# GCN_circulars

GRB_name: GRB110709A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12123
SUBJECT: GRB 110709A: Enhanced Swift-XRT position
DATE:    11/07/09 22:12:44 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 3951 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 110709A, 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 = 238.89144, +40.92427 which is equivalent
to:

RA (J2000): 15h 55m 33.95s
Dec (J2000): +40d 55' 27.4"

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: GRB110709B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12124
SUBJECT: GRB 110709B: Swift detection of renewed activity at T+11 minutes. 
DATE:    11/07/09 22:17:07 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), 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 21:43:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a second event (trigger=456969) from the same location as trigger
456967.  Swift did not slew to this location. However, it was already
on the boresight of all 3 instruments from the previous trigger. 
The BAT on-board calculated location is 
RA, Dec 164.647, -23.464, which is 
   RA(J2000) = 10h 58m 35s
   Dec(J2000) = -23d 27' 49"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a broad hump begining
around T-100, followed by an episode of several overlapping
peaks structure with a duration of about 40 s, and another peak at T+200s,
for a total duration of this outburst of at least 300 s.  The peak count rate
was ~5000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

This is a second outburst from the same location as
GRB 110709B at T+11 minutes, with comparable intensity and
light curve characteristics to the initial outburst. 

The light curve is sharp with rapid variations on the 1-second
timescale, which is uncharacteristic of late time flares
in GRB afterglows.  There is no obvious bright activity
seen in the BAT lightcurve between the two outbursts. 

The location is well away from the Galactic plane, and its spectrum is 
much harder than typical Galactic transients. 

This is a highly unusual event, and follow-up observations
should be a high priority. 


GRB_name: GRB110709A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12125
SUBJECT: GRB 110709A : Xinglong TNT upper limit
DATE:    11/07/09 23:40:40 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L.P. Xin, M,Zhai, 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 GRB110709A (Holland et al. GCN 12118)
with Xinglong TNT telescope at 15:30:49 (UT), 6 min after 
the burst. A series of R-band images were obtained. 
After combining 10*20s R-band images, no any new source was found within
the errorbox  of X-ray counterpart,down to 3 sigma 
upper limit of R~19.1 mag at the mean time of 7.5 min after 
the burst. 

This message may be cited.

For more information about Xinglong GRBs Follow-up
observations, please visit the website:
http://www.xinglong-naoc.org/grb/ 


GRB_name: GRB110709B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12126
SUBJECT: GRB 110709B: possible quiescent source in DSS
DATE:    11/07/09 23:41:46 GMT
FROM:    Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>

A.J. Levan (University of Warwick) reports:

"Inspection of DSS-II images of the region around GRB 110709B (Cummings
et al. GCN 12122) shows a faint optical source at a location of

RA(J2000) 10:58:37.34
DEC(J2000) -23:27:21.6

offset 3.9" from the centre of the XRT error circle (which currently
has a 5.3", 90% confidence error).

The source is apparently also detected in USNO-A2.0, with reported
magnitudes of B=21.2, R=17.9 (although at this faint level the 
associated errors are large). This source may be a quiescent counterpart
of GRB 110709B, although could also be an unrelated background (or
foreground) source. The probability of chance alignment with a 
source with R~18 in this error region is ~1-2% (e.g. Bloom, Kulkarni,
Djorgovski 2002, AJ 123, 1111)"


GRB_name: GRB110709A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12127
SUBJECT: GRB 110709A: Swift-BAT refined analysis
DATE:    11/07/10 00:18:48 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), S. T. Holland (CRESST/USRA/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-239 to T+733 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110709A (trigger #456939)
(Holland, et al., GCN Circ. 12118).  The BAT ground-calculated position is
RA, Dec = 238.895, 40.918 deg, which is 
   RA(J2000)  =  15h 55m 34.8s 
   Dec(J2000) = +40d 55' 06.4" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 91%.
 
The mask-weighted light curve shows at least 8 peaks starting at T-5 sec,
with the brightest peak at ~T+34 sec, and returning to background
at ~T+100 sec.  T90 (15-350 keV) is 44.7 +- 1.0 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-4.3 to T+65.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.24 +- 0.03.  The fluence in the 15-150 keV band is 1.0 +- 0.02 x 10^-05 erg/cm2.
The 1-sec peak photon flux measured from T+34.31 sec in the 15-150 keV band
is 6.2 +- 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/456939/BA/


GRB_name: GRB110709B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12128
SUBJECT: GRB 110709B: Gemini-South optical observations
DATE:    11/07/10 01:27:35 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger (Harvard) reports on behalf of a larger collaboration:

"We observed the field of the unusual GRB 110709B (GCNs 12122, 12124) with
GMOS on the Gemini-South 8-m telescope starting on 2011 July 10.032 UT (3.2
hr after the initial trigger).  Images were obtained at high airmass and in
poor seeing (1.7").  In a stack of 5x180 sec r-band exposures we find a
single faint source within the XRT error circle (GCN 12122) at (J2000):

RA = 10:58:37.38
DEC = -23:27:21.21

With an uncertainty of about 0.3" in each coordinate.  This source is
consistent with the position of the DSS-II source reported by Levan (GCN
12126).  Additional analysis is in progress."


