitting absorption column is  2.4 (+0.7, -0.6) x 10^21 cm^-2, in
excess of the Galactic value of 2.6 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.33 (+0.13, -0.14)
and a best-fitting absorption column of 1.16 (+0.32, -0.18) x 10^21
cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.3 x 10^-11 (5.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.16 (+0.32, -0.18) x 10^21 cm^-2
Galactic foreground: 2.6 x 10^20 cm^-2
Excess significance: 10.8 sigma
Photon index:      2.33 (+0.13, -0.14)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00449578.

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


GRB_name: GRB110319A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11811
SUBJECT: GRB 110319A: Swift-BAT refined analysis
DATE:    11/03/19 14:28:25 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
A. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110319A (trigger #449578)
(Melandri, et al., GCN Circ. 11807).  The BAT ground-calculated position is
RA, Dec = 356.510, -66.008 deg, which is 
   RA(J2000)  =  23h 46m 02.4s 
   Dec(J2000) = -66d 00' 28.7" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows two overlapping peaks starting
at ~T_zero, peaking at ~T+5 and ~T+13 sec, and ending at ~T+30 sec.
T90 (15-350 keV) is 19.3 +- 1.6 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.3 to T+31.3 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.31 +- 0.43, 
and Epeak of 21.9 +- 7.0 keV (chi squared 54.2 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+13.10 sec in the 15-150 keV band is
2.2 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.55 +- 0.08 (chi squared 86.5 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/449578/BA/
 


GRB_name: GRB110319A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11812
SUBJECT: GRB 110319A: Swift/UVOT Detection
DATE:    11/03/19 15:19:16 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@astro.psu.edu>

M. H. Siegel (PSU), S. T. Holland (CRESST/USRA/GSFC) and A. Melandri  
(INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110319A
65s after the BAT trigger (Melandri et al, GCN Circ 11807). We identify
an optical afterglow near the enchanced XRT position given by Melandri
et al. (GCN Circ. 11810).  The transient is only detected in the optical
filters and shows fading between the first and second orbits.

The preliminary UVOT position is:

     RA (J2000)  23:46:00.69  =  356.50287 (deg)
    Dec (J2000) -66:00:40.4   =  -66.01122 (deg)

with an estimated uncertainty of 0.44 arcsec (radius, 90% confidence,
statistical + systematic).  Preliminary 3-sigma upper limits and  
magnitudes
using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627)  
for the
exposures are:

Filter    T_start(s) T_stop(s)  Exp(s)   Mag
white (fc)      65      215    147     18.36+-0.07
white         3924     5560    393     20.32+-0.22
v             4336     5971    393    >19.56
b             3719     5355    393     19.51+-0.21
b            11317    11950    615    >20.63
u              277      395    115     18.13+-0.13
u             4950    11310   1081     19.76+-0.18
uvw1          4745     4945    196    >19.72
uvw1          9497    10397    885    >20.58
uvm2          4540     4740    196    >19.64
uvm2          5976     6172    193    >19.69
uvw2          4131     4330    196    >19.91
uvw2          5566     5766    196    >19.91

The values quoted above 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: GRB110319B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11813
SUBJECT: GRB 110319B found in ground analysis of Swift-BAT data
DATE:    11/03/20 02:31:42 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings (UMBC/CRESST/NASA-GSFC), D. M. Palmer (Los Alamos),
B. Sbarufatti (INAF-OAB/IASFPA), C. Gronwall (PSU)

At 19:34:02, during a Swift slew, Fermi GBM detected a burst.  The
IPN was alerted.  In a mosaic image of BAT slew event data a strong
source is found at RA, Dec 326.074, -56.773, which is:

RA (J2000)  21h 44m 17.8s
Dec (J2000) -56d 46m 24s

with an estimated uncertainty of 3 arcmin radius (90% confidence).
The burst was in the fully-coded field of view from the trigger
time to the end of the Swift slew.  This position is 60 degrees
(2.2 hours) from the Sun.

GRB 110319B was a long GRB with a T90 about 18 seconds. The
lightcurve as seen by BAT was a single FRED.

A Swift TOO is scheduled to begin at 03:10 March 20, 2011.

The BA for this burst is B. Sbarufatti (INAF-OAB/IASFPA).


GRB_name: GRB110319B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11814
SUBJECT: GRB 110319B: Swift-XRT afterglow candidate.
DATE:    11/03/20 12:01:02 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF-OAB/IASFPA) report on behalf of the Swift-XTR team

We have analysed 4.9 ks of XRT data for the Swift/BAT-detected burst:
GRB110319B (Cummings et al. et al. GCN Circ. 11813), from 27.7 ks to 35.9
ks after the  Swift/BAT trigger. The data are entirely in Photon
Counting (PC) mode.  An X-ray source is detected within the Swift/BAT
error circle. Using 2442 s of PC mode data and 2 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 = 326.09490,
-56.78240 which is equivalent to:

RA (J2000): 21h 44m 22.77s
Dec(J2000): -56d 46' 56.5"

with an uncertainty of 2.4 arcsec (radius, 90% confidence). This
position is 53 arcsec from the Swift/BAT position.  The source has a
mean count rate of 9.4e-03 ct/sec; we cannot determine at the present
time whether it is fading.

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


GRB_name: GRB110319B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11815
SUBJECT: GRB 110319B: GROND upper limits
DATE:    11/03/20 15:19:22 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

A. Updike (GSFC), J. Greiner, T. Kruehler, F. Schrey (all MPE Garching), 
A. Nicuesa Guelbenzu and S. Klose (both TLS Tautenburg) report on behalf 
of the GROND team.

We observed the field of GRB 110319B (GBM trigger 322256044 at 19:34:02 UT; 
Swift slew source, Cummings et al., GCN #11813) simultaneously in g'r'i'z'JHK 
with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO 
telescope at La Silla Observatory (Chile).

Observation started at 08:24 UT, which is 12.9 h after the trigger, and
were obtained under clear skies with an airmass of around 2.0 and seeing
of 1.6".

In stacked images with a total integration time of 25 min in g'r'i'z and
20 min in JHK (mid-time 9:12 UT), we do not detect a source in the 2.4" XRT 
error circle of the X-ray counterpart candidate (Sbarufatti et al., 
GCN #11814) to the following 3-sigma upper limits (AB system):

g' > 23.1 
r' > 23.2 
i' > 23.2 
z' > 23.2 
J  > 21.1 
H  > 20.5


These magnitudes are calibrated against GROND zeropoints and are not
corrected for the expected Galactic foreground extinction corresponding to
a reddening of E_(B-V)=0.03 mag in the direction of the burst (Schlegel et
al. 1998).

GROND is currently cooling down after hardware maintenance, and hence no 
proper K band data are available for this burst.


GRB_name: GRB110318B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11816
SUBJECT: GRB 110318B: Swift/UVOT Upper Limits 
DATE:    11/03/21 14:53:29 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) and
R. Margutti (INAF-OAB)
report on behalf of the Swift/UVOT team:

      The Swift/UVOT observed the field of GRB 110318B starting 58 s
after the BAT trigger (Margutti, et al., 2011, GCN Circ. 11799).
Settled observations started at 76 s.  We do not detect an optical
afterglow at the UVOT-enhanced XRT position (Evans, et al., 2011, GCN
Circ. 11803) in any of the UVOT filters.  Preliminary 3-sigma upper
limits for detecting a source in the finding charts and in the
co-added images, are

Filter      T_start   T_stop    Exp(s)      Mag
-----------------------------------------------
white (fc)       76      226       147    >21.5
                868     1018       147    >21.5

    v           619     7035       529    >20.6
    b           545     7693       370    >21.2
    u           289     7649       756    >21.2
 uvw1           668     7445       529    >20.8
 uvm2          5602     7239       393    >20.5
 uvw2          1024     6829       236    >20.3
white            76     6623       626    >22.2
-----------------------------------------------

     The quoted magnitudes and upper limits have not been corrected
for the expected Galactic extinction along the line of sight
corresponding to a reddening of E_{B-V} = 0.46 mag (Schlegel, et al.,
1998, ApJS, 500, 525).


GRB_name: GRB110319B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11817
SUBJECT: GRB 110319B: Swift/UVOT Upper Limits
DATE:    11/03/21 21:07:01 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F.E. Marshall (NASA/GSFC) and B. Sbarufatti (INAF-OAB/IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110319B
27685 s after the Fermi/GBM trigger (Cummings et al., GCN Circ. 11813).
No optical afterglow consistent with the XRT position
(Sbarufatti, GCN Circ. 11814) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are:

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

white            28512        35117         1570         >21.8
v                29340        35964         1678         >20.0
u                27685        34323         1597         >20.8

The values quoted above 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: GRB110319B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11818
SUBJECT: GRB 110319B BAT refined analysis
DATE:    11/03/22 15:38:58 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), A. Melandri (INAF-OAB), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):

Using the data set from T-48 to T+52 sec, we report further analysis of
GRB 110319B (Cummings, et al., GCN Circ. 11813).  The refined BAT position
is RA, Dec =  326.088, -56.774 deg, which is
    RA(J2000)  =  21h 44m 21.1s
    Dec(J2000) =  -56d 46m 26s
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
This position is 33 arcsec from the XRT position of the candidate
afterglow.  The partial coding was 100%.

The mask-weighted light curve shows a single FRED peak starting at ~T-3 sec,
peaking at ~T0, and ending at ~T+20 sec.  T90 (15-350 keV) is 14.5 +- 2 sec
(estimated error including systematics).

The time-averaged spectrum from T-3.5 to T+16.5 sec is best fit by a simple
power law.  This fit gives a photon index 1.39 +- 0.05.  For this
model the total fluence in the 15-150 keV band is 1.0 +- 0.1 x 10-6  erg/cm2
and the 1-sec peak flux measured from T0 sec in the 15-150 keV band is
1.25 +- 0.15 ph/cm2/sec.


GRB_name: GRB101225A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11819
SUBJECT: GRB 101225A: revised analysis of narrow band imaging
DATE:    11/03/22 19:16:23 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir (U. Leicester) and A. J. Levan (U. Warwick) report:

We have re-reduced and re-analysed more thoroughly the imaging reported
in GCN 11642. While it remains the case that the optical transient is
detected in the H-alpha narrow-band filter, and at best marginally present
in the r-band, the significance of the excess H-alpha detection is reduced. 
Within the associated errors the revised photometry is broadly consistent
with the red colour of the transient at this time (the narrow-band filter being
somewhat redward of the central wavelength of the r-band filter), and hence,
the data do not require significant line emission. This argument for a z~0
origin is therefore weakened.


GRB_name: GRB110319B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11820
SUBJECT: GRB 110319B Swift-XRT afterglow confirmation 
DATE:    11/03/24 16:31:02 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF-OAB/IASFPA) reports on behalf of the Swift-XRT team:

Swift performed a second target of opportunity observation of
GRB 110319B on March 23, 2011.

The XRT began observing the field at 2011-03-23 17:57:33 UT, that is
T+340 ks ( 3.9 days) (Cummings, GCN Circ. 11813).
Using 4.9 ks of Photon Counting mode data we find that the source
reported previously (Sbarufatti, GCN Circ. 11814) has faded down to
a 3-sigma upper limit of 0.002 counts/s.
Assuming a power law decay starting from the first source detection
the upper limit is consistent with a decay index steeper than
alpha = 0.6.

The fading nature of the source confirms its afterglow origin.

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


GRB_name: GRB110318B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11822
SUBJECT: GRB110318B : MOA optical upper limit
DATE:    11/03/25 16:40:17 GMT
FROM:    Suzuki Daisuke at MOA-II  <dsuke@stelab.nagoya-u.ac.jp>

D. Suzuki (STE Lab. Nagoya Univ.), P.J. Tristram (Mt. John University
Observatory),
S. Kobara, K. Omori, H. Naito and T. Sako (STE Lab. Nagoya Univ.)
on behalf of the MOA Collaboration report :

We searched for an optical afterglow of GRB110318B (GCN 11799, R. Margutti
et al.)
starting from 15:40 UT on 2011 March 18 (13 minutes after the burst)
with the MOA-II 1.8m telescope at Mt.John observatory in New Zealand.
In a single image of a 60 sec exposure with a wideband Red filter (center
wavelength ~ 750nm and FWHM ~ 250nm), we did not find any object
within the error circle of the Swift XRT source position (GCN 11803, P.A.
Evans et al.).
A 3 sigma upper limit is set in the I magnitude at 20.7 mag.

This photometry was done by using the DoPhot and calibrated against
the USNO-B1.0 catalog stars, and not corrected for the Galactic extinction.


GRB_name: GRB110328B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11831
SUBJECT: GRB 110328B: Fermi GBM detection
DATE:    11/03/29 12:02:10 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 12:29:19.19 UT on 28 March 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110328B (trigger 323008161 / 110328520).

The on-ground calculated location, using the GBM trigger 
data, is RA = 121.1, DEC = 45.8 (J2000 degrees, 
equivalent to 8h 4m, 45d 48'), with an uncertainty 
of 1.2 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 31 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of a single pulse
with a duration (T90) of about 120 s (50-300 keV). 
The time-averaged spectrum from T0+0.003 s to T0+122.882 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.17 (+0.04/-0.04) and
the cutoff energy, parameterized as Epeak, is 538 (+96/-70) keV.

The event fluence (10-1000 keV) in this time interval is 
(2.6 +/- 0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0+4.93  s in the 10-1000 keV band 
is 5.8 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well with 
Epeak = 369 (+115/-69) keV, alpha = -1.11 +/-0.06
and beta =  -1.94 (+0.10/-0.22).

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


GRB_name: GRB110213A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11832
SUBJECT: GRB 110213A, the review of the sky area in plate archives
DATE:    11/03/29 13:00:03 GMT
FROM:    Valentyna Golovnya at Main Astro Obs,Kyiv  <golov_v@ukr.ne>

GRB 110213A, the review of the sky area in plate archives 
V.V. Golovnya, L.M. Kizyun, L.K. Pakuliak (Main Astro Obs, Kyiv)
report: 

We have undertaken the review of the sky area of GRB 110213A
(J.P. Osborne et al. GCN11712)  on astronegatives, collected  
in Ukrainian NAS Main astronomical observatory plate archive  
(1976-1996). All the plates with the possible object appearance 
are digitized using Microtek ScanMaker 9800XL TMA flatbed scanner
and have been placed into Golosiiv Plate Archive database DBGPA  
with open access to them. 

The list of plates is given in the table:
YYYYMMDD UT Plates Exp. LimMag
19831203 19:41:42 GUA040C000261A  16.0 15.50
19840128 16:46:54 GUA040C000282A  13.5 15.25
19840128 17:07:51 GUA040C000283A  13.5 15.25
19841019 22:27:46 GUA040C000514A  16.3 16.90
19851109 21:12:03 GUA040C000773A  16.0 15.90
19871023 22:27:36 GUA040C001142   16.0 16.40
19871023 22:48:58 GUA040C001143A  16.0 17.85
19871223 18:25:56 GUA040C001174   16.0 15.50
19871223 18:49:42 GUA040C001175   16.2 17.85
19891026 22:17:26 GUA040C001526A  17.0 16.15

We detect the object at the pointed place (J.P. Osborne et al)
on the plates GUA040C001143A and GUA040C001175. Brightness of 
the object is estimated as V mag = 16.8.

Plates: the plate's identifier in GUA040C archive of DWA 
        (D/F=400/2000, M=103"/mm) of the Ukrainian NAS Main
        Astro obs in Kyiv (Marsden's number - 83)[1].
Exp.   - Duration of the maximum exposure (minutes). 
LimMag - Limited V mag, derived in the 8 minutes area around 
        the location given in J.P. Osborne et al. GCN 11712: 
        RA(J2000)= 02h 51m 51.37s, Dec(J2000)= +49d 16' 21.2". 

The preview images of 10 areas together with  
the 15x7 min.of arc area from SkyMap can be found in  
http://gua.db.ukr-vo.org/img/grb/110213A/index.html
The images with full resolution are available via e-mail on 
demand.

References: 
1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0), 
http://gua.db.ukr-vo.org 


GRB_name: GRB110328B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11835
SUBJECT: GRB 110328B: Fermi-LAT Detection
DATE:    11/03/29 16:58:08 GMT
FROM:    Vlasios Vasileiou at LUPM/Fermi-LAT  <Vlasios.Vasileiou@lupm.in2p3.fr>

V. Vasileiou (CNRS/IN2P3/LUPM), N. Omodei (Stanford), J. Chiang (SLAC),
G. Vianello (SLAC), D. Kocevski (SLAC), and J. Racusin (NASA/GSFC)
report on behalf of the Fermi-LAT collaboration.

The Fermi-Large Area Telescope (LAT) detected GRB 110328B on 28 March 2011
at 12:29:31 UT, using an automated on-ground analysis. This GRB was also
independently detected by the GBM (von Kienlin, GCN 11831) and INTEGRAL SPI-ACS.

The source is not detectable using our standard 0.1 - 300 GeV dataset.
However, it is detectable if the lower energy threshold is reduced to 50 MeV. Using
this dataset, we obtain a localization of RA, DEC (J2000 deg) = 117.6, 43.2
(07h 50m 24s, 43d 12' 00"), with an error of 1.7 deg (68% CL; statistical),
compatible with the GBM localization. At the trigger time, the localization
was at angle of ~33 degrees from the LAT boresight and ~45 degrees from the Earth's
limb.

Using a non-standard data selection that increases the low energy tens-of-MeV
acceptance at the expense of a greater background, we find that the detected
emission consists of a single pulse starting approximately at the time of the
GBM trigger and lasting ~40 sec. According to preliminary spectral fits
using this non-standard dataset, the spectral index of the detected
emission is -3.31 +-  0.21 (68% CL), steeper than the Band-function beta
reported by the GBM (-1.94 (+0.10/-0.22)). This suggests the presence of
a spectral break between few MeV and few tens-of-MeV energies.

Further analysis is ongoing.

The Fermi LAT point of contact for this burst is Vlasios Vasileiou
(vlasios.vasileiou@lupm.in2p3.fr).

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: GRB110402A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11857
SUBJECT: GRB 110402A: Swift detection of a burst
DATE:    11/04/02 00:48:01 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), C. Pagani (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
C. J. Saxton (UCL-MSSL), M. C. Stroh (PSU), C. A. Swenson (PSU) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 00:12:57 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110402A (trigger=450545).  Swift slewed to the burst at T+9 min. 
The BAT on-board calculated location is RA, Dec 197.419, +61.242 which is 
   RA(J2000) = 13h 09m 41s
   Dec(J2000) = +61d 14' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed multiple short spikes
with a total duration of about 40 sec.  The peak count rate
was ~9000 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 00:22:01.5 UT, 544.3 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 197.4014,
61.2527 which is equivalent to:
   RA(J2000)  = 13h 09m 36.33s
   Dec(J2000) = +61d 15' 09.6"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 49 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 1.62
x 10^20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 547 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
0.02. 

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


GRB_name: GRB110402A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11858
SUBJECT: GRB 110402A: Liverpool Telescope Observations
DATE:    11/04/02 02:12:26 GMT
FROM:    Carole Mundell at ARI, JMU,Liverpool  <cgm@astro.livjm.ac.uk>

C.G. Mundell (Liverpool), A. Melandri (INAF-OAB) and N. Tanvir (Leicester) report on behalf of a larger collaboration:

"The 2-m Liverpool Telescope robotically followed up GRB110402
(SWIFT trigger 450545; Ukwatta et al. GCN 11857) 14.85 min after the GRB 
trigger time.

We identify a faint source detected within the XRT error circle in R, i' 
and z' band images at:

RA = 13:09:36.64   Dec = +61:15:09.7   +/-0.1" (J2000)

with  R = 20.8 (+/-0.1)    mag at t=28.0 min
       I = 20.75 (+/-0.17) mag at t= 33.0 min  (vs USNOB1)

Fading is yet to be confirmed.

This message may be cited"


GRB_name: GRB110402A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11859
SUBJECT: GRB 110402A: NOT afterglow confirmation 
DATE:    11/04/02 02:51:06 GMT
FROM:    Giorgos Leloudas at Dark Cosmology Centre  <giorgos@dark-cosmology.dk>

G. Leloudas (DARK/NBI), D. Xu (WIS), P. Jakobsson (U. Iceland), M.
Bayliss (U. Chicago/KICP), report on behalf of a larger collaboration:

We observed the field of GRB 110402A (Ukwatta  et al., GCN 11857) with
the Nordic Optical Telescope (La Palma, Spain) equipped with MOSCA.

Observations started at 01:26:09.0 UT (73.9 mins after the GRB).
We obtained 3x300 s in the R filter.
We detect a transient within the XRT error circle consistent with the
position reported in Mundell et al. (GCN 11858).

Between the 1st and 3rd exposures, the optical transient shows  
marginal decay from 21.10 +- 0.02  to 21.17 +- 0.04 mag, calibrated  
with respect to the USNO
B1 star 1512-0199231 (R1= 16.71 mag).

Since the object has also faded by 0.3 mag with respect to GCN 11858,  
we suggest that this is the afterglow of GRB 110402A.


GRB_name: GRB110402A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11860
SUBJECT: GRB 110402A: Enhanced Swift-XRT position
DATE:    11/04/02 05:37:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 1602 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 110402A, 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 = 197.40226, +61.25285 which is equivalent
to:

RA (J2000): 13h 09m 36.54s
Dec (J2000): +61d 15' 10.3"

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: GRB110402A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11861
SUBJECT: GRB 110402A: PAIRITEL NIR Upper Limits
DATE:    11/04/02 06:02:36 GMT
FROM:    Adam Morgan at U.C. Berkeley  <qmorgan@gmail.com>

A. N. Morgan, C. R. Klein, and J. S. Bloom (UC Berkeley) report:

We observed the field of GRB 110402A (Ukwatta et al., GCN 11857) with
the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began
at 2011-04-02 04:28:41 UT, ~4.26 hours after the Swift Trigger.  In
mosaics (effective exposure time of 0.63 hours) taken simultaneously
in the J and H filters, we do not detect any source at the optical
afterglow location (Mundell et al., GCN 11858, Leloudas et al., GCN
11859).  Our preliminary Ks band reduction is corrupted.

The preliminary photometry yields:

post burst
t_mid (hr) exp.(hr) filt  U. Limit (3 sig)
4.77       0.63     J     > 19.1
4.77       0.63     H     > 18.2

Further observations are ongoing to obtain a deeper limit.  All
magnitudes are given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values.


GRB_name: GRB110402A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11863
SUBJECT: GRB 110402A: further NOT observations
DATE:    11/04/02 08:44:59 GMT
FROM:    Giorgos Leloudas at Dark Cosmology Centre  <giorgos@dark-cosmology.dk>

G. Leloudas (DARK/NBI), D. Xu (WIS), J. Hjorth (DARK/NBI), P.  
Jakobsson (U. Iceland), M. Bayliss (U. Chicago/KICP), report on behalf  
of a larger collaboration:

We re-observed the field of GRB 110402A (Ukwatta  et al., GCN 11857)  
with the Nordic Optical Telescope (La Palma, Spain) equipped with  
MOSCA. We obtained two more 600 s R-band exposures starting at 02:38  
UT and 04:24 UT.

In the table below we summarize all photometry obtained at the NOT,  
where we have also re-calibrated the photometry in Leloudas et al.  
(GCN 11859) based on several USNO B1.0 stars in the field:

t_start (min)  R (mag)
83.1  21.15 +- 0.06
96.6  21.10 +- 0.08
145.5  21.10 +- 0.06
251.6  21.50 +- 0.07

The source has faded significantly between our last two observations  
confirming its transient nature.


GRB_name: GRB110402A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11864
SUBJECT: GRB 110402A: early optical limit by "Pi of the Sky"
DATE:    11/04/02 10:16:16 GMT
FROM:    Grzegorz Wrochna at Soltan Inst.for Nuclear Studies  <wrochna@fuw.edu.pl>

M.Sokolowski,T.Batsch,A.Majcher,A.Majczyna,K.Nawrocki,J.Uzycki,G.Wrochna (IPJ, Swierk),
M.Cwiok,W.Dominik,L.W.Piotrowski,A.F.Zarnecki (University of Warsaw),
K.Malek,L.Mankiewicz,R.Opiela,M.Siudek,V.Repei (CFT PAN),
G.Kasprowicz,M.Zaremba (Warsaw University of Technology),
from the "Pi of the Sky" collaboration (http://grb.fuw.edu.pl  ).
M. Jelinek and A. J.Castro-Tirado (IAA-CSIC Granada) on behalf of a larger collaboration.

The wide field "Pi of the Sky North" apparatus installed in the BOOTES-1
station at ESAt/INTA-CEDEA in Mazagon (Huelva, Spain;
http://grb.fuw.edu.pl/pi/index.html#piinta_site.htm  )
observed field of GRB 110402A at the time of Fermi-GMB and Swift-BAT triggers.
No new source brighter than 11 mag has been identified on 10s exposures:

t_start - t0      start (UT)  end (UT)     3-sigma limit

       -6           00:12:52    00:13:02     11.0
       +7           00:13:05    00:13:15     11.0

where limit is based on the reference star magnitudo in V filter.


GRB_name: GRB110402A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11865
SUBJECT: GRB 110402A: Swift-XRT refined Analysis
DATE:    11/04/02 11:17:47 GMT
FROM:    Claudio Pagani at U of Leicester  <cp232@star.le.ac.uk>

C. Pagani (U. Leicester) and T. N. Ukwatta (MSU) report on behalf of
the Swift-XRT team:

We have analysed 6.8 ks of XRT data for GRB 110402A (Ukwatta  et al.
GCN Circ. 11857), from 552 s to 24.7 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
11860).

The late-time light curve (from T0+6.4 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.3 (+/-0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.31 (+0.25, -0.27). The
best-fitting absorption column is  10.0 (+2.9, -5.6) x 10^20 cm^-2, in
excess of the Galactic value of 1.6 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.3 x 10^-11 (4.8 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      10.0 (+2.9, -5.6) x 10^20 cm^-2
Galactic foreground: 1.6 x 10^20 cm^-2
Excess significance: 2.9 sigma
Photon index:      2.31 (+0.25, -0.27)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00450545.

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


GRB_name: GRB110402A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11866
SUBJECT: GRB 110402A: Swift-BAT refined analysis
DATE:    11/04/02 13:59:12 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110402A (trigger #450545)
(Ukwatta, et al., GCN Circ. 11857).  The BAT ground-calculated position is
RA, Dec = 197.432, 61.247 deg, which is 
   RA(J2000)  =  13h 09m 43.7s 
   Dec(J2000) = +61d 14' 49.6" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 10%.
 
The mask-weighted light curve shows 5 spikes (each with a duration less than 0.5 sec)
with the first at ~T+1.5 sec and the last at ~T+6 sec.  These are followed
by softer emission out to ~T+90 sec.  T90 (15-350 keV) is 60.9 +- 6.9 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-0.4 to T+69.7 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.59 +- 0.17.  The fluence in the 15-150 keV band is 3.4 +- 0.4 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+3.18 sec in the 15-150 keV band
is 4.1 +- 0.7 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/450545/BA/


GRB_name: GRB110402A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11868
SUBJECT: GRB 110402A: Konkoly observations
DATE:    11/04/02 15:46:10 GMT
FROM:    Janos Kelemen at Konkoly Obs/Hungary  <kelemen@konkoly.hu>

J. Kelemen,(Konkoly Obs.)
on behalf of the GRB OT observing program at the Konkoly Observatory.

We observed the field of GRB 110402A using the enhanced Swift-XRT position
A.P. Beardmore et al. (GCN 11860) with a 60/90 cm Schmidt telescope located at
the Mountain Station of the Konkoly Observatory. Within the XRT error circle
we found an OT candidate at the position:

RA(2000) 13h 09m 36.64s
Dec(2000) +61d 15' 09.7" 

With an uncertainty of 0.15 arcsec.

For the photometry of the source on the coadded frames (total exp time 900
sec) nearby stars of the UCAC3 catalogue were used.

Time from 
the trigger    magnitude       Band
----------------------------------------
9523 sec      21.0 +/- 0.2      R 

Further observations planned.


GRB_name: GRB110402A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11869
SUBJECT: Konus-Wind observation of GRB 110402A
DATE:    11/04/02 18:09:18 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The long GRB 110402A, (Swift/BAT trigger=450545:
Ukwatta et al., GCN 11857; Stamatikos et.al, GCN 11866)
triggered Konus-Wind at T0=00781.989s UT (00:13:01.989)

The burst light curve started with a hard multi-peaked pulse
followed, after ~5s, by a softer decaying emission.
The total duration of of the burst is ~70 s.
The emission in the initial hard pulse is seen up to ~5 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110402_T00781/

As observed by Konus-Wind the burst
had a fluence of (1.6  0.5)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0,
of (2.3  0.9)x10-5 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+65.792 s) is best fitted
in the 20 keV - 5 MeV range by a simple
power law function with the photon index
= (1.67  0.09), chi2 = 86.6/78 dof.

The spectrum at the maximum count rate
(measured from T0 to T0+0.256 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.03 (-0.14, +0.16),
and Ep = 1395(-604, +1835) keV,
chi2 = 23.9/21 dof.

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


GRB_name: GRB110402A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11870
SUBJECT: GRB 110402A: Spectral lag indicates short hard burst
DATE:    11/04/03 00:24:08 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S.D. Barthelmy (GSFC) and J. Norris (BSU)
report:

For GRB 110402A (Trigger 450545, GCNs 11857 & 11866),
the spectral lag analysis of the Swift-BAT data from T+0.8 sec to T+6.0 sec
(the initial 5 spikes), yields a lag of 3.7 +2.5/-2.9 msec for the
25-50 to 100-300 keV bands using a lightcurve binning of 4 msec.
While the 5.2 sec duration for the 5 spikes is formally beyond
the cononical 2-s boundary in duration for short bursts,
the small lag value favors a short burst identification.

We note that there is on-going, much softer emission from T+5 to T+78 sec,
and lacking sufficient structure to yield a significant lag measurement.


GRB_name: GRB110402A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11871
SUBJECT: GRB 110402A:  Swift/UVOT detection of afterglow candidate
DATE:    11/04/03 02:32:55 GMT
FROM:    Craig Swenson at PSU/Swift  <cswenson@astro.psu.edu>

C. A. Swenson (PSU) and T. N. Ukwatta (MSU)report on behalf
of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110402A
548 s after the BAT trigger (Ukwatta et al., GCN Circ. 11857).
We find a faint new source consistent with the enhanced XRT position
(Beardmore et al., GCN Circ. 11860).

Preliminary magnitudes and 3-sigma upper limits using the UVOT
photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter        T_start(s)    T_stop(s)   Exp(s)    Mag
---------------------------------------------------------------------
white_FC         548           698       147     >20.5
white            548         24657      1628      20.89 0.11
v                704         18897       510     >20.1
b                803         24593      1544      20.84 0.20
u                778         30417       430     >20.6
w1               754         30390      1296      20.39 0.22
m2              7176          7376       197     >19.7
w2              6767         18791      1112      20.29 0.20

The values quoted above 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: GRB110402A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11873
SUBJECT: GRB 110402A: MITSuME Okayama and Ishigakijima Optical upper limits
DATE:    11/04/03 13:13:07 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 110402A (Ukwatta et al., GCN 11857)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory
and the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.

We did not find any new point source within the enhanced XRT error
circle (Beardmore et al., GCNC 11860) in all the three bands. We
could not detect the previously reported afterglow
(Mundell et al., GCN 11858).


Ishigakijima Astronomical Observatory:
The observation started on 2011-04-02 12:18:01 UT, (~12.1 h
after the burst).

T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.53014    12:56:21    3540.0    >21.4  >21.4  >20.4
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


Okayama Astrophysical Observatory:
The observation started on 2011-04-02 13:51:58 UT, (13.7 h
after the burst).

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

T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.56634    13:48:29    8400.0    >19.6  >20.0  >19.4
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110402A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11875
SUBJECT: GRB 110402A afterglow observation
DATE:    11/04/04 13:29:54 GMT
FROM:    Xavier Bros at Anysllum Obs  <anysllum@gmail.com>

X. Bros, Agrupaci=C3=B3 Astron=C3=B2mica de Sabadell, Spain,
has done a positive observation of GRB 110402A afterglow
on three unfiltered images done from ANYSLLUM OBSERVATORY, Ager, Spain
using a Newtonian reflector of 350mm f4.6.

1) exp 180 sec at 0h 52m 12 sec UT of 2011/04/02 (39 minutes 15 sec after SWIFT detection)
2) exp 300 sec at 0h 57m 26 sec UT (44 minutes 29 sec after SWIFT detection)
3) exp 300 sec at 1h 07m 48 sec UT (54 minutes 51 sec after SWIFT detection)

The afterglow is visible in all of these images. Position measured using
UCAC 2 reference stars:

13h 09m 36.57s
+61d 15' 10.2"

Magnitude estimation on the combined add image (180sec+300sec+300sec)
of 20.8CR, (unfiltered) using R reference stars from USNO A2.0 (18.7R,
18.8R, 19.5R).
The image is linked in: http://anysllum.com/GRB%20110402A%20X%20Bros.jpg

[GCN OPS NOTE(04apr11).  This circular was delayed in distribution for 15 hours
while an account was set up.]


GRB_name: GRB110402A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11876
SUBJECT: GRB 110402A: optical observations in Mondy
DATE:    11/04/04 14:33:37 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of GRB 110402A  (Ukwatta et al. GCN 11857) with 
AZT-33IK telescope of Sayan observatory (Mondy) on April, 2 between (UT) 
13:04:22 - 14:37:38 under  moderate weather condition and seeing of about 
2". In a stacked image we clearly detect optical counterpart (Mundell et al. 
GCN 11858, Leloudas et al. GCN 11859). The position of the counterpart is 
(J2000) RA= 13:09:36.42 Dec= +61:15:10.35 with uncertainty of 0,4" in both 
coordinates. The position is 1.7" apart from initial position reported by 
Mundell et al. (GCN 11858). The photometry is based on the USNO B1 star 
1512-0199231 assuming R= 16.71

T0+         Filter,   Exposure, OT mag.,            UpperLimit (3 sigma)
(mid, d)              (s)


0.56809    R        5430    21.35 +/- 0.10       22.9

Since the position of counterpart is marginally different from initial 
position and the R-magnitude does not change since 251.6 minutes after burst 
(see Leloudas et al. GCN 11863) we can suggest that host galaxy dominates in 
our observations.

[GCN OPS NOTE(30apr11): Per author's request, Elunko was changed to Klunko.]


GRB_name: GRB110402A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11877
SUBJECT: GRB 110402A: Fermi GBM detection
DATE:    11/04/04 16:15:43 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

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

"At 00:12:58.54 UT on 02 April 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110402A (trigger 323395980 / 110402009).
which was also detected by the Swift/BAT (Ukwatta et al. 2011, GCN 11857)
The GBM on-ground location is consistent with the Swift position.
 