GRB_name: GRB110709B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12129
SUBJECT: GRB 110709B: GROND Detection of an Afterglow Candidate
DATE:    11/07/10 01:36:14 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike@clemson.edu>

Adria C. Updike (NASA/GSFC), Felipe Olivares E., Jochen Greiner (both MPE
Garching), and D. Alexander Kann (Tautenburg Obs.) report on behalf of the
GROND team:

We observed the field of the extremely long GRB 110709B (Swift trigger
456967; Cummings et al., GCN #12122, Barthelmy et al., GCN #12124)
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 22:34 UT on the 9th of July 2011, 62 minutes after
the GRB trigger, and are continuing. They were performed at an average
seeing of 1.5" and at an average airmass of 1.3.

We found two point sources within the 5".3 Swift/XRT error circle reported
by Cummings et al. (GCN #12122). The first one is consistent with the source
in the DSS which was reported by Levan (GCN # 12126) and confirmed by
Berger (GCN #12128) and we furthermore detect a second, fainter source at

RA (J2000) = 10h 58m 37.03s

DEC (J2000) = -23d 27' 20.8"

with an uncertainty of 0.5" in each coordinate.

Based on 460 s of total exposures with mid-time 94 min after the trigger,
we estimate preliminary r'-band magnitudes of 20.9 +/- 0.1 for the DSS
source and 22.15 +/- 0.15 for the second source, both calibrated against
GROND zero points (in AB system). The given magnitudes are not corrected
for the Galactic foreground extinction corresponding to a reddening of
E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).

At the moment, we cannot confirm if this second source is fading, but
we suggest it as an afterglow candidate for GRB 110709B.


GRB_name: GRB110709B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12130
SUBJECT: GRB 110709B: Preliminary Swift-BAT refined analysis
DATE:    11/07/10 01:47:27 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),
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):
 
We report further analysis of BAT GRB 110709B (triggers #456967 and #456969;
Cummings, et al., GCN Circ. 12122 and Barthelmy, et al., GCN Circ. 12124).

Because of the interesting nature of this event, we are posting preliminary
versions of the "refined" processing on the two triggers of GRB 110709B.
The automated analysis of each trigger is provided separately.  We will likely
post the final refined analysis later when all of the full data is downlinked,
and the combined analysis can be performed.

At present, the first of the two BAT triggers (trigger #456967) consists 
of data from T-61 to T+234 sec.  The second trigger (trigger #456969) consists
of only a small amount of data from T-11 to T+63 sec.  The two triggers
are 645 sec apart.

The BAT ground-calculated position of the first trigger (#456967) is,
RA, Dec = 164.668, -23.470 deg, which is 
   RA(J2000)  =  10h 58m 40.3s 
   Dec(J2000) = -23d 28' 11.4" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 57%.   The position derived from the second trigger 
(#456969) is RA, Dec = 164.664, -23.500 deg, which is 
   RA(J2000)  =  10h 58m 39.4s 
   Dec(J2000) = -23d 29' 59.6" 
with an uncertainty of 3.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100% (on the BAT bore sight as a result of the
slew from the first trigger).  The two positions are separated by
1.8 arcmin.

The mask-weighted light curve of the first trigger, trigger #456967, 
shows the first peak of the cluster of peaks starting at ~T-30 sec
(note that the partial downlinked data start only at T-61 sec),
peaks at ~T+15 sec, and ends at T+130 or T+170 sec.
T90 (15-350 keV) is 55.6 +- 3.2 sec (estimated error including systematics).
 
The time-averaged spectrum of the data for the first trigger, trigger
#456967, from T-27.4 to T+46.7 sec is best fit by a simple power-law model.
The power law index of the time-averaged spectrum is 1.29 +- 0.04.
The fluence in the 15-150 keV band is 9.4 +- 0.2 x 10-6 erg/cm2.
The 1-sec peak photon flux measured from T+13.59 sec in the 15-150 keV band
is 3.4 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 

The mask-weighted light curve of the second trigger, #456969, 
shows emission starting some time before the current data set
starting at T=21:43:25.4 - 11 sec  and extending beyond the
T=21:43:25.4 + 63 sec of the partially downlinked data.
 
The time-averaged spectrum of the second trigger, #456969, 
from T-8.2 to T+52.8 sec is best fit by a power law with an
exponential cutoff.  This fit gives a photon index 1.08 +- 0.17, 
and Epeak of 171.5 +- 81.8 keV (chi squared 36.6 for 56 d.o.f.).
A fit to a simple power law gives a photon index of 1.39 +- 0.04
(chi squared 47.2 for 57 d.o.f.).  All the quoted errors are
at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
  Trigger 456967:  http://gcn.gsfc.nasa.gov/notices_s/456967/BA/
  Trigger 456969:  http://gcn.gsfc.nasa.gov/notices_s/456969/BA/


GRB_name: GRB110709B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12131
SUBJECT: GRB 110709B : A possible source in USNO B 1.0
DATE:    11/07/10 01:49:29 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin and J.Y Wei reports:

We noted that A. J. Levan reports (GCN 12126) that a source 
was detected in USNO-A2.0, with a magnitude of B=21.2, R=17.9.

Its coordinates are:
RA(J2000): 10:58:37.34
DEC(J2000): -23:27:21.6
Epoch:(J2000)

We check the USNO-B1.0 catalog and find that this source above 
reported by Levan (GCN 12126) disappeared in USNO-B1.0 catalog.
However, another source was detected in USNO-B1.0
at the errorbox of X-ray counterparts.

Its coordinates are 
RA(J2000) 10:58:37.00
DEC(J2000) -23:27:19.94
Epoch:(J2000)
Its magnitudes are reported as R=19.69, B=21.08.

The coordinates are consistent with the report of Updike et al. (GCN 12129).

Further observations are encouraged, especially the redshift measurement,
to check out weather this source is the counterpart of GRB 110709B or 
just a foreground or background source.


GRB_name: GRB110709B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12132
SUBJECT: GRB 110709B: Gemini-South additional analysis and photometry
DATE:    11/07/10 02:10:22 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger (Harvard) reports on behalf of a larger collaboration:

"Additional inspection and photometry of our Gemini-South r-band image (GCN
12128) reveals a second, fainter source (S2) at the following coordinates
(J2000):

RA = 10:58:36.955
DEC = -23:27:20.62

with an uncertainty of about 0.8" (due to centroid uncertainty).  This
position is consistent with the faint source detected by GROND (GCN 12129).

Photometry of the two sources using the Gemini-South/GMOS standard
photometric zero-point yields the following magnitudes:

S1:  r = 21.28+/-0.05 mag ("DSS" source)
S2:  r = 22.18+/-0.12 mag

Taken at face value, the brightness of S2 is consistent with the GROND value
(r=22.15+/-0.15 mag; GCN 12129), suggesting that S1 has actually faded by
about 0.3+/-0.15 mag between 1 and 3.2 hours after the initial trigger.

Alternatively, if the offset relative to the GROND photometry of S1
(r=20.9+/-0.1 mag) is due to a zero-point offset, the resulting brightness
of S2 is r = 21.9+/-0.1 mag.  This is marginally consistent with the GROND
value (r=22.15+/-0.15 mag) which was obtained about 2.2 hours earlier than
our observations.

To determine which scenario is correct relative to the GROND photometry, we
measure the brightness of the star at:

RA = 10:58:38.053
DEC = -23:26:31.78

to be r = 18.25 mag."


GRB_name: GRB110709A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12133
SUBJECT: GRB 110709A: Fermi GBM observation
DATE:    11/07/10 03:12:50 GMT
FROM:    Valerie Connaughton at UAH/NSSTC  <valerie.connaughton@nasa.gov>

V. Connaughton (UAH) reports on behalf of the Fermi GBM Team:

"At 15:24:27.37 UT on 09 July 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110709A (trigger 331917869 / 110709642),
which was also detected by the Swift/BAT (Holland et al. 2011,
GCN 12118) and the Swift/XRT (Evans et al. 2011,  GCN 12119).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at trigger time was 54 degrees.
Approximately 6 - 200 s from trigger time, the Fermi spacecraft executed
an automatic maneuver in response to a command from GBM, in
order to place the burst closer to the LAT boresight, and observed
this position for the following 2.5 hours, subject to Earth limb
constraints.

The GBM light curve shows several bright peaks from trigger time
to 50-s post-trigger, with a duration (t90) of 43.5 s (50-300 keV).
The time-averaged spectrum from T0-4.096 s to T0+62.5 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.16 +/- 0.02 and
the cutoff energy, parametrized as Epeak, is 533 +/- 37 keV.

The event fluence (10-1000 keV) in this time interval is
(4.43 +/- 0.07)E-5 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+25.28 s in the 10-1000 keV band
is 15.4 +/- 1.7 ph/s/cm^2.

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


GRB_name: GRB110709A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12134
SUBJECT: GRB110709A: upper limits from CAHA 1.23m and OSN 1.5m
DATE:    11/07/10 04:51:05 GMT
FROM:    Juan Carlos Tello at IAA-CSIC  <jtello@iaa.es>

J.C.Tello, J. Gorosabel, A. Castro-Tirado, M. Fernandez (IAA-CSIC Granada, Spain) and N. Huelamo (CAB-CSIC Madrid, Spain) reports on behalf of a larger collaboration:

We observed GRB110709A detected by Swift/BAT (Holland et al. 2011, GCN 12118) with CAHA 1.23m and OSN 1.5m telescopes.

Centro Astronmico Hispano Alemn (CAHA) 1.23m's observation in R filter lasted from July 9th 20:35 to 21:42 UT (e.g. 5.18-6.29 hours after trigger). At 8x420 sec co-added frames centred on XRT position (Evans et al. 2011, GCN 12119) we do not detect any new source down to limiting magnitude R=22.7, calibrated against USNO B1.0.

The I band frames from 1.5m Observatorio de Sierra Nevada (OSN) were taken on July 9th. On co-added I band frames, taken between 20:44 and 22:03 UT, with total exposure 4200 sec, we report limiting magnitude I=20.4 (calibrated against USNO B1.0). On V frames with total duration 1200 sec, acquired between 21:24 and 21:42 UT, we do not see any new source down to limiting magnitude V=21.6 (Calibrated against GSC 2.3).