The angle from the Fermi LAT boresight is 134.5 degrees.

The GBM light curve consists of multiple sharp pulses
with a duration (T90) of about 36 s (50-300 keV).
The time-averaged spectrum from T0-2.4 s to T0+59 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.29 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 1025 +/- 409 keV

The event fluence (10-1000 keV) in this time interval is
(1.3 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.8 s in the 10-1000 keV band
is 7.82 +/- 0.47 ph/s/cm^2.

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


GRB_name: GRB110401A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11878
SUBJECT: GRB 110401A: Fermi GBM detection
DATE:    11/04/04 16:33:52 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

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

"Fermi Gamma-Ray Burst Monitor trigger at 22:04:19.63 UT on 01 April 2011,
tentatively classified as "Below Horizon" by the flight software,
is in fact due to GRB 110401A (trigger 323388261  / 110401920).

The on-ground calculated location, using the GBM trigger
data, is RA = 268.56, DEC = 26.87 (J2000 degrees,
equivalent to 17 h 54 m, 26 d 52'), with an uncertainty
of 3.8 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 94 degrees.

The GBM light curve shows 2 strong pulses
with a duration (T90) of about 2 s (50-300 keV).

The time-averaged spectrum from T0-0.32 s to T0+0.704 s is
well fit by a Band function with Epeak = 1194 +/- 406 keV,
alpha = -0.66 +/- 0.15, and beta = -2.36 +/- 0.53

The event fluence (10-1000 keV) in this time interval is
(1.51 +/- 0.09)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.256 s in the 10-1000 keV band
is 3.53 +/- 0.25 ph/s/cm^2.

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


GRB_name: GRB110402A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11879
SUBJECT: GRB 110402A: Konus-Wind spectral lags and detailed energetics
DATE:    11/04/04 17:05:29 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks and D. Svinkin on behalf of the Konus-Wind team,
report:

1. The further analysis of the Konus-Wind detection (GCN 11869)
of GRB 110402A (GCN 11857, 11866) confirms the zero spectral
lag in the initial hard pulse reported with the Swift-BAT data
(Barthelmy and Norris, GCN 11870).
The following lag values between the Konus-Wind light curves
are obtained:
-------------------------------------------------------------
LC1(keV)     LC2(keV)   Search Interval(s) Scale   Lag(ms)
-------------------------------------------------------------
G2(70-300)   G1(18-70)   -0.512:+0.320     8 ms   +3.5  12.5
G3(300-1160) G1(18-70)   -0.512:+0.280     8 ms   +3.2  12.3
G3(300-1160) G2(70-300)  -0.340:+0.320     4 ms   -0.3  4.8
-------------------------------------------------------------
The errors are given on 1 sigma level.

2. The total burst fluence S=(1.6  0.5)x10-5 erg/cm2 reported
in GCN 11869 is divided between the hard initial pulse and
the softer extended emission as follows:
T0(-0.512 : +2.816) -> S1=(5.7  1.9)x10-6 erg/cm2 (initial pulse)
T0(2.816 : +65.792) -> S2=(9.9  2.9)x10-6 erg/cm2 (extended emission)

The K-W spectrum of the latter part (measured from T0+8.448s
to T0+65.792s) can be fitted in the 20-5000 keV range
by the simple power law function with the index of (1.81  0.13),
chi2 = 93.4/78

The errors are given on 90% confidence level.

All times are given relative to K-W T0=781.989s UT.


GRB_name: GRB090424A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11883
SUBJECT: Comparison of ICSP VLF observation of GRB 090424 with satellite observations
DATE:    11/04/05 11:09:52 GMT
FROM:    Sandip K. Chakrabarti at S.N. Bose Nat. Centre for Basic Sci.  <chakraba@bose.res.in>

Sushanta K. Mondal (ICSP), Sandip K. Chakrabarti (S. N. Bose Centre and ICSP),
Asit Choudhury (ICSP, Malda branch), Achintya Chatterjee (ICSP, Malda Branch),
and D. Bhowmick (ICSP)

Indian Centre for Space Physics observed the ionospheric perturbation
due to GRB 090424 (GCN No. 9316) through monitoring VLF signals from various
transmitters.
The final analysis with corrected time stamp
(http://www.bose.res.in/~chakraba/grb090424.html) suggests
that VLF signals were spreaded out for few seconds due to ionospheric effects.


GRB_name: GRB090424A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11884
SUBJECT: ICSP VLF observation of multiple SGR-like bursts from 1E 1841-045 on Feb. 9, 2011
DATE:    11/04/05 12:30:16 GMT
FROM:    Sandip K. Chakrabarti at S.N. Bose Nat. Centre for Basic Sci.  <chakraba@bose.res.in>

ICSP VLF observation of multiple SGR-like bursts from 1E 1841-045 on Feb. 9, 2011

Sushanta K. Mondal (ICSP), Sandip K. Chakrabarti (S. N. Bose Centre and ICSP),
Debashis Bhowmick (ICSP)

We observed several sudden ionospheric disturbances on Feb. 9th, 2011 in signals
transmitted from several stations. One of them (occurring at 05:14:26 UT)
coincided
exactly with the observed time of Fermi (GCN #11684) but there
were many both before and after within a few hundred seconds. All these events
were observed in both phase and amplitude, indicating that the disturbances
were real.
One image of the amplitude/phase from various transmitting stations as
obtained by our
receiver at Sitapur station is in http://www.bose.res.in/~chakraba/gbm090211.html.
The entire set of events were riding on a 'B' type flare, but we suspect our
events are
not parts of any solar flare, as the time durations of the signals involved appear
to be too short (similar to our GRB090424 for our VLF signal; see GCN No.11883)
Since GCN #11684 observes only one signal (corresponding to spikes at 18866s
in our Figure), we request others to check if there were any observations at
the times when other VLF signals were seen.


GRB_name: GRB110402A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11885
SUBJECT: GRB 110402A: LOAO Optical Observation
DATE:    11/04/05 14:06:32 GMT
FROM:    Yiseul Jeon at SNU/CEOU  <ysjeon@astro.snu.ac.kr>

Yiseul Jeon, Myungshin Im (SNU), and Yuji Urata (NCU)

We observed GRB 110402A (Ukwatta et al. GCN 11857) in R, I, z,
and Y-bands using the 1 meter telescope at Mt. Lemmon, AZ, USA.
The observations started at Arpil 2, 04:18:22UT(245.4 min after the BAT trigger),
with the total integration time in each filter at 3 x 300 sec.
A faint source is identified at the positon reported in Mundell et al. (GCN 11858).
A preliminary analysis shows that the R-band magnitude is R=21.0 +- 0.3,
calibrated using R2 magnitude of USNO-B1 stars in the vicinty.

We thank the LOAO operator, J. Yoon for his assistance for this
observation.

[GCN OPS NOTE(05apr11):  This circular was delay in distribution
by ~10 hours waiting for a new accont to be enetered.]


GRB_name: GRB110402A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11887
SUBJECT: GRB 110402A: Suzaku WAM observation of the prompt emission
DATE:    11/04/06 13:18:47 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro@phy.saitama-u.ac.jp>

T. Yasuda, Y. Terada, M. Tashiro, W. Iwakiri, K. Takahara (Saitama U.),
T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.),
N. Vasquez (Tokyo Tech.) K. Yamaoka (Aoyama Gakuin U.), S. Sugita
(Nagoya U.), M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA),
Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Ohmori, M. Yamauchi (Univ. of
Miyazaki), Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of
Tokyo), on behalf of the Suzaku WAM team, report:

The GRB 110402A (Swift/BAT trigger #450545; Ukwatta et al.) triggered
the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range
of 50 keV - 5 MeV at 2011-04-02 00:12:58.49 UT (=T0).

The observed light curve shows a multi-peaked structure starting at
T0-1.5s, ending at T0+83.5s, with a duration (T90) of about 70 seconds.
The fluence in 100 - 1000 keV was 9.1 (+0.9, -0.9) x 10^-6 erg/cm^2.

The 1-s peak flux measured from T0+1s was 5.72 photons/cm^2/s in the
same energy range.

Preliminary result shows that the time-averaged spectrum from T0-1.5 s
to T0+83.5 s is well fitted by a single power-law with a photon index of
1.57 (+0.11, -0.10) (chi^2/d.o.f = 44.73/31).

All the quoted errors are at statistical 90% confidence level, in which
the systematic uncertainties are not included.

The light curves for this burst will be update at:

http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB110402A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11888
SUBJECT: Redshift of GRB 110402A theoretically estimated
DATE:    11/04/06 17:12:29 GMT
FROM:    Remo Rufinni at ICRA  <ruffini@icra.it>

R. Ruffini, L. Izzo, A.V. Penacchioni, C.L. Bianco (ICRANet, ICRA and Rome University "La Sapienza") report:

From theoretical considerations on the transparency of the P-GRB (between t0 and t0+6 s), we infer for GRB 110402A a redshift z between 2.02 and 2.48. We strongly encourage a spectroscopic identification of the redshift.


GRB_name: GRB110402A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11889
SUBJECT: GRB 110402A: fading optical afterglow
DATE:    11/04/06 17:50:56 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev (CrAO), A. Pozanenko (IKI), A. Volnova (SAI MSU) on behalf of 
larger GRB follow up collaboration report:

We observed the field of GRB 110402A  (Ukwatta et al. GCN 11857) with Shajn 
telescope of CrAO  observatory  on Apr. 3 between (UT) 18:41 and 19:59 under 
seeing of about 2.6 arsces. We took several frames with exposure of 60s in 
R-band. On a stacked image we detected the optical counterpart (Mundell et 
al. GCN 11858, Leloudas et al. GCN 11859). The counterpart has coordinates 
(J2000) RA = 13h 09m 36.63s, Dec = +61d 15' 09.5'' with uncertainty of 0.1" 
in both coordinates which are fully compatible with initial counterpart 
coordinates (Mundell et al. GCN 11858). The photometry is based on the USNO 
B1.0 star 1512-0199231 (13 09 43.16 +61 14 38.5) assuming R=16.71.

T0+         Filter,   Exposure, mag.                uplim (3 sigma)
(mid, d)               (s)

1.79672  R         73x60       23.11+/-0.12  24.4 


GRB_name: GRB110406A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11890
SUBJECT: GRB 110406A: An exceptionally bright burst detected by INTEGRAL SPI-ACS
DATE:    11/04/06 20:24:50 GMT
FROM:    Volodymyr Savchenko at ISDC,U of Geneve  <volodymyr.savchenko@unige.ch>

V. Savchenko, C. Ferrigno, E. Bozzo, M. Nikolajuk, M. Beck (ISDC), S.
Mereghetti (INAF/IASF-Milano). V. Beckmann (APC), Arne Rau (MPE), J.
Borkowski (CAMK/Torun), D. Gtz (CEA/Saclay), and A. von Kienlin (MPE)
report on behalf of the INTEGRAL SPI-ACS GRB team:

An exceptionally bright burst has been detected by the SPI
Anti-Coincidence System (ACS) on-board INTEGRAL at 2011-04-06T03:44:10.
The SPI-ACS light curve shows a single smooth peak with a peak
count rate of ~19000 counts/50msec of a duration of about 3 seconds.
The roughly estimated energy peak flux is of the order of 6e-5
erg/cm2/s. This was one of the brightest bursts ever detected with SPI-ACS.

The SPI-ACS light curves are available (both as images and data files)
at http://isdc.unige.ch/Soft/ibas/ibas_acs_web.cgi

The light curves, binned at 50 ms, are derived from 91 independent
detectors with different lower energy thresholds (mainly between 80 keV
and 150 keV) and an upper threshold at about 100 MeV. The ACS response
varies as a function of the GRB incident angle. For these reasons we
caution that the count rates cannot be easily translated into physical
flux units. It is not possible to localize a burst based on the SPI-ACS
data.


GRB_name: GRB110402A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11892
SUBJECT: Redshift of GRB 110402A theoretically estimated (revised)
DATE:    11/04/06 23:11:23 GMT
FROM:    Remo Rufinni at ICRA  <ruffini@icra.it>

R. Ruffini, L. Izzo, A.V. Penacchioni, C.L. Bianco (ICRANet, ICRA and Rome University "La Sapienza") report:

A more accurate evaluation of GRB 110402A rebinned data leads to an estimate of the redshift z between 0.7 and 1.0.


GRB_name: GRB110406A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11893
SUBJECT: Konus-Wind observation of GRB 110406A
DATE:    11/04/07 13:16:00 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The exceptionally bright GRB 110106A, (Savchenko et al., GCN 11890)
triggered Konus-Wind at T0=13446.671s UT (03:44:06.671)

The burst light curve consists of a single FRED-like pulse,
the total duration of the burst is ~8 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/GRB110406_T13446/

The non-zero spectral lag between the Konus-Wind light curves
is evident, the following values are obtained:
-------------------------------------------------------------
LC1(keV)     LC2(keV)   Search interval(s) Scale   Lag(ms)
-------------------------------------------------------------
G2(70-300)   G1(18-70)   -0.048:+2.016     16 ms  +58  6
G3(300-1160) G1(18-70)   -0.016:+1.968     16 ms  +127  6
G3(300-1160) G2(70-300)  -0.048:+2.016     16 ms  +64  5
-------------------------------------------------------------

As observed by Konus-Wind the burst
had a fluence of (4.8  0.5)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.160s,
of (1.5  0.1)x10-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+9.216 s) can be fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.24 (-0.07, +0.08),
the high energy photon index beta = -2.30 (-0.25, +0.15),
the peak energy Ep = 326(-42, +49) keV,
chi2 = 117/89 dof.

The spectrum at the maximum count rate
(measured from T0+0.064 to T0+0.256 s) is best fit
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.61 (-0.13, +0.15),
the high energy photon index beta = -2.05 (-0.12, +0.10),
the peak energy Ep = 417(-64, +77) keV,
chi2 = 56.5/56 dof.

All the quoted results are preliminary.
The lag errors are given on 1 sigma level.
All other quoted errors are at the 90% confidence level.


GRB_name: GRB110407A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11894
SUBJECT: GRB 110407A: Swift detection of a burst
DATE:    11/04/07 14:18:56 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. W. Wolf (PSU), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), S. Campana (INAF-OAB),
V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), B. Gendre (ASDC), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), O. M. Littlejohns (U Leicester),
V. Mangano (INAF-IASFPA), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), C. Pagani (U Leicester),
K. L. Page (U Leicester), P. Romano (INAF-IASFPA), M. H. Siegel (PSU),
E. Sonbas (GSFC/USRA/Adiyaman Univ.), R. L. C. Starling (U Leicester),
G. Stratta (ASDC), M. C. Stroh (PSU), C. A. Swenson (PSU),
G. Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/ORAU) and
T. N. Ukwatta (MSU) report on behalf of the Swift Team:

At 14:06:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110407A (trigger=450884).  Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 185.997, +15.718 which is
   RA(J2000)  =  12h 23m 59s
   Dec(J2000) = +15d 43' 04"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty).  Even for an image trigger, the BAT lightcurve
shows a smooth peak about 100 sec long with a peak roughly at T+20 sec.

The XRT began observing the field at 14:09:20.4 UT, 159.3 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 186.0333, +15.7115 which is equivalent to:
   RA(J2000)  = 12h 24m 07.99s
   Dec(J2000) = +15d 42' 41.3"
with an uncertainty of 5.2 arcseconds (radius, 90% containment). This
location is 127 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy.

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 167 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
0.03.

Burst Advocate for this burst is C. W. Wolf (cwolf AT astro.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: GRB110407A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11895
SUBJECT: GRB 110407A: Swift detection of a burst
DATE:    11/04/07 14:18:57 GMT
FROM:    Chris Wolf at PSU  <cwolf@astro.psu.edu>

C. W. Wolf (PSU), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), S. Campana (INAF-OAB),
V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), B. Gendre (ASDC), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), O. M. Littlejohns (U Leicester),
V. Mangano (INAF-IASFPA), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), C. Pagani (U Leicester),
K. L. Page (U Leicester), P. Romano (INAF-IASFPA), M. H. Siegel (PSU),
E. Sonbas (GSFC/USRA/Adiyaman Univ.), R. L. C. Starling (U Leicester),
G. Stratta (ASDC), M. C. Stroh (PSU), C. A. Swenson (PSU),
G. Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/ORAU) and
T. N. Ukwatta (MSU) report on behalf of the Swift Team:

At 14:06:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110407A (trigger=450884).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 185.997, +15.718 which is 
   RA(J2000)  =  12h 23m 59s
   Dec(J2000) = +15d 43' 04"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  Even for an image trigger, the BAT lightcurve
shows a smooth peak about 100 sec long with a peak roughly at T+20 sec. 

The XRT began observing the field at 14:09:20.4 UT, 159.3 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 186.0333, +15.7115 which is equivalent to:
   RA(J2000)  = 12h 24m 07.99s
   Dec(J2000) = +15d 42' 41.3"
with an uncertainty of 5.2 arcseconds (radius, 90% containment). This
location is 127 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 167 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
0.03. 

Burst Advocate for this burst is C. W. Wolf (cwolf AT astro.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: GRB110407A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11896
SUBJECT: GRB 110407A: Prompt enhanced Swift-XRT position
DATE:    11/04/07 14:44:46 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

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

Using  promptly downlinked XRT event data for GRB 110407A, we find an
enhanced XRT position of the afterglow: RA, Dec: 186.0313, 15.7117
which is equivalent to:
   RA (J2000)  = 12 24 7.51
   Dec (J2000) = +15 42 42.1
with an uncertainty of 2.1 arc sec (radius, 90% confidence). Analysis
of the promptly available data is online at
http://www.swift.ac.uk/sper/450884.

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: GRB110407A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11897
SUBJECT: GRB 110407A: MASTER early optical observations
DATE:    11/04/07 14:51:40 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, 
D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, 
A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka

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

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB110407   25 sec s after 
notice time and 107 sec after GRB time at 2011-04-07 14:08:28.65 UT. On 
our first (20s exposure) set we haven't found optical transient  within 
SWIFT-BAT error-box.
The 5-sigma unfiltred upper limit has been about 17.8 mag

MASTER II robotic telescope in Tunka also pointed on GRB110407 at same 
time in two polarizations. Unfortunately during this moment there was a 
strong clouds in the given direction and a upper limit very small.

The message may be cited.


GRB_name: GRB110407A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11898
SUBJECT: GRB 110407A :   Xinglong TNT upper limit
DATE:    11/04/07 15:18:55 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L.P. Xin, Y. Urata, Z. X. Ling, Y.L. Qiu, J.Y. Wei, J. Wang, J.S. Deng, 
C. Wu, X. H. Han on behalf of EAFON report:

We began to observe GRB110407A ( Wolf et al., GCN 11894) 
with Xinglong TNT telescope at  14:28:05(UT), 21.5min after 
the burst, under the dusty and cloudy wheather. 
A series of R-band images were obtained. 
No any new source was found within the errorbox  of X-ray 
counterpart ( Wolf et al., GCN 11894 ), down to 3 sigma 
upper limit of R ~ 18.3 mag, derived from USNO B1.0 R2 magnitude, at the
mean time of 26 min after the burst

This message may be cited.


GRB_name: GRB110407A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11899
SUBJECT: GRB 110407A : Lulin optical afterglow detection 
DATE:    11/04/07 16:48:39 GMT
FROM:    Kuiyun Huang at ASIAA  <ljhuang@asiaa.sinica.edu.tw>

GRB 110407A : Lulin optical afterglow detection 

C.J. Chuang, C.S. Lin, Y. Urata (NCU) and K.Y. Huang (ASIAA) on behalf
of the EAFON cooperation:

The 1-m telescope at Lulin Observatory started to observe GRB110407A
(Wolf et al. GCN 11849) at 21 minutes after the BAT trigger.  A series
of our r'-band observations found a fading optical source in the XRT
error region reported by Evans (GCN 11896). The position of the optical 
afterglow candidate is 

RA(J200) = 12:24:07.534 
Dec(J200) = +15:42:46.63
with 1" error.

We estimated the brightness of the optical transient against with
several SDSS stars.

Time (sec)  mag(AB)  error
1438        20.9     0.1
4758        22.7     0.3

This message may be cited 


GRB_name: GRB110406A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11900
SUBJECT: IPN triangulation of the bright GRB110406A
DATE:    11/04/07 20:48:04 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley on behalf of the Mars Odyssey and MESSENGER GRB teams,

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

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

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, 
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,

D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, W.
Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team, 

A. von Kienlin, X. Zhang, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team,

K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro,
Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM team,

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of
the Swift-BAT team, and

J. Goldsten, on behalf of the MESSENGER NS GRB team, report:

The bright GRB110406A (GCN 11890, 11893), was detected by Mars Odyssey
(HEND), MESSENGER (GRNS), Konus-Wind, INTEGRAL SPI-ACS, Suzaku WAM,
RHESSI, and Swift BAT (outside the coded field of view).  We have
triangulated it to a preliminary, 3 sigma confidence error box whose
corners are:


       RA(2000)                          DEC(2000)
 17.008898= 1 h  8 m  2.14 s     36.015742= 36 o  0 '  56.67 "
 16.578396= 1 h  6 m 18.82 s     35.984576= 35 o 59 '   4.48 "
 18.141649= 1 h 12 m 34.00 s     35.601842= 35 o 36 '   6.63 "
 17.702525= 1 h 10 m 48.61 s     35.586179= 35 o 35 '  10.24 "

The best-fit position is RA, Dec= 17.340, +35.809.  The error
box area is ~600 sq. arcmin. 

Due to its proximity to the Sun, this position cannot be observed
by Swift.

This error box can be improved.


GRB_name: GRB110407A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11902
SUBJECT: GRB 110407A: Swift-BAT refined analysis
DATE:    11/04/07 23:10:05 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), C. W. Wolf (PSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+800 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110407A (trigger #450884)
(Wolf, et al., GCN Circ. 11894).  The BAT ground-calculated position is
RA, Dec = 186.022, 15.726 deg, which is 
   RA(J2000)  =  12h 24m 05.3s 
   Dec(J2000) = +15d 43' 33.2" 
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 77%.
 
The mask-weighted light curve shows several overlapping peaks starting
at ~T-10 sec, peaking at ~T+15 sec, and ending around T+275 sec.
T90 (15-350 keV) is 145 +- 15 sec (estimated error including systematics).
 
The time-averaged spectrum from T-2.9 to T+158.8 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.73 +- 0.64, 
and Epeak of 57.9 +- 15.1 keV (chi squared 46.5 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.7 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+27.64 sec in the 15-150 keV band is
0.5 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.73 +- 0.12 (chi squared 55.6 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/450884/BA/


GRB_name: GRB110407A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11903
SUBJECT: GRB 110407A: Enhanced Swift-XRT position
DATE:    11/04/07 23:12:56 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 2767 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 110407A, 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 = 186.03111, +15.71170 which is equivalent
to:

RA (J2000): 12h 24m 7.47s
Dec (J2000): +15d 42' 42.1"

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

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

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


GRB_name: GRB110407A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11904
SUBJECT: GRB 110407A: NOT optical observations
DATE:    11/04/08 01:20:18 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

Daniele Malesani (DARK/NBI), Paul Vreeswijk (Univ. Iceland), Dong Xu 
(WIS), Johan Fynbo (DARK/NBI), Pall Jakobsson (Univ. Iceland), Ingvar 
Svardh (NOT), and Martin Nielsen (NOT), report on behalf of a larger 
collaboration:

We observed the field of GRB 110407A (Wolf et al., GCN 11895) with the 
Nordic Optical Telescope equipped with MOSCA. Observations were carried 
out in the R band, with a seeing of ~1.6", for a total observation time 
of 50 minutes. The mean time of the observation was Apr 7.943 UT (8.52 
hr after the GRB).

At the position of the optical and X-ray transient (Chuang et al., GCNs 
11899, 11901; Evans et al., GCN 11903), we detect a source close to the 
detection limit. Its magnitude is R = 23.2 +- 0.20 (Vega) based on 
calibration against the SDSS r band.


GRB_name: GRB110407A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11905
SUBJECT: GRB 110407A: MITSuME Okayama and Ishigakijima Optical upper limits
DATE:    11/04/08 02:55:55 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 110407A (Wolf et al., GCN 11894)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory
and the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.

We did not find any new point source within the enhanced XRT error
circle (Evans et al., GCNC 11903) in all the three bands. We
could not detect the previously reported afterglow
(Chuang et al., GCN 11899).

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

Okayama Astrophysical Observatory:
The observation started on 2011-04-07 14:08:27, (1.8 min
after the burst).

T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.00472    14:13:28     540.0    >19.3  >19.1  >18.2
0.07701    15:57:35    6840.0    >20.3  >20.2  >19.4
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

Ishigakijima Astronomical Observatory:
The observation started on2011-04-07 15:51:28 UT, (1.7 h
after the burst).

T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.12244    17:02:59    1080.0    >20.9  >20.7  >19.7
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110407A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11906
SUBJECT: GRB 110407A: GROND Detection of the Optical Afterglow
DATE:    11/04/08 08:10:39 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

D. A. Kann (TLS Tautenburg), P. Schady and J. Greiner (both MPE  
Garching) report on behalf of the GROND team:

We observed the field of GRB 110407A (Swift trigger 450884; Wolf et  
al., GCN #11894) simultaneously in g'r'i'z'JHK with GROND (Greiner et  
al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La  
Silla Observatory (Chile).

Observations started at 00:50 UT on April 8, 11 hours after the GRB  
trigger, and continued until ~03:30 UT. They were performed at a  
seeing of 1.5-2.5" and at an average airmass of 1.5.

We detect a point source within the 1.7 arcsec enhanced Swift-XRT  
error circle (Evans et al., GCN #11903), consistent with the optical  
afterglow detection reported by Chuang et al. (GCN #11901) and  
Malesani et al. (GCN #11904) in the g'r'i'z' bands. In an exposure of  
102 mins at a mid-observing time of 02:31 UT (12.5 hours after the BAT  
trigger), we estimate a preliminary r'-band magnitude (in the AB  
system) of 23.9+/-0.1.

The r'-band magnitude is calibrated against SDSS field stars and has  
not been corrected for the expected Galactic foreground extinction  
corresponding to a reddening of E_(B-V)=0.03 mag in the direction of  
the burst (Schlegel et al. 1998).


GRB_name: GRB110407A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11907
SUBJECT: GRB110407A: UVOT Upper Limits
DATE:    11/04/08 12:05:39 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) & C. W. Wolf (PSU) report on behalf of the 
Swift-UVOT team

The Swift/UVOT began settled observations of the field of GRB 110407A 168s
after the trigger (Wolf et al., GCN Circ. 11895). We do not detect a 
source at the position of the X-ray (Evans et al., GCN Circ. 11896, 11903) 
or optical afterglow reported by Lulin (Chuang et al, GCN Circ. 11899, 
11901), NOT (Malesani et al., GCN Circ. 11904) and GROND (Kann et al, GCN 
Circ. 11906).

Preliminary magnitudes using the UVOT photometric system (Poole et al. 
2008,MNRAS, 383, 627) for the finding chart (FC) and summed exposures at the
location of the optical afterglow are:

Filter  T_start(s)  T_stop(s)   Exp(s)       Mag/3sigUL
#####################################################
wh (FC)    168        317       147          >20.82
wh    607        6514      580          >21.59
u (FC)    327        577       246          >20.11
u          732        6104      413          >20.41
v          658        6873      382          >19.74
b    583        6309      432          >20.75
uvw1    708        5899      413          >20.34
uvm2    5493       5693      197          >19.75
uvw2       808        6719      413          >20.68
#####################################################

The values quoted above 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: GRB110407A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11908
SUBJECT: GRB 110407A: MASTER optical observations 
DATE:    11/04/08 15:16:15 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. 
Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka

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

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in 
Blagoveschensk was pointed to the  GRB110407   25 sec  after notice time and 
107 sec after GRB time at 2011-04-07 14:08:28.65 UT. On our first (20s 
exposure) set we haven't found optical transient  within SWIFT-BAT 
error-box up to 17.8 mag (5 sigma unfiltered)(Yurkov et al., GCN Circ No 
11897).

The results of the follow observations are:

T_mean-Tgrb [s]   Tstart     exptime   3 sigma-mlimit    Coadd
     209          14:08:28           200            19.7       5
    1143     14:14:03          1220            21.3      10
    2341   14:14:03          3380            22.0      22
    3640    14:14:03          5720            22.5      35

There is no OT at the Lulin position (Chuang et al., GCN Circ 11899)


The message may be cited.


GRB_name: GRB110406A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11909
SUBJECT: GRB 110406A: Positional coincidence with NGC 404
DATE:    11/04/08 15:43:53 GMT
FROM:    Antonia Rowlinson at U.of Leicester  <bar7@star.le.ac.uk>

A. Rowlinson, P.T. O'Brien, N.R. Tanvir (U. Leicester) and A.J. Levan
(U. Warwick) report:

We note that the the error box of the bright short hard GRB 110406A
detected by INTEGRAL SPI-ACS and the IPN (GCNs 11890, 11893, 11900)
overlies NGC 404, a dwarf galaxy at a distance of ~3 Mpc. The IPN
error box and the extent of NGC 404 are overlayed on a GALEX FUV image
here: http://www.star.le.ac.uk/~bar7/NGC404_FUV.jpg

NGC 404 is a recently rejuvinated lenticular galaxy, forming the
majority of its new stars in a ring with a star formation rate of
2.5e-3 M_sol yr^-1 (Thilker et al., 2010, ApJ, 714, L171).

If this GRB is associated with NGC 404, the isotropic energy released
would be ~6e46 erg (20 keV - 10 MeV) using the Konus-Wind spectral fit
(GCN 11893) which would be consistent with an SGR giant flare origin,
while the presence of a young stellar population within this galaxy
would also be consistent with this model. For comparison, the giant
flare from SGR 1806-20 had Eiso ~3.7e46 erg (Hurley et al., 2005,
Nature, 434, 1098).


GRB_name: GRB110407A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11912
SUBJECT: GRB 110407A: SMARTS optical limit
DATE:    11/04/08 23:35:14 GMT
FROM:    Bethany Cobb at GWU  <bcobb@gwu.edu>

B. E. Cobb (GWU), reports:

Using the ANDICAM instrument on the SMARTS 1.3m telescope at CTIO,
we obtained optical imaging of the error region of GRB 110407A
(GCN 11894, Wolf et al.) with a mid-exposure time of
2011-04-08 02:12 UT (~12.1 hrs post-burst). The total summed
exposure time amounted to 36 minutes in I.

No optical sources is detected at the position of
the optical afterglow of GRB 110407A (GCN 11901, Chuang et al.;
GCN 11904, Malesani et al.; GCN 11906, Kann et al.) to
a limit of I > 20.3. Optical photometry is calibrated against
Landolt standard stars.


GRB_name: GRB110407A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11914
SUBJECT: GRB 110407A:VLF observations on 20.27kHz
DATE:    11/04/09 16:17:17 GMT
FROM:    Matus Kocka at AI AS CR, Ondrejov  <kocka.mat@gmail.com>

Matus Kocka (AI AS CR), Rudolf Slosiar (Rudy BASE Observatory
Bojnice), Vladimir Karlovsky (Observatory Hlohovec), Richard Marko (AI
AS CR), Jan Karlovsky (Observatory Hlohovec), Rene Hudec (AI AS CR)


We observed the ionospheric perturbation on Apr. 7th which started at
14:06:21 UT from 3 different VLF receivers, so called SID monitors
(Sudden Ionospheric Disturbance) on ICV channel 20.27kHz. This event
is with a high probability GRB 110407A (Wolf et al., GCN 11895). The
detectors are located in Bojnice (Slovakia), Hlohovec (Slovakia) and
Brno (Czech Republic). Those places are so far apart that we can rule
out a possibility of a local disturbance.

The plot from all three SID-monitors is here:
http://zeus.asu.cas.cz/~koci/grb110407a/GRB110407A_vlf.png

Further analysis is ongoing.


GRB_name: GRB110407A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11916
SUBJECT: GRB 110407A: Swift-XRT refined Analysis
DATE:    11/04/11 03:58:19 GMT
FROM:    Chris Wolf at PSU  <cwolf@astro.psu.edu>

C. W. Wolf (PSU) reports on behalf of the Swift-XRT team:

We have analysed 26 ks of XRT data for GRB 110407A (Wolf  et al. GCN
Circ. 11894), from 147 s to 272.1 ks after the BAT trigger. The data
comprise 593 s in Windowed Timing (WT) mode (the first 10 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et
al. (GCN. Circ 11896).

After initial flaring (T>0.9 ks), the light curve can be modeled by a
broken power-law model, with an initial decay index of alpha1=2.19
(+0.12, -0.11). A break occurs at T+13.6 ks followed by a plateau phase
with a decay index of alpha2 = 0.4 (+0.5, -0.7).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.80 (+/-0.05). The
best-fitting absorption column is  1.00 (+/-0.13) x 10^21 cm^-2, in
excess of the Galactic value of 2.0 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.87 (+0.21, -0.11)
and a best-fitting absorption column of 8.4 (+5.1, -2.7) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.2 x 10^-11 (5.0 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      8.4 (+5.1, -2.7) x 10^20 cm^-2
Galactic foreground: 2.0 x 10^20 cm^-2
Excess significance: 5.2 sigma
Photon index:      1.87 (+0.21, -0.11)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00450884.

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


GRB_name: GRB110411A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11918
SUBJECT: GRB 110411A: Swift detection of a burst
DATE:    11/04/11 19:44:17 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

D. Grupe (PSU), S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC),
J. M. Gelbord (PSU), J. A. Kennea (PSU), C. B. Markwardt (NASA/GSFC),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU),
E. Sonbas (GSFC/USRA/Adiyaman Univ.), R. L. C. Starling (U Leicester),
C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report on behalf of the
Swift Team:

At 19:34:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110411A (trigger=451165).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA, Dec 291.437, +67.732 which is 
   RA(J2000) = 19h 25m 45s
   Dec(J2000) = +67d 43' 55"
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 120 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 19:36:18.2 UT, 126.4 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 291.43966,
67.71117 which is equivalent to:
   RA(J2000)  = 19h 25m 45.52s
   Dec(J2000) = +67d 42' 40.2"
with an uncertainty of 3.8 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 (6.92 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 5.4
(+3.77/-2.83) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 1.26e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 135 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.10. 