This message may be cited.


GRB_name: GRB110709B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12135
SUBJECT: Konus-Wind observation of GRB 110709B
DATE:    11/07/10 10:56:50 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 110709B (Swift-BAT trigger #456967:
Cummings et al., GCN 12122; Barthelmy et al., GCN 12130)
triggered Konus-Wind at T0=77564.576s UT (21:32:44.576)

The burst light curve shows a multi-peaked
pulse with a total duration of ~70 s.
The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110709_T77564/

As observed by Konus-Wind the burst
had a fluence of (2.6  0.2)x10-5 erg/cm2,
and a 256-ms peak flux, measured from T0+13.824 s,
of (1.1  0.1)x10-5 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+41.216 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.0 (-0.13, +0.14),
and Ep = 278(-32, +43) keV,
chi2 = 62.7/73 dof.

The spectrum at the maximum count rate
(measured from T0+8.448 to T0+16.640 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -0.56 (-0.26, +0.30),
and Ep = 231(-28, +38) keV,
chi2 = 65.9/73 dof.

The renewed source activity (Swift-BAT trigger #456969:
Barthelmy et al., GCN 12124) fell into the telemetry gap
but was recorded by the instrument's spare count
rate measurement channel. This low-resolution record
(in the 70-300 keV energy range) shows a double-pulsed
structure lasting for ~100 s from T0+573 s to T0+675 s
(21:42:17 - 21:43:59) and having slightly weaker intensity
as compared to the initial burst.

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


GRB_name: GRB110709B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12136
SUBJECT: GRB 110709B: Enhanced Swift-XRT position
DATE:    11/07/10 11:33:08 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 9216 s of XRT Photon Counting mode data and 18 UVOT
images for GRB 110709B, 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 = 164.65448, -23.45489 which is equivalent
to:

RA (J2000): 10h 58m 37.08s
Dec (J2000): -23d 27' 17.6"

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: GRB110709B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12137
SUBJECT: GRB 110709B: correction to GCN 12135 (Konus-Wind peak flux)
DATE:    11/07/10 13:10:28 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks on behalf of the Konus-Wind team:

The correct value of GRB 110709B peak energy flux
measured by Konus-Wind is (1.1  0.1)x10-6 erg/cm2/s,
this is an order of magnitude lower than it is reported
in GCN 12135.

We apologize for this misprint.


GRB_name: GRB110709A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12138
SUBJECT: Konus-Wind observation of GRB 110709A
DATE:    11/07/10 13:35:02 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 GRB 110709A (Swift-BAT trigger #456939:
Holland et al., GCN 12118; Sakamoto et al., GCN 12127)
triggered Konus-Wind at T0=55470.576s UT (15:24:30.062)

The burst light curve consists of several partially overlapped
pulses, a total duration of the burst ~60 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/GRB110709_T55470/

As observed by Konus-Wind the burst
had a fluence of (3.7  0.3)x10-5 erg/cm2,
and a 256-ms peak flux, measured from T0+12.544 s,
of (4.1  0.4)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+48.896 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.03 (-0.07, +0.07),
and Ep = 356(-34, +42) keV,
chi2 = 72.6/76 dof.

The spectrum at the maximum count rate
(measured from T0+7.963 to T0+16.128 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -0.72 (-0.12, +0.13),
and Ep = 523(-68, +87) keV,
chi2 = 72.4/76 dof.

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


GRB_name: GRB110709A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12139
SUBJECT: GRB110709A: MITSuME Ishigakijima Optical upper limits
DATE:    11/07/10 14:07:27 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 110709A (Holland et al., GCN 12118)
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 15:27:30 UT (~3 min after the burst).
We did not find any new point source within the Enhanced XRT circle
(Osborne, et al., GCN 12123) in all the three bands.

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
------------------------------------------------------
0.00487    15:31:30     420.0    >19.9  >19.8  >18.7
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110709B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12140
SUBJECT: GRB 110709B: Swift/UVOT Detection of Possible Optical Flaring 
DATE:    11/07/10 14:35:59 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) and
J. R. Cummings (GSFC/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110709B
91 s after the initial BAT trigger (Cummings et al., GCNC 12122).  We
detect a source at the location of the GROND source reported by Updike
et al. (GCNC 12129).  The preliminary UVOT position is:

     RA (J2000)  10:58:37.03  =  164.65429 (deg)
    Dec (J2000) -23:27:20.9   =  -23.45581 (deg)

with an estimated uncertainty of 0.49 arcsec (radius, 90% confidence,
statistical + systematic).  Preliminary photometry indicates that this
source may have flared at approximately the time of the second BAT
trigger (Barthelmy et al., GCNC 12124).  Preliminary magnitudes and
3-sigma upper limits, using the UVOT photometric system (Poole et
al. 2008, MNRAS, 383, 627) for the white exposures are:

Filter    T_start(s) T_stop(s)  Exp(s)   Mag   Err
white (fc)     91       241     147   >21.1   3-sigma upper limit
white         583       603      19    20.10  0.49 
white         756       776      19    19.74  0.37
white         858      1008     147    20.94  0.34
white (fc)   6245      6444     197    21.19  0.38

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 mag in the direction of the
burst (Schlegel et al. 1998).  Further analysis of the Swift/UVOT data
is ongoing.


GRB_name: GRB110709A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12141
SUBJECT: GRB 110709A: Swift-XRT refined Analysis
DATE:    11/07/10 17:11:25 GMT
FROM:    Giulia Stratta at ASDC  <stratta@asdc.asi.it>

G. Stratta (ASDC), V. D'Elia (ASDC) and S. T. Holland
(CRESST/USRA/GSFC) report on behalf of the Swift-XRT team:

We have analysed 9.6 ks of XRT data for GRB 110709A (Holland  et al.
GCN Circ. 12118), from 71 s to 19.3 ks after the  BAT trigger. The data
comprise 565 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN. Circ 12119).

The late-time light curve (from T0+5.2 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.72 (+/-0.10).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.21 (+0.09, -0.08). The
best-fitting absorption column is  7.5 (+0.6, -0.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.5 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.07 (+/-0.11) and a
best-fitting absorption column of 7.3 (+/-0.7) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 5.0 x 10^-11 (1.0 x 10^-10) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7.3 (+/-0.7) x 10^21 cm^-2
Galactic foreground: 1.5 x 10^20 cm^-2
Excess significance: 17.8 sigma
Photon index:      2.07 (+/-0.11)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00456939.

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


GRB_name: GRB110709B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12142
SUBJECT: GRB 110709B: Swift-XRT refined Analysis
DATE:    11/07/10 22:13:25 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

V. D'Elia, G. Stratta and J. R. Cummings (NASA/UMBC) report on behalf
of the Swift-XRT team:

We have analysed 16 ks of XRT data for GRB 110709B (Cummings  et al.
GCN Circ. 12122), from 70 s to 36.8 ks after the  BAT trigger. The data
comprise 2.3 ks 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 12136).

The light curve shows a prolonged and powerful flaring activity up to
T0+2 ks. The late-time light curve (from T0+5.4 ks) can be modelled
with  a power-law decay with a decay index of alpha=1.08 (+/-0.04).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.550 (+/-0.020). The
best-fitting absorption column is  1.79 (+/-0.07) x 10^21 cm^-2, in
excess of the Galactic value of 5.6 x 10^20 cm^-2 (Kalberla et al.
2005). We stress that this fit averages over strong spectral
variations. In fact, the hard-to-soft band ratio during this time
period varies from about 0.5 to about 3. The PC mode spectrum has a
photon index of 2.19 (+/-0.08) and a best-fitting absorption column of
2.14 (+0.22, -0.21) 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 (6.0 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.14 (+0.22, -0.21) x 10^21 cm^-2
Galactic foreground: 5.6 x 10^20 cm^-2
Excess significance: 16.8 sigma
Photon index:      2.19 (+/-0.08)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00456967.

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


GRB_name: GRB110709B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12143
SUBJECT: GRB 110709B: burst detection from Swift-BAT slew data
DATE:    11/07/10 22:39:52 GMT
FROM:    Antonio Copete at Harvard U  <acopete@head.cfa.harvard.edu>

A. Copete, J. Grindlay (Harvard)
S. Barthelmy, C. Markwardt, N. Gehrels (NASA/GSFC)

We report the detection of the early emission from GRB 110709B (GCNs 12122, 12124) by the BAT Slew Survey (BATSS) in the slew that started at 21:32:53 UT and lasted 55 sec, immediately following the original on-board detection. The ground-calculated position is RA, Dec = 164.654, -23.464 deg, which is
 RA  (J2000) = 10h 58m 37.0s
 Dec (J2000) = -23d 27' 51"
with an uncertainty of 1.8 arcmin (90% confidence radius, incl. systematics). The trigger was issued as a result of simultaneous independent detections of 44.0 and 31.3 sigma from imaging in the 15-50 keV and 50-150 keV energy bands, respectively. The burst mask-tagged lightcurve in the 15-150 keV band shows a fading profile with several overlapping peaks within it, from the start of the the slew at T+14s until fading into the background at T+48s during the course of the slew.

The time-averaged spectrum over the 34 sec duration of the burst within the slew is best fit by a power law with an exponential cutoff, with photon index 1.06 +- 0.18, and Epeak of 175.7 (+151.3/-44.5) keV. The fluence in the 15-150 keV band is 4.9 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux (from T+17.0s, 15-150 keV) is 3.35 +- 0.25 photons/cm2/sec. All errors are quoted at 90% confidence level.

The analysis software for the BAT Slew Survey has undergone a thorough revision, and its burst-finding function to process downlinked slew data and issue automated real-time alerts is now fully operational. At the current rate of ~80 ksec of instrument exposure time downlinked per month (about 30% of all slew data), it is expected to to detect ~0.5 new bursts per month, separate from those already detected in pointing mode. BATSS alert notices are distributed through the GCN:
http://gcn.gsfc.nasa.gov/gcn/swift.html#tc2x2


GRB_name: GRB110709B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12144
SUBJECT: GRB 110709B BAT refined analysis
DATE:    11/07/10 23:00:09 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@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),
A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU/NASA/GSFC), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+1608 sec, we report further analysis
of BAT GRB 110709B (triggers #456967 and #456969) (Cummings, et al.,
GCN Circ. 12122, Barthelmy, et al., GCN Circ. 12124, and Barthelmy, et
al., GCN Circ. 12130), where T is the time of the first trigger.