Burst Advocate for this burst is D. Grupe (grupe AT astro.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: GRB110411A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11919
SUBJECT: GRB 110411A: MASTER optical observations
DATE:    11/04/11 21:16:53 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, 
N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, 
D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka(Siberia) was pointed to the  GRB110411A 19 sec s after 
notice time and 44 sec after GRB time at 2011-04-11 19:34:55.3 UT in two 
polarizations.
On our first (10s exposure) set we haven't found optical  transient 
within SWIFT error-box (ra=19 25 45 dec=+67 43 48 r=0.050000).
The 5-sigma upper limit has been about 17.5 mag
Observations and data reduction is continued.
The message may be cited.


GRB_name: GRB110411A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11920
SUBJECT: GRB 110411A: Enhanced Swift-XRT position
DATE:    11/04/11 23:56:36 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 2358 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 110411A, 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 = 291.44219, +67.71167 which is equivalent
to:

RA (J2000): 19h 25m 46.13s
Dec (J2000): +67d 42' 42.0"

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: GRB110411A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11921
SUBJECT: GRB 110411A, Swift-BAT refined analysis
DATE:    11/04/12 00:05:34 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110411A (trigger #451165)
(Grupe, et al., GCN Circ. 11918).  The BAT ground-calculated position is
RA, Dec = 291.427, 67.706 deg which is
     RA(J2000)  =  19h 25m 42.5s
     Dec(J2000) = +67d 42' 21.0"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.

The burst had multiple peaks with gradual rise and fall. The two largest peaks
were centered around T+5 sec and T+60 sec.  T90 (15-350 keV) is 80.3 +- 5.2 sec
(estimated error including systematics).

The time-averaged spectrum from T-11.9 to T+86.3 sec is best fit by a power
law with an exponential cutoff.  This fit gives a photon index 1.51 +- 0.31,
and Epeak of 41.0 +- 8.1 keV (chi squared 49.70 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 3.3 +- 0.2 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+4.73 sec in the 15-150 keV band is
1.3 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.05 +- 0.07 (chi squared 59.73 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/451165/BA/


GRB_name: GRB110412A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11922
SUBJECT: GRB 110412A: Swift detection of a burst
DATE:    11/04/12 07:44:19 GMT
FROM:    Jonathan Gelbord at PSU/Swift  <jgelbord@astro.psu.edu>

J. M. Gelbord (PSU), V. D'Elia (ASDC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), V. Mangano (INAF-IASFPA),
C. B. Markwardt (NASA/GSFC), J. P. Osborne (U Leicester),
C. Pagani (U Leicester), K. L. Page (U Leicester), M. H. Siegel (PSU)
and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team:

At 07:33:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110412A (trigger=451191).  Swift did not slew to the location
because the position is in an observing constraint.  The BAT on-board 
calculated location is RA, Dec 133.492, +13.517 which is 
   RA(J2000) = 08h 53m 58s
   Dec(J2000) = +13d 30' 60"
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 30 sec.  The peak count rate
was ~600 counts/sec (15-350 keV), at ~20 sec after the trigger. 

Due to a Moon observing constraint, Swift cannot slew to the BAT
position until 15:08 UT on 2011 April 14. There will thus be no XRT or
UVOT data for this trigger before this time. 

Burst Advocate for this burst is J. M. Gelbord (jgelbord AT astro.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: GRB110411A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11923
SUBJECT: GRB 110411A : Xinglong TNT OT candidate
DATE:    11/04/12 09:03:58 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L.P. Xin, Z. X. Ling, Y.L. Qiu, J.Y. Wei, J. Wang, 
J.S. Deng, C. Wu, X. H. Han on behalf of EAFON report:

We began to observe GRB110411A ( Grope et al., GCN 11918) 
with Xinglong TNT telescope at  19:35:32 (UT), 81 sec after 
the burst. A series of White and R-band images were obtained. 
With the combination of all R-band images of 37*60 sec 
exposure time, we detected an new source nearby the 
errorbox  of X-ray counterpart ( Goad et al., GCN 11920 ).

The coordinates of new source are:

Ra:    19:25:45.65 
Dec:   67:42:39.1
Epoch: J2000

The uncertainty of the coordinates is about 1 arc. 

The brightness of this source is estimated to be about 
21 +/- 0.2 mag in the R band, at the mean time of 38 min 
after the burst, comparing to an USNO B1.0 R2 reference star, 
of which the coordinates are 
19:25:52.432 +67:43:44.07 J2000 R2=16.18mag.

We proposed that the new source be the optical 
counterpart of GRB 110411A.

This message may be cited.


GRB_name: GRB110411A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11924
SUBJECT: GRB 110411A: MASTER prompt and follow-up optical limits
DATE:    11/04/12 11:00:43 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. 
Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in 
Tunka(Siberia) was pointed to the  GRB110411A (Grupe et al., GCN 11918) 19 
sec s after notice time and 44 sec after GRB time at 2011-04-11 19:34:55.3 UT in two polarizations.
A series of Polarization, White and R-band images were obtained.
We have not found OT at Xinglong TNT OT candidate position (Xin et al., GCN Circ 11923). 
The results from two tubes are:
(GRB Time = 2011-04-11 19:34:11 UT)

Date time      Exp.time    Limit Filt.(W-white)
    UT                   (s)   (5-sigma)
2011-04-11 19:34:55 10 17.4 W
2011-04-11 19:34:55 10 18.0 W
2011-04-11 19:35:23 10 14.8 P/
2011-04-11 19:35:23 10 15.4 P\
2011-04-11 19:35:50 20 15.5 P/
2011-04-11 19:35:51 20 16.0 P\
2011-04-11 19:36:29 30 16.0 P/
2011-04-11 19:36:29 30 16.5 P\
2011-04-11 19:37:17 40 16.0 P/
2011-04-11 19:37:18 40 16.7 P/
2011-04-11 19:38:14 50 16.3 P\
2011-04-11 19:38:14 50 16.9 P/
2011-04-11 19:39:22 60 16.5 P\
2011-04-11 19:39:22 60 17.0 P/
2011-04-11 19:40:39 80 16.6 P\
2011-04-11 19:40:39 80 17.2 P/
2011-04-11 19:42:14 3790 19.4 P\
2011-04-11 19:42:14 100 17.0 P/
2011-04-11 19:42:15 3970 18.9 P\
2011-04-11 19:42:15 100 17.7 P/
2011-04-11 19:44:10 120 17.4 P\
2011-04-11 19:44:11 120 17.4 P/
2011-04-11 19:46:26 150 17.8 P\
2011-04-11 19:46:26 150 17.7 P/
2011-04-11 19:49:11 180 18.1 P\
2011-04-11 19:49:12 180 17.9 P/
2011-04-11 19:52:30 180 18.0 P\
2011-04-11 19:52:30 180 17.9 P/
2011-04-11 19:55:46 180 18.1 P\
2011-04-11 19:55:46 180 18.0 P/
2011-04-11 19:59:02 180 18.1 P\
2011-04-11 19:59:02 180 18.1 P/
2011-04-11 20:02:17 180 18.1 P\
2011-04-11 20:02:18 180 18.1 P/
2011-04-11 20:05:33 180 18.1 P\
2011-04-11 20:05:34 180 18.1 P/
2011-04-11 20:08:49 180 18.0 P\
2011-04-11 20:08:49 180 18.0 P/
2011-04-11 20:12:06 180 18.0 P\
2011-04-11 20:12:06 180 18.0 P/
2011-04-11 20:15:23 180 18.1 P\
2011-04-11 20:15:24 180 18.0 P/
2011-04-11 20:18:40 180 18.1 P\
2011-04-11 20:18:41 180 18.0 P/
2011-04-11 20:21:57 180 18.1 P\
2011-04-11 20:21:58 180 18.0 P/
2011-04-11 20:25:14 180 18.0 P\
2011-04-11 20:25:14 180 18.0 P/
2011-04-11 20:28:38 180 18.1 P\
2011-04-11 20:28:40 180 18.0 P/
2011-04-11 20:31:56 180 18.1 P\
2011-04-11 20:31:57 180 18.0 P/
2011-04-11 20:35:13 180 18.0 P\
2011-04-11 20:35:13 180 17.9 P/
2011-04-11 20:38:32 180 18.1 P\
2011-04-11 20:38:32 180 17.9 P/
2011-04-11 20:41:48 180 17.8 P\
2011-04-11 20:41:48 180 17.9 P/
2011-04-11 20:45:04 180 17.8 P\
2011-04-11 20:45:04 180 17.9 P/
2011-04-11 20:48:20 180 17.8 P\
2011-04-11 20:48:20 180 17.7 P/
2011-04-11 20:51:45 180 17.7 P\
2011-04-11 20:51:46 180 17.7 P/
2011-04-11 20:59:09 180 19.0 W
2011-04-11 20:59:09 900 19.4 W
2011-04-11 20:59:09 180 18.8 R
2011-04-11 20:59:09 900 19.2 R
2011-04-11 21:02:42 180 18.7 W
2011-04-11 21:02:43 180 18.8 R
2011-04-11 21:06:52 180 18.5 W
2011-04-11 21:06:52 180 18.5 R
2011-04-11 21:10:28 180 18.2 W
2011-04-11 21:10:28 180 18.3 R
2011-04-11 21:14:04 180 18.0 W
2011-04-11 21:14:04 180 18.0 R

The message may be cited.


GRB_name: GRB110411A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11925
SUBJECT: GRB 110411A: Swift/UVOT Upper Limits
DATE:    11/04/12 11:59:12 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N.P.M. Kuin (MSSL/UCL) and D. Grupe (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110411A
135 s after the BAT trigger (Grupe et al., GCN Circ. 11918).
No optical afterglow consistent with the XRT (Goad et al., GCN Circ.
11920) or the Xinglong (Xin et al., GCN Circ. 11923) positions
is detected in the initial UVOT exposures.

Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

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

white_FC           135          285          147         >21.3
u_FC               347          597          246         >20.4
white              135         7753          883         >22.2
v                  677         8164          607         >19.9
b                  603         7548          586         >21.1
u                  347         7343          637         >20.4
w1                 726         7139          391         >20.2
m2                 701         8326          508         >20.1
w2                 653         7959          607         >20.9

The values quoted above 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: GRB110412A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11926
SUBJECT: GRB 110412A: Fermi GBM observation
DATE:    11/04/12 13:16:29 GMT
FROM:    Arne Rau at MPE  <arau@mpe.mpg.de>

Arne Rau (MPE) reports on behalf of the Fermi GBM Team:

"At 07:33:35.71  UT on 12 April 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110412A (trigger 07:33:35.71  / 110412315) which was also detected by the Swift/BAT
(Gelbord et al. 2011, GCN 11922). The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 53 degrees.

The GBM light curve shows a single peak with a duration (T90) of about 16 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+18.9 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.7 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 87 +/- 5 keV

The event fluence (10-1000 keV) in this time interval is
(2.2 +/- 0.1)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+5.8 s in the 10-1000 keV band is 2.7 +/- 0.2 ph/s/cm^2.

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


GRB_name: GRB110411A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11927
SUBJECT: GRB 110411A: Swift-XRT refined Analysis
DATE:    11/04/12 16:26:11 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <grupe@astro.psu.edu>

D. Grupe (PSU) reports on behalf of the Swift-XRT team:

We have analyzed 11 ks of XRT data for GRB 110411A (Grupe  et al. GCN
Circ. 11918), from 117 s to 37.2 ks after the  BAT trigger. The data
comprise 64 s in Windowed Timing (WT) mode (the first 8 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 11920).

The light curve can be modeled with a series of power-law decays. The
initial decay index is alpha=6.0 (+/-0.6). At T+230 s  the decay
flattens to an alpha of 0.58 (+0.11, -0.12) before breaking again at
T+4446 s to a final decay with index alpha=1.39 (+0.27, -0.24).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.93 (+0.23, -0.21). The
best-fitting absorption column is  1.02 (+0.14, -0.12) x 10^22 cm^-2,
in excess of the Galactic value of 6.9 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.0 x 10^-11 (2.3 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.02 (+0.14, -0.12) x 10^22 cm^-2
Galactic foreground: 6.9 x 10^20 cm^-2
Excess significance: 13.5 sigma
Photon index:      2.93 (+0.23, -0.21)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00451165.

With an excess absorption column density of 9.5 x 10^21 cm^-2 following
the relation in Grupe et al. (2007, AJ, 133, 2216) the estimated 
 maximum redshift of the afterglow is z < 1.0.

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


GRB_name: GRB110411A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11928
SUBJECT: GRB 110411A: optical limits from OSN
DATE:    11/04/12 18:26:34 GMT
FROM:    Martin Jelinek at Inst.Astrophys.Andalucia,Granada  <mates@iaa.es>

A. Sota, J. Gorosabel and M. Jelinek (IAA-CSIC), 
report on behalf of a larger collaboration.

"We have observed the XRT error circle (Goad et al. GCNC
11920) of GRB 110411A (Grupe et al. GCNC 11918) with the 1.5m
telescope of Observatorio de Sierra Nevada, Granada, Spain.
The observations were carried out on April 12.06606-12.12741
UT (6.01-7.49 hours post trigger) in the R and I bands with an
exposure time of 8x300s in each band. No object is detected
within the XRT error circle down to R < 23.5 and I < 22.4,
calibrated against USNO B1.0".


GRB_name: GRB110412A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11929
SUBJECT: GRB 110412A: Swift-BAT refined analysis
DATE:    11/04/12 20:13:44 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), J. M. Gelbord (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110412A (trigger #451191)
(Gelbord, et al., GCN Circ. 11922).  The BAT ground-calculated position is
RA, Dec = 133.491, 13.488 deg, which is 
   RA(J2000)  =  08h 53m 57.9s 
   Dec(J2000) = +13d 29' 15.4" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 18%.
 
The mask-weighted light curve shows a FRED-like pulse starting at ~T+10 sec,
peaking at ~T+20 sec, and ending at ~T+45 sec.  T90 (15-350 keV) is
23.4 +- 4.1 sec (estimated error including systematics).
 
The time-averaged spectrum from T+13.7 to T+40.4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.54 +- 0.14.  The fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+18.96 sec in the 15-150 keV band
is 2.0 +- 0.4 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/451191/BA/


GRB_name: GRB110411A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11930
SUBJECT: GRB 110411A: PAIRITEL NIR Upper Limits
DATE:    11/04/12 22:35:19 GMT
FROM:    Adam Morgan at U.C. Berkeley  <qmorgan@gmail.com>

A. N. Morgan, A. Cucchiara, and J. S. Bloom (UC Berkeley) report:

We observed the field of GRB 110411A (Grupe et al., GCN 11918) with the 1.3m
PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2011-04-12
09:53:13 UT, ~14.3 hours after the Swift Trigger.  In  mosaics (effective
exposure time of 1.22 hours) taken simultaneously in the J, H, and Ks
filters, we do not detect any source at the optical afterglow candidate
location (Xin et al., GCN 11923).

The preliminary photometry yields:

post burst
t_mid (hr) exp.(hr) filt  U. Limit (3 sig)
15.37      1.22     J     > 18.7
15.37      1.22     H     > 18.0
15.37      1.22     H     > 16.6

All magnitudes are given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values.


GRB_name: GRB110414A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11931
SUBJECT: GRB 110414A: Swift detection of a burst
DATE:    11/04/14 08:00:18 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>

R. L. C. Starling (U Leicester), A. P. Beardmore (U Leicester),
V. D'Elia (ASDC), P. A. Evans (U Leicester), J. M. Gelbord (PSU),
B. Gendre (ASDC), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), A. Melandri (INAF-OAB),
K. L. Page (U Leicester), A. Rowlinson (U Leicester),
M. Stamatikos (OSU/NASA/GSFC), G. Stratta (ASDC) and
G. Tagliaferri (INAF-OAB) report on behalf of the Swift Team:

At 07:42:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110414A (trigger=451343).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 97.876, +24.361 which is 
   RA(J2000) = 06h 31m 30s
   Dec(J2000) = +24d 21' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed multiple-peaked structure
with a duration of about 50 sec.  The peak count rate
was ~400 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 07:44:36.8 UT, 142.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 97.8726,
24.3624 which is equivalent to:
   RA(J2000)  = 06h 31m 29.42s
   Dec(J2000) = +24d 21' 44.7"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 12 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 3.05
x 10^21 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 4.11e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of nominal 250 seconds with the U filter
starting 308 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. Data from the 2.7'x2.7' sub-image are
not available at this time. 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 0.33. 

Burst Advocate for this burst is R. L. C. Starling (rlcs1 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: GRB110414A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11932
SUBJECT: GRB 110414A : Faulkes Telescope North observations
DATE:    11/04/14 12:57:35 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri (INAF-OAB), C. Guidorzi (U. Ferrara), C.G. Mundell  
(Liverpool JMU),
A. Gomboc, J. Japelj and D. Kopac (U. Ljubljana) on behalf of a large
collaboration report:


The 2-m Faulkes Telescope North robotically followed up GRB110414A  
(SWIFT
trigger 451343; Starling et al. GCN 11931) starting about 4 min after  
the
GRB trigger time. Observations were performed automatically with BVRi  
filters.

We do not detect any clear fading object inside the reported XRT  
position
down to a limiting magnitude of R~20.0. We do detect a faint  
uncatalogued
source, in one single SDSS-i exposure, inside the XRT error circle with
coordinates:

RA = 06:31:29.37
Dec = +24:21:45.9  (+/- 1 arcsec)

This object is not detected in subsequent SDSS-i frames. Fading is yet
to be confirmed.

This message may be cited.


GRB_name: GRB110414A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11934
SUBJECT: GRB 110414A: Enhanced Swift-XRT position
DATE:    11/04/14 20:36:53 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 1551 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 110414A, 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 = 97.87261, +24.36241 which is equivalent
to:

RA (J2000): 06h 31m 29.43s
Dec (J2000): +24d 21' 44.7"

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

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

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


GRB_name: GRB110414A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11935
SUBJECT: GRB 110414A: Swift-XRT refined Analysis
DATE:    11/04/14 22:46:27 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>

R. L. C. Starling (U Leicester) reports on behalf of the Swift-XRT
team:

We have analysed 9.1 ks of XRT data for GRB 110414A (Starling  et al.
GCN Circ. 11931), from 131 s to 22.7 ks after the  BAT trigger. The
data comprise 18 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
Osborne et al. (GCN. Circ 11934).

The late-time light curve (from T0+5.1 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.67 (+0.23, -0.22).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.72 (+/-0.15). The
best-fitting absorption column is  5.0 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 3.0 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.32 (+0.17, -0.16)
and a best-fitting absorption column of 4.0 (+/-0.6) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.0 x 10^-11 (8.4 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.0 (+/-0.6) x 10^21 cm^-2
Galactic foreground: 3.0 x 10^21 cm^-2
Excess significance: 11.7 sigma
Photon index:      2.32 (+0.17, -0.16)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00451343.

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


GRB_name: GRB110414A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11936
SUBJECT: GRB 110414A: Swift/UVOT Upper limits
DATE:    11/04/14 23:01:09 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard@astro.psu.edu>

T.A. Pritchard (PSU) and R. L. C. Starling (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110414A
151 s after the BAT trigger (Starling et al., GCN Circ. 11931).
No optical afterglow consistent with the XRT position
(Starling et al., GCN Circ. 11931) is detected in the initial UVOT 
exposures.

Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are:

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

white_FC           150          300          147        >20.6
u_FC               308          558          246        >19.4
white              150         1013          334        >21.3
v                  639          831           39        >18.4
b                  565          758           39        >18.9
u                  308          733          265        >19.5
w1                 689          709           19        >18.5
m2                 664          856           39        >18.8
w2                 615          807           39        >19.2

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.33 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110414A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11937
SUBJECT: GRB 110414A: Swift-BAT Refined Analysis
DATE:    11/04/14 23:49:34 GMT
FROM:    Michael Stamatikos at OSU/GSFC  <michael.stamatikos-1@nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), 
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt 
(GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos 
(OSU/NASA/GSFC), R. L. C. Starling (U Leicester), J. Tueller (GSFC), T. N. Ukwatta 
(MSU) (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 110414A (trigger #451343) (Starling, et al., 
GCN Circ. 11931).  The BAT ground-calculated position is 
RA, Dec = 97.876, 24.349 deg which is 
   RA(J2000)  =  06h 31m 30.2s 
   Dec(J2000) = +24d 20' 56.5" 
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial 
coding was 30%. 
 
The mask-weighted lightcurve shows several overlapping peaks with the first starting 
at ~T-100 sec, the main peaks at T-33, T+0, T+10, T+25, and a small peak at ~T+120 
sec, and ending at ~T+130 sec. T90 (15-350 keV) is 152.0 +- 73.2 sec (estimated error 
including systematics). 

The time-averaged spectrum from T-38.4 to T+135.6 sec is best fit by a simple 
power-law model.  The power law index of the time-averaged spectrum is 1.70 +- 0.14. 
The fluence in the 15-150 keV band is 3.5 +- 0.3 x 10^-06 erg/cm2. The 1-sec peak 
photon flux measured from T+8.62 sec in the 15-150 keV band is 1.1 +- 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/451343/BA/


GRB_name: GRB110414A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11938
SUBJECT: GRB110414A: MITSuME Okayama Optical upper limits
DATE:    11/04/15 02:12:07 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 the MITSuME collaboration:

We observed the field of GRB 110414A (Starling et al., GCN 11931)
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 2011-04-14 10:35:42 UT (~2.9 h after
the burst). We did not find any new point source within the
Enhanced XRT circle (Osborne et al., GCN 11934) in all the three
bands.

Three sigma upper limits of the OT are listed below. We used
GSC2.3 catalog for flux calibration.


T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.16212    11:35:41    6180.0    >19.3  >19.2  >18.4
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110414A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11939
SUBJECT: GRB 110414A: GROND upper limits
DATE:    11/04/15 20:24:50 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann (TLS Tautenburg), J. Elliott, and J. Greiner (both MPE Garching)
report on behalf of the GROND team:

We observed the field of GRB 110414A (Swift trigger 451343; Starling et
al., GCN 11931) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla
Observatory (Chile).

Observations started at 23:17 UT on April 14, 15.58 hours after the GRB
trigger, and continued until 00:38 UT. They were obtained under
challenging conditions, partially in astronomical twilight, with seeing of
1".5, average airmass of 2.1, bright moonlight and passing cirrus. From
exposures of 1379 s in g'r'i'z' and 1440 s in JHK, no source is detected
within the UVOT-enhanced XRT error circle reported by Osborne et al. (GCN
11934) or at the position of the possible i' detection (Melandri et al.,
GCN 11932) down to the following 3 sigma upper limits (all in AB):

g' > 23.0,

r' > 23.3,

i' > 22.9,

z' > 22.9,

J > 20.1,

H > 19.7 and,

K > 17.3

If the i' detection of Melandri et al. (GCN 11932) is confirmed, our
observations show the source has faded and is thus likely the afterglow of
GRB 110414A.

The given limits are derived based on calibrating the images against GROND
zeropoints and 2MASS field stars and are not corrected for the Galactic
foreground extinction corresponding to a reddening of E_(B-V) = 0.331 in
the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB110414A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11940
SUBJECT: GRB110414A: MITSuME Ishigakijima Optical upper limits
DATE:    11/04/15 22:48:58 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

D. Kuroda (OAO, NAOJ),  H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 110414A (Starling et al., GCN 11931)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.

The observation started on 10:57:59 UT (~3.3 h after the burst).
We did not find any new point source within the Enhanced XRT circle
(Osborne et al., GCN 11934) in all the three bands.

Three sigma upper limits of the OT are listed below. We used
GSC2.3 catalog for flux calibration.


T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.17783    11:58:19    6180.0    >19.7  >19.8  >19.1
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110420A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11941
SUBJECT: GRB 110420A: Swift detection of a burst with optical counterpart
DATE:    11/04/20 11:17:43 GMT
FROM:    David Burrows at PSU/Swift  <burrows@astro.psu.edu>

V. Mangano (INAF-IASFPA), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
J. M. Gelbord (PSU), B. Gendre (ASDC), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
P. T. O\'Brien (U Leicester), C. Pagani (U Leicester),
P. Romano (INAF-IASFPA), A. Rowlinson (U Leicester),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU),
M. Stamatikos (OSU/NASA/GSFC) and R. L. C. Starling (U Leicester)
report on behalf of the Swift Team:

At 11:02:24 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110420A (trigger=451757).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 2.165, -37.855 which is 
   RA(J2000) = 00h 08m 40s
   Dec(J2000) = -37d 51' 17"
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 20 sec.  The peak count rate
was 4000 counts/sec (15-350 keV), at 10 sec after the trigger. 

The XRT began observing the field at 11:03:51.6 UT, 87.6 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 2.16337, -37.88696 which
is equivalent to:
    RA(J2000)  = 00h 08m 39.21s
    Dec(J2000) = -37d 53' 13.1"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 115 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.  We cannot determine whether the source is
fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.26 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.8
(+2.08/-1.84) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 8.02e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 97 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 00:08:39.27 = 2.16364
  DEC(J2000) = -37:53:12.0  = -37.88667
with a 90%-confidence error radius of about 0.75 arc sec. This position is 1.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.77 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01. 

Burst Advocate for this burst is V. Mangano (vanessa 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: GRB110420A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11942
SUBJECT: GRB 110420A: Enhanced Swift-XRT position
DATE:    11/04/20 17:26:35 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 1599 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 110420A, 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 = 2.16355, -37.88627 which is equivalent
to:

RA (J2000): 00h 08m 39.25s
Dec (J2000): -37d 53' 10.6"

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

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

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


GRB_name: GRB110420A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11943
SUBJECT: GRB 110420A: Swift-XRT refined Analysis
DATE:    11/04/20 20:28:46 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano (INAF-IASFPA) and B. Sbarufatti (INAF OAB/INAF-IASFPA)
report on behalf of the Swift-XRT team:

We have analysed 1.9 ks of XRT data for GRB 110420A (Mangano  et al.
GCN Circ. 11941), from 77 s to 17.0 ks after the  BAT trigger. The data
comprise 57 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 11942).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=3.87 (+0.31, -0.29). At T+181 s  the decay
flattens to an alpha of 0.23 (+0.08, -0.09) before breaking again at
T+11.0 ks to a final decay with index alpha=3.9 (+1.8, -2.1).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 4.2 (+0.5, -0.4). The
best-fitting absorption column is  1.9 (+0.6, -0.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.37 (+0.16, -0.15)
and a best-fitting absorption column of 2.1 (+/-0.4) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.5 x 10^-11 (6.4 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.1 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^20 cm^-2
Excess significance: 8.8 sigma
Photon index:      2.37 (+0.16, -0.15)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00451757.

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


GRB_name: GRB110420B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11944
SUBJECT: GRB 110420B: Swift detection of a short hard burst
DATE:    11/04/20 22:51:27 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

B. Sbarufatti (INAF-OAB/IASFPA), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), M. M. Chester (PSU), V. D'Elia (ASDC),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), V. Mangano (INAF-IASFPA), A. Melandri (INAF-OAB),
D. M. Palmer (LANL), M. Stamatikos (OSU/NASA/GSFC) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 22:42:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110420B (trigger=451794).  Swift did not immediately slew
because of an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 320.049, -41.264, which is 
   RA(J2000)  =  21h 20m 12s
   Dec(J2000) = -41d 15' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
with a duration of about 64 milli-sec.  The peak count rate
was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until 
T0+40.4 minutes. There will be no XRT or UVOT data until
this time. 

Burst Advocate for this burst is B. Sbarufatti (boris.sbarufatti AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB110420A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11945
SUBJECT: GRB 110420A: Swift-BAT refined analysis
DATE:    11/04/20 23:59:45 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

GRB 110420A: Swift-BAT refined analysis
 
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), V. Mangano (INAF-IASFPA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+242 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110420A (trigger #451757)
(Mangano, et al., GCN Circ. 11941).  The BAT ground-calculated position is
RA, Dec = 2.164, -37.877 deg which is 
   RA(J2000)  =  00h 08m 39.3s 
   Dec(J2000) = -37d 52' 35.5" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 15%.
 
The mask-weighted light curve shows a single peak with some structure
starting at ~T-15 sec, peaking at ~T+8 sec, and ending at ~T+35 sec.
T90 (15-350 keV) is 11.8 +- 0.9 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.1 to T+16.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.30 +- 0.07.  The fluence in the 15-150 keV band is 5.9 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+8.04 sec in the 15-150 keV band
is 14.0 +- 0.9 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/451757/BA/


GRB_name: GRB110420B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11946
SUBJECT: GRB 110420B: Swift-BAT refined analysis
DATE:    11/04/21 01:20:10 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), B. Sbarufatti (INAF-OAB/IASFPA),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT SHB GRB 110420B (trigger #451794)
(Sbarufatti, et al., GCN Circ. 11944).  The BAT ground-calculated position is
RA, Dec = 320.045, -41.277 deg, which is 
   RA(J2000)  =  21h 20m 10.9s 
   Dec(J2000) = -41d 16' 38.0" 
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.
 
The mask-weighted light curve shows a FRED-like pulse starting at ~T+0.00
and ending at ~T+0.08 sec.  T90 (15-350 keV) is 0.084 +- 0.021 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-0.004 to T+0.100 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index -1.52 +- 2.56, 
and Epeak of 79.5 +- 30.0 keV (chi squared 67.2 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 5.3 +- 1.1 x 10^-8 erg/cm2
and the 1-sec peak flux measured from T-0.45 sec in the 15-150 keV band is
0.7 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.11 +- 0.27 (chi squared 73.8 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/451794/BA/


GRB_name: GRB110420B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11947
SUBJECT: GRB 110420B: Swift-XRT afterglow candidate
DATE:    11/04/21 07:06:31 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF-OAB/IASFPA), V. Mangano (INAF/IASFPA) report on behalf
of the Swift-XRT team:

We have analyzed 4.5 ks of XRT data for GRB 110420B (Sbarufatti  et al.
GCN Circ. 11944), from 2.6 ks to 14.4 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. We find an afterglow candidate
with XRT position RA, Dec = 320.10472, -41.29713 which is equivalent to:

RA (J2000): 21 20 25.13
Dec(J2000): -41 17 49.7

with an uncertainty of 4.0 arcsec (radius, 90% confidence). We cannot
determine at the present time whether the source is fading. The source
lies 3.2 arcmin from the BAT onboard position and 2.95 arcmin from the BAT
refined position (Markwardt et al., GCN Circ. 11946). The observed rate is
4.5 x 10^-3 counts/s  (1.4 x 10^-13 erg cm^-2 s^-1), corresponding to a
3.8 sigma level detection.

More data are needed in order to confirm the nature of the source.


GRB_name: GRB110420A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11948
SUBJECT: GRB 110420A Swift/UVOT Observations
DATE:    11/04/21 10:10:04 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) & V. Mangano (INAF-IASFPA) report on behalf of the Swift-UVOT team

The Swift/UVOT began settled observations of the field of GRB 110420A 97s 
after the trigger (Mangano et al., GCN Circ. 11941). We detect a source 
at a refined position of RA(J2000), DEC(J2000)= 2.16363deg,-37.88664deg. 
This is equivalent to:

    RA (J2000)  00:08:39.27
   Dec (J2000) -37:53:11.9

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence). 
This is consistent with the position of the X-ray afterglow 
(Beardmore et al., GCN Circ. 11942). The afterglow is detected in 
all filters providing a photometric redshift limit of z~<1.6.

Preliminary magnitudes using the UVOT photometric system (Poole et al. 2008, 
MNRAS, 383, 627) for the finding chart (FC) and summed exposures at the 
location of the optical afterglow are:

Filter  T_start(s)  T_stop(s)   Exp(s)       Mag
#####################################################
wh (FC)     97         247       147     17.81 +/- 0.05
wh           761        781       19       18.10 +/- 0.17
u (FC)      309        559      246      17.46 +/- 0.07
u               712        732       19       17.96 +/- 0.36
v                811        831       19       18.20 +/- 0.67
b           737        757       19       18.04 +/- 0.28
uvw1   688        707       19       17.08 +/- 0.24
uvm2   663        683       19       17.73 +/- 0.41
uvw2         614        634       19       17.91 +/- 0.35
#####################################################

The values quoted above 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: GRB110420B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11949
SUBJECT: GRB 110420B, GROND observations
DATE:    11/04/21 12:35:44 GMT
FROM:    Andrea Rossi at TLS Tautenburg  <rossi@tls-tautenburg.de>

P. Afonso (MPE Garching), A. Rossi, S. Klose (TLS Tautenburg), and J. 
Greiner (MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 110420B (Swift trigger 451794; Sbarufatti et
al. GCN 11944) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope on La Silla.

Observations started at 7:00 UT on April 21, 8.15 hours after the GRB 
trigger. They were obtained under challenging sky conditions, with a 
seeing > 1.5 arcsec, an average airmass of 1.7, bright moonlight, and 
passing cirrus.

In a first epoch, centered on the refined BAT error circle (Markwardt et 
al., GCN 11946), we do not detect any new object 
down to the DSS2 limit. The XRT error circle (Sbarufatti et al., GCN 
11947) was not covered by these observations in g'r'i'z'.

A subsequent epoch started about 30 min later and was centered on the XRT 
afterglow candidate (Sbarufatti et al., GCN 11947). Here we note the 
presence of a relatively bright object at the border of the XRT error 
circle at coordinates RA, DEC (J2000) 21:20:25.389, -41:17:51.79 (+/- 0.5 
arcsec), which could be a galaxy seen nearly face-on. This object is also 
visible in the DSS2-red image.  Unfortunately, due to the bad seeing we 
cannot decide with certainty at the moment if this object is a galaxy or a 
star. Its r'-band magnitude is r'(AB)  = 19.5 +/- 0.1. No other source is 
detected inside the XRT error circle down to r'(AB) = 23.2.

Magnitudes are derived by calibrating the images against GROND zeropoints 
and 2MASS field stars. We note that the Galactic reddening along the line 
of sight is E(B-V) = 0.03 mag (Schlegel et al. 1998).


GRB_name: GRB110420B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11950
SUBJECT: GRB 110420B: Spectral lag indicates short hard burst
DATE:    11/04/21 13:39:01 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S.D. Barthelmy (GSFC) and J. Norris (BSU)
report:

For GRB 110420B (Trigger 451794, GCNs 11944 & 11946),
the spectral lag analysis of the Swift-BAT data for 40 msec
covering the spike, yields a lag of 0.6 +/-2.0 msec for the
25-50 to 100-300 keV bands and 2.4 +4/-2 msec for the
15-25 to 50-100 keV bands, both using a lightcurve binning of 2 msec.


GRB_name: GRB110420A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11951
SUBJECT: Konus-Wind observation of GRB 110420A
DATE:    11/04/21 13:41:09 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
P. Oleynik, M. Ulanov, D. Svinkin, and
T. Cline on behalf of the Konus-Wind team, report:

The long soft GRB 110420A (Swift-BAT trigger #451757: Mangano et al., 
GCN 11941; Krimm et al., GCN 11945) triggered Konus-Wind at 
T0(KW)=39750.543 s UT (11:02:30.543).

The burst light curve shows a single pulse started at ~T0(KW)-9 s with a 
duration of ~18 s.

As observed by Konus-Wind the burst
had a fluence of 6.54(-0.53, +0.64)x10^-6 erg/cm2,
and a 256-ms peak flux measured from T0-0.320 s
of (1.11 +/- 0.17)x10^-6 erg/cm2/s
(both in the 20 - 500 keV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+8.448 s) is well fitted (in the 20 - 500 keV
range) by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.71(-0.26, +0.31),
and Ep = 43(-18, +17) keV (chi2 = 31.1/39 dof).
Fitting by GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy
photon index: beta < -2.61 (chi2 = 31.1/38 dof).

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

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB110420_T39750/


GRB_name: GRB110420B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11952
SUBJECT: GRB 110420B: Fermi GBM observation
DATE:    11/04/21 13:55:31 GMT
FROM:    Lin Lin at UAH/NAOC  <ll0005@uah.edu>

Lin Lin (UAH)
reports on behalf of the Fermi GBM Team:

"At 22:42:11.73 UT on 20 April 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110420B (trigger 325032133 / 110420946).

This burst was also detected by the Swift/BAT
(Sbarufatti et al. 2011, GCN 11944).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 123 degrees.

The GBM light curve shows a fast rise slow decay peak,
with a duration (T90) of about 0.048 s (50-300 keV).
The time-averaged spectrum from T0-0.024 s to T0+0.040 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.12 +/- 0.31 and
the cutoff energy, parameterized as Epeak, is 296.8 +/- 58.7 keV.

The event fluence (10-1000 keV) in this time interval is
(2.65 +/- 0.36)E-7 erg/cm^2. The 0.008-sec peak photon flux measured
starting from T0-0.016 s in the 10-1000 keV band
is 44.1 +/- 6.1 ph/s/cm^2.

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


GRB_name: GRB110420B
Detection_method: retraction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11953
SUBJECT: GRB 110420B: Swift-XRT afterglow candidate retraction
DATE:    11/04/21 14:09:18 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF-OAB/IASFPA) and V. Mangano (INAF/IASFPA) report on 
behalf of the Swift XRT team:

Further observations of the field of GRB 110420B (Sbarufatti  et al.
GCN Circ. 11944) have shown that the X-ray source reported by Sbarufatti 
et al. (GCN Circ. 11947) has not faded.  Moreover, the position is 
marginally consistent with the known X-ray source 1RXS J212024.5-411816. 
Therefore we conclude that the XRT source is not the burst afterglow.

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


GRB_name: GRB110420A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11954
SUBJECT: GRB110420A: GROND detection of the Optical/NIR Afterglow Candidate
DATE:    11/04/21 14:18:16 GMT
FROM:    Jonny Elliott at MPE/GROND  <jonnyelliott@mpe.mpg.de>

P. Afonso, J. Elliott, and J. Greiner (MPE Garching) report on behalf of
the GROND team:

We observed the field of GRB 110420A (Swift trigger 451757; Mangano et
al., GCN #11941) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla
Observatory (Chile).

Observations started at 09:34 UT on April 21, 22.5 hours after the GRB
trigger. They were performed at an average seeing of 1.8'' and at an
average airmass of 2.3.

We confirm the detection of the single point source reported by Oates et
al. (GCN #11948).

Based on the first 142-s exposures in r', we estimate a preliminary
magnitude (AB system) of

r' = 20.6 +/- 0.1 mag.

In combination with the early UVOT detection, this would imply a decay
slope of 0.85 between 700 s and 22.5 hours.

Given magnitudes are calibrated against GROND zeropoints and are not
corrected for the expected Galactic foreground extinction corresponding to
a reddening of E_(B-V)=0.014 mag in the direction of the burst (Schlegel
et al. 1998).


GRB_name: GRB110420B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11955
SUBJECT: GRB 110420B: Swift/UVOT Upper Limits
DATE:    11/04/21 14:29:56 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) & B. Sbarufatti (INAF-OAB/IASFPA) report on behalf of the Swift-UVOT team

The Swift/UVOT began settled observations of the field of GRB 110420B
2562 s after the BAT trigger (Sbarufatti et al., GCN Circ. 11944).
No optical afterglow is found within the BAT error circle.

Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
###############################################################
white_FC          2562         2711          147         >20.6
white             2562         4765          540         >20.5
v                 3541        16124         1322         >19.9
b                 2926        22368          621         >20.4
u                 2720        28151         1730         >20.0
w1                3950        28007         2844         >19.6
m2                3745        27103         2416         >19.5
w2                3336        15211         1279         >19.7
###############################################################

The values quoted above 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: GRB110422A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11957
SUBJECT: GRB 110422A: Swift detection of a burst
DATE:    11/04/22 16:04:43 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano (INAF-IASFPA), D. N. Burrows (PSU), V. D'Elia (ASDC),
N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), B. Gendre (ASDC),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), P. Romano (INAF-IASFPA),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU) and
C. A. Swenson (PSU) report on behalf of the Swift Team:

At 15:41:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located the bright GRB 110422A (trigger=451901).  Swift slewed to 
the burst after a 12 minute observing constraint delay. 
The BAT on-board calculated location is 
RA, Dec 111.995, +75.106 which is 
   RA(J2000) = 07h 27m 59s
   Dec(J2000) = +75d 06' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex peak
structure with a duration of about 50 sec.  The peak count rate
was ~24000 counts/sec (15-350 keV), at ~8 sec after the trigger. 

The XRT began observing the field at 15:55:30.4 UT, 814.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 112.0580, +75.1077 which is equivalent to:
   RA(J2000)  = 07h 28m 13.92s
   Dec(J2000) = +75d 06' 27.7"
with an uncertainty of 6.1 arcseconds (radius, 90% containment). This
location is 58 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 821 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 0.03. 

Burst Advocate for this burst is V. Mangano (vanessa 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: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11958
SUBJECT: GRB 110422A: Mondy optical observations
DATE:    11/04/22 17:25:29 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We started observation of the field of GRB 110422A (Mangano  et al. GCN 
11957) with AZT-33IK on Apr. 22 (UT) 15:58.    We detected new object, not 
presented in DSS2 in coordinates (J2000) 07 28 10.972 +75 06 24.87 with 
statistical uncertainty of 1" in booth coordinates. The object is close to 
the current XRT position. The first image was unfiltered, while after 
detection we started several series in R-filter. The brightness of the 
object in the first image taken 16 min after burst onset is R=18.3 in 
comparison with nearby USNOB-1.0 field stars. We suggest that the object is 
the afterglow of GRB 110422A.
The finding chart can be found at
http://grb.rssi.ru/GRB110422A/grb110422A_AZT33IK.png
Observation is continuing. 

[GCN OPS NOTE(23apr11): Per author's request, Elunko was changed to Klunko.]


GRB_name: GRB110422A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11959
SUBJECT: GRB 110422A: Swift-BAT refined analysis
DATE:    11/04/22 18:14:12 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
V. Mangano (INAF-IASFPA), C. B. Markwardt (GSFC), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+195 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110422A (trigger #451901)
(Mangano, et al., GCN Circ. 11957).  The BAT ground-calculated position is
RA, Dec = 112.057, 75.100 deg, which is 
   RA(J2000)  =  07h 28m 13.7s 
   Dec(J2000) = +75d 05' 58.8" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 22%.
 
The mask-weighted light curve shows several overlapping peaks starting
at ~T-15 sec, peaking at ~T+8 sec, and ending at ~T+60 sec.  At the 3-sigma
level, there is another peak from T+70 to T+115 sec.  T90 (15-350 keV)
is 25.9 +- 0.6 sec (estimated error including systematics).
 
The time-averaged spectrum from T-11.2 to T+40.3 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.86 +- 0.10, 
and Epeak of 149.4 +- 18.5 keV (chi squared 46.5 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 4.1 +- 0.1 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T+6.90 sec in the 15-150 keV band is
30.7 +- 1.0 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.35 +- 0.00 (chi squared 118.3 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/451901/BA/


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11960
SUBJECT: GRB 110422A: MASTER earlier OT polarization observations
DATE:    11/04/22 21:09:53 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. 
Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

  MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Tunka (Baykal lake) was pointed to the  GRB 110422A 34 sec 
after notice time and 53 sec after GRB time at 2011-04-22 15:42:48.507 UT. 
On our first (10s exposure) double  set we  found optical transient 
within SWIFT error-box (Palmer et al.11959). The position coincided with 
Elunko et al. GCN 11958.
The polarizated magnitude in R band is  ~16.5+-0.4 .
We see  OT on all next images in both polarizations.
Is seems some brightenning during first minutes.
The reduction is continuated.
  The message may be cited.


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11961
SUBJECT: GRB 110422A: NOT optical observation
DATE:    11/04/22 22:19:20 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

Dong Xu (WIS), Anders Thygesen, Fatemeh Kiaee (NOT), and Pall
Jakobsson (U. Iceland) report on behalf of a large collaboration:

We observed the field of GRB 110422A (Mangano  et al., GCN 11957) at
the Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained
2x300 s R-band images with a median time 21:11:33.3 UT (i.e., 5.49397
hr after the BAT trigger). The images, with an airmass ~1.5,  were
taken under the windy condition.

A new optical source is detected at coordinates

(RA,Dec)(J2000) = (07:28:11.06, +75:06:25.00)
(error-radius:  ~ 0.1 arcsec),

being consistent with the finding in Elunko et al. (GCN 11958) and
Gres et al. (GCN 11960). Note that this position is southwest of and
outside the XRT error circle reported at http://www.swift.ac.uk/sper/.
The source has R~20.0 mag, calibrated with the #1651-0050630 star
(R1=19.08) in the USNO B1 catalog.

Further observation is planned as long as the weather could stay
observable at La Palma.


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11962
SUBJECT: GRB 110422A: SAO RAS optical observations
DATE:    11/04/22 23:53:33 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin (SAO RAS, Niznijh Arkhyz, Russia), report:

The field of GRB 110422A (Mangano  et al., GCN 11957) were observed
with the Zeiss-1000 telescope of SAO RAS, Russia. The observations
were carried out in the B and Rc bands at 18:39:11 -- 19:00:08 UT,
April, 22 (~3 hours after the trigger).

The magnitude of OT (Elunko et al. GCN 11958, Gres et al. GCN 11960
and Xu et al. GCN 11961) were measured as R = 19.13 +/- 0.13 in
comparison with nearby USNO-B1.0 stars (R2 magnitudes).

The message may be cited.


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11963
SUBJECT: GRB 110422A: TNG optical observations
DATE:    11/04/23 00:25:49 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri, P. D'avanzo, D. Fugazza (INAF-OAB) and E. Palazzi (INAF-IASFBo)
on behalf of a larger collaboration report:

We observed the field of GRB 110422A (Mangano et al. GCN 11957) with the 3.6m
TNG equipped with the Dolores camera. Few sets of unfiltered images were acquired
starting on Apr 22.89 UT (i.e. ~5.7 hours after the burst event).

The optical afterglow (Elunko et al. GCN 11958; Gres et al. GCN 11960;  Xu et al.
GCN 11961, Moskvitin GCN 11962) is clearly detected in all our frames. The observed
magnitudes (calibrated with respect to the same star used in GCN 11961) are

Dt_start  t_exp    R_mag   err
   [hr]            [s]
---------------------------------------------
  5.777      60.0    20.17   0.03
  5.934      60.0    20.24   0.05
  5.998      60.0    20.03   0.05
  8.052      60.0    20.24   0.04

Our observations, coupled with previous observations reported on GCNs imply a
power-law decay index for the optical afterglow of ~0.55.

Further observations are ongoing.

We thank the TNG staff for their support, in particular Massimo Cecconi
and Giovanni Mainella.

[GCN OPS NOTE(23apr11): Per author's request, the last sentence was added.]


GRB_name: GRB110422A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11964
SUBJECT: GRB 110422A: correction to the GCN circ. 11958
DATE:    11/04/23 00:35:18 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI) report:

In the GCN circ. 11958 due to misprint the author's name is spelled 
incorrectly. The names of the author's of the GCN circ. 11958 should be read 
as follows:

E. Klunko (ISTP), A. Pozanenko (IKI)

I apologize for possible inconvenience.


GRB_name: GRB110422A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11965
SUBJECT: GRB 110422A: Enhanced Swift-XRT position
DATE:    11/04/23 04:00:39 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 1328 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 110422A, 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 = 112.04671, +75.10666 which is equivalent
to:

RA (J2000): 07h 28m 11.21s
Dec (J2000): +75d 06' 24.0"

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: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11966
SUBJECT: GRB 110422A: THO optical observations
DATE:    11/04/23 04:09:32 GMT
FROM:    Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen@kassiopeia.net>

Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:

Taurus Hill Observatory's (A95) Celestron C-14 (OTA) telescope 14"
FL 3910 mm with NextGEN 0.5X optical reducer and SBIG ST-8XME 
camera were used to detect GRB 110422A optical afterglow. The 
observations were started at 2011-04-22 20:26:30 (UT) and stopped at 
2011-04-22 20:57:20 (UT) (~5 hours after the trigger). Six unfiltered 
observations with 300s exposure time were made. The afterglow was 
detected at following position RA 7 28 10.98 and DEC +75 06 25.4 
consistent those given by Elunko E. et al. (GCN 11958) to within positional
errors.

The following magnitudes were obtained from the observations using 
NOMAD1 1651-0051346 (R = 16.040) as the comparison:

Tmid(s)+T0  Filter          Exp (sec)     Mag      Mag err   Limit (sigma 3)
17285           unfilt          300             19.5         0.7         19.7
17535           unfilt          300             19.6         0.8         19.7
18152           unfilt          300             19.4         0.7         19.7
18462           unfilt          300             19.7         0.9         19.7

 
A png image of the 3x300sec clear filter observations is available at the 
following URL link:
http://cutenews.kassiopeia.net/data/upimages/GRB_110422A_OA_THO.png


GRB_name: GRB110422A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11967
SUBJECT: GRB 110422A: CQUEAN griz Observation
DATE:    11/04/23 06:42:52 GMT
FROM:    Yiseul Jeon at SNU/CEOU  <ysjeon@astro.snu.ac.kr>

 Yiseul Jeon, Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ),
 Soojong Pak, Hyeongju Jeong, (Kyunghee University)

 We observed GRB 110422A (Mangano et al. GCN 11957) with griz
filters using CQUEAN camera on the 2.1m telescope at the McDonald
observatory, TX. The observation started at 2011 April 23, 02:53:11 UT,
about 11.19 hours after the BAT trigger.
 We confirm a bright afterglow in all the griz images at the location
reported earlier (Xu et al. GCN 11961; Evans et al. GCN 11965), with
a preliminary photometry of r ~ 20.36 +- 0.05  AB mag, based on the
photometric standard star data taken on the same night.
 Further analysis of the data is ongoing.


GRB_name: GRB110422A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11968
SUBJECT: GRB 110422A: Swift-XRT refined Analysis
DATE:    11/04/23 11:27:20 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano (INAF-IASFPA) and B. Sbarufatti (INAF OAB/INAF IASFPA)
report on behalf of the Swift-XRT team:

We have analysed 3.5 ks of XRT data for GRB 110422A (Mangano  et al.
GCN Circ. 11957), from 804 s to 12.7 ks after the  BAT trigger. The
data comprise 394 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 Evans
et al. (GCN. Circ 11965).

The light curve can be modelled with an initial power-law decay with an
index of alpha=1.02 (+/-0.03), followed by a break at T+7585 s to an
alpha of 2.2 (+0.5, -0.4).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.99 (+/-0.09). The
best-fitting absorption column is  1.94 (+0.26, -0.24) x 10^21 cm^-2,
in excess of the Galactic value of 4.2 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.13 (+0.11, -0.10)
and a best-fitting absorption column of 2.28 (+0.31, -0.29) 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 (6.3 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.28 (+0.31, -0.29) x 10^21 cm^-2
Galactic foreground: 4.2 x 10^20 cm^-2
Excess significance: 12.8 sigma
Photon index:      2.13 (+0.11, -0.10)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00451901.

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


GRB_name: GRB110422A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11969
SUBJECT: GRB 110422A: Swift/UVOT Detection of optical afterglow
DATE:    11/04/23 13:02:09 GMT
FROM:    Alice Breeveld at MSSL-UCL  <aab@mssl.ucl.ac.uk>

A. A. Breeveld (MSSL-UCL) and V. Mangano (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110422A
822 s after the BAT trigger (Mangano et al., GCN Circ. 11957).
An optical afterglow consistent with the optical position found by 
Klunko et al. (GCN 11958) and others is found in the UVOT, and is 
clearly fading. It is detected in initial exposures in both white and 
b, and also in v and u when the initial exposures are summed up.
Preliminary magnitudes and 3-sigma upper limits using the UVOT 
photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first 
finding chart (FC) exposure and subsequent exposures are:

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

white_FC           822          972          147         18.80 Â± 0.12
white (summed)    1054         1766          97.2        19.5 Â± 0.23
white             7837         8037          197          >20.4
v (summed)        1104         2336          156         18.72 Â± 0.35
b                 1029         1049          19.4        18.02 Â± 0.3
b (summed)        1202         2435          156         18.97 Â± 0.22
u (summed)        1004         2410          175         18.8 Â± 0.26
w1 (summed)        980         2385          175         >19.4
m2 (summed)       1128         2360          156         >19.4
w2 (summed)       1079         2310          156         >19.6

The values quoted above 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).

[GCN OPS NOTE(23apr11): Per author's request, the spelling on the Klunko
reference was corrected.]


GRB_name: GRB110422A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11970
SUBJECT: GRB 110422A: Further NOT observation
DATE:    11/04/23 22:23:51 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

D. Xu (WIS), J. P. U. Fynbo (DARK/NBI), M. Nielsen (NOT), and P.
Jakobsson (U. Iceland) report on behalf of a large collaboration:

We continued to observe the field of GRB 110422A (Mangano  et al., GCN
11957) at the Nordic Optical Telescope (NOT) equipped with ALFOSC. We
obtained 2x300 s, 3x300 s, and 3x300 s images in the R, V, and I
filters, respectively. The images, with an airmass ~1.5, were still
taken with strong wind.

The optical afterglow (Elunko et al., GCN 11958; Xu et al., GCN 11961)
has decayed to R=21.41+/-0.10 mag with a median time 21:06:08.9 UT on
April 23 (i.e., 29.4 hr after the BAT
trigger), compared with our previous measurement R=20.00+/-0.02 mag,
both calibrated with the #1651-0050630 star (R1=19.08) in the USNO B1
catalog. The observations at the two epochs indicates a power-law
decay index of ~0.8 for the R-band lightcurve.


GRB_name: GRB110422A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11971
SUBJECT: Konus-Wind observation of GRB 110422A
DATE:    11/04/24 09:30:07 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
P. Oleynik, M. Ulanov, D. Svinkin, and
T. Cline on behalf of the Konus-Wind team, report:

The long bright GRB 110422A (Swift-BAT trigger #451901: Mangano et al.,
GCN 11957; Palmer et al., GCN 11959) triggered Konus-Wind at
T0(KW)=56502.948 s UT (15:41:42.948).
The burst light curve shows a multipeaked structure with a
duration of ~40 s.

As observed by Konus-Wind the burst
had a fluence of (8.56 +/- 0.02)x10^-5 erg/cm2,
and a 64-ms peak flux measured from T0+18.128 s
of (1.20 +/- 0.15)x10^-5 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+38.656 s) can be fitted (in the 20 keV - 2 MeV
range) by the GRB (Band) model for which:
the low-energy photon index is alpha = -0.65 +/- 0.06,
the high energy photon index beta = -2.96(-0.19, +0.14),
the peak energy Ep = 152 +/- 5 keV (chi2 = 96.8/64 dof).
The spectrum at the maximum count rate
(measured from T0+17.664 to T0+18.432 s) is well fitted
(in the 20 keV - 2 MeV range) by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.53 (-0.14, +0.17),
the high energy photon index beta = -2.65 (-0.62, +0.28),
the peak energy Ep = 246(-34, +37) keV (chi2 = 55.7/48 dof).

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

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB110422_T56502/


GRB_name: GRB110422A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11972
SUBJECT: GRB110422A: MITSuME  Ishigakijima Optical Observation
DATE:    11/04/24 13:08:22 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 110422A (Mangano et al., GCNC 11957)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.

The observation started on 2011-04-23 12:44:54 UT, (~21 hours after
the burst). We detected the previously reported afterglow
(Klunko et al., GCNC 11958; Gres et al., GCNC 11960) in Rc band.

Photometric results and three sigma upper limits of the OT are
listed below. We used GSC2.3 catalog for flux calibration.


#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc  Rc_err   Ic
----------------------------------------------------------------------
0.89834    13:15:32    2400.0   >21.0  20.9  0.3   >19.3
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

[GCN OPS NOTE(24apr11): Per author's request, the "110322" was
changed to "110422A" in the first sentence.]


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11973
SUBJECT: GRB 110422A: optical observations in CrAO
DATE:    11/04/24 22:48:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev,  K. Antoniuk (CrAO), A. Pozanenko (IKI) report on behalf of 
larger GRB  follow-up collaboration:

We observed  the field of the Swift GRB 110422A (Mangano  et al., GCN 
11957) with AZT-11 telescope of CrAO between  Apr. 22 (UT) 19:13 and  20:11. 
We clearly detect the afterglow (Klunko et al. GCN 11958, Gres et al. GCN 
11960, Xu et al. GCN 11961). The photometry is based on the USNO B1.0 star 
1651-0050626   (07 28 13.15 +75 06 51.5) assuming R=18.56 :

T0+      Filter,   Exposure, mag.
(mid, d)              (s)

0.1675  R        20x180       19.32  +/-0.08


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11974
SUBJECT: GRB110422A: NOT optical follow-ups
DATE:    11/04/25 21:46:49 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

Dong Xu (WIS), Erkki Kankare, Tuomas Kangas (U. Turku), and Pall
Jakobsson (U. Iceland) report on behalf of a large collaboration:

We continued to observe the field of GRB 110422A (Mangano et al., GCN
11957) at the Nordic Optical Telescope (NOT) equipped with ALFOSC. We
obtained 2x360 s in the R filter with some clouds and a seeing ~0.9".

The optical afterglow (Elunko et al., GCN 11958; Gres et al., GCN
11960; Xu et al., GCN 11961) has decayed to R=22.5+/-0.2 mag with a
median time 21:17:58.8 UT on April 25 (i.e., 77.6 hr after the BAT
trigger), calibrated with the #1651-0050630 star (R1=19.08) in the
USNO B1 catalog.


GRB_name: GRB110422A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11975
SUBJECT: GRB 110422A: Herschel observation scheduled
DATE:    11/04/25 21:51:12 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

Dong Xu (WIS), Maohai Huang (CAS), Bing Zhang (UNLV) report on behalf
of a large collaboration:

European Space Agency's Herschel Space Observatory is scheduled to
make far infrared photometric observations of GRB 110422A on 30 April
around 14UT in 70m and 170m bands, and two follow-ups on 2-3 May
(time to be decided) in 70,170,250,350,500m bands, and on 6-7 May in
250,350,500m bands. This would be the first time a cosmological GRB
is observed in 70-350m. Other facilities are encouraged to obtain
results of GRB 110422A across the spectrum on those Herschel observing
days.


GRB_name: GRB110422A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11976
SUBJECT: GRB 110422A: Suzaku WAM observation of the prompt emission 
DATE:    11/04/26 11:08:37 GMT
FROM:    Masanori Ohno at ISAS/JAXA  <ohno@astro.isas.jaxa.jp>

W. Iwakiri, Y. Terada, M. Tashiro,  K. Takahara, T. Yasuda (Saitama U.),
T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.),
N. Vasquez (Tokyo Tech.) K. Yamaoka (Aoyama Gakuin U.),
M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA),
S. Sugita (Nagoya U.), Y. E. Nakagawa (Waseda U.),
N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki),
Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo),
on behalf of the Suzaku WAM team, report:

The bright GRB 110422A (Swift/BAT trigger #451901 ; Mangano et al., GCN
11957; Palmer et al., GCN 11959) triggered the Suzaku Wide-band All-sky
Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 15:41:45
UT (=T0).

The observed light curve shows a multi-peaked structure starting at
T0-2s, ending at T0+35s with a duration (T90) of about 22 seconds. The
fluence in 100 - 1000 keV was 3.60 (+/- 0.14) x10-5 erg/cm2.
The 1-s peak flux measured from T0+18s was 14.5 (+/- 0.9) photons/cm2/s
in the same
energy range.

Preliminary result shows that the time-averaged spectrum from T0-2s to
T0+35s is well fitted by a single power-law with a photon index
of 2.83 (+/- 0.11) (chi2/d.o.f = 21.3/14).
All the quoted errors are at statistical 90% confidence level.


The light curves for this burst will be appeared at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB110422A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11977
SUBJECT: GRB 110422A: tentative redshift from TNG
DATE:    11/04/26 15:51:06 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), D. Fugazza (INAF/Brera), P. D'Avanzo 
(INAF/Brera), V. D'Elia (ASI/ASDC), A. Melandri (INAF/Brera), S. 
Piranomonte (INAF/Roma), J.P.U. Fynbo (DARK/NBI), M. Cecconi (INAF/TNG), 
G. Mainella (INAF/TNG), report on behalf of a larger collaboration:

We observed the afterglow of GRB 110422A (Mangano et al., GCN 11957; 
Klunko et al., GCN 11958) with the Italian TNG located in La Palma. A 
single 700 s spectroscopic exposure could be taken due to rising 
humidity (see also Melandri et al., GCN 11963). Observations started on 
2011 April 22.998 UT (8.25 hr after the GRB). The adopted grism was 
LR-B, covering the wavelength range 3600-8200 AA.

We detect a clear absorption feature at 4290 AA. Interpreting this as 
the (unresolved) CIV doublet yields a redshift of z = 1.77. At the same 
redshift we find a few other lines which we interpret as due to Si IV 
and Fe II. We thus propose z = 1.77 to be the redshift of GRB 110422A.


GRB_name: GRB110422A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11978
SUBJECT: GRB 110422A: Redshift confirmation from GTC
DATE:    11/04/26 17:34:58 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI), A.J. Castro-Tirado, J. Gorosabel
(IAA-CSIC) report on behalf of a larger collaboration:

We have observed the afterglow of GRB 110422A  (Mangano et al., GCNC
11957; Klunko et al., GCNC 11958) using the 10.4m GTC telescope located in
La Palma (Spain). Spectroscopic observations were performed with mean
epoch of April 25th at 22:55 UT (3.3 days after the burst) and consisted
of a single 1800s exposure using the R500B grating (resolution ~500).

The spectrum shows several absorption features that we identify as due to
C IV, Al II, Al III, Fe II, Mg II, and Mg I at a redshift of
1.770+/-0.001, consistent with the results of Malesani et al. (GCNC
11977). We hence confirm this to be the redshift of the GRB.

We acknowledge excellent support from the GTC staff, in particular Rene
Ruten.


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11979
SUBJECT: GRB 110422A: optical observations in CrAO, second epoch
DATE:    11/04/26 20:25:41 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev,  K. Antoniuk (CrAO), A. Pozanenko (IKI) report on behalf of 
larger GRB  follow-up collaboration:

We observed  the field of the Swift GRB 110422A (Mangano  et al., GCN 11957) 
with AZT-11 telescope of CrAO between  Apr. 24 (UT) 19:21 - 21:10. We detect 
the afterglow (Klunko et al. GCN 11958, Gres et al. GCN 11960, Xu et al. GCN 
11961). The photometry is based on the USNO B1.0 star 1651-0050626   (07 28 
13.15 +75 06 51.5) assuming R=18.56:

T0+      Filter,   Exposure, mag.
(mid, d)              (s)

2.1910   R        36x180       21.3 +/-0.3


GRB_name: GRB110426A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11980
SUBJECT: GRB 110426A: MAXI/GSC detection of a GRB
DATE:    11/04/27 00:33:16 GMT
FROM:    Motoko Suzuki at RIKEN  <motoko@crab.riken.jp>

S. Nakahira (RIKEN), H. Negoro (Nihon U.), M. Matsuoka ,
T. Mihara, M. Sugizaki, M. Serino, T. Yamamoto, T. Sootome (RIKEN), 
S. Ueno, H. Tomida, M. Kohama, M. Ishikawa (JAXA),
N. Kawai, M. Morii, K. Sugimori, R. Usui, T. Toizumi (Tokyo Tech),
A. Yoshida, K. Yamaoka (AGU),
H. Tsunemi, M. Kimura, H. Kitayama (Osaka U.), 
M. Nakajima, F. Suwa (Nihon U.), 
Y. Ueda, K. Hiroi, M. Shidatsu (Kyoto U.),
Y. Tsuboi, T. Matsumura, K. Yamazaki (Chuo U.)
report on behalf of the MAXI team:

At the scan transit centered at UT 2011-04-26T15:08:36,
MAXI/GSC detected a short X-ray transient lasting about 18 seconds 
within the 46 seconds triangular transit response of MAXI/GSC.
Judging from its location and spectral hardness ratio, this transient is
probably a gamma-ray burst.
  
Since the emission was detected only for a fraction of the triangular 
transit response, the uncertainty of its position along the scan direction 
is large.  Without assuming the source constancy, we obtain a rectangular 
error box (90%C.L.) with the following corners: 
  
(R.A., Dec) = (+219.64 deg,-9.51 deg) = (14 38 34, -09 30 36)(J2000)
(R.A., Dec) = (+222.36 deg,-12.97 deg) = (14 49 26, -12 58 12)(J2000)
(R.A., Dec) = (+222.57 deg,-12.77 deg) = (14 50 17, -12 46 12)(J2000)
(R.A., Dec) = (+219.84 deg,-9.31 deg) = (14 39 21, -09 18 36)(J2000)

There is additional systematic uncertainty of 0.2 deg (90% containment radius).

The preliminary flux (2-20 keV) of the source was at least 200 mCrab.
There was no significant detection at the transit location in the
previous and following orbits (92 min before or after the detection) 
with an upper limit of 20 mCrab.  There is no known bright X-ray source 
at the detected position. 
  
  Follow-up observations are encouraged.


GRB_name: GRB110426A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11981
SUBJECT: GRB 110426A: MASTER synchronous with MAXI/GSC  observations 
DATE:    11/04/28 08:09:19 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. 
Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk


First we pointed to FERMI trigger N325523188 (ra=217.133 dec=-12.333
err=32.42) at 15:07:28 (62 sec after trigger time). We observed this area 
to 15:08:33, until the next more exact FERMI  alert  (ra=205.160 
dec=-11.570 err=10.9) comes.
Unfortunately, after that replacement, the part of MAXI error-box has left 
a FOV of ours widefield cameras. We observ this new place to 15:13:33.

We coadd all wide field (500 square degrees) camera unfiltered images. 
There is no OT from automatical identification. 
So we have following results:


T_start     T_s-T_fermi     T_s-T_maxi     exptime    limit    Cover_MAXI
15:07:28       62 sec        -68 sec        55 sec     13.0      100 %
15:08:33      126 sec         -3 sec       250 sec     13.8       85 %

First  epoch image 
http://observ.pereplet.ru/images/evgeny/grb110426a1.jpeg
Second epoch image 
http://observ.pereplet.ru/images/evgeny/grb110426a2.jpeg
Black lines is MAXI error_box.

  The main  MASTER  telescopes (40 sm) also made observations in 
2 polarizations, in the center of each of FERMI error-boxes, but them FOV 
(4 sq. degree) it has appeared not enough for observ at least parts MAXI
error-box.


GRB_name: GRB110428A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11982
SUBJECT: GRB 110428A: Fermi-LAT Detection
DATE:    11/04/29 01:54:25 GMT
FROM:    Vlasios Vasileiou at LUPM/Fermi-LAT  <Vlasios.Vasileiou@lupm.in2p3.fr>

V. Vasileiou (CNRS/IN2P3/LUPM), N. Omodei (Stanford University), D. 
Kocevski (SLAC), F. Piron (CNRS/IN2P3/LUPM),
on behalf of the Fermi Large Area Telescope collaboration.

Based on an on-ground analysis, the Large Area Telescope (LAT),
on-board the Fermi Gamma-ray Space Telescope, detected high energy 
emission extending up to ~3 GeV from the GBM-detected GRB 110428A 
(trigger 325675112). The detected emission lasts up to ~200 seconds.

We obtain a localization of RA, DEC (J2000 deg) = 5.30, 64.80 (00h 21m 
12s, 64d 47' 42.0"), (galactic l=119.71 deg, b=2.11 deg), with a 
statistical error of 0.15 deg (68% CL), compatible with the GBM 
localization. The burst was initially at an angle of ~34 degrees to the 
LAT boresight and triggered an autonomous repoint of the spacecraft.
According to preliminary spectral fits, the spectral index of the 
detected emission is -1.5+-0.1 (68% CL) at E>100MeV energies.

Further analysis is ongoing.

The Fermi LAT point of contact for this burst is Vlasios Vasileiou
(vlasios.vasileiou@lupm.in2p3.fr).

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: GRB110428A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11983
SUBJECT: Konus-Wind observation of GRB 110428A
DATE:    11/04/29 13:56:48 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
P. Oleynik, M. Ulanov, D. Svinkin, and
T. Cline on behalf of the Konus-Wind team, report:

The long bright GRB 110428A localized by Fermi-LAT (Vasileiou et al.,
GCN 11982) triggered Konus-Wind at T0=33509.450 s UT (09:18:29.450).
The burst light curve shows two pulses started at ~T0-9 s with a total 
duration of ~15 s.

As observed by Konus-Wind the burst
had a fluence of 2.70(-0.16, +0.15)x10^-5 erg/cm2,
and a 64-ms peak flux measured from T0+1.296 s
of 8.47(-1.17, +1.18)x10^-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+13.568 s) can be fitted (in the 20 keV - 2 MeV
range) by the GRB (Band) model for which:
the low-energy photon index is alpha = -0.30(-0.11, +0.12),
the high energy photon index beta = -3.00(-0.58, +0.27),
the peak energy Ep = 184(-10, +12) keV (chi2 = 78.2/59 dof).
The spectrum at the maximum count rate
(measured from T0+0.256 to T0+1.536 s) can be fitted
(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 = -0.19(-0.13, +0.14),
and Ep = 257(-16, +17) keV (chi2 = 63.1/52 dof).
Fitting by GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy
photon index: beta < -3.5 (chi2 = 63.1/51 dof).