The BAT ground-calculated position for the second event (trigger #456969)
is RA, Dec = 164.655, -23.456 deg which is
      RA(J2000)  =  10h 58m 37.3s
      Dec(J2000) = -23d 27' 20.9"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.  This position is 1.0 arcmin from the ground-
calculated position of the first event (trigger #456967), which had an
estimated uncertainty of 1.1 arcmin.  The position of 456969 is
0.07 arcmin from the enhanced XRT position (Beardmore et al., GCN Circ
12136).  The two events are clearly from the same object.

The main emission in the first event lasted from about T-28 sec to
T+55 sec with a faint declining emission detectable to about T+180 sec.
T90 (15-350 keV) of the first event was 55.6 +- 3.2 sec.  There was no
flux detectable in BAT from about T+180 to about T+485 sec.  The second
event lasted from T+485 sec to T+865 sec with a variety of peaks and
spikes on top of an ongoing emission.  T90 (15-350 keV) of the second
event was 259.2 +- 8.8 sec (estimated error including systematics).
Considering the two events as a whole, T90 was about 846 +- 6 seconds.
The lightcurve of the second event was clearly different from the first,
so the unusual separation of two episodes of bright emission was not the
result of gravitational lensing.

The separation of episodes is unusual but not unprecedented. For instance,
GRBs 041219A, 060124, 070721B, and 050820A also had multiple episodes
separated by long intervals with no detectable emission.

The source came into the BAT FOV at ~T-75 (during a slew that started at
T-200sec and settled at ~T-20 sec.).  The source was above the Earth
horizon for about 20 minutes prior to trigger 456967.  We cannot rule out
faint or soft emission prior to about T-75 sec, but for 20 minutes prior
to the first trigger, there was no strong emission above about 50 keV.

The time-averaged spectrum of the data for the first trigger, trigger
#456967, from T-27.4 to T+46.7 sec is best fit by a simple power-law model.
The power law index of the time-averaged spectrum is 1.29 +- 0.04.  The
fluence in the 15-150 keV band is 9.4 +- 0.2 x 10-6 erg/cm2.  The 1-sec
peak photon flux measured from T+13.59 sec in the 15-150 keV band is
3.4 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The time-averaged spectrum from T+518.5 to T+855.3 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
1.44 +- 0.04 x 10^-05 erg/cm2.  The 1-sec peak photon flux measured from
T+1.06 sec in the 15-150 keV band is 3.9 +- 0.2 ph/cm2/sec.  All the quoted
errors are at the 90% confidence level.

Examination of archival pre-trigger data from when the location of
GRB 110709B was in the BAT field of view reveals no significant precursor
emission.  In the two observations closest in time to the trigger,  upper
limits are set at 0.005 ct/s/cm2 (T-6903 to T-6345 sec) and 0.004 ct/s/cm2
(T-12526 to T-11986 sec) and T-6903 to T-6345 sec).  There is also no
emission detected in daily averages going back to 2011 June 1, with an
average upper limit of 0.002 ct/s/cm2 (~8 mCrab).  All errors are 1-sigma
for the 15-50 keV energy band.

In the 70-month averaged BAT Hard X-ray Survey, the three-sigma upper limit
at the position of the XRT counterpart for GRB 110709B is
6.4e-12 ergs/cm2/sec in the 14-195 keV band.

The results of the batgrbproduct analysis are available at
     Trigger 456967:  http://gcn.gsfc.nasa.gov/notices_s/456967/BA/
     Trigger 456969:  http://gcn.gsfc.nasa.gov/notices_s/456969/BA/
   http://gcn.gsfc.nasa.gov/notices_s/comb_456967_456969/BA/top.html


GRB_name: GRB110708A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12145
SUBJECT: GRB 110708A: Konkoly observations
DATE:    11/07/10 23:41:05 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 INTEGRAL GRB 110708A (Gotz et al., GCN 12112) using
the Swift-XRT position provided by Valerio D'Elia. (GCN 12115) with a 60/90 cm
Schmidt telescope located at the Mountain Station of the Konkoly Observatory. We
coadded 6 red sensitive CCD images without filter with 300 sec exposure time
each. On the coadded frame we checked the position RA=22:40:27.33,
dec=+53:57:42.8 (J2000) provided by Daniel Perley (GCN 12116). Very near to
Perley's position, at RA=22:40:27.24, dec=+53:57:43.6 (J2000) we found a faint
marginally visible source which can be identical to Perley's object. Due to
the effect of the nearby dense asterism exact photometry was not possible. The
brightness of this source according to our estimation (based on nearby UCAC-3
stars) is 23 +/-.5 magnitude in R the band. If Perley's and our object are
identical we can suggest a fading nature for this source.   