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

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB110428_T33509/


GRB_name: GRB110428A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11984
SUBJECT: GRB 110428A : Swift-XRT observations
DATE:    11/04/29 14:46:44 GMT
FROM:    Andrea Melandri at INAF-OAB  <andrea.melandri@brera.inaf.it>

A. Melandri, P. D'Avanzo, R. Margutti (INAF-OAB), B. Sbarufatti (INAF- 
OAB/IASFPA) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the  
Swift Team:

At 00:47 UT, April 29th, 2011, Swift began a Target of Opportunity  
observation of the Fermi GBM/LAT discovered burst GRB 110428A  
(Vasileiou et al. GCN 11982), ~55.6 ks after the Fermi detection.

In 4.8 ks of Photon Counting mode data, we detect two sources within  
the Fermi-LAT error circle (0.15 deg radius, 68% CL) at the following  
positions:

Source 1:
RA(J2000):   00 21 50.47
Dec(J2000): +64 48 52.4
with an uncertainty of 4.6 arcsec.

Source 2:
RA(J2000):   00 22 22.22
Dec(J2000): +64:50:57.1
with an uncertainty of 7.1 arcsec.

Uncertainty radii are given at 90% containment.

We note that the position of Source 1 is consistent with a known  
ROSAT source (1RXS J002150.5+644850) also present in the DSS. Source  
2 is an uncatalogued object.

The two sources have a count rate of about (1.2e-2 +/- 1.8e-3) and  
(2.9e-3 +/- 9.1e-4) cts/s, respectively. It is not possible to  
determine whether these sources are fading given the current  
statistics. Further Swift-XRT observations of the field are planned.  
We encourage ground-based follow-up observations.

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


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11985
SUBJECT: GRB 110422A: Update of Herschel FIR observation schedule
DATE:    11/04/29 17:15:41 GMT
FROM:    Maohai Huang at NAOC  <mhuang@nao.cas.cn>

Maohai Huang (NAOC), Bing Zhang (UNLV), Dong Xu (WIS), Jinsong Deng
(NAOC), Liping Xin (NAOC), Yulei Qiu (NAOC) report on behalf of
Herschel OT1_mhuang01 Open Time program:

This is an update of ESA's schedule to search and observe far infrared
after glowof GRB 110422A using photometers of PACS (70,110micron) and
SPIRE (250, 350, 500micron) instruments on-board Herschel Space
Observatory, with sensitivities of several mJy/beam.

Date ----- Time ---- Instrument
2011-04-30T13:59:28UT PacsPhoto
2011-04-30T14:15:29UT PacsPhoto
2011-05-03T19:28:25UT SpirePhoto
2011-05-04T01:24:55UT PacsPhoto
2011-05-04T01:40:56UT PacsPhoto
2011-05-08T02:43:38UT SpirePhoto
2011-05-09T21:41:44UT PacsPhoto
2011-05-09T21:57:45UT PacsPhoto
2011-05-13T18:47:21UT SpirePhoto
For more details and updates (if any) see
http://herschel.esac.esa.int/observing/ScheduleReport.html

We strongly encourage ground and space instruments to collect data across
full spectral range, especially in X-ray, optical, near/mid IR,
millimeter/submillimeter, and radio bands, of GRB 110422A on observing
days of Herschel.


GRB_name: GRB110422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11986
SUBJECT: GRB 110422A: optical observations in CrAO
DATE:    11/05/01 10:22:01 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed  the field of the Swift GRB 110422A (Mangano  et al., GCN 11957) 
with ZTSh telescope of CrAO on Apr. 28 between  (UT) 20:43: and  21:52. We 
clearly detect the afterglow (Klunko et al. GCN 11958, Gres et al. GCN 
11960, Xu et al. GCN 11961). The photometry is based on the USNO B1.0 star 
1651-0050626   (07 28 13.15 +75 06 51.5) assuming R=18.56 :

T0+      Filter,   Exposure, mag.
(mid, d)              (s)

6.2328  R        55x60       22.28  +/-0.14


GRB_name: GRB110428A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11988
SUBJECT: GRB 110428A: Suzaku WAM observation of the prompt emission
DATE:    11/05/02 10:21:42 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro@phy.saitama-u.ac.jp>

W. Iwakiri, Y. Terada, M. Tashiro, K. Takahara, T. Yasuda (Saitama U.),
T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.),
N. Vasquez (Tokyo Tech.) K. Yamaoka (Aoyama Gakuin U.),
M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA),
S. Sugita (Nagoya U.), Y. E. Nakagawa (Waseda U.),
N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki),
Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo),
on behalf of the Suzaku WAM team, report:

The long bright GRB 110428A localized by Fermi-LAT (Vasileiou et al.,
GCN 11982) was observed the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy range of 50 keV - 5 MeV at 09:18:30 UT (=T0).

The observed light curve shows double-peaked structure starting at
T0-2s, ending at T0+10 s with a duration (T90) of about 5 seconds. The
fluence in 100 - 1000 keV was 1.31 (-0.43, +2.03) x 10^-5 erg/cm^2.
The 1-s peak flux measured from T0+4 s was
9.91 (-0.34, +1.19) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from
T0-2s to T0+10s is well fitted by a power-law with exponential cutoff
model :
dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
alpha 1.11 (-0.22, +0.19), and Epeak 195.5 (-14.4, +15.9) keV 
(chi2/d.o.f. = 15.8/20).
All the quoted errors are at statistical 90% confidence level.


GRB_name: GRB110428A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11989
SUBJECT: GRB 110428A : X-ray afterglow confirmation
DATE:    11/05/02 19:15:40 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri, P. D'Avanzo, R. Margutti (INAF-OAB), B. Sbarufatti (INAF- 
OAB/IASFPA) report on behalf of the  Swift Team:

Swift continued to monitor the field of GRB 110428A (Vasileiou et  
al., GCN 11982) in two different observations carried out on April  
29th and May 1st, 2011.

In the final 18.49 ks of data (at a mean T-T0 = 2.07 days after the  
burst event) we still detect Source #1 reported by Melandri et al.  
(GCN 11984) with count rate of (1.6e-2 +/- 1.1e-3) cts/s, consistent  
with a constant flux for this source.

Source #2 is no longer detected with a 3 sigma upper limit of 1.4e-3  
cts/s. The probability for this source of having a constant flux is  
8e-6. This is evidence of the fading of Source #2 with respect to the  
XRT observation reported in Melandri et al. (GCN 11984). Therefore we  
consider Source #2 as the X-ray afterglow of GRB 110428A.

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


GRB_name: GRB110426A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11990
SUBJECT: GRB 110426A:  Swift/XRT non-detection
DATE:    11/05/03 13:51:45 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.krimm@nasa.gov>

H. A. Krimm (GSFC/USRA),V. D'Elia (ASDC) and G. Stratta (ASDC), report on
behalf of the Swift team:

Swift XRT and UVOT instruments observed the center of the error rectangle
for the MAXI-detected GRB 110426A (Nakahira et al, GCN Circ. 11980) on
two occasions.  The first observation was for 5 ks starting 7 ks after
the MAXI trigger.  In this observation four point sources were found.
One is consistent with a source in the Digitized Sky Survey and the other
three were  of <3-sigma significance.  The second observation, also 5 ks,
began 250 ks after then trigger.  In the second observation, the DSS source
was detected without having faded and two other weak sources were seen at
different locations.  Since there is no evidence for a fading source in
the XRT field of view, we conclude that we have not detected the afterglow
of GRB 110426A.
     However, we note that the reported 90% error box for GRB 110426A
(Nakahira et al, GCN Circ. 11980) is approximately eight times the size
of the XRT field of view. Therefore, it is likely that the true GRB
location is outside the observed field.


GRB_name: GRB110503A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11991
SUBJECT: GRB 110503A: Swift detection of a burst with a bright optical counterpart
DATE:    11/05/03 17:59:20 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

M. Stamatikos (OSU/NASA/GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
N. P. M. Kuin (UCL-MSSL), O. M. Littlejohns (U Leicester),
V. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
P. T. O\'Brien (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), P. Romano (INAF-IASFPA), M. H. Siegel (PSU),
R. L. C. Starling (U Leicester), C. A. Swenson (PSU),
E. Troja (NASA/GSFC/ORAU) and T. N. Ukwatta (MSU) report on behalf of
the Swift Team:

At 17:35:45 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110503A (trigger=452685).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 132.800, +52.216 which is 
   RA(J2000)  =  08h 51m 12s
   Dec(J2000) = +52d 12' 56"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single structure
with a duration of about 10 sec.  The peak count rate
was ~17,000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 17:37:19.2 UT, 93.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 132.7778, +52.2067 which is equivalent to:
   RA(J2000)  = 08h 51m 06.67s
   Dec(J2000) = +52d 12' 24.1"
with an uncertainty of 5.1 arcseconds (radius, 90% containment). This
location is 58 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of nominal 150.000 seconds with the White
filter starting 212 seconds after the BAT trigger. There is a candidate
afterglow in the list of sources generated on-board at
  RA(J2000)  = 08:51:06.24 = 132.77598
  DEC(J2000) = +52:12:27.5  =  52.20764
with a 90%-confidence error radius of about 1.10 arc sec. This position is 5.2
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.75. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.02. 

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


GRB_name: GRB110503A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11992
SUBJECT: GRB 110503A: Enhanced Swift-XRT position
DATE:    11/05/03 21:46:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 995 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110503A, 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 = 132.77598, +52.20753 which is equivalent
to:

RA (J2000): 08h 51m 6.24s
Dec (J2000): +52d 12' 27.1"

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

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

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


GRB_name: GRB110503A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11993
SUBJECT: GRB 110503A: Redshift from 10.4m GTC
DATE:    11/05/03 22:50:27 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI), A.J. Castro-Tirado, J.C. Tello
(IAA-CSIC), A. Cabrera Lavers, D. Reverte (GTC) report on behalf of a
larger
collaboration:

We have observed the afterglow of GRB 110503A (Stamatikos et al.
GCNC11991) using OSIRIS at the 10.4m GTC telescope (La Palma, Spain).
Observations consisted on 2x900s using the R500B grating, starting at
21:36UT (4.0h after the burst). In a preliminary analysis, using archival
calibrations, we detect a high signal to noise ratio continuum with
absorption features that include SiIV, SiII, CIV, FeII, AlII, AlIII, ZnII,
MgII and MgI at a common redshift of z=1.613, which we identify as the
redshift of the afterglow.


GRB_name: GRB110503A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11994
SUBJECT: GRB 110503A: NOT afterglow photometry 
DATE:    11/05/03 22:52:47 GMT
FROM:    Giorgos Leloudas at Dark Cosmology Centre  <giorgos@dark-cosmology.dk>

G. Leloudas (DARK/NBI),  D. Xu (WIS), A. de Ugarte Postigo (DARK/NBI), P. Jakobsson (U. Iceland), L. Guaita, A. Sandberg (OKC/Stockholm), report on behalf of a larger collaboration.

We used the Nordic Optical Telescope (La Palma, Spain) equipped with MOSCA to observe GRB 110503A (Stamatikos et al., GCN 11991).
Observations were conducted in the UBVRI filters starting at 21:18 UT (222.3 min after the BAT trigger). The exposure times were 600, 300, 300, 300 and 400 s respectively. 

The afterglow is well detected in all filters at a position consistent with the UVOT observations (Stamatikos et al., GCN 11991). 

Photometry, using stars 1422-0232263 and 1422-0232264 of the USNO B1.0 catalog as comparison, gives B ~ 19.7 and R ~ 19.3.


GRB_name: GRB110503A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11995
SUBJECT: GRB 110503A: Swift-BAT refined analysis
DATE:    11/05/03 23:14:58 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-124 to T+689 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110503A (trigger #452685)
(Stamatikos, et al., GCN Circ. 11991).  The BAT ground-calculated position is
RA, Dec = 132.799, 52.211 deg which is 
   RA(J2000)  =  08h 51m 11.8s 
   Dec(J2000) = +52d 12' 40.4" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 11%.
 
The mask-weighted light curve shows a single FRED-like peak starting
at ~T-4 sec, peaking at ~T+0.2 sec, and returning to background around
T+20 sec.  There there is a long low-level emission from T+50 to T+200 sec.
T90 (15-350 keV) is 10.0 +- 3.5 sec (estimated error including systematics).
 
The time-averaged spectrum from T-6.6 to T+16.3 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.88 +- 0.25, 
and Epeak of 133 +- 54 keV (chi squared 84.4 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.00 +- 0.04 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T-0.12 sec in the 15-150 keV band is
29.7 +- 1.5 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.35 +- 0.06 (chi squared 95.5 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/452685/BA/


GRB_name: GRB110503A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11996
SUBJECT: GRB 110503A - TLS Afterglow Observations
DATE:    11/05/03 23:19:12 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann, S. Schmidl, C. Hoegner, B. Stecklum, S. Schumann and M.
Hartmann (TLS Tautenburg) report:

We observed the afterglow of GRB 110503A (M. Stamatikos et al., GCN 11991,
G. Leloudas et al., GCN 11994) at z=1.613 (A. de Ugarte Postigo et al.,
GCN 11993) with the 2m/1.34m Schmidt telescope of the Thueringer
Landessternwarte Tautenburg under excellent observing conditions (low
airmass, good transparency and seeing) starting during dawn at 0.098715
days after the GRB.

Observations consisted of 3 x 180 s each in Z, Ic, Rc, V, B, followed by 3
x 300 s each in Z, Ic, Rc, V, B. The afterglow is detected on the single
images.

Assuming the USNO-B1.0 1421-0227752 star at RA = 08:51:10.01 (132.791692)
Dec. = +52:11:04.75 (+52.184653) has R = 16.91 (mean of R1 and R2 mags,
0.06 mags difference), we find for two Rc band observations:

t (days after trigger) = 0.1187616, Rc = 19.07 +/- 0.03
t (days after trigger) = 0.1750347, Rc = 19.51 +/- 0.04

Errors are statistical only.

Observations are continuing as weather permits with 600 s exposures in all
five colors.

This message may be cited.


GRB_name: GRB110503A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11997
SUBJECT: GRB 110503A: redshift confirmation from TNG
DATE:    11/05/04 00:28:12 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF/OAB), V. D'Elia (ASI/ASDC), L. Di Fabrizio, A. Gurtu
(INAF/TNG), report on behalf of a larger collaboration:

We observed the optical afterglow of GRB 110503A (Stamatikos et al. GCN
11991) with the Italian TNG located in La Palma, equipped with the DOLORES
camera in spectroscopic mode.
The optical afterglow (Leloudas et al. GCN 11994; Kann et al. GCN 11996)
is clearly detected in the unfiltered acquisition image, with a magnitude
R~19.5 at at t-t0=4.85 hours (using the calibration of Kann et al. GCN
11996).

A low-resolution spectrum was taken at a mean time t-t0=5.25 hours. The
adopted grism was LR-B, covering the wavelength range 3900-8200 AA with a
resolution of R~600.
Using a preliminary wavelength calibration we clearly detect several
absorption features, including CIV, SiII, AlIII, AlII, MgII and MgI, all
at a common redshift z=1.61, in agreement with the value reported by de
Ugarte Postigo et al. (GCN 11993).
At the same redshift we also detect the fine structure line SiII*1533.
This absorption feature is likely produced in the GRB host, further
supporting the statement that z=1.61 is the afterglow redshift.


GRB_name: GRB110503A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11998
SUBJECT: GRB 110503A: PAIRITEL NIR Detection
DATE:    11/05/04 06:36:46 GMT
FROM:    Adam Morgan at U.C. Berkeley  <qmorgan@gmail.com>

A. N. Morgan, and J. S. Bloom (UC Berkeley) report:

We observed the field of GRB 110503A (Stamatikos et al., GCN 11991)
with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona under poor sky
conditions. Observations began at 2011-05-04 02:46:35 UT, ~9.2 hours
after the Swift Trigger.  In mosaics (effective exposure time of 1.28
hours) taken simultaneously in the J and H filters, we marginally
detect a source at the optical afterglow location (Stamatikos et al.,
GCN 11991; Leloudas et al., GCN 11994; Kann et al., GCN 11996).  Our
preliminary Ks band reduction is corrupted.

The preliminary photometry yields:

post burst
t_mid (hr) exp.(hr) filt  mag    m_err
10.2       1.28     J     18.19  0.26
10.2       1.28     H     17.86  0.36

All magnitudes are given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values.


GRB_name: GRB110503A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11999
SUBJECT: GRB 110503A: Swift-XRT refined Analysis
DATE:    11/05/04 07:00:38 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) and M. Stamatikos (OSU/NASA/GSFC) report on
behalf of the Swift-XRT team:

We have analysed 8.2 ks of XRT data for GRB 110503A (Stamatikos  et al.
GCN Circ. 11991), from 166 s to 28.4 ks after the  BAT trigger. The
data comprise 1.1 ks in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN. Circ 11992).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.059 (+/-0.013).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.86 (+/-0.04). The
best-fitting absorption column is  2.2 (+/-0.6) x 10^21 cm^-2, at a
redshift of 1.613, in addition to the Galactic value of 2.6 x 10^20
cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index
of 2.01 (+/-0.08) and a best-fitting absorption column of 2.4 (+/-1.0)
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 (4.3 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 2.6 x 10^20 cm^-2
Intrinsic column:    2.4 (+/-1.0) x 10^21 cm^-2 at z=1.613
Photon index:      2.01 (+/-0.08)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00452685.

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


GRB_name: GRB110503A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12000
SUBJECT: GRB 110503A: Swift/UVOT Observations
DATE:    11/05/04 10:58:36 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) & M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift-UVOT team

The Swift/UVOT began settled observations of the field of GRB 110503A 212s 
after the trigger (Stamatikos et al., GCN Circ. 11991). We detect a fading 
source in all filters at a refined position of RA(J2000), DEC(J2000)= 
132.77588 deg,52.20767 deg. This is equivalent to:

     RA (J2000)   8:51:06.21
    Dec (J2000)  52:12:27.6

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence).
This is consistent with the UVOT position reported in Stamatikos et al. 
(GCN Circ. 11991) and with the enhanced position of the X-ray afterglow 
(Goad et al., GCN Circ. 11992).
 
Preliminary magnitudes using the UVOT photometric system (Poole et al. 2008, 
MNRAS, 383, 627) for the finding chart (FC) and summed exposures at the 
location of the optical afterglow are:

Filter  T_start(s)  T_stop(s)   Exp(s)       Mag
#####################################################
wh (FC)    212        362        147     15.82 +/- 0.02
wh         864        1014       147     17.09 +/- 0.03
v          368        388        20      16.23 +/- 0.14
b          469        488        19      16.79 +/- 0.10      
u          445        464        19      15.87 +/- 0.09
uvw1       419        438        19      16.15 +/- 0.15
uvm2       394        414        19      17.27 +/- 0.32
uvw2       519        539        19      17.72 +/- 0.31
#####################################################

The values quoted above 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: GRB110503A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12001
SUBJECT: GRB 110503A: SARA-N Observations and Photometric Calibration
DATE:    11/05/04 17:13:05 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike@clemson.edu>

Adria C. Updike (NASA/GSFC), D. A. Kann (TLS Tautenburg), Dieter H.
Hartmann (Clemson University), and Ken Rumstay (Valdosta State University)
report:

We observed the field of GRB 110503A (M. Stamatikos et al., GCN 11991)
with the SARA-North 0.9m telescope located at KPNO under good conditions
beginning about 13 hours after the trigger and continuing for half an
hour.  We detect the afterglow in each 120 sec exposure.  In a stacked 20
min image with mean time 0.5484375 days after the trigger, we detect the
afterglow at R = 20.20 +/- 0.07 using the SDSS-derived magnitude of the
comparison star given by Kann et al. (GCN 11996).  Further observations
are planned.

The comparison star utilized by Kann et al. has the following SDSS
magnitudes (transformation from Lupton (2005) and Jordi et al. (2006):

u = 21.214
g = 18.546
r = 17.166
i = 16.485
z = 16.111

and Vega magnitudes:

U = 20.431
B = 19.193
V = 17.802
R = 16.819
I = 15.942
Z = 15.562


GRB_name: GRB110503A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12002
SUBJECT: GRB 110503A: Millimeter observation from SMA
DATE:    11/05/04 22:25:52 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI), G. Petitpas (SMA) and S. Martin (ESO)
report on behalf of a larger collaboration:

We have observed the afterglow of GRB 110503A (Stamatikos et al.
GCNC11991) with the Submillimeter Array (SMA, Hawaii, U.S.A.).
Observations were performed at 217GHz (1.4 mm) using 5 antennas under
unstable weather conditions (optical depth at 225 GHz ~0.25, humidity
~50%). The GRB field was observed for 268 minutes (on-source), starting at
1:15 UT, with mean epoch on 4 May at 5:36 UT, 12.0 hours after the burst.
We do not detect any significant flux at the position of the optical
afterglow, imposing a 3-sigma detection limit of 5.1 mJy.

[GCN OPS NOTE(05may11): Per author's request, the burst name
in the Subject-line was corrected.]


GRB_name: GRB110503A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12003
SUBJECT: GRB 110503A: Centimeter observation from EVLA
DATE:    11/05/04 23:24:57 GMT
FROM:    Dale A. Frail at NRAO  <dfrail@nrao.edu>

Dale A. Frail (NRAO), Ashley Zauderer (Harvard), and Edo Berger
(Harvard) report on behalf of a larger collaboration:

We imaged a field toward the Swift burst GRB 110503A (GCN 11991,11995)
with the EVLA starting on 2011 May 4.04 (i.e. 7.4 hrs after the
burst).  The EVLA observed at two frequencies (1 GHz bandwidth each)
centered at 19.2 GHz and 24.5 GHz. In a preliminary data analysis we
find a unresolved radio source within the UVOT error circle (GCN
12000) with a mean flux density of 160 +/- 15 uJy and a position
(J2000) of RA=08:51:06.21, Dec.=+52 12 27.43, with a conservative
error of +/-0.05 arcsec.

We caution that these results are only preliminary. Further
observations are planned.


GRB_name: GRB110503A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12004
SUBJECT: GRB 110503A: R-band Detection
DATE:    11/05/05 00:43:08 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im (CEOU/Seoul National Univ), Hyun-Il Sung (KASI),
and  Yuji Urata (NCU) on behalf of EAFON

We observed GRB 110503A (Stamatikos et al., GCN 11991) in R-band
with a 1.0-m telescope at Mt. Lemmon, Arizona. The observation
started at 05-04-03:24:30 UT. We detect the afterglow with a
magnitude at R ~ 20.28 +- 0.09 mag (mid-time of ~10.0 hrs after
BAT alert) based on the photometry calibration star reported by
Updike et al.(GCN 12001).

Further analysis of the data and the follow-up observations of
the object is ongoing. We thank the LOAO operator, I.-K. Baek
for her assistance with the observation.


GRB_name: GRB110503A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12005
SUBJECT: GRB 110503A: optical observation in CrAO
DATE:    11/05/05 01:01:22 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Pavlenko (CraO), A. Volnova (SAI MSU), A. Baklanov (CrAO), A. Pozanenko 
(IKI)  on behalf of  larger GRB follow up collaboration report:

We observed the field of GRB 110503A  (Stamatikos  et al. GCN  11991) with 
Shajn telescope of CrAO  observatory  on May. 3 starting (UT) 23:56. We took 
several frames with exposure of 60s in R-band. The afterglow (Stamatikos  et 
al. GCN  11991)  is well detected  in each single frame.  A preliminary 
photometry is based on the USNO B1.0 star  1421-0227752  (08:51:10.01 
+52:11:04.75)    assuming R=16.819   (Updike et al. GCN 12001):

T0+         Filter,   Exposure, mag.
(mid, d)               (s)

0.26433    R         60       19.00 +/- 0.08
0.27991    R         60       19.24 +/- 0.18
0.29450    R         60       19.22 +/- 0.08


GRB_name: GRB110422A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12006
SUBJECT: GRB 110422A: Herschel FIR observation preliminary report
DATE:    11/05/05 03:12:33 GMT
FROM:    Maohai Huang at NAOC  <mhuang@nao.cas.cn>

Maohai Huang (NAOC), Bing Zhang (UNLV), Dong Xu (WIS), Jinsong Deng
(NAOC), Liping Xin (NAOC), Yulei Qiu (NAOC) report on behalf of Herschel
OT1_mhuang01 Open Time program:

Herschel Space Observatory has observed GRB 110422A according to the
plan (Huang et al GCN 11985).  Preliminary data reduction has shown
statistically significant (S/N ~ 10) detection in 170um and 250um bands
at a few mJy level. Scheduled follow-up observations and further
analyses of foreground/background sources will be conducted to
determine whether the emission is variable (dominated by the afterglow)
or from the host galaxy of GRB 110422A and Galactic ISM.


GRB_name: GRB110422A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12007
SUBJECT: GRB 110422A: MASTER  first 30 min OT light curve 
DATE:    11/05/05 06:42:02 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. 
Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

  MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Tunka (Baykal lake) was pointed to the  GRB 110422A (Mangano 
et al., GCN Circ 11957)  53 sec after GRB time at 2011-04-22 15:42:48.507 UT (Gres et al., GCN Circ 
11960). We see  OT (Klunko et al. GCN 11958) on all  images in both 
polarizations in R-band.

The results of the our photometry are:

  mag     err    exp      t-t_trig  mag  err exp     t-t_trig
  R/              s        mean (hours)    R\          s    mean (hours)
14.89 0.29 10 0.0166          15.28 0.43 10 0.0163
15.03 0.17 20 0.0272   15.3 0.25 20 0.0272
16.04 0.47 30 0.0400          15.73 0.31 30 0.0397
15.73 0.38 40 0.0551    15.77 0.38 40 0.0548
16.35 0.41 50 0.0729   16.05 0.27 50 0.0724
16.53 0.37 60 0.0938   16.53 0.32 60 0.0934
16.36 0.45 80 0.1190   16.35 0.41 80 0.1186
16.68 0.34 100 0.1502   16.78 0.33 100 0.1498
17.74 0.79 120 0.1871   17.17 0.34 120 0.1868
17.78 0.59 150 0.2319         17.52 0.33 150 0.2315
17.26 0.3 180 0.2834   17.56 0.32 180 0.2831
17.22 0.33 180 0.3403   17.78 0.48 180 0.3399
17.2 0.32 180 0.3957   18.32 0.87 180 0.3952
17.59 0.45 180 0.4513   18.71 1.27 180 0.4510
18.08 0.91 180 0.5066   19.25 2.64 180 0.5063

The LC's are available at:
http://observ.pereplet.ru/images/GRB110422/grb110422.png

  The message may be cited.


GRB_name: GRB110503A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12008
SUBJECT: Konus-Wind observation of GRB 110503A
DATE:    11/05/05 09:50:41 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The long GRB 110503A, (Swift/BAT trigger=452685:
Stamatikos et al., GCN 11991; Sakamoto et.al, GCN 11995)
triggered Konus-Wind at T0=63341.862s UT (17:35:41.862)

The burst light curve consists of a single pulse
with a total duration of ~12 s.
The emission is seen up to ~4 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110503_T63341/

As observed by Konus-Wind the burst
had a fluence of (2.6  0.2)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.304 s,
of (1.0  1)x10-5 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+10.752 s) is best fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.98 (-0.08, +0.09),
the high energy photon index beta = -2.7 (-0.5, +0.2),
the peak energy Ep = 219(-19, +20) keV,
chi2 = 69.5/76 dof.

The spectrum at the maximum count rate
(measured from T0+1.792 s to T0+2.560 s) can be fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.44 (-0.16, +0.19),
the high energy photon index beta = -2.75 (-0.4, +0.3),
the peak energy Ep = 211(-23, +25) keV,
chi2 = 55.4/48 dof.

Assuming the afterglow redshift z = 1.61 (de Ugarte Postigo et al.,
GCN 11993; D'Avanzo et al., GCN 11997) and a standard cosmology model
with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73,
the isotropic energy release E_iso is (1.77  0.15)x10^53 erg,
the peak luminosity L_iso_max is (1.83  0.18)x10^53 erg/s,
and Ep_rest is 570  50 keV.

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


GRB_name: GRB110503A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12009
SUBJECT: GRB 110503A optical observations
DATE:    11/05/05 10:50:09 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Eric Broens (Mol, Belgium) and David Boyd (West Challow, Oxfordshire, UK) 
separately reported to the AAVSO International High Energy Network the 
following optical observations of GRB 110503A (GCN Circ. #11991, 
Stamatikos et al.):

E. Broens (VVS WVS, Belgium) reports a detection of GRB 110503A at CR = 
19.6 +/- 0.2 on 2011 May 3.921 UT (JD 2455685.421; midpoint of exposures), 
approximately 4.5 hours after the Swift trigger (GCN Circ. #11991, 
Stamatikos et al.).  Broens obtained 41 frames of 60 seconds exposure in a 
clear filter using a 0.2-meter f7 SCT telescope with SBIG ST-7MXE CCD 
camera.  An ensemble of three nearby SDSS stars were used as comparisons, 
with their R-band magnitudes calculated using the Jester et al. (2009, AJ 
130, 873) relations.  Comparison stars used were: SDSS J085110.53+521301.8 
(R = 17.98) and SDSS J085110.02+521104.6 (R=17.20).  The measured position 
of the GRB was:

  RA: 08 51 06.3 , Dec: +52 12 26.9

Prior to acquisition of the unfiltered frames, a total of thirty 60-second 
frames (1800s total) were taken with a Cousins R filter centered at 2011 
May 3.895 approximately four hours after the burst.  The filtered 
observations yielded an upper limit of Rc < 18.7.


D. Boyd (West Challow, Oxfordshire, UK) reports V-band optical time series 
of GRB 110503A obtained using a 0.35-m SCT with a Starlight Express 
SXVR-H9 CCD camera.  A total of 150 60-second frames were obtained, and 
these were stacked in groups of 30 to obtain five 1800-second 
integrations.  The burst was detected in all frames.  The resulting 
time-series are as follows:

2011 May 3.89920 UT V=19.40 +/- 0.04
2011 May 3.92022 UT V=19.57 +/- 0.04
2011 May 3.94123 UT V=19.71 +/- 0.04
2011 May 3.96225 UT V=19.74 +/- 0.05
2011 May 3.98326 UT V=19.96 +/- 0.05

Magnitudes were obtained using Astrometrica software using UCAC3 for 
positions and photometry; Boyd reports that magnitudes were obtained using 
varying ensembles of between 14 and 19 stars per stacked image. Boyd also 
notes that the coorindates of the GRB on all frames was

  RA: 08 51 06.19 , Dec: +52 12 27.3 (J2000)


The AAVSO International High Energy Network was made possible through 
grants from the Charles Curry Foundation and NASA.


GRB_name: GRB110503A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12010
SUBJECT: GRB 110503A: Jet Break seen from TLS
DATE:    11/05/06 00:36:27 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann, S. Schmidl, B. Stecklum and C. Hoegner (TLS Tautenburg) report:

Observations of GRB 110503A (M. Stamatikos et al., GCN 11991) and its
afterglow are continuing at TLS Tautenburg (D. A. Kann et al., GCN 11996).
In the first night, we observed for a total of 6 hours, with conditions
becoming worse (increasing airmass and passing clouds). 43 detections in
BVRIZ were secured.

In the second night, observational conditions were challenging, with
passing clouds and high airmass at the time observations could begin. We
obtained 3 x 300 s in Rc, 3 x 450 s in V and only a single 450 s B
observation. The afterglow is faintly detected in the Rc and V stacks as
well as the B image. Using the comparison star of GCN 11996, as calibrated
by A. Updike et al. (GCN 12001), we find:

t (days after trigger) = 1.24878, Rc = 21.39 +/- 0.12

We re-observed the afterglow position in the third night under moderate
conditions (low airmass, good seeing, but low transparency). We obtained 6
x 600 s in the Rc band. Even in the stack, the afterglow is only faintly
detected. We find:

t (days after trigger) = 2.14026, Rc = 22.63 +/- 0.28

Fitting our Rc band data shows a clear break, with alpha_1 = 0.83 +/-
0.03, alpha_2 = 2.3 +/- 0.6 (due to sparse data with large errors), t_b =
1.06 +/- 0.14 days. While both the post-break decay slope as well as the
break time are insecure due to sparsity of the data, the data point at
2.14 days lies a complete magnitude under the extrapolation of the early
decay, making the existence of a break itself secure.

We propose this is the jet break of the afterglow.

Deeper follow-up with telescopes of larger aperature is highly encouraged.

This message may be cited.


GRB_name: GRB110503A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12011
SUBJECT: GRB 110503A: TAROT Calern observatory optical observations
DATE:    11/05/06 16:56:18 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Klotz A. (CESR-OMP), Gendre B. (ASDC),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 110503A detected by SWIFT
(trigger 451901) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 1.9h after the GRB trigger
(trigger occured during daytime). The elevation of
the field decreased from 69 degrees above horizon
and weather conditions were good.

We detect the candidate couterpart mentioned by
Stamatikos et al. 2011 (GCNC 11991) on co-added
series of exposures. We used the reference star
USNO B1.0 1421-0227752 (08:51:10.01 +52:11:04.75
J2000) described by Kann et al. 2011 (GCNC 11996)
assuming  R=16.819 (Updike et al. GCN 12001).

start   stop   R
1.96h - 2.65h  18.42 +/- 0.15
2.71h - 3.99h  19.11 +/- 0.10
4.04h - 5.33h  19.51 +/- 0.12
5.38h - 7.43h  19.93 +/- 0.15

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

From 1.96h to 7.43h, the decay slope is alpha = 1.1.


GRB_name: GRB110428A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12012
SUBJECT: GRB 110428A: Fermi-GBM observation
DATE:    11/05/06 18:25:50 GMT
FROM:    David Tierney at UCD  <david.tierney@ucd.ie>

D. Tierney (UCD) and G. Fitzpatrick (UCD)
report on behalf of the Fermi GBM Team: 

"At 09:18:30.41 UT on 28 April 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110428A (trigger 325675112 / 110428388)
which was also detected by the Fermi-LAT 
(V. Vasileiou et al. 2011, GCN 11982),
Konus-Wind (S. Golenetskii et al. 2011, GCN 11983),
and Suzaku WAM (W. Iwakiri et al. 2011, GCN 11988).
The GBM on-ground location is consistent with the Swift-XRT position
(A. Melandri et al. 2011, GCN 11984).

The GBM light curve consists of a single pulse
with a duration (T90) of 5.6 +/- 0.2 s (50-300 keV). 
The time-averaged spectrum from T0+1.8 s to T0+9 s is 
best fit by a Band function with Epeak = 175.60 (+3.95/-3.82) keV, 
alpha = -0.20 (+0.03/-0.03), and beta = -2.88 (+0.10/-0.12)
(C-Stat 559.66 for 482 d.o.f.).

The event fluence (10-1000 keV) in this time interval is 
(2.27 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured 
starting from T0+7 s in the 10-1000 keV band 
is 26.8 +/- 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: GRB110426A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12013
SUBJECT: GRB 110426A: Fermi GBM detection
DATE:    11/05/09 23:47:06 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <Alexander.J.VanDerHorst@nasa.gov>

A.J. van der Horst and A. Camero-Arranz (USRA) report on behalf of
the Fermi GBM Team:

"At 15:06:26.61 UT on 26 April 2011, the Fermi Gamma-Ray Burst Monitor
triggered on GRB 110426A (trigger 325523188 / 110426629). The on-ground
calculated location, using the GBM trigger data, is RA = 219.9, Dec = -8.7
(J2000 degrees, equivalent to 14h40m, -8d43'), with an uncertainty of
2.1 degrees (radius, 1-sigma containment, statistical only; there is
additionally a systematic error which is currently estimated to be 2
to 3 degrees). The angle from the Fermi LAT boresight is 88 degrees.

This is most likely the same source as the one that MAXI/GSC reported
in GCN 11980. Although MAXI/GSC triggered 130 seconds later than GBM on
GRB 110426A, the locations obtained by both instruments are consistent.
The GBM light curve consists of multiple peaks with a duration (T90) of
328 +/- 3 s (50-300 keV), indicating that the source was still active
when MAXI/GSC detected it.

The time-averaged spectrum from T0-4.1 s to T0+327.7 s is adequately fit
by a simple power law function with index -2.28 +/- 0.01. The event fluence
(10-1000 keV) in this time interval is (4.54 +/- 0.06)E-5 erg/cm^2.
The 1-sec peak photon flux measured starting from T0+216.1 s in the
10-1000 keV band is 6.7 +/- 0.4 ph/s/cm^2.

We note that there is bursting emission detected in GBM starting ~40
minutes before the trigger. This emission is significantly softer than
the ~6 minute emission episode after the GBM trigger time. The start of
the spectrally soft bursts is consistent with Sco X-1 coming out of
Earth occultation. The GRB 110426A location, however, is not consistent
with Sco X-1 and thus a separate source.

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


GRB_name: GRB110503A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12014
SUBJECT: GRB 110503A optical observation
DATE:    11/05/16 15:06:57 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Andrea Tasselli (Lincoln, Lincolnshire, UK) reports to the AAVSO 
International High Energy Network the following optical observation of GRB 
110503A (GCN Circ. #11991, Stamatikos et al.):

A. Tasselli (Lincoln, Lincolnshire, UK) reports a detection of GRB 110503A 
at an unfiltered, Sloan r-derived magnitude of cr = 19.1 +/- 0.1 on 2011 
May 05.9167 (JD 2455685.4167; midpoint of exposures), approximately 4 
hours after the Swift trigger (GCN Circ. #11991, Stamatikos et al.). 
Tasselli obtained 30 unfiltered images of 120 seconds exposure for a total 
of 3600 seconds.  Tasselli used a 0.2-meter Maksutov-Cassegrain (f/6.8) 
with a Starlight SXV-H9 CCD camera.  Photometry of the OT was done using 
the Iris photometry package with an ensemble of six SDSS stars:

SDSS J085118.11+521119.2, r=14.756;
SDSS J085118.96+521055.4, r=15.565;
SDSS J085110.02+521104.6, r=17.177;
SDSS J085119.59+521406.2, r=13.871;
SDSS J085131.83+521343.8, r=13.893; and
SDSS J085110.53+521301.8, r=17.749.

The position of the OT was measured using the Astrometrica package with 55 
UCAC3 reference stars, and was found to be

  RA(J2000)  =  08 51 06.2
  Dec(J2000) = +52 12 30

in good agreement with other measurements.

The AAVSO International High Energy Network was made possible through 
grants from the Charles Curry Foundation and NASA.


GRB_name: GRB110519A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12015
SUBJECT: GRB 110519A: Swift detection of a burst
DATE:    11/05/19 02:26:31 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. J. Saxton (UCL-MSSL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), J. M. Gelbord (PSU),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), S. R. Oates (UCL-MSSL),
K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and
M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team:

At 02:12:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110519A (trigger=453628).  Swift did not slew because
of a Moon observing constraint. 
The BAT on-board calculated location is 
RA, Dec 261.629, -23.408 which is 
   RA(J2000)  =  17h 26m 31s
   Dec(J2000) = -23d 24' 29"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a FRED pulse with a 
duration of about 35 sec.  The peak count rate was ~4000 counts/sec 
(15-350 keV), at ~1 sec after the trigger. 

Due to a Moon observing constraint, Swift cannot slew to the BAT
position until 23:19 UT on 2011 May 20. There will thus be no XRT or
UVOT data for this trigger before this time. 

Although we note that this location is within 10 degrees of the 
Galactic center, we believe that this is very likely a cosmological 
GRB due to the strength of its emission above 100 keV. 

Burst Advocate for this burst is C. J. Saxton (cjs2 AT mssl.ucl.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: GRB110519A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12016
SUBJECT: GRB 110519A, Swift-BAT refined analysis
DATE:    11/05/19 13:02:09 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.krimm@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), C. J. Saxton (UCL-MSSL),
J. Tueller (GSFC), T. N. Ukwatta (MSU) (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 110519A (trigger #453628)
(Saxton, et al., GCN Circ. 12015).  The BAT ground-calculated position is
RA, Dec = 261.638, -23.426 deg which is
     RA(J2000)  =  17h 26m 33.0s
     Dec(J2000) = -23d 25' 32.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.  The mask-weighted light curve shows a FRED
profile starting at T-5 sec, peaking at T+3 seconds, and decaying gradually
with a featureless profile out to T+70 sec.  A preplanned slew took the
source out of the BAT field of view at T+130 sec. T90 (15-350 keV) is
27.2 +- 3.0 sec (estimated error including systematics).

The time-averaged spectrum from T-4.7 to T+37.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.09 +- 0.06.  The fluence in the 15-150 keV band is 4.0 +- 0.1 x 10-06
erg/cm2. The 1-sec peak photon flux measured from T+2.17 sec in the
15-150 keV band is 4.6 +- 0.3 ph/cm2/sec.  All the quoted errors are at
the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/453628/BA/


GRB_name: GRB110428A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12017
SUBJECT: Radio observations of GRB 110428A with the EVLA
DATE:    11/05/19 19:33:20 GMT
FROM:    Poonam Chandra at Royal Mil. College Canada  <Poonam.Chandra@rmc.ca>

"Poonam Chandra (RMC), Dale A. Frail (NRAO), S. Bradley Cenko 
(Berkeley), Fiona Harrison  (Caltech) and Srinivas Kulkarni (Caltech) 
report:

We observed the Fermi burst GRB 110428A (Vasileiou et al. GCN 11982) 
with the Expanded
Very Large Array (EVLA) at various radio frequencies between April 30 
and May 13. We did not detect any significant radio source within the 
7.1" error circle of source 2 (Melandri et al. GCN 11984). Below are the 
details and 3-sigma upper limits from our observations:

Epoch                   Frequency            3-sigma upper limit          
Apr 30.45 UT        4.5 GHz                93 
uJy                                
Apr 30.45 UT        7.9 GHz                66 
uJy                                
May 3.50 UT         4.5 GHz                66 
uJy                                
May 3.50 UT         7.9 GHz                54 
uJy                               
May 6.74 UT         4.5 GHz                87 
uJy                                
May 6.74 UT         7.9 GHz                60 
uJy                                
May 10.48 UT       22.45 GHz            240 
uJy                               
May 13.41 UT       8.33 GHz              35 
uJy                                

We thank the EVLA staff for scheduling our observations so promptly. The 
National Radio Astronomy  Observatory is a facility of the National 
Science Foundation operated under cooperative agreement by Associated 
Universities, Inc."


GRB_name: GRB110518A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12018
SUBJECT: IPN localization of bright GRB 110518A
DATE:    11/05/19 23:20:59 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,

K. Hurley on behalf of the Mars Odyssey and MESSENGER GRB teams,

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

J. Goldsten on behalf of the MESSENGER GRNS GRB team,

A. von Kienlin, X. Zhang, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team,

D. Smith, J. McTiernan, R. Schwartz, and W. Hajdas, on behalf
of the RHESSI GRB team,

and

J. Cummings, D. Palmer, S. Barthelmy, N. Gehrels, and H. Krimm, on
behalf of the Swift-BAT team, report:

Konus-Wind, Swift (BAT), INTEGRAL SPI-ACS, RHESSI, Mars Odyssey (HEND), 
and MESSENGER (GRNS) observed the long bright GRB 110518A at about 
20:38:14 UT. The burst was outside the coded  field of view of the BAT.

We have triangulated it to a 3 sigma error box whose coordinates are:
-----------------------------------------------
    RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
   67.180 (04h 28m 43s)   -34.195 (-34d 11' 43")
Corners:
   67.910 (04h 31m 38s)   -33.755 (-33d 45' 18")
   66.826 (04h 27m 18s)   -34.525 (-34d 31' 28")
   66.438 (04h 25m 45s)   -34.626 (-34d 37' 35")
   67.529 (04h 30m 07s)   -33.864 (-33d 51' 51")
-----------------------------------------------
The error box area is 536 sq. arcmin.
The maximum distance between the box corners is 1.5 deg.
This error box may be improved.

Spectral information will be reported in a forthcoming GCN Circular.


GRB_name: GRB110518A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12019
SUBJECT: Konus-Wind observation of GRB 110518A
DATE:    11/05/20 12:32:02 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The long bright GRB 110518A (localized by IPN:
Golenetskii et al., GCN 12018)
triggered Konus-Wind at T0=74290.767s UT (20:38:10.767)

The burst light curve consists of two major pulses,
a total duration of the burst is ~35 s.
The emission in the first harder multi-peaked pulse
is seen up to ~8 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110518_T74290/

As observed by Konus-Wind the burst
had a fluence of (6.5  0.8)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.400 s,
of (4.7  0.5)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+35.072 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.29 (-0.07, +0.08),
the high energy photon index beta = -2.30 (-0.35, +0.15),
the peak energy Ep = 229(-35, +43) keV,
chi2 = 102.6/84 dof.

The spectrum at the maximum count rate
(measured from T0+0.256 s to T0+0.512 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.46 (-0.16, +0.18),
the high energy photon index beta = -2.6 (-0.7, +0.3),
the peak energy Ep = 535(-88, +123) keV,
chi2 = 50.4/48 dof.

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


GRB_name: GRB110520A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12020
SUBJECT: GRB 110520A: Swift detection of a burst
DATE:    11/05/20 20:51:25 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

M. De Pasquale (UCL-MSSL), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
S. Campana (INAF-OAB), V. D'Elia (ASDC), P. A. Evans (U Leicester),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL),
C. B. Markwardt (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC), C. J. Saxton (UCL-MSSL),
M. H. Siegel (PSU), C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report
on behalf of the Swift Team:

At 20:28:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110520A (trigger=453747).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 134.375, +56.402 which is 
   RA(J2000)  =  08h 57m 30s
   Dec(J2000) = +56d 24' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a FRED-like pulse
with a duration of about 30 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 20:30:28.3 UT, 100.1 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 134.34208, 56.42720 which
is equivalent to:
   RA(J2000)  = 08h 57m 22.10s
   Dec(J2000) = +56d 25' 37.9"
with an uncertainty of 3.7 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. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.73 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.5
(+1.48/-1.31) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 103 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 0.03. 

Burst Advocate for this burst is M. De Pasquale (mdp AT mssl.ucl.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: GRB110520A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12021
SUBJECT: GRB 110520A: MASTER-NET optical observations
DATE:    11/05/20 20:53:04 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina,
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, 
D.Zimnukhov, M.Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University

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

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

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

  MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Ural(Kaurovka) was pointed to the  GRB110520A 53 sec after 
GRB time and 23 sec after the trigger  at 2011-05-20 20:29:41.097 UT.
On our first (10s exposure) set we  haven't found optical transient 
within SWIFT error-box (ra=08 57 31 dec=+56 23 59 r=0.050000).
The our unfilterd 5-sigma upper limit has been about 17.0 mag

  MASTER II  robotic telescope in Tunka(Siberia) also pointed to this GRB, 
28 sec after trigger time in two polarizations. But the Sun was too high
  (only 5 deg. below horizont) and upper limit is about 15.0 mag on the 
bosh  first 10 sec sets.

This message may be cited.


GRB_name: GRB110520A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12022
SUBJECT: GRB 110520A: TAROT Calern observatory optical observations
DATE:    11/05/20 21:00:28 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Klotz A. (CESR-OMP), Gendre B. (ASDC),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 110520A detected by SWIFT
(trigger 453747) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 45s after the GRB trigger
(15s after the notice). The elevation of the field decreased from
51 degrees above horizon and weather conditions
were good.

The date of trigger : t0 = 2011-05-20T20:28:48

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 in the XRT error box with a
limiting magnitude of:
t0+44.9s to t0+104.9s : R > 17.3

The second image is 30.0s exposure in tracking mode:
t0+119.6s to t0+149.6s : R > 18.5

We co-added a series of exposures:
t0+119.6s to t0+310.9s : R > 19.0

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

This message may be cited.


GRB_name: GRB110520A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12023
SUBJECT: GRB 110520A: Liverpool Telescope Observations
DATE:    11/05/20 22:50:48 GMT
FROM:    James Smith at ARI,Liverpool John Moors U  <rjs@astro.livjm.ac.uk>

R.J. Smith (Liverpool), A Melandri (INAF-OAB), N. Tanvir (Leicester), C.G. Mundell (Liverpool) report on behalf of a larger collaboration:

The 2-m Liverpool Telescope followed up GRB110520A (SWIFT trigger 453747; De Pasquale et al. GCN 12020) and obtained a 1200sec r' integration centred 1.36 hours after the SWIFT burst time.
We do not detect any optical transient to a 3 sigma detection limit of R > 23.5, based on comparison to nearby USNO-B catalogue stars.

No further observations are planned.

This message may be cited.


GRB_name: GRB110520A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12024
SUBJECT: GRB 110520A: Skynet/DAO optical observations
DATE:    11/05/20 23:03:37 GMT
FROM:    Aaron LaCluyze at U.North Carolina  <lacluyze@physics.unc.edu>

A. LaCluyze, M. Maturi, K. Ivarsen, J. Haislip, D. Reichart, J. Moore, 
A. Trotter, A. Foster, R.Egger, A. Oza, E. Speckhard, J. A. Crain, and 
M. Nysewanderreport:

Skynet observed the Swift/XRT localization of GRB 110520A (Swift 
trigger#453747) with the Dolomites Astronomical Observatory located at 
the Carlo Magno Hotel Spa Resort in Italy.  Due to local twilight, 
observations in SDSS g',r',i' and z' did not begin until ~25 minutes 
after the trigger.

We do not detect an optical transit within the Swift error circle in any 
filter.   Our earliest time photometry yields the following 3-sigma 
limiting magnitudes: g' 17.8 (mean time of 26.78 minutes after trigger), 
r' 19.7 (mean time of 31.32 minutes after trigger, two combined 
exposures), i' 18.5 (mean time of 37.10 minutes after trigger, two 
combined exposures), z' 17.8 (mean time of 41.95 minutes after trigger) 
based on comparison ~6 nearby SDSS sources.

This message may be cited.


GRB_name: GRB110520A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12025
SUBJECT: GRB 110520A - NOT optical observation
DATE:    11/05/21 01:13:53 GMT
FROM:    Steve Schulse at U. of Iceland  <steve@raunvis.hi.is>

S. Schulze (U. Iceland), D. Xu (WIS), D. Malesani (DARK/NBI), P.  
Jakobsson (U. Iceland),
S. Asadi, A. Barekat, L. Guaita, I. A. Gumus, S. Lindgren,  J.  
Lindkvist, K. Migotto, A. Razza,
T. Strm, F. Taddia, G. Olofsson (Stockholm Observatory), report on  
behalf of a larger
collaboration:

We observed the field of GRB 110520A (De Pasquale et al., GCN 12020)  
with the
Nordic Opitcal Telescope (NOT) equipped with ALFOSC. We obtained 3x600 s
R-band and 6x300 s I-band images. Observations started at 21:19:16.9 UT
on May 20 (i.e., 0.8414 hr after the burst).

An optical source is clearly detected in each of the stacked R-band  
and I-band images
at coordinates

RA(J2000)  = 08:57:21.84
Dec(J2000) = +56:25:40.2
Error-radius: ~0.1 arcsec

which is 2.7 arcsec away of the XRT position center reported at
http://www.swift.ac.uk/sper/index.php.

This source has R~23.7 mag at a median time 1.118 hrs post-burst,  
calibrated with the
#1464-0205280 star (R1=18.97, R2=18.92) in the USNO B1 catalog. At the  
moment
our data does not allow to test for variability of the source.


GRB_name: GRB110520A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12026
SUBJECT: GRB 110520A: WHT IR observations
DATE:    11/05/21 01:50:43 GMT
FROM:    Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>

A.J. Levan (U. Warwick), N.R. Tanvir (U. Leicester), R. Canning (U.
Cambridge), F. Riddick (ING) report on behalf of a larger collaboration:

"We observed the location of GRB 110520A (GCN 12020) using the William
Herschel Telescope equipped with LIRIS. Observations began at 22:21
UT on 20 May 2011, 1.9 hours after the burst, and were conducted
in the zYJHK bands. We do not find any sources with the XRT
localization of GRB 110520A, down to preliminary limiting magnitudes
of z>22.1, J>20.8, H>20.1, K>19.5, calibrated against SDSS and 2MASS
observations of the field.

We do note two sources which lie just outside the XRT localization.
The object noted by Schulze et al. (GCN 12025) is very weakly
detected in our images, while an additional object at

RA(J2000) 08:57:22.02 
DEC(J2000) 56:25:35.31 
+/- 0.2"

is also present in all our observed bands, but is offset ~4" from
the XRT location.  At this stage we cannot ascertain if either of
these sources is a plausible afterglow for GRB 110520A."


GRB_name: GRB110520A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12027
SUBJECT: GRB 110520A: Enhanced Swift-XRT position
DATE:    11/05/21 06:17:49 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 1918 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 110520A, 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 = 134.34074, +56.42735 which is equivalent
to:

RA (J2000): 08h 57m 21.78s
Dec (J2000): +56d 25' 38.5"

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

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

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


GRB_name: GRB110520A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12028
SUBJECT: GRB 110520A: Swift-XRT refined Analysis
DATE:    11/05/21 09:08:51 GMT
FROM:    Andy Beardmore at U Leicester  <apb@star.le.ac.uk>

A.P. Beardmore (U. Leicester) and M. De Pasquale (UCL-MSSL) report on
behalf of the Swift-XRT team:

We have analysed 11 ks of XRT data for GRB 110520A (De Pasquale  et al.
GCN Circ. 12020), from 84 s to 25.2 ks after the  BAT trigger. The data
comprise 74 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 Osborne et
al. (GCN. Circ 12027).

The light curve initially follows a power-law decline with decay index
alpha=2.0, then shows a small flare from T+137 s to T+516 s, reaching a
peak count rate of 12 c/s at T+254 s, after which it decays with an
index of 1.42 (+0.12, -0.11).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.77 (+/-0.17). The
best-fitting absorption column is  2.9 (+/-0.6) x 10^21 cm^-2, in
excess of the Galactic value of 2.7 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 5.0 x 10^-11 (7.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.9 (+/-0.6) x 10^21 cm^-2
Galactic foreground: 2.7 x 10^20 cm^-2
Excess significance: 7.4 sigma
Photon index:      1.77 (+/-0.17)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00453747.

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


GRB_name: GRB110520A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12029
SUBJECT: GRB 110520A: IAC80 I-band observations
DATE:    11/05/21 11:40:58 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (IAA-CSIC, Granada), R. Barrena (IAC, Tenerife), A.J. Castro-Tirado (IAA-CSIC, Granada), A. de Ugarte Postigo (DARK/NBI, Copenhagen), D. Malesani (DARK/NBI, Copenhagen), report on behalf of a larger collaboration:

"We have observed the field of GRB 110520A (De Pasquale et al., GCNC 12020) with the 82cm IAC80 telescope located at the Observatory of Teide, Tenerife. The observations were carried out in the I band on May 20.87397-20.94593 UT (0.495-2.222 hours after the GRB). No object is detected within the enhanced XRT error circle (Osborne et al. GCN 12027) down to I~22.1 (calibration based on USNO-B1). The objects noted by Schulze et al. (GCNC 12025) and Levan et al. (GCNC 12026) are not present in our co-added image."


GRB_name: GRB110520A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12030
SUBJECT: GRB 110520A: Swift-BAT refined analysis
DATE:    11/05/21 15:04:26 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), M. De Pasquale (UCL-MSSL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110520A (trigger #453747)
(De Pasquale, et al., GCN Circ. 12020).  The BAT ground-calculated position is
RA, Dec = 134.363, 56.418 deg which is 
   RA(J2000)  =  08h 57m 27.1s 
   Dec(J2000) = +56d 25' 04.9" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 69%.
 
The mask-weighted light curve shows a single FRED peak starting at ~T-2 sec,
peaking at ~T+4 sec, and ending at ~T+40 sec.  T90 (15-350 keV)
is 15.7 +- 1.8 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.2 to T+16.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.13 +- 0.10.  The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+4.15 sec in the 15-150 keV band
is 1.1 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/453747/BA/


GRB_name: GRB110521A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12031
SUBJECT: GRB 110521A: Swift detection of a burst
DATE:    11/05/21 16:05:05 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), J. M. Gelbord (PSU),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), C. B. Markwardt (NASA/GSFC),
A. Melandri (INAF-OAB), P. T. O\'Brien (U Leicester),
C. Pagani (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL)
and E. Sonbas (GSFC/USRA/Adiyaman Univ.) report on behalf of the Swift
Team:

At 15:51:31.45 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110521A (trigger=453788).  Swift slewed immediately to this burst. 
The BAT on-board calculated location is 
RA, Dec 120.144, +45.798, which is 
   RA(J2000)  =  08h 00m 35s
   Dec(J2000) = +45d 47' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a few pulses with a 
total duration of about 20 sec.  The peak count rate was ~1800 counts/sec 
(15-350 keV), at ~8 sec after the trigger. 

The XRT began observing the field at 15:53:10.0 UT, 98.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
120.1327, 45.8264 which is equivalent to:
   RA(J2000)  = 08h 00m 31.84s
   Dec(J2000) = +45d 49' 35.1"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 106 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 (4.51 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 5.5
(+2.93/-2.35) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 8.07e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 104 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.09. 

Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.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: GRB110520A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12032
SUBJECT: Swift/UVOT observations of GRB110520A
DATE:    11/05/21 16:10:32 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

  M. De Pasquale (MSSL-UCL) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110520A
104 s after the BAT trigger (De Pasquale et al., GCN Circ. 12020).
No optical afterglow consistent with the enhanced XRT position (Osborne et 
al., GCN Circ. 12027) or at the position of the NOT and WHT sources 
(Schulze et  al., GCN Circ 12025; Levan et al. GCN Circ 12026) is detected 
in the initial and in the summed UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

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

white_FC           104          253          147  >21.1
u_FC               316          565          246  >20.4
white              104        30973         3040  >22.9
v                  645        23608         2083  >21.0
b                  571        36751         2946  >22.1
u                  316        42529         3178  >21.8
w1                 694        41871         2965  >21.8
m2                 842        40964         2262  >21.8
w2                 621        19418         1911  >22.0

The values quoted above 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: GRB110521A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12033
SUBJECT: GRB 110521A: MASTER synchronous and early optical observations limit
DATE:    11/05/21 18:50:06 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina,
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, 
M.Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University


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

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



  MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka(Siberia) was pointed to the  GRB110521A (Oates et al.,
GCN Circ 12031) 32 sec s after notice time and 92 sec after GRB
time at 2011-05-21 15:53:03.316 UT. On 
our first (20s exposure) set we haven't found optical transient  within 
SWIFT error-box .
  The 3-sigma upper limit has been about 16.0  mag

The Swift erros box was inside FOV of the one of the 2 Very Wide Field 
Cameras (2x480 square degrees, 2x12 Mpixs).
We have images before, during and after GRB .
The 3-sigma upper limit has been about 12.0  mag each image (5 s 
exposition).
The data reduction is continued.

This message may be cited.


GRB_name: GRB110521A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12034
SUBJECT: GRB 110521A: Enhanced Swift-XRT position
DATE:    11/05/21 21:41:09 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 428 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110521A, 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 = 120.13290, +45.82658 which is equivalent
to:

RA (J2000): 08h 00m 31.90s
Dec (J2000): +45d 49' 35.7"

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: GRB110521A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12035
SUBJECT: GRB 110521A: Swift-BAT refined analysis
DATE:    11/05/21 22:10:48 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
S. R. Oates (UCL-MSSL), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+529 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110521A (trigger #453788)
(Oates, et al., GCN Circ. 12031).  The BAT ground-calculated position is
RA, Dec = 120.132, 45.818 deg, which is 
   RA(J2000)  =  08h 00m 31.7s 
   Dec(J2000) = +45d 49' 05.3" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows several overlapping peaks starting
at ~T_zero, with the maximum peak at ~T+8 sec, and ending at ~T+18 sec.
There is a low significance tail out to around T+60 sec.
T90 (15-350 keV) is 13.8 +- 3.3 sec (estimated error including systematics).
 
The time-averaged spectrum from T+0.2 to T+18.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.90 +- 0.22.  The fluence in the 15-150 keV band is 4.4 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+7.88 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/453788/BA/


GRB_name: GRB110521A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12036
SUBJECT: GRB 110521A - NOT optical observation
DATE:    11/05/22 00:54:55 GMT
FROM:    Steve Schulse at U. of Iceland  <steve@raunvis.hi.is>

S. Schulze (U. Iceland), D. Xu (WIS), P. Jakobsson (U. Iceland), T.
Pursimo (NOT Observatory), report on behalf of a larger collaboration:

We observed the field of GRB 110521A (Oates et al., GCN 12031) with
the Nordic Opitcal Telescope (NOT) equipped with ALFOSC. We obtained
3x300 s R-band and 6x300 s I-band images. Observations started at
22:01 UT on May 21 (i.e., 6.1604 hrs after the burst).

We do not detect any source in the stacked R-band and I-band images at
the refined XRT position (Beardmore et al., GCN 12034).

The limiting magnitudes are R ~ 24.4 mag at the mid-exposure time
t = 6.285 hrs post-burst, and I ~ 23.8 mag at the mid-exposure time
t = 6.745 hrs post-burst, calibrated with the #1358-0196725 star
(R1 = 19.57, R2 = 19.58, and I =18.81) in the USNO B1 catalogue.


GRB_name: GRB110520A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12037
SUBJECT: GRB 110520A: NOT optical follow-ups
DATE:    11/05/22 01:47:36 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

D. Xu (WIS), S. Schulze, P. Jakobsson (U. Iceland), T. Pursimo (NOT),
report on behalf of a larger collaboration:

We continued to observe the field of GRB 110520A (De Pasquale et al.,
GCN 12020) with the Nordic Opitcal Telescope (NOT) equipped with
ALFOSC. We obtained 6x300 s R-band images, starting at 23:02:40.4 UT
on May 21 (i.e., 26.565 hrs after the burst).

There was nothing visible within the enhanced XRT error circle
(Osborne et al., GCN 12027). The optical source identified in our
previous imaging (Schulze et al., GCN 12025) is ~1.9" northeast away
of the center of the enhanced XRT error circle, which has a radius of
1.5" (90% C.L.). The source is still point-like and has R=23.7+/-0.1
mag, same as our previous measurement.

The optical source noted by Levan et al. (GCN 12026) was clearly
detected in our previous imaging. It was largely point-like and had
R=23.9+/-0.1 mag, calibrated with the #1464-0205280 star (R1=18.97,
R2=18.92) in the USNO B1 catalog. Now it has become extended (about
3.5" southeast away of the center of the enhanced XRT error circle)
and decayed to R=24.5+/-0.2 mag.


GRB_name: GRB110521A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12038
SUBJECT: GRB 110521A: Swift-XRT refined analysis
DATE:    11/05/22 09:18:34 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

O. M. Littlejohns (U. Leicester) and S. R. Oates (UCL-MSSL) reports on
behalf of the Swift-XRT team:

We have analysed 21 ks of XRT data for GRB 110521A (Oates  et al. GCN
Circ. 12031), from 87 s to 47.7 ks after the  BAT trigger. The data
comprise 61 s in Windowed Timing (WT) mode (the first 8 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 12034).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.5 (+0.4, -0.3). At T+299 s  the decay
steepens to an alpha of 7.1 (+2.9, -1.3) before breaking again at T+529
s to a final decay with index alpha=1.0 (+0.5, -1.9).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.0 (+0.3, -0.6). The
best-fitting absorption column is  4.3 (+1.5, -2.6) x 10^21 cm^-2, in
excess of the Galactic value of 4.5 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.7 x 10^-11 (7.9 x 10^-11) erg
cm^-2 count^-1.

A summary of the PC-mode spectrum is thus:
Total column:      4.3 (+1.5, -2.6) x 10^21 cm^-2
Galactic foreground: 4.5 x 10^20 cm^-2
Excess significance: 2.7 sigma
Photon index:      2.0 (+0.3, -0.6)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00453788.

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


GRB_name: GRB110521A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12039
SUBJECT: GRB 110521A: Swift/UVOT Upper Limits
DATE:    11/05/22 09:22:55 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110521A
105 s after the BAT trigger (Oates et al., GCN Circ. 12031).
No optical afterglow consistent with the XRT position
(Beardmore et al., GCN Circ. 12034) is detected in the initial UVOT exposures.

Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
---------------------------------------------------------------
white_FC           105          255          147         >20.4
u_FC               263          513          246         >20.0
white              105         6615          766         >21.0
v                  594        41254         2261         >20.5
b                  519        30377         1766         >21.1
u                  263        36155         3624         >21.7
w1                 644        35466         3860         >22.0
m2                 618        41934         3564         >22.3
w2                 570        40340         2262         >22.3
--------------------------------------------------------------

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.09 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110521A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12040
SUBJECT: GRB 110521A: MASTER prompt optical  limit 
DATE:    11/05/23 09:31:10 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina,
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, 
D.Zimnukhov, M.Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University


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

V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka

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

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


The Swift erros box has casually appeared inside FOV of the one of the 2 
Very Wide Field Cameras (Gres et al., GCN Circ 12033).
We have images before, during and after GRB .
The 3-sigma  upper limit has been about 12.0  mag (unfiltered, close 
to V)  each image (5 s exposition).
The upper limit of coadded images during 15 sec GRB is 12.7.
The corresponding optical fluence less than  10^-9 erg/cm^2
The best-fitting absorption column is  4.3 (+1.5, -2.6) x 10^21 cm^-2, in
excess of the Galactic value of 4.5 x 10^20 cm^-2  (Littlejohns et al., 
GCN Circ 12038).
The fluence in the 15-150 keV band is 4.4 +- 0.5 x 10^-7 erg/cm2 
(Barthelmy et al., GCN Circ 12035).
So including ~2 mag absorption:

                   Fluence_opt/Fluemce_gamma(15-150) < ~1/60

The video is available at 
http://observ.pereplet.ru/images/GRB110521A/grb110521A.gif .

This message may be cited.


GRB_name: GRB090429B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12043
SUBJECT: EVLA afterglow limits on the high z GRB090429B
DATE:    11/05/28 12:16:12 GMT
FROM:    Dale A. Frail at NRAO  <dfrail@nrao.edu>

Dale A. Frail (NRAO), Ashley Zauderer (Harvard), Edo Berger (Harvard)
and Poonam Chandra (RMC) report on behalf of a larger collaboration:

We used the EVLA to image a field toward the Swift burst GRB 090429B
(GCNs 9281, 9288, 9290, 9298), for which a photometric redshift of
z=9.4 has been recently claimed (Cucchiara et al. astro-ph/1105.4915).

The EVLA observed at two frequencies (1 GHz bandwidth each) centered
at 4.93 GHz and 6.68 GHz on 2011 April 4.38 UT and 2011 May 6.13 UT.
No radio source is detected at the NIR afterglow position. Combining
the data from both epochs we derive a 3-sigma limit of 16.6 microJy.
This limit corresponds to a spectral luminosity of 2e31 erg/s/Hz.

We also reduced archival data taken at a frequency of 8.46 GHz on 2009
April 30.28 UT. The 3-sigma limit for this observation is 132 microJy.


GRB_name: GRB110529A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12044
SUBJECT: LAT Observations of GRB110529A
DATE:    11/05/29 21:31:17 GMT
FROM:    Julie McEnery at NASA/GSFC  <julie.e.mcenery@nasa.gov>

Julie McEnery (NASA/GSFC), Johan Bregeon (INFN Pisa) and
Dan Kocevski (SLAC)  report on behalf of the Fermi-LAT collaboration.

The Fermi Large Area Telescope (LAT) detected emission from GRB
110529A also detected by GBM (trigger 328322924) at 00:48:42.87 UT
on May 29, 2011.

The GBM location was inside the LAT field of view at an angle of
~30 degrees to the LAT boresight; no significant excess is seen
using standard analysis procedures.

Using a non-standard data selection, over 30 counts above background
were detected within a 0.1 s interval coinciding with the time of the
GBM emission. This data selection has insufficient spatial resolution
to provide a reliable LAT localization.

Since an excess of events were not seen using the standard analysis
selection, this detection is likely due to low energy gamma-rays
(below 100 MeV).

Further analysis is ongoing.


GRB_name: GRB110529A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12045
SUBJECT: Konus-Wind observation of GRB 110529A
DATE:    11/05/30 13:48:54 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The short hard GRB 110529A (GBM trigger 328322924, GCN 12044)
triggered Konus-Wind at T0=2920.249s UT (00:48:40.249)

The burst light curve consists of a single sharp pulse
with a total duration of ~0.57 s.
The emission is seen up to ~5 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110529_T02920/

As observed by Konus-Wind the burst
had a fluence of (5.1  1.1)x10-6 erg/cm2,
and a 16-ms peak flux, measured from T0,
of 7.0(-3.0,+2.2)x10-5 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+0.256 s) is best fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.43 (-0.36, +0.89),
the high energy photon index beta = -1.7 (-0.3, +0.2),
the peak energy Ep = 428(-226, +363) keV,
chi2 = 14.3/26 dof.