Time from
the trigger    magnitude       Band
----------------------------------------
154435 sec      23 +/- 0.5      R       marginal detection 


GRB_name: GRB110709A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12146
SUBJECT: GRB 110709A: Konkoly observations
DATE:    11/07/11 00:52:33 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 110709A (trigger=456939) S. T. Holland et al.
(GCN 12118) using the enhanced Swift-XRT position provided by P. A. Evans.
(GCN 12119) with a 60/90 cm Schmidt telescope located at the Mountain Station
of the Konkoly Observatory. We coadded 6 red sensitive CCD images without
filter with 300 sec exposure time each. On the coadded frame we checked the
position RA (J2000) = 15:55:33.86 Dec (J2000) = +40:55:28.0 provided by J. P.
Osborne et al. (GCN 12123). We found a faint marginaly visible source at the
position RA (J2000) = 15:55:33.96 Dec (J2000) = +40:55:27.7 within the error
circle of the astrometricaly corrected X-ray position. Based on nearby UCAC-3
stars the brightness of this object in the R band is 21.4 +/- 0.2  magnitude.    


Time from
the trigger    magnitude       Band
----------------------------------------
27374 sec      21.4 +/- 0.2      R      
 


GRB_name: GRB110709A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12148
SUBJECT: GRB 110709A: Swift/UVOT Upper Limits   
DATE:    11/07/11 18:54:50 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/USRA/GSFC)
reports on behalf of the Swift/UVOT team:

      The Swift/UVOT observed the field of GRB 110709A starting 56 s
after the BAT trigger (Holland et al., 2011, GCNC 12118).  Settled
observations started at 74 s.  We do not detect an optical afterglow
at the UVOT-enhanced XRT position (Osborne, et al., 2011, GCNC 12123)
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  ESPOSURE       Mag
---------------------------------------------------
white (FC)       74         224       147     >21.7
    u (FC)      287         536       246     >21.0
white (FC)      865        1014       147     >21.8
---------------------------------------------------
    v           616        7409       549     >20.9
    b           542      19,323      2148     >22.5
    u           287      18,560      2337     >22.2
 uvw1           666      17,646      1383     >21.7
 uvm2          5978        7614       393     >20.7
 uvw2           591        7204       490     >21.2
white            74      13,546      1538     >23.1
---------------------------------------------------

     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} = 0.02 mag, Schlegel et al. 1998, ApJS,
500, 525).


GRB_name: GRB110708B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12150
SUBJECT: IPN triangulation of GRB 110708B (long duration, extremely intense)
DATE:    11/07/12 03:40:05 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,

J. Goldsten on behalf of the MESSENGER GRNS GRB 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:

On 2011 July 8 at about 13:59:46 UT, an extremely intense, long duration 
GRB was observed by Konus-Wind, INTEGRAL (SPI-ACS), MESSENGER, and Swift 
(BAT) (outside the coded field of view).  We have triangulated it to the 
following 3 sigma error box:
  -----------------------------------------------
    RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
  170.382 (11h 21m 32s)   -50.569 (-50d 34' 09")
Corners:
  170.638 (11h 22m 33s)   -50.604 (-50d 36' 14")
  169.949 (11h 19m 48s)   -50.926 (-50d 55' 34")
  170.126 (11h 20m 30s)   -50.534 (-50d 32' 02")
  170.810 (11h 23m 14s)   -50.209 (-50d 12' 32")
-----------------------------------------------

The error box area is 489 sq. arcmin.
The maximum distance between the box corners is 0.9 deg.
This error box may be improved.


GRB_name: GRB110709B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12151
SUBJECT: GRB 110709B: Submm observations from APEX
DATE:    11/07/12 04:59:13 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI), A. Lundgren, C. De Breuck, G. Siringo, R.
Parra and C. Agurto (ESO) report on behalf of a larger collaboration:

We have observed the field of GRB 110709B (Cummings et al. GCN 12122)
using LABOCA/APEX at Chajnantor (Chile) in the 870 micrometer band.
Observations  began on July 11 2011 at 21:31 UT (2.00 days after the
burst), with an on source  time of 106 min and PWV of 0.8mm. We used the
photometric mode, centred at the refined XRT position (Beardmore et al.
GCN 12136).

Initial data reduction, using CRUSH and BoA does no not detect any
significant emission, obtaining a formal flux on the source position of
1.4+/-2.3mJy (3-sigma limit of 6.9mJy).

We acknowledge the effort done by the APEX staff to get the telescope back
into operations after a 3m snow fall at Chajnantor.


GRB_name: GRB110709A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12152
SUBJECT: GRB 110709A: Suzaku WAM observation of the prompt emission
DATE:    11/07/12 09:02:58 GMT
FROM:    Yoshitaka Hanabata at Hiroshima U  <hanabata@hep01.hepl.hiroshima-u.ac.jp>

Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, M. Ohno, Y. Fukazawa
(Hiroshima U.), T. Yasuda, Y. Terada, M. Tashiro, W. Iwakiri,
K. Takahara (Saitama 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 bright long GRB110709A (Swift/BAT trigger #456939, GCN 12118;
Holland et al.) triggered the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 15:24:27.951 UT (=T0).

The observed light curve shows multiple peaks starting at T0 s, ending
at T0+45 s, with a duration (T90) of about 41.5 seconds. The fluence in
100 - 1000 keV was 2.02 (-0.26, +0.10) x 10^-5 erg/cm^2. The 1-s peak
flux measured from T0+7 s was 4.10 (-0.96, +0.10) photons/cm^2/s in the
same range.