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


GRB_name: GRB110530A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12046
SUBJECT: GRB 110530A: Swift detection of a burst with an optical afterglow
DATE:    11/05/30 15:49:56 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

P. D'Avanzo (INAF-OAB), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), S. Campana (INAF-OAB),
V. D'Elia (ASDC), J. M. Gelbord (PSU), B. Gendre (ASDC),
C. Gronwall (PSU), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
V. Mangano (INAF-IASFPA), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), P. T. O\'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report
on behalf of the Swift Team:

At 15:31:02 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110530A (trigger=454473).  Swift slewed after 11 minutes
because of an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 282.045, +61.932, which is 
   RA(J2000)  =  18h 48m 11s
   Dec(J2000) = +61d 55' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
with a duration of about 20 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 15:38:16.7 UT, 434.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 282.06718, 61.92861 which is equivalent
to:
   RA(J2000)  = 18h 48m 16.12s
   Dec(J2000) = +61d 55' 43.0"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 39 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.65
x 10^20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 437 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 18:48:16.35 = 282.06814
  DEC(J2000) = +61:55:45.1  =  61.92920
with a 90%-confidence error radius of about 0.71 arc sec. This position is 2.8
arc sec. from the center of the XRT error circle. The estimated magnitude is
20.31 with a 1-sigma error of about  0.18. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.06. 

Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB110529A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12047
SUBJECT: GRB 110529A: Fermi GBM detection
DATE:    11/05/30 16:42:47 GMT
FROM:    Michael Burgess at UAH  <james.m.burgess@nasa.gov>

J. Michael Burgess (UAH) and Sylvain Guiriec (UAH)
report on behalf of the Fermi GBM Team:

"At 00:48:42.87 UT on 29 May 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located the very bright and short
GRB 110529A (trigger 110529034 / 110529034).

The on-ground calculated location, using the GBM trigger
data, is RA = 118.33, DEC = 67.91 (J2000 degrees,
equivalent to 7h 53m, +67d 54'), with an uncertainty
of 1.5 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
The angle from the Fermi LAT boresight is 30 degrees.

This GRB was also observed by Konus-Wind (GCN 12045).

The GBM light curve consists of two short bright peaks
with a duration (T90) of about 0.41s (50-300 keV).
The time-averaged spectrum from T0-0.0 s to T0+.44s is
adequately fit by a Band function with
Epeak = 1161 +/- 265 keV, alpha = -0.88 +/- 0.06,
and beta = -2.05+/- 0.15

The event fluence (10-1000 keV) in this time interval is
(2.32 +/- 0.01)E-6 erg/cm^2. The 0.256-sec peak photon flux
measured starting from T0+0.00 s in the 10-1000 keV band
is 23.6826 +/- 0.68 ph/s/cm^2.

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


GRB_name: GRB110530A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12048
SUBJECT: GRB 110530A: MITSuME Akeno Optical Observation
DATE:    11/05/30 16:54:31 GMT
FROM:    Yoichi Yatsu at Tokyo Tech.  <yatsu@hp.phys.titech.ac.jp>

Y. Yatsu, K.Kawakami, Y. Aoki, K. Tokoyoda, M. Hayashi, S. Song,
R. Usui, and N. Kawai (Tokyo Tech)  report on behalf of the MITSuME
collaboration:

We observed GRB110530A (D'Avanzo et al, GCN12046)
with the optical three color (g, Rc, and Ic) CCD camera attached
to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The follow-up observation was started at 15:31:02, ~2min after the BAT trigger.
And we detected a very faint object within the XRT error circle in R-band.
The measured R-band magnitude is shown below.

T0+[s]   MID-UT   T-EXP[sec]    g'             Rc           Ic
-----------------------------------------------------------------------
125    15:39:42          660           ---   18.84 +/- 0.65   ---
-----------------------------------------------------------------------
T0+ : Elapsed time after the burst [sec]
T-EXP: Total Exposure time [sec]

Photometric results and are listed below. We used GSC2.3 catalog for
flux calibration.


GRB_name: GRB110530A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12049
SUBJECT: GRB 110530A: Swift-BAT refined analysis
DATE:    11/05/30 17:57:42 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
P. D'Avanzo (INAF-OAB), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110530A (trigger #454473)
(D'Avanzo, et al., GCN Circ. 12046).  The BAT ground-calculated position is
RA, Dec = 282.045, 61.953 deg, which is 
   RA(J2000)  =  18h 48m 10.8s 
   Dec(J2000) = +61d 57' 11.2" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 98%.
 
The mask-weighted light curve shows a single pulse starting at ~T-50 sec
with a slow rise, peaking at ~T+2 sec, and ending at ~T+15 sec.
T90 (15-350 keV) is 19.6 +- 3.1 sec (estimated error including systematics).
 
The time-averaged spectrum from T-4.5 to T+17.4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.06 +- 0.24.  The fluence in the 15-150 keV band is 3.3 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.01 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/454473/BA/


GRB_name: GRB110530A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12050
SUBJECT: GRB 110530A: MASTER OT observations 
DATE:    11/05/30 18:08:57 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina,
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, 
D.Zimnukhov,
M.Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University


V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka

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

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

  MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka(Siberia) was pointed to the  GRB 110530A (D'Avanzo et 
al, GCN12046)  12 sec s after notice time and 73 sec after GRB time at
2011-05-30 15:32:15.215 UT. On our first (10s exposure) set 
we haven't found optical transient  within 
SWIFT error-box.
The 5-sigma upper limit has been about 15.2 mag (Polarization + R band).

The OT appears at 15:42:14 UT  (t_start-t_triger = 673 s, Exp_time=130s). 
Mag ~18.3 (R).

After that we see OT on our images in different filters 
(R,I,Unfiltered,R+P).
20 min ago (2011-05-30 17:44:42):  R ~19.5+-0.5.

The reduction is continued.

This message may be cited.

[GCN OPS NOTE(30may11):  Per author's request, the subject line
was changed from "110521" to "110530".]


GRB_name: GRB110530A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12051
SUBJECT: GRB 110530A: Correction to GCN Circ 12050
DATE:    11/05/30 18:13:51 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

Vladimir Lipunov.

The GCN Circular N 12050 correct subject is:

GRB 110530A: MASTER OT observations

I am sorry.


GRB_name: GRB110530A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12052
SUBJECT: GRB 110530A: optical observations at Mt. Terskol
DATE:    11/05/30 21:51:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev, I. Sokolov (Terskol Branch of Institute of 
Astronomy), Yu. Bronich (IC AMER of NASU),  A.Pozanenko (IKI) on behalf of 
larger GRB follow up collaboration report:

We observed the optical afterglow  of the Swift   GRB 110530A (D'Avanzo et 
al, GCN 12046) with Zeiss-2000 and Zeiss-600 telescopes of Mt.Terskol 
observatory. Optical afterglow is detected in a stacked images. The 
photometry is based on the star USNO-B1.0 1519-0265568 (RA=18 48 15.86, 
Dec=+61 56 15.0) assuming R=16.08  is following

UT (mid time), Exposure,   Filter,     OT

18:00              12 x 30 s    R(gunn)  20.32 +/- 0.08
18:58              24 x 150 s  R           20.6   +/- 0.2 


GRB_name: GRB110530A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12053
SUBJECT: GRB110530A: MITSuME Okayama Optical Observation
DATE:    11/05/31 02:34:34 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 the MITSuME collaboration:

We observed the field of GRB 110530A (D'Avanzo et al., GCNC 12046)
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 2011-05-30 15:41:32 UT (~11 min after
the burst). We detected the previously reported afterglow
(Yatsu et al., GCNC 12048) in Rc and Ic bands.


Photometric results and are listed below. We used GSC2.3 catalog for
flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'    Rc  Rc_err   Ic  Ic_err
----------------------------------------------------------------------
0.06460    17:04:03    5520.0   >20.3  19.8   0.2   19.6   0.2
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110530A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12054
SUBJECT: GRB 110530A: NOT optical observations
DATE:    11/05/31 03:04:40 GMT
FROM:    Annalisa De Cia at U of Iceland  <annalisa@raunvis.hi.is>

A. De Cia, P. Vreeswijk (U. of Iceland), D. Xu (Weizmann Inst.),
J. Telting (NOT) and P. Jakobsson (U. of Iceland)

report on behalf of a larger collaboration:

We observed the field of D'Avanzo et al. (GCN 12046) with the
2.5m NOT telescope at Roque de los Muchachos Observatory (La
Palma, Spain) equipped with ALFOSC, starting at 22:18 UT (6.8h
after the burst). The optical afterglow is detected, within the
XRT error circle reported by D'Avanzo et al., at R ~ 21.3,
calibrated against the USNO-B1.0 1519-0265568 star (R2=16.08)
also adopted by Andreev et al. GCN 12052.

Preliminary reduction of the subsequent spectroscopic
observations does not show any evident absorption lines, given
the poor S/N. A rough limit on the source redshift z<2.7 may be
placed by the non-detection of Lyman alpha absorption in the
spectra.


GRB_name: GRB110530A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12055
SUBJECT: GRB 110530A: Enhanced Swift-XRT position
DATE:    11/05/31 09:27:07 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 8011 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 110530A, 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 = 282.06843, +61.92897 which is equivalent
to:

RA (J2000): 18h 48m 16.42s
Dec (J2000): +61d 55' 44.3"

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

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

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


GRB_name: GRB110530A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12056
SUBJECT: GRB 110530A: Xinglong TNT  observation
DATE:    11/05/31 12:08:30 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L.P. Xin, Y.L. Qiu, J.Y. Wei, J. Wang, J.S. Deng, 
C. Wu, X. H. Han on behalf of EAFON report:

We began to observe GRB 110530A (D'Avanzo et al, GCN 12046) 
with Xinglong TNT telescope at 15:33:15(UT), 133 sec after 
the burst. The optical afterglow is clearly detected in all images.
The brightness is 20.7 mag in R band relative to the reference star
of Andreev et al. (GCN Circ. 12052) at the mean time of 10000 sec 
after the burst. 

More observations are encouraged. 

This message may be cited.
.


GRB_name: GRB110530A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12057
SUBJECT: GRB 110530A: Swift/UVOT Detection of a Fading Afterglow
DATE:    11/05/31 14:14:04 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110530A
438 s after the BAT trigger (D'Avanzo et al., GCN Circ. 12046).
A fading source consistent with the enhanced XRT position
(Evans et al., GCN Circ. 12055) is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  18:48:16.40 = 282.06833 (deg.)
    Dec (J2000) = +61:55:44.9  =  61.92913 (deg.)
with an estimated uncertainty of 0.65 arc sec. (radius, 90% confidence).

Preliminary detections using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag
white              438         1015          295         20.31 +/- 0.10
white             7070         8315         1042         21.52 +/- 0.21

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.06 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110530A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12058
SUBJECT: GRB 110530A: Swift-XRT refined Analysis
DATE:    11/05/31 15:02:01 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB) reports on behalf of the Swift-XRT team:

We have analysed 12 ks of XRT data for GRB 110530A (D'Avanzo  et al.
GCN Circ. 12046), from 446 s to 43.1 ks after the  BAT trigger. The
data comprise 29 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN. Circ 12055).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=0.81 (+0.05, -0.04).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.30 (+0.09, -0.17). The
best-fitting absorption column is  2.8 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 5.6 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.7 x 10^-11 (7.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.8 (+/-0.5) x 10^21 cm^-2
Galactic foreground: 5.6 x 10^20 cm^-2
Excess significance: 9.2 sigma
Photon index:      2.30 (+0.09, -0.17)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00454473.

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


GRB_name: GRB110530A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12059
SUBJECT: GRB 110530A: optical observations at Mt. Terskol, second epoch
DATE:    11/06/01 20:03:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev, I. Sokolov (Terskol Branch of Institute of 
Astronomy), Yu. Bronich (IC AMER of NASU),  A. Pozanenko (IKI) on behalf of 
larger GRB follow up collaboration report:

We observed the optical afterglow  of the Swift   GRB 110530A (D'Avanzo et 
al, GCN 12046) with Zeiss-2000 telescope of Mt.Terskol observatory On May, 
31 between (UT) 21:41-22:11.  At  the place of optical afterglow we detect 
extended object (elongated from SE to NW) with brightness R(gunn) ~ 22.7 
calibrated against  the star USNO-B1.0 1519-0265568 (RA=18 48 15.86, Dec=+61 
56 15.0) and assuming R=16.08.

Coordinates of South-East part of the extended object are  (J2000) 18 48 
16.27   +61 55 45.3  which is ~2" apart from position of the optical 
afterglow (J2000) 18 48 16.39   +61 55 45.16  obtained in our first epoch 
observations (Andreev et al. GCN 12052). The accuracy of  astrometry  is 
about 0.7" in both coordinates. One can suggest  the extended object might 
be a bright host of GRB 110530A.
The finding chart can be found at 
http://grb.rssi.ru/GRB110530A/grb110530_2m110531.jpg 


GRB_name: GRB110529A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12061
SUBJECT: GRB 110529A: Suzaku WAM observation of the prompt emission
DATE:    11/06/03 06:33:41 GMT
FROM:    Satoshi Sugita at Aoyama Gakuin U.  <sugita@phys.aoyama.ac.jp>

S. Sugita (Nagoya U.), Y. E. Nakagawa (Waseda U.),
W. Iwakiri, Y. Terada, M. Tashiro,  K. Takahara, T. Yasuda (Saitama U.),
T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.),
K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA),
N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki),
Y. Urata, P. Tsai, C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ.
of Tokyo),
on behalf of the Suzaku WAM team, report:

The bright short GRB 110529A  (McEnery et al., GCN 112044)
triggered the Suzaku Wide-band  All-sky Monitor (WAM) which covers an
energy range of 50 keV - 5 MeV at 2011-05-29 00:48:42.855 UT (=T0).

The observed light curve shows a single FRED-like peak
starting at T0s, ending  at T0+0.438s, with a duration
(T90) of 0.344 +/- 0.049 seconds.
The fluence in 100 - 1000 keV was 1.93 (+/- 0.12) x 10^-6 erg/cm^2.
 The 1-s peak flux measured from T0s was 7.16 (+/- 0.45) photons/cm^2/s
in the same  energy range.

Preliminary result shows that the time-averaged spectrum from
T0s to T0+0.5s is well fitted by a power-law with exponential cutoff model:
  dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
  alpha       1.02 (-0.20, 0.16)), and
  Epeak       1052 (-196, +254) keV (chi^2/d.o.f. = 55.9/52).

We also shows the results with the same spectrum
fitted by a GRB Band model fixing beta of -2.5
the low-energy photon index alpha: -0.80 (-0.26, 0.34),
the high-energy photon index beta: -2.5 (fixed),
and the peak energy Epeak: 791 (-161, 242) keV (chi^2/d.o.f = 53.6/52).

All the quoted errors are at statistical 90% confidence level.

The light curves for this burst are available at:
 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB110530A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12062
SUBJECT: GRB 110530A: optical observations in Mondy observatory
DATE:    11/06/03 20:44:08 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the optical afterglow  of the Swift   GRB 110530A (D'Avanzo et 
al, GCN 12046) with AZT-33IK telescope of Sayan observatory (Mondy) on May, 
30 between (UT) 16:06:01 - 19:14:06 (i.e. t0+0.0243 d -- t0+0.1549 days 
after burst trigger). We took several series of 60 s exposures in R. Optical 
afterglow is detected in single images in the beginning of the observations 
while in the end we stacked images in 180 - 300 s combined exposures. The 
photometry is based on the USNO-B1.0 1519-0265568 star (RA=18 48 15.86, 
Dec=+61 56 15.0) assuming R=16.08.   In particular, the photometry

UT (mid time), Exposure,   Filter,     OT
18:04               5x60          R           20.25 +/- 0.06
18:54               5x60          R           20.58 +/- 0.07

coincide with the photometry reported earlier (Andreev et al., GCN 12052).

Preliminary light curve can be found at

http://grb.rssi.ru/GRB110530A/GRB110530A_AZT33IK_lc.png

One can note a non-monotonous light curve decay with possible rebrightening 
at  0.03 d and 0.53 d and general power law decay index of about 0.9. 


GRB_name: GRB110604A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12063
SUBJECT: GRB 110604A Detection by IPN Spacecraft and Swift-BAT
DATE:    11/06/06 12:50:45 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf
of the Swift-BAT team, and

K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team

K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro,
Y. Terada, T. Murakami, and K. Makishima, on behalf of the Suzaku WAM
team

At 14:49:45.666 GRB 110604A triggered Konus-Wind.  The Interplanetary
Network was alerted.  The burst was also detected by Swift-BAT,
MESSENGER (GRNS), Suzaku WAM, and INTEGRAL SPI-ACS.  Triangulation
yielded overlapping annuli that partly intersected the BAT field of
view.  A sub-threshold peak on the edge of the corresponding BAT image
was consistent with the annuli.  The BAT location is
RA, Dec 271.003, +18.472 or

RA (J2000)     18h 04m 00.7s
Dec (J2000)    18d 28' 19.2"

with an estimated uncertainty of 5 arcmin radius.

The burst was about 30 seconds long with 4 separated peaks.  The usual
detailed BAT products will not be available for this burst, since the
coding was only about 0.2%.

A Swift TOO request has been approved.


GRB_name: GRB110604A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12064
SUBJECT: Konus-Wind observation of GRB 110604A
DATE:    11/06/06 14:36:17 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The long GRB 110604A (detected and localized by IPN
and Swift-BAT: Barthelmy et al., GCN 12063)
triggered Konus-Wind at T0=53385.666s UT (14:49:45.666)

The burst light curve consists of several multi-peaked pulses,
a total duration of the burst is ~45 s.
The emission is seen up to ~8 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110604_T53385/

As observed by Konus-Wind the burst
had a fluence of (3.1  0.3)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.880 s,
of (4.6  0.5)x10-6 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+37.376 s) is best fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.10 (-0.08, +0.10),
the high energy photon index beta = -3.2 (<-2.6),
the peak energy Ep = 166(-16, +15) keV,
chi2 = 71.7/76 dof.

The spectrum at the maximum count rate
(measured from T0 to T0+5.376 s) is best fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.8 (-0.1, +0.1),
the high energy photon index beta = -3.0 (-2.5, +0.3),
the peak energy Ep = 183(-14, +17) keV,
chi2 = 64.7/70 dof.

Also, both spectra show, in the 2-8 MeV range,
a hint of a weak additional hard spectral component.

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


GRB_name: GRB110610A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12065
SUBJECT: GRB 110610A: Swift detection of a burst
DATE:    11/06/10 15:36:34 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC),
J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), P. T. O\'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
A. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC),
M. H. Siegel (PSU), C. A. Swenson (PSU), G. Tagliaferri (INAF-OAB),
E. Troja (NASA/GSFC/ORAU) and T. N. Ukwatta (MSU) report on behalf of
the Swift Team:

At 15:21:32 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110610A (trigger=455155).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 308.151, +74.823 which is 
   RA(J2000)  =  20h 32m 36s
   Dec(J2000) = +74d 49' 22"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several peaks
with a duration of about 60 sec.  The peak count rate
was ~6000 counts/sec (15-350 keV), at ~35 sec after the trigger. 

The XRT began observing the field at 15:22:43.9 UT, 71.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 308.17636, 74.82415 which
is equivalent to:
   RA(J2000)  = 20h 32m 42.33s
   Dec(J2000) = +74d 49' 26.9"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 24 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 (1.32 x
10^21 cm^-2, Kalberla et al. 2005), with an excess column of 9.4
(+4.45/-3.60) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 8.90e-10 erg cm^-2 s^-1 (0.2-10
keV). 

Due to a bright star in the field of view, UVOT products will be delayed. 

Burst Advocate for this burst is F. E. Marshall (marshall 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: GRB110610A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12066
SUBJECT: GRB 110610A: MASTER-NET optical observations
DATE:    11/06/10 15:52:40 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

  E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, 
N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, 
D.Zimnukhov, M. Kornilov,A.Sankovich
  Sternberg Astronomical Institute, Moscow State University

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

  V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
  Ural State University, Kourovka

  V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
  Blagoveschensk Educational State University, Blagoveschensk

  MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka(Siberia) was pointed to the  GRB110610.64 30 sec s after 
notice time and 55 sec after GRB time at 2011-06-10 15:22:27.062 UT. On 
our first (10s exposure) set we haven't found optical transient  within 
SWIFT error-box (ra=20 32 35 dec=+74 49 11 r=0.050000).
  The 5-sigma upper limit has been about 15.0 mag
  The message may be cited.


GRB_name: GRB110604A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12067
SUBJECT: Swift detection of the X-ray afterglow of GRB 110604A
DATE:    11/06/10 17:07:44 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF-OAB/IASFPA), J. Cummings (GSFC), M. De Pasquale 
(MSSL) report on behalf of the Swift Team.

We have analyzed 14.5 ks of Photon Counting data for GRB 110604A 
(Barthelmy et al., GCN 12063), observed from 138 ks to 425 ks after the 
Konus-Wind trigger.

We find a single, fading source inside the XRT field of view. Using 2497 
s of XRT Photon Counting mode data and 2 UVOT images, 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 = 
270.85885, +18.39961 which is equivalent to:

RA (J2000):   18h 03m 26s.12
Dec(J2000):  +18d 23' 58".6

with an uncertainty of 2.4 arcsec (radius, 90% confidence). This is 9.3 
arcmin away from the initial IPN position. The source was first detected 
at a level of (1.2+/-0.2)E-3 counts/s (equivalent to 5.1E-13 erg cm^-2 
s^-1), 138 ks after the trigger, and has faded to a level of 
(1.4+/-0.6)E-3 counts/s at 421 ks (equivalent to 6.0E-14 erg cm^-2 
s^-1). Another Swift observation is planned for June 14, 2011 in order 
to confirm fading.

No optical source is found within the XRT error circle. Preliminary 
3-sigma upper limits using the UVOT photometric system (Poole et al. 
2008, MNRAS, 383, 627) are:


Filter  T_start (s)   T_end (s)  Exp (s)  mag
white    207930       237252     1399     >22.9
v        208162       237295     516      >19.6
u        207698       240533     2864     >21.5


The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.24 in the direction of the 
burst (Schlegel et al. 1998).

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


GRB_name: GRB110610A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12068
SUBJECT: GRB 110610A: Swift-BAT refined analysis
DATE:    11/06/10 19:57:20 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110610A (trigger #455155)
(Marshall, et al., GCN Circ. 12065).  The BAT ground-calculated position is
RA, Dec = 308.205, 74.827 deg, which is 
   RA(J2000)  =  20h 32m 49.1s 
   Dec(J2000) = +74d 49' 37.3" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.
 
The mask-weighted light curve shows several overlapping peaks starting
at ~T-15 sec, with the first peak at ~T+3 sec, the highest peak at ~T+35 sec,
and ending at ~T+55 sec.  Emission may continue (~1-sigma level) out to T+170 sec.
T90 (15-350 keV) is 46.4 +- 5.7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-11.1 to T+58.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.51 +- 0.05.  The fluence in the 15-150 keV band is 4.9 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+34.42 sec in the 15-150 keV band
is 4.2 +- 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/455155/BA/


GRB_name: GRB110610A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12069
SUBJECT: GRB 110610A: Enhanced Swift-XRT position
DATE:    11/06/10 20:10:29 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.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 916 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110610A, 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 = 308.17906, +74.82533 which is equivalent
to:

RA (J2000): 20h 32m 42.97s
Dec (J2000): +74d 49' 31.2"

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


GRB_name: GRB110610A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12070
SUBJECT: GRB 110610A: Swift/UVOT Upper Limits
DATE:    11/06/10 22:11:43 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110610A
4561 s after the BAT trigger (Marshall et al., GCN Circ. 12065).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 12069) is detected in the initial UVOT 
exposures. The usual UVOT finding chart exposures were not taken
because of a nearby bright star.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are:

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

v                 4561         6408          590         >19.7
w1                4971         6817          590         >20.5
m2                4766         6612          590         >20.8
w2                4356         6203          590         >20.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.44 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110610A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12071
SUBJECT: GRB 110610A: Swift-XRT refined Analysis
DATE:    11/06/11 07:21:04 GMT
FROM:    Antonia Rowlinson at U.of Leicester  <bar7@star.le.ac.uk>

A. Rowlinson (U. Leicester) and F. E. Marshall (NASA/GSFC) report on
behalf of the Swift-XRT team:

We have analysed 9.4 ks of XRT data for GRB 110610A (Marshall  et al.
GCN Circ. 12065), from 62 s to 24.2 ks after the  BAT trigger. The data
comprise 79 s in Windowed Timing (WT) mode (the first 8 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 12069).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=2.8 (+/-0.4). At T+174 s  the decay
flattens to an alpha of 0.18 (+0.21, -0.32) before breaking again at
T+984 s to a final decay with index alpha=1.33 (+0.12, -0.10).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.18 (+0.20, -0.19). The
best-fitting absorption column is  8.2 (+1.3, -1.2) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 x 10^21 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 5.1 x 10^-11 (1.2 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      8.2 (+1.3, -1.2) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^21 cm^-2
Excess significance: 11.4 sigma
Photon index:      2.18 (+0.20, -0.19)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00455155.

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


GRB_name: GRB110610A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12072
SUBJECT: GRB 110610A: 1.23m CAHA optical observations
DATE:    11/06/12 20:41:02 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (IAA-CSIC, Granada), P. Kubanek (IAA-CSIC, Granada & U.  
Valencia), report on behalf of a larger collaboration:

"We have taken two optical data sets of the Swift GRB 110610A  
(Marshall et al., GCN 12065) field using the 1.23m Calar Alto  
telescope. The observations were carried out in the I-band on June  
11.0013--11.1579 UT and June 11.9093--12.1599 UT (8.67-12.44 hours and  
30.46-36.48 hours post trigger, respectively). We do not detect any  
optical source consistent with the XRT error circle (Goad et al., GCNC  
12069) down to a limiting magnitude of I=20.6 (3 sigma, calibrated  
against USNO-B1.0)".


GRB_name: GRB110610A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12073
SUBJECT: GRB 110610A: Fermi GBM detection
DATE:    11/06/15 00:42:24 GMT
FROM:    Shaolin Xiong at UAH  <sx0002@uah.edu>

Shaolin Xiong (UAH)
reports on behalf of the Fermi GBM Team:

"At 15:21:32.549 UT on 10 June 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110610A (trigger 329412094 / 110610640),
which was also detected by the Swift/BAT (Marshall et al. 2011, GCN 12065).
The GBM on-ground location is consistent with the Swift position.
This burst was also detected by INTEGRAL SPI-ACS and Suzaku WAM.

The angle from the Fermi LAT boresight is 59 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 40 s (50-300 keV).
The time-averaged spectrum from T0+0.0 s to T0+39.4 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.97 +/- 0.05 and
the cutoff energy, parameterized as Epeak, is 189.9 +/- 14.0 keV.
The event fluence (10-1000 keV) in this time interval is
(8.70 +/- 0.35)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+33.7 s in the 10-1000 keV band is 5.97 +/- 0.25 ph/s/cm^2.

A Band function fits the spectrum equally well with
Epeak = 170.0 +/- 19.8 keV, alpha = -0.93 +/- 0.07
and beta = -2.23 +/- 0.20.

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


GRB_name: GRB110610A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12074
SUBJECT: GRB 110610A: Suzaku WAM observation of the prompt emission
DATE:    11/06/15 09:43:15 GMT
FROM:    Satoshi Sugita at Aoyama Gakuin U.  <sugita@phys.aoyama.ac.jp>

S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), N. Vasquez (Tokyo Tech.),
T. Uehara, Y. Hanabata, T. Takahashi, M. Ohno, Y. Fukazawa (Hiroshima U.),
Y. Terada, M. Tashiro, W. Iwakiri, K. Takahara, T. Yasuda (Saitama U.),
M. Kokubun, T. Takahashi (ISAS/JAXA),
Y. E. Nakagawa (Waseda U.), N. Ohmori, M. Akiyama, M. Yamauchi (Univ.
of Miyazaki),
Y. Urata, P. Tsai, C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ.
of Tokyo),
on behalf of the Suzaku WAM team, report:

The long GRB 110610A (Swift/BAT trigger #455155, GCN 12065; Marshall et al.,)
triggered the Suzaku Wide-band  All-sky Monitor (WAM) which covers an
 energy range of 50 keV - 5 MeV at 15:22:6.198 UT (=T0).

The observed light curve shows a multi-peaked structure starting at
T0-53s, ending
 at T0+10s with a duration  (T90) of 47 +/- 10 seconds.
 The fluence in 100 - 1000 keV was  4.57 (-0.60, +0.53) x 10^-6 erg/cm^2.
 The 1-s peak flux measured from T0+1s was 1.44 +/- 0.15
photons/cm^2/s in the same  energy range.

result shows that the time-averaged spectrum from T0-53s to
T0+10s is well fitted by a single power-law with a photon index
of 2.07 (-0.13, 0.15) (chi^2/d.o.f = 34.5/26).

All the quoted errors are at statistical 90% confidence level.

The light curves for this burst are available at:
 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB110604A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12075
SUBJECT: GRB 110604A: Suzaku WAM observation of the prompt emission
DATE:    11/06/16 10:16:24 GMT
FROM:    Norisuke Ohmori at Miyazaki U  <ohmori@astro.miyazaki-u.ac.jp>

M. Akiyama, N. Ohmori, M. Yamauchi (Univ. of Miyazaki),
M. Ohno, T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.),
S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), N. Vasquez (Tokyo Tech.),
Y. Terada, M. Tashiro, W. Iwakiri, K. Takahara, T. Yasuda (Saitama U.),
M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa (Waseda U.),
Y. Urata, P. Tsai, C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ.
of Tokyo), on behalf of the Suzaku WAM team, report:

The bright GRB 110604A (IPN and Swift/BAT ; Barthelmy et al., GCN 12063) 
triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy
range of 50 keV - 5 MeV at 14:49:42 UT (=T0).

The observed light curve shows a multi-peaked structure starting at
T0-13s, ending at T0+31s with a duration (T90) of about 27 seconds. There 
is a possible precursor at T0-13s with a duration of about 1 second. The
fluence in 100 - 1000 keV was 1.96 (-0.12, +0.10) x10^-5 erg/cm^2.
The 1-s peak flux measured from T0+2s was 7.68 (-0.98, +0.75) photons/cm^2/s
in the same energy range.

Preliminary result shows that the time-averaged spectrum including the precursor
from T0-13s to T0+31s is well fitted by a single power-law with a photon index
of 2.49 (-0.15, +0.17) (chi^2/d.o.f = 14.0/15).
All the quoted errors are at statistical 90% confidence level.

The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB110618A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12077
SUBJECT: IPN triangulation of GRB110618A (long duration, extremely intense)
DATE:    11/06/22 21:51:10 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley, on behalf of the Mars Odyssey and MESSENGER GRB teams,

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, 
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,

J. Goldsten, on behalf of the MESSENGER NS GRB team, 

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

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

A. von Kienlin, X. Zhang, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team, 

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

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of
the Swift-BAT team, report:

On 2011 June 18 at 08:47:25 UT, an extremely intense, long duration GRB
was observed by Fermi (GBM), INTEGRAL (SPI-ACS), Konus-Wind, MESSENGER,
Mars Odyssey, and Swift (outside the coded field of view).  We have
triangulated it to the following 3 sigma error box, whose area is 1.41
square degrees:

-----------------------------------------------
    RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
  176.808 (11h 47m 14s)   -71.688 (-71d 41' 16")
Corners:
  176.474 (11h 45m 54s)   -70.272 (-70d 16' 19")
  175.222 (11h 40m 53s)   -71.703 (-71d 42' 12")
  177.247 (11h 48m 59s)   -73.095 (-73d 05' 42")
  178.392 (11h 53m 34s)   -71.659 (-71d 39' 33")
-----------------------------------------------

Some improvement in this localization is possible.  The spectral and
temporal properties of this burst will appear in a forthcoming GCN.


GRB_name: GRB110618A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12078
SUBJECT: Konus-Wind observation of GRB 110618A
DATE:    11/06/23 10:21:30 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The long hard GRB 110618A (localized by IPN: Hurley et al., GCN 12077)
triggered Konus-Wind at T0=31673.867 s UT (08:47:53.867)

The burst light curve consists of a single long hard pulse
with unusually gentle onset and a total duration of ~250 s.
The emission is seen up to ~5 MeV, a hard-to-soft spectral
evolution is noticeable in the course of the event.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110618_T31673/

As observed by Konus-Wind the burst
had a fluence of (1.1  0.1)x10-4 erg/cm2,
and a 256-ms peak flux, measured from T0+1.280 s,
of (2.0  0.2)x10-6 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+229.632 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.40 (-0.08, +0.10),
and Ep = 569(-160, +304) keV,
chi2 = 78.1/73 dof.

The spectrum at the maximum count rate
(measured from T0 to T0+8.448 s) can be fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.12 (-0.06, +0.06),
and Ep = 524(-96, +138) keV,
chi2 = 88.7/73 dof.

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


GRB_name: GRB110604A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12080
SUBJECT: GRB 110604A: final update on Swift-XRT observations
DATE:    11/06/23 15:15:42 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF-OAB/IASFPA), J. Cummings (GSFC/UMBC), report on 
behalf of the Swift Team.

Swift-XRT performed further observations on the afterglow candidate 
announced in Sbarufatti et al. (GCN 12067). The source has faded with 
respect to the initial observation (1.2E-2 counts/s), and has dropped 
below the threshold for detection. The latest observations contain a 20 
ks exposure, corresponding to a 3-sigma upper limit of 1.3E-3 counts/s, 
confirming that the source was X-ray the afterglow of GRB 110604A.

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


GRB_name: GRB110618A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12081
SUBJECT: GRB 110618A: SMARTS optical observations
DATE:    11/06/23 16:54:30 GMT
FROM:    Bethany Cobb at GWU  <bcobb@gwu.edu>

B. E. Cobb (GWU), reports:

Using the ANDICAM instrument on the SMARTS 1.3m telescope at CTIO,
we obtained optical imaging of part of the error region of GRB 110618A
(GCN 12077, Hurley et al.) approximately 113 hours (4.7 days)
post-burst. Nine individual 5-minute I-band exposures were
obtained, tiled around the center of the IPN error region
(RA/Dec: 11h47m14s -71d41'16").  Each image is 6'x6', so these
images cover approximately 0.09 square degrees, e.g. the central 6% of
the IPN error region.

Preliminary visual comparison to the DSS reveals no new optical
sources in the SMARTS images (limited by the slightly shallower depth
of the DSS imaging).  This does not rule out the possibility of
an afterglow candidate contained in a relatively bright host
galaxy (additional SMARTS imaging is being obtained for further
analysis).


GRB_name: GRB110625A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12088
SUBJECT: GRB 110625A: Swift detection of a burst
DATE:    11/06/25 21:25:19 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

K. L. Page (U Leicester), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
V. D'Elia (ASDC), S. T. Holland (CRESST/USRA/GSFC),
F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester),
D. M. Palmer (LANL), P. Romano (INAF-IASFPA), C. J. Saxton (UCL-MSSL),
M. H. Siegel (PSU), M. C. Stroh (PSU) and T. N. Ukwatta (MSU) report
on behalf of the Swift Team:

At 21:08:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110625A (trigger=456073).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 286.750, +6.753, which is 
   RA(J2000)  =  19h 07m 00s
   Dec(J2000) = +06d 45' 10"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several bright peaks
with a total duration of about 60 sec.  The peak count rate
was ~20,000 counts/sec (15-350 keV), at ~13 sec after the trigger. 

The XRT began observing the field at 21:10:48.8 UT, 140.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 286.73189, 6.75386
which is equivalent to:
   RA(J2000)  = 19h 06m 55.65s
   Dec(J2000) = +06d 45' 13.9"
with an uncertainty of 3.8 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. 

A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density. 

The initial flux in the 2.5 s image was 1.72e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
205 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 large, but uncertain extinction expected. 

Burst Advocate for this burst is K. L. Page (kpa 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: GRB110625A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12089
SUBJECT: GRB 110625A: ROTSE-III Optical Limits 
DATE:    11/06/25 22:24:00 GMT
FROM:    Weikang Zheng at U.of Michigan  <zwk@umich.edu>

W. Zheng (U Mich) and W. Rujopakarn (Steward), report on behalf of the ROTSE
collaboration: 

ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe,
Turkey, responded to GRB 110625A (Swift trigger 456073; Page et al., GCN
12088), producing images beginning 6.8 s after the GCN notice time. An
automated response took the first image at 21:08:48.8 UT, 20.3 s after the
burst, and during the gamma-ray emission, under fair conditions. We took 10
5-sec, 10 20-sec and 110 60-sec exposures. These unfiltered images are
calibrated relative to USNO A2.0 (R). Imaging is on going.

Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle or the XRT error circle, for both single
images and coadding into sets of 10. Individual images have limiting
magnitudes ranging from 15.5-16.6; we set the following specific limits. 

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?

--------------------------------------------------------------------

21:08:48.8   21:10:56.3       127     16.9           20.3       Y

21:11:05.2   21:15:42.8       277     17.5          156.7       Y

21:15:51.7   21:20:29.5       277     17.5          443.2       Y

 


GRB_name: GRB110625A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12091
SUBJECT: GRB 110625A: Swift-BAT refined analysis
DATE:    11/06/26 06:32:26 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), K. L. Page (U Leicester), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+602 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110625A (trigger #456073)
(Page, et al., GCN Circ. 12088).  The BAT ground-calculated position is
RA, Dec = 286.751, 6.755 deg, which is 
   RA(J2000)  =  19h 07m 00.3s 
   Dec(J2000) = +06d 45' 17.8" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 5%.
 
The mask-weighted light curve shows a series of peaks starting at ~T-12 sec,
with major peaks at ~T-5, ~T+2, ~T+13 and ~T+18, followed by a long tail
ending at ~T+350 sec.  T90 (15-350 keV) is 44.5 +- 10.1 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-6.2 to T+140.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.44 +- 0.04.  The fluence in the 15-150 keV band is 2.8 +- 0.1 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+13.74 sec in the 15-150 keV band
is 49.5 +- 2.4 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/456073/BA/


GRB_name: GRB110625A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12092
SUBJECT: GRB 110625A: Swift-XRT refined Analysis
DATE:    11/06/26 11:56:14 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K. L. Page (U Leicester) reports on behalf of the Swift-XRT team:

We have analysed 4.1 ks of XRT data for GRB 110625A (Page  et al. GCN
Circ. 12088), from 129 s to 34.9 ks after the  BAT trigger. The data
comprise 96 s in Windowed Timing (WT) mode (the first 10 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The best available XRT position  (using the promptly downlinked
event data, the XRT-UVOT alignment and matching UVOT field sources to
the USNO-B1 catalogue) is RA, Dec = 286.7327, 6.7553 which is
equivalent to:

RA (J2000): 19 06 55.85
Dec(J2000): +06 45 19.2

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

The light curve can be modelled with an initial power-law decay with an
index of alpha=1.12 (+0.04, -0.03), followed by a break at T+18.7 ks to
an alpha of 2.7 (+7.3, -1.2). There are insufficient data to constrain
this steeper decay well at this time.

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.5 (+/-0.4). The
best-fitting absorption column is  6.3 (+1.1, -1.0) x 10^22 cm^-2, in
excess of the Galactic value of 1.4 x 10^22 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.8 (+/-0.4) and a
best-fitting absorption column of 5.9 (+1.3, -1.1) x 10^22 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 1.1 x 10^-10 (3.2 x 10^-10) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.9 (+1.3, -1.1) x 10^22 cm^-2
Galactic foreground: 1.4 x 10^22 cm^-2
Excess significance: 8.7 sigma
Photon index:      1.8 (+/-0.4)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00456073.

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


GRB_name: GRB110625A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12093
SUBJECT: Konus-Wind observation of GRB 110625A
DATE:    11/06/26 13:56:21 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The long bright GRB 110625A (Swift-BAT trigger #456073:
Page et al., GCN 12088; Palmer et al., GCN 12091)
triggered Konus-Wind at T0=76105.088s UT (21:08:25.088)

The burst light curve consists of several multi-peaked pulses,
a total duration of the burst is ~60 s.
The emission is seen up to ~8 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110625_T76105/

As observed by Konus-Wind the burst
had a fluence of (6.1  0.6)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+20.992 s,
of (1.5  0.2)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+58.880 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.05 (-0.08, +0.08),
the high energy photon index beta = -2.7 (-0.5, +0.2),
the peak energy Ep = 190(-14, +17) keV,
chi2 = 79.7/87 dof.

The spectrum at the maximum count rate
(measured from T0+20.992 to T0+21.504 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.8 (-0.2, +0.2),
the high energy photon index beta = -2.5 (-0.5, +0.2),
the peak energy Ep = 168(-24, +40) keV,
chi2 = 45.2/46 dof.

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


GRB_name: GRB110625A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12094
SUBJECT: GRB 110625A: Konkoly observations
DATE:    11/06/26 14:50:30 GMT
FROM:    Janos Kelemen at Konkoly Obs/Hungary  <kelemen@konkoly.hu>

J. Kelemen,(Konkoly Obs.) 
on behalf of the GRB OT observing program at the Konkoly Observatory. 

We observed the field of GRB 110625A (trigger=456073) using the Swift-XRT 
position provided by K.L. Page et al. (GCN 12088) with a 60/90 cm Schmidt 
telescope located at the Mountain Station of the Konkoly Observatory. We 
coadded 4 CCD images with 300 sec exposure time each. After checking the 
coadded frame we did not find any OT brighter than 21.5 mag in R the band 
within the XRT error circle. 
The photometry based on UCAC-3 stars around the field.

Time from
the trigger    magnitude       Band 
---------------------------------------- 
5829 sec      21.5 +/- 0.2      R       Upper Limit!


GRB_name: GRB110625A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12095
SUBJECT: GRB 110625A: NIR Source
DATE:    11/06/26 15:06:17 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Ji Hoon Kim, Dohyeong Kim, and Duho Kim
(CEOU/Seoul National University), on behalf of a larger collaboration

We observed GRB 110625A (Page et al. GCN 12088) in zYHK filters 
with UKIRT starting at 2011 June 26,10:08:47 UT. Within the enhanced XRT
error circle (Page et al. GCN 12092), we detect a NIR source in all the 
filters, whose coordinate is

RA=19:06:55.8,   Dec=06:45:19.2

with positional error of ~0.5". K-band magnitude is found to be 
about 17.5 mag, calibrated against a 2MASS star at (19:06:55.65, 06:45:16.2)

The variability of the source is being examined with additional data.


GRB_name: GRB110625A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12096
SUBJECT: GRB 110625A: GROND detection of a source inside the XRT error circle
DATE:    11/06/26 16:13:01 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

R. Filgas (MPE Garching), A. Rossi, A.D. Kann (both TLS Tautenburg), 
A. Rau and J. Greiner (both MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 110625A (Swift trigger 456073; Page et
al., GCN #12088) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla
Observatory (Chile).

Observations started at 02:24 UT on June 26, 5.3 hours after the GRB
trigger, continued until 03:11 UT, and were obtained at high airmass. 
A second epoch was obtained starting at 05:35, 8.46 hours after the burst, 
and finished at 07:06 UT.

Inside the refined XRT error circle (Page et al., GCN #12092) we found a 
single source at

 RA,DEC (J2000)= 19:06:55.89, +06:45:19.5

(+-0.3"), consistent with the source reported by Im at al., GCN #12095.
Over the course of 5 hrs, no variability is detected in relative photometry 
measured against a field star at RA,DEC(J200)=19:06:56.99,+06:45:20.4 
with z_AB = 19.4 mag.

We measure the following magnitudes (all in AB) from the first 1440s and 
1200s of exposure in g'r'i'z' and JHK, respectively:

g' > 24.3
r' = 24.1 +/- 0.2
i' = 22.6 +/- 0.1
z' = 21.5 +/- 0.1
J =  21.1 +/- 0.7
H > 18.6
K > 17.8

The photometry were derived by calibration against GROND zeropoints and 
2MASS field stars and are not corrected for the Galactic foreground extinction 
corresponding to a reddening of E_(B-V) ~ 10.5 mag in the direction of the burst 
(Schlegel et al. 1998).

Given the lack of variability and a color much bluer than would be expected
according to the strong foreground extinction, we suggest that this 
optical/near-IR source is likely a Galactic object unrelated to GRB 110625A.


GRB_name: GRB110625A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12097
SUBJECT: GRB 110625A: Fermi LAT detection
DATE:    11/06/26 19:52:11 GMT
FROM:    Thomas P.H. Tam at Nat.Tsing Hua U.  <grbtom@gmail.com>

P.H.T. Tam and A.K.H. Kong (NTHU) report:

We report on the detection of >100 MeV gamma-ray emission from the direction
of GRB 110625A (Swift trigger
456073; Page et al., GCN #12088) using the Fermi Large Area Telescope
(LAT).

The GRB position was outside the LAT field of view (i.e., >75 deg with
respect to the LAT boresight) at the burst
onset (T0; 2011-06-25 UT 21:08:28; GCN #12088). However, prominent emission
up to several GeV was detected
from the GRB direction around T0+200s to T0+500s, during which the light
curve seems to resemble a double-peak
structure. Using the data obtained from the above period, we localized the
LAT emission at RA, DEC (J2000 deg) =
286.6, 6.9, with a statistical error of ~0.3 deg (68% CL), which is
compatible with the refined Swift/XRT position (Page
et al., GCN #12092). A preliminary spectral fit gives a photon spectral
index of around -3 at energies above 100
MeV.


GRB_name: GRB110625A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12098
SUBJECT: GRB 110625A: 1.23m CAHA I-band observations
DATE:    11/06/26 23:50:14 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (IAA-CSIC), V. Terron (IAA-CSIC), P. Ferrero (IAC),
M. Jelinek (IAA-CSIC), P. Kubanek (IAA-CSIC  & U. Valencia),
M. Fernandez (IAA-CSIC), report on behalf of a larger collaboration:

"We observed the field of GRB 110625A (Page et al.,  GCN 12088)
with the 1.23m telescope of Calar Alto observatory. We obtained
45x60s I-band images on June 25.88457--25.93027 UT
(i.e, starting 5.32 min after the trigger).

In the co-added image, we detect a source at RA(J2000)=19:06:55.88,
DEC(J200)=06:45:19.4 (+/-0.5") which is consistent with the objects
reported by Im et al. (GCN 12095) and Filgas et al. (GCN 12096).
Using as photometric reference the USNO B1.0 star located at RA(J2000)
= 19:06:56.17, DEC(J2000)=06:44:25.9 with I=16.56, we derived a
preliminary magnitude of I=20.6 (Vega system) for the object
inside the XRT error circle.

This magnitude might indicate some degree of fading with respect
to the i-band AB mag reported by Filgas et al. (GCN 12096).
However, we are still cautious on the possible association
of this object with the GRB.

Further multi-band observations are encouraged."

[GCN OPS NOTE(27jun11): Per author's request, the "July" in the
second sentence was changed to "June".]


GRB_name: GRB110625A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12099
SUBJECT: GRB 110625A: Swift/UVOT Upper Limits  
DATE:    11/06/27 19:57:15 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) and K. L. Page (U Leicester)
report on behalf of the Swift/UVOT team:

      The Swift/UVOT observed the field of GRB 110625A starting 127 s
after the BAT trigger (Page et al., 2011, GCNC 12088).  Settled
observations started at 205 s.  We do not detect an optical afterglow
(or the source reported by Im et al., 2011, GCNC 12095) at the
UVOT-enhanced XRT position (Page, et al., 2011, GCNC 12092) in any of
the UVOT filters.  Preliminary 3-sigma upper limits for detecting a
source in the finding charts and in the co-added images, are

Filter      TSTART     TSTOP    Exposure     Mag
------------------------------------------------
    u (FC)     205       455         246   >20.7
               858      1008         147   >20.4

    v          511      1233          97   >19.5
    b          460      1332         117   >20.6
    u          205      1307         471   >21.1
 uvw1          560      1282          78   >19.5
 uvm2          535       703          39   >18.4
 uvw2          486      1339          98   >19.8
------------------------------------------------

     The quoted magnitudes and upper limits have not been corrected
for the large, but uncertain, Galactic extinction along the line of
sight to this burst (E_{B-V} = 10.52 mag, Schlegel et al. 1998, ApJS,
500, 525).


GRB_name: GRB110625A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12100
SUBJECT: GRB 110625A: Fermi GBM and LAT observations
DATE:    11/06/27 21:24:51 GMT
FROM:    David Gruber at MPE  <dgruber@mpe.mpg.de>

David Gruber (MPE), Nicola Omodei (Stanford U.), Vandiver Chaplin (UAH), 
J. Chiang (KIPAC/SLAC), J. McEnery (NASA/GSFC), J. L. Racusin (NASA/GSFC) 
report on behalf of the Fermi GBM and LAT Teams: 

At 21:08:18.24 UT on 25 June 2011, the Fermi Gamma-Ray Burst Monitor 
triggered and located GRB 110625A (trigger 330728900 / 110625881), which 
was also detected by the Swift/BAT (Page et al. 2011, GCN 12088). The GBM 
on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 88 degrees at the trigger time. 
Moreover, this burst was bright enough to result in a Fermi spacecraft 
autonomous rapid repoint (ARR) maneuver.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve shows several pulses with a duration (T90) of about 
27.7 +/- 1.4 s (50-300 keV). The time-averaged spectrum from T0-2.048 s 
to T0+60.417 s is best fit by a power law function with an exponential 
high-energy cutoff.  The power law index is -0.95 +/- 0.01 and the cutoff 
energy, parameterized as Epeak, is 209 +/- 3 keV.

The event fluence (10-1000 keV) in this time interval is 
(6.71 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured starting 
from T0+23.9 s in the 10-1000 keV band is 77.3 +/- 0.7 ph/s/cm^2.

A Band function fits the spectrum equally well with Epeak= 175 +/- 5 keV, 
alpha = -0.85 +/- 0.02 and beta = -2.37 +/- 0.05. 

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

The ARR maneuver put the GRB inside the Fermi/LAT field of view 
for several hundred seconds (from ~100-600 seconds after the GBM trigger).

The Spacecraft continued its maneuver toward the Fermi GBM flight software 
reconstructed position, that was off by 68 degrees from the Enhanced Swift/XRT 
position (GCN 12092), providing non-optimal exposure for LAT follow-up 
observations.

We analyzed the LAT data and we see significant high-energy emission from a 
point source coincident with the XRT position, confirming the already 
reported results by P.H.T. Tam and A.K.H. Kong (GCN 12097). 

We model the source spectrum with a power law model N(e) = N0 e^{\beta}, and 
the background including both the contribution from the Galactic diffuse 
emission and the isotropic contribution due to the residual contamination of 
charged particles.

We detect the GRB in two distinct time periods. In the first time bin (from 
237.1 seconds to 316.2 seconds after the GBM trigger), we measure a flux 
(100 MeV-10 GeV) of (4.9 +/- 1.9) x 1e-05 ph/cm^2/s and a spectral index beta 
of -2.1 +/- 0.3, with a Test Statistic TS=31.

In the second time bin, from 421.7 to 562.3 seconds after the GBM trigger, 
the measured flux is (3.7 +/- 1.5) x 1e-5  ph/cm^2/s with spectral index beta 
of -3.6 +/- 0.8 and a TS=19 (stat errors only).

The Fermi LAT point of contact for this burst is Nicola Omodei (nicola.omodei@gmail.com).

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: GRB110625A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12102
SUBJECT: GRB 110625A: Suzaku WAM observation of the prompt emission
DATE:    11/06/30 01:17:50 GMT
FROM:    Takeshi Uehara at Hiroshima U  <uehara@hirax7.hepl.hiroshima-u.ac.jp>

M. Mizuno, T. Uehara, Y. Hanabata, T. Takahashi, M. Ohno, Y. Fukazawa (Hiroshima U.),
S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), N. Vasquez (Tokyo Tech.),
Y. Terada, M. Tashiro, W. Iwakiri, K. Takahara, T. Yasuda (Saitama U.),
M. Kokubun, T. Takahashi (ISAS/JAXA),
Y. E. Nakagawa (Waseda U.), N. Ohmori, M. Akiyama, M. Yamauchi (Univ.of Miyazaki),
Y. Urata, P. Tsai, C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ.of Tokyo),
on behalf of the Suzaku WAM team, report:

The bright GRB 110625A (Swift/BAT trigger #456073 ; Page et el., GCN 12088 ; Fermi/LAT detection ; Tam and Kong GCN 12097, Gruber et al., GCN 12100)

triggered the Suzaku Wide-band  All-sky Monitor (WAM) which covers an
energy range of 50 keV - 5 MeV at 2011-06-25 21:08:22.01 UT (=T0).

The observed light curve shows a multi-peaked structure (starting at T0-1s, ending
at T0+28s) with a duration
(T90) of about 24 seconds. The fluence in 100 - 1000 keV was 2.54 (+/-0.09) x 10^-05  erg/cm^2. 

The 1-s peak flux measured from T0+20s was 13.6 (+/-1.0) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-1s to
T0+28s is well fitted by a single power-law with a photon index of 2.26 (+/- 0.09) (chi^2/d.o.f = 31.7/24).

However, there might be some calibration
uncertainties in the flux value because GRB photons came to the WAM detector by passing through the large Ne dewar of the X-ray micro-calorimeter (XRS).

All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.

The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB110705A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12108
SUBJECT: GRB 110705A: Fermi GBM detection
DATE:    11/07/05 11:54:33 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 03:37:11.94 UT on 05 July 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110705A (trigger 331529833 / 110705151).

The on-ground calculated location, using the GBM trigger 
data, is RA = 160.6, DEC = +24.0 (J2000 degrees, 
equivalent to 10h 42m, 24d 0'), with an uncertainty 
of 4.7 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
 
The angle from the Fermi LAT boresight is 75 degrees.

This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of one short spike  
with a duration (T90) of about 0.2 s (50-300 keV). 
The time-averaged spectrum from T0-0.016 s to T0+0.208 s is 
best fit by a Band function with Epeak = 1010 +90/-80 keV, 
alpha = -0.17  +/- 0.07, and beta = -3.0 +0.2/-0.4.

The event fluence (10-1000 keV) in this time interval is 
(3.3 +/- 0.1)E-06 erg/cm^2. The 0.016-sec peak photon flux measured 
starting from T0+0.0 s in the 10-1000 keV band 
is 50 +/- 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: GRB110705A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12110
SUBJECT: IPN triangulation of short hard GRB 110705A
DATE:    11/07/07 23:52:18 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,

K. Hurley on behalf of the Mars Odyssey and MESSENGER GRB teams,

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

J. Goldsten on behalf of the MESSENGER GRNS GRB team,

K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro,
Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM team,

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

J. Cummings, D. Palmer, S. Barthelmy, N. Gehrels, and H. Krimm, on
behalf of the Swift-BAT team,

and

A. von Kienlin, X. Zhang, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team, report:

The short hard GRB 110705A (Fermi/GBM trigger 331529833: von Kienlin, 
GCN 12108) was also detected by Konus-Wind, INTEGRAL (SPI-ACS), Suzaku 
(WAM), MESSENGER (GRNS), Mars Odyssey (HEND), and Swift (BAT). The burst 
was outside the coded  field of view of the BAT.

We have triangulated it to a 3 sigma error box whose coordinates are:
-----------------------------------------------
    RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
  156.024 (10h 24m 06s)   +40.099 (+40d 05' 56")
Corners:
  155.925 (10h 23m 42s)   +39.620 (+39d 37' 11")
  156.230 (10h 24m 55s)   +40.438 (+40d 26' 16")
  156.122 (10h 24m 29s)   +40.574 (+40d 34' 26")
  155.820 (10h 23m 17s)   +39.759 (+39d 45' 31")
-----------------------------------------------

The error box area is 354 sq. arcmin.
The maximum distance between the box corners is 0.97 deg.
This error box may be improved.

The GBM location (von Kienlin, GCN 12108) is 16.6 deg from the center of 
the IPN box.


GRB_name: GRB110705A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12111
SUBJECT: Konus-Wind observation of GRB 110705A
DATE:    11/07/08 05:34:20 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The short hard GRB 110705A (Fermi/GBM trigger 331529833 / 110705151:
von Klienin, GCN 12108; localized by IPN: Golenetskii et al., GCN 12110)
triggered Konus-Wind at T0=13029.942s UT (03:37:09.942)

The burst light curve shows double-peaked pulse
with a total duration of ~0.25 s.
The emission is seen up to ~5 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110705_T13029/

As observed by Konus-Wind the burst
had a fluence of (6.0  1.0)x10-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.144 s,
of (3.7  0.9)x10-5 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+0.256 s) is best fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.14 (-0.28, +0.37),
the high energy photon index beta = -2.7 (<-2.1),
the peak energy Ep = 820(-146, +205) keV,
chi2 = 20.9/30 dof.

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


GRB_name: GRB110708A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12112
SUBJECT: GRB 110708A: a long GRB detected by INTEGRAL
DATE:    11/07/08 07:15:45 GMT
FROM:    Diego Gotz at CEA  <diego.gotz@cea.fr>

D.Gotz (CEA-Saclay), S.Mereghetti, A.Paizis (IASF-Milano),  J.  
Borkowski (CAMK, Torun), E. Bozzo, C.Ferrigno, M. Beck, V. Savchenko  
(ISDC, Versoix),
on behalf of the IBAS Localization Team  report:

a  gamma ray burst lasting about 50 s has been detected by IBAS in the  
IBIS/ISGRI data at 04:43:22  U.T. of July 8.

Its refined coordinates (J2000) are:

   RA:  340.1208 [degrees]
   DEC: +53.9597 [degrees]

with an uncertainty of 1.6  arcmin (90% c.l.).

A preliminary analysis gives a  20-200 keV peak flux of about 0.8 ph/ 
cm2 s  (2 s integration time), and a fluence of about 2e-6 erg/cm2.

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


GRB_name: GRB110625A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12113
SUBJECT: GRB 110625A, the review of the sky area in plate archives
DATE:    11/07/08 10:03:08 GMT
FROM:    Valentyna Golovnya at Main Astro Obs,Kyiv  <golov_v@ukr.ne>

V.V. Golovnya (Main Astro Obs, Kyiv)
report: 
We have undertaken the review of the sky area in vicinity of 
GRB 110625A (K.L.Page GCN Circ.12092) on astronegatives, 
collected in Ukrainian NAS Main astronomical observatory 
plate archive (1976-1996). All the plates with the possible 
object appearance are digitized using Microtek ScanMaker 
9800XL TMA and Epson Expression 10000XL flatbed scanners and 
have been placed into Golosiiv Plate Archive database DBGPA 
with open access to them.
 
 The list of plates is given in the table:
YYYYMMDD TimeUT --Plates-- Exp. LimMag Star USNOA2 
19770902.184249 GUA040C000707B 47.0 15.00 0900-13913512
19770902.184249 GUA040D000708 47.0 15.45 0900-13913709
19900627.223953 GUA040C001670A 18.0 15.45 0900-13913709
19910612.234249 GUA040C001797 22.5 15.00 0900-13913512
19910615.232702 GUA040C001810 22.5 15.00 0900-13913512
19910719.204216 GUA040C001841 22.5 16.20 0900-13907267
19921130.153019 GUA040C000153B 20.0 12.75 0900-13888502
19921201.154830 GUA040D000160 05.5 12.75 0900-13888502
19921201.154840 GUA040C000161B 15.3 12.75 0900-13888502
19921201.162733 GUA040C000163B 15.0 13.20 0900-13901311
19940714.214044 GUA040C002338 20.5 15.45 0900-13913709
Plates-the plate's identifier in GUA040C and GUA040D archives
        of DWA (D/F=400/2000, M=103"/mm) of the Ukrainian NAS 
        Main Astro obs in Kyiv (Marsden's number - 83)[1].
Exp.   - Duration of the maximum exposure (minutes). 
LimMag - Limited V mag, derived in the 15 minutes area around 
       the location given in Page GCN Circ.12092: 
       RA(J2000): 19h 06m 55.85s, Dec(J2000): +06d 45' 19.2"
Star USNOA2 - Comparison star.
  The preview images of 11 areas together with  
the 15x15 min.of arc area from SkyMap can be found in  
http://gua.db.ukr-vo.org/img/grb/110625A/index.html
The images with full resolution are available via e-mail on 
demand.
References: 
1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0),
http://gua.db.ukr-vo.org


GRB_name: GRB110705A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12114
SUBJECT: GRB 110705A: Suzaku WAM observation of the prompt emission
DATE:    11/07/08 13:19:27 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro@phy.saitama-u.ac.jp>

T. Yasuda, Y. Terada, M. Tashiro, W. Iwakiri, K. Takahara (Saitama U.),
T. Uehara, Y. Hanabata, T. Takahashi, M. Mizuno, M. Ohno, Y. Fukazawa
(Hiroshima U.), S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.),
M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa (Waseda U.), N.
Ohmori, M. Akiyama, M. Yamauchi (Univ.of Miyazaki), Y. Urata, P. Tsai,
C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ.of Tokyo), on behalf
of the Suzaku WAM team, report:

The short GRB 110705A (Fermi Gamma-Ray Burst Monitor trigger 331529833,
GCN12108; von Kienlin et al.) triggered the Suzaku Wide-band All-sky
Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at
03:37:11.933 UT (=T0).

The observed light curve shows double-peaked structure starting at
T0+0.008s, ending at T0+0.258s with a duration (T90) of about 0.25
seconds. The fluence in 100 - 1000 keV was
2.31(+0.10/-0.13) x 10^-6 erg/cm^2. The 1-s peak flux measured from T0
was 4.24 (+0.19/-0.20) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0 to
T0+1s is well fitted by a power-law with exponential cutoff model:
dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha of
0.30 (+0.18/-0.10), and Epeak of 1030 (+139/-113) keV
(chi^2/d.o.f. = 45/53).

All the quoted errors are at statistical 90% confidence level.

The light curves for this burst will be available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB110708A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12115
SUBJECT: GRB 110708A: Swift/XRT afterglow candidate for the INTEGRAL burst
DATE:    11/07/08 23:20:47 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

V. D'Elia, G. Stratta (ASDC) and J. Cannizzo (GSFC)
report, on behalf of the Swift team:

Swift XRT began a 5ks target of opportunity observation of the field  
of INTEGRAL
burst GRB 110708A (Gotz et al., GCN circ 12112) on 14:25:40 UT, 34.9  
ks after the
burst trigger. In the first 4.6 ks of data, we detect a source,
located at RA, Dec 340.11178, 53.96182 which is equivalent
to:

RA(J2000) = 22h 40m 26.82s
Dec(J2000) = +53d 57' 42.5"

with an uncertainty of 5.7 arcseconds (radius, 90% containment). This
location is 21 arcseconds from the INTEGRAL reported position, within  
the INTEGRAL error box.
The source count rate is 4.7E-03+/-1.2E-03 cts/s. At the present  
stage, we cannot assess if the source is fading.

This circular is an official product of the Swift Team.

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.


GRB_name: GRB110708A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12116
SUBJECT: GRB 110708A: Lick observations
DATE:    11/07/09 05:54:15 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley, K. Clubb, M. Ganeshalingam, M. Ellison, D. Cohen, and J. 
S. Bloom (UC Berkeley) report:

We observed the position of INTEGRAL GRB 110708A (Gotz et al., GCN 
12112) with the 1-meter Nickel telescope at Lick Observatory starting at 
07:30:18 UT, 2.78 hours after the trigger.  We acquired four exposures 
of 300 seconds each (20 minutes total integration) in the I-band filter.

The XRT position given by D'Elia et al. (GCN 12115) lies near the center 
of an asterism of five bright, nearby point-sources (one of which is 
inside the XRT error circle), all of which are also visible in USNO 
imaging and are likely Galactic stars.  There is a possible, marginal 
detection of a fainter source within the XRT error circle at:

RA=22:40:27.33, dec=+53:57:42.8 (J2000)

The approximate magnitude of this object, if real, is I~20.5 (calibrated 
relative to USNO I-band).  It is fainter than the DSS limit and also too 
faint to clearly detect in individual exposures, so we cannot 
conclusively associate it with GRB 110708A at this time.

We identify no other objects within the XRT error circle to a limiting 
magnitude of I > 20.3, although the limit is complicated due to crowding 
from the nearby stars.


GRB_name: GRB110708A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12117
SUBJECT: GRB 110708A: Liverpool Telescope observations
DATE:    11/07/09 09:27:11 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

Z. Cano (Liverpool JMU), C. Guidorzi (U. Ferrara),
R.J. Smith (Liverpool JMU) report on behalf of a
large collaboration:

On 2011 July 08 at 04:46:10 UT the 2-m Liverpool Telescope
automatically began observing the INTEGRAL GRB 110708A
(Gotz et al., GCN Circ. 12112) using the gri filters,
corresponding to 168 s after the burst trigger time.

Inside the XRT error circle (D'Elia et al. GCN Circ. 12115)
we do not detect any uncatalogued source. In particular,
we do not detect the possible optical counterpart
mentioned by Perley et al. (GCN Circ. 12116) down to
the following limiting magnitudes:

Mid time from    Total Exp   Filter    Magnitude
trigger (min)    (s)
------------------------------------------------
20.1               30        i > 20.1
34.7              300        i > 20.4
33.0              360        r > 21.2
------------------------------------------------

Magnitudes have been calibrated from the nearby USNOB-1
star 1439-0418943 (RA=340.114656, Dec=+53.964514,
R2=16.51 mag, I=15.85 mag).


GRB_name: GRB110709A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12118
SUBJECT: GRB 110709A: Swift detection of a burst
DATE:    11/07/09 16:23:57 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC), S. D. Barthelmy (GSFC),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC),
B. Gendre (ASDC), C. Gronwall (PSU), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA), M. H. Siegel (PSU) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 15:24:29 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110709A (trigger=456939).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 238.895, +40.898, which is 
   RA(J2000)  =  15h 55m 35s
   Dec(J2000) = +40d 53' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows 8 roughly equal bright peaks
with a total duration of about 50 sec.  The peak count rate
was ~12,000 counts/sec (15-350 keV), at ~18 sec after the trigger. 

The XRT began observing the field at 15:25:34.7 UT, 65.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 238.8931, +40.9232 which is equivalent to:
   RA(J2000)  = 15h 55m 34.34s
   Dec(J2000) = +40d 55' 23.5"
with an uncertainty of 4.9 arcseconds (radius, 90% containment). This
location is 92 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 73 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
0.02. 

Burst Advocate for this burst is S. T. Holland (Stephen.T.Holland 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: GRB110709A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12119
SUBJECT: GRB 110709A: Prompt enhanced Swift-XRT position
DATE:    11/07/09 16:26:49 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

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

Using  promptly downlinked XRT event data for GRB 110709A, we find an
enhanced XRT position of the afterglow: RA, Dec: 238.8911, 40.9244
which is equivalent to:
   RA (J2000)  = 15 55 33.86
   Dec (J2000) = +40 55 28.0
with an uncertainty of 2.0 arc sec (radius, 90% confidence). Analysis
of the promptly available data is online at
http://www.swift.ac.uk/sper/456939.

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: GRB110709A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12120
SUBJECT: GRB 110709A: MASTER-NET optical observations
DATE:    11/07/09 16:45:29 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

  E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. 
Kornilov,A.Sankovich
  Sternberg Astronomical Institute, Moscow State University

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

  V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
  Ural State University, Kourovka

  V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
  Blagoveschensk Educational State University, Blagoveschensk

MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka(Siberia) was pointed to the GRB110709.64 29 sec s after 
notice time and 54 sec after GRB time at 2011-07-09 15:25:23.161 UT. On 
our first (10s exposure) set we haven't found optical transient within 
SWIFT error-box (Holland et al., GCN 110709A).
The 3-sigma upper limit has been about 16.0 mag (V band + polarizator)
The message may be cited.


GRB_name: GRB110708A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12121
SUBJECT: GRB 110708A: Swift/UVOT Observations
DATE:    11/07/09 21:12:03 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard@astro.psu.edu>

T. A. Pritchard (PSU) and V. D'Elia (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110708A
34934 s after the INTEGRAL trigger (Gotz et al., GCN Circ. 12112).
A faint detection of a source is detected inside of the Swift/XRT error
circle (V. D'Elia et al., GCN Circ 12115) and is consistent with the
position of the marginal detection by D. A. Perley et al.,
GCN Circ. 12116.  The source appears to be of constant brightness across
UVOT exposures  Preliminary 3-sigma magnitudes using the UVOT photometric
system (Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are:

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

v                34934        46819         1711         19.2 +/- 0.1
v                52022        58006         930          19.1 +/- 0.2
u                35462        53313         2220 >20.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.55 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110709B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12122
SUBJECT: GRB 110709B: Swift detection of a burst
DATE:    11/07/09 21:46:06 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

J. R. Cummings (NASA/UMBC), S. D. Barthelmy (GSFC),
D. N. Burrows (PSU), C. Gronwall (PSU),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
C. B. Markwardt (NASA/GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU),
R. L. C. Starling (U Leicester) and C. A. Swenson (PSU) report on
behalf of the Swift Team:

At 21:32:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110709B (trigger=456967).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 164.614, -23.484 which is 
   RA(J2000)  =  10h 58m 27s
   Dec(J2000) = -23d 29' 01"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows overlapping peaks
with a total duration of about 60 sec.  The peak count rate
was ~4200 counts/sec (15-350 keV), at ~30 sec after the trigger. 

The XRT began observing the field at 21:34:00.4 UT, 80.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 164.6552, -23.4550 which is equivalent to:
   RA(J2000)  = 10h 58m 37.24s
   Dec(J2000) = -23d 27' 17.9"
with an uncertainty of 5.3 arcseconds (radius, 90% containment). This
location is 171 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 91 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  0.05. 

Burst Advocate for this burst is J. R. Cummings (jayc 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.)