Preliminary result shows that the time-averaged spectrum from T0 s to
T0+45 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha       1.37 (-0.61, +0.49), and
 Epeak       431 (-113, +173) keV (chi^2/d.o.f. = 18.0/12).

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: 1.34 (-0.49, +0.74)
and the peak energy Epeak: 407 (-96, +158) keV (chi^2/d.o.f = 17.4/12). 
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: GRB110708B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12153
SUBJECT: Konus-Wind observation of GRB 110708B
DATE:    11/07/12 11:09:16 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 110708B
(localized by IPN: Golenetskii et al., GCN 12150)
triggered Konus-Wind at T0=50386.394s UT (13:59:46.394)

The burst light curve consists of three main pulse groups,
with a total duration of ~60 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/GRB110708_T50386/

As observed by Konus-Wind the burst
had a fluence of (9.4  0.9)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+12.288 s,
of (4.0  0.5)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+47.616 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.78 (-0.08, +0.08),
the high energy photon index beta = -2.4 (-0.2, +0.15),
the peak energy Ep = 294(-28, +30) keV,
chi2 = 67.8/84 dof.

The spectrum at the maximum count rate
(measured from T0+12.544 to T0+12.580 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.55 (-0.12, +0.14),
the high energy photon index beta = -3.3 (<-2.9),
the peak energy Ep = 586(-81, +97) keV,
chi2 = 33.3/47 dof.
This spectrum is equally well fitted
by a power law with exponential cutoff model, for which
alpha = -0.59 (-0.07, +0.07),
and Ep = 617(-69, +82) keV,
chi2 = 34.2/48 dof.

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


GRB_name: GRB110709B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12155
SUBJECT: GRB 110709B: Additional Gemini observations and deep limits on an optical afterglow
DATE:    11/07/14 01:20:27 GMT
FROM:    Wen-fai Fong at CFA  <wfong@cfa.harvard.edu>

W. Fong and E. Berger (Harvard) report:

"We re-observed the location of GRB 110709B (GCNs 12122, 12124) with GMOS on
the Gemini-South 8-m telescope starting on 2011 July 13.958 UT (4.1 days
after the initial trigger).  Images were obtained in mediocre seeing
(1.35").  In a stack of 5x180 sec r-band exposures we still detect sources
S1 and S2 (GCNs 12126, 12128, 12129, 12132). Neither source exhibits
evidence for fading in photometry relative to several nearby stars, and in
digital image subtraction using the ISIS package.  We further note that both
S1 and S2 are located outside of the refined XRT error circle (GCN 12136).

We do not detect any other sources within the refined XRT circle in either
of our Gemini epochs to a limit of >23.8 mag at delta-t=3.2 hours and >25.1
mag at 4.1 days.  A comparison to the X-ray flux density at 3.2 hours
(F_nu,X ~ 12 microJy**) requires a spectral index of beta_OX > 0.4 for F_nu
~ nu^beta.  This is a highly unusual spectral index since typical values are
beta_OX ~ -0.6 to -1, and events with beta_OX > -0.5 are considered "dark
bursts".  Such an unusual spectral index may be indicative of a high
redshift origin (z>4.5 based on r-band non-detection) or a non-GRB origin
similar to the recent GRB 110328A."

** http://www.swift.ac.uk/xrt_curves/00456967/

[GCN OPS NOTE(14jul11): Per author's request, the missing footnote was added.]


GRB_name: GRB110709A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12156
SUBJECT: GRB 110709A / EVLA upper limits
DATE:    11/07/14 06:10:34 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

A. Zauderer, E. Berger, and W. Fong (Harvard) report on behalf of a 
larger collaboration:

We observed the position of GRB 110709A (GCN #12118) with the EVLA at
5.8 GHz and 22 GHz starting on 2011 July 10.12 UT (~12 hours after the
burst).  In ~20 min integration time on source at each frequency, no
radio source is detected within the XRT error circle (GCN #12123) to a
3-sigma limit of 60 microJy/bm (5.8 GHz) and 104 microJy/bm (22 GHz).

We acknowledge the EVLA staff for their support of these observations.


GRB_name: GRB110709B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12157
SUBJECT: GRB 110709B: Swift/UVOT Observations 
DATE:    11/07/15 12:00:00 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) and
J. R. Cummings (CRESST/UMBC/GSFC)
report on behalf of the Swift/UVOT team:

      The Swift/UVOT observed the field of GRB 110709B starting 70 s
after the BAT trigger (Cummings et al., 2011, GCNC 12122).  Settled
observations started at 91 s.  We do not detect a source at the
UVOT-enhanced XRT position (Beardmore, et al., 2011, GCNC 12136) 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
---------------------------------------------------
white (FC) &     91 &       241 &     147 &   >21.1
    u (FC) &    303 &       553 &     246 &   >20.5
white (FC) &    858 &      1008 &     147 &   >21.3
---------------------------------------------------
    v     &     633 &    64,817 &    3519 &   >21.5
    b     &     558 &    54,124 &    3664 &   >22.4
    u     &     303 &    59,906 &    4680 &   >22.2
 uvw1     &     682 &    59,264 &    4730 &   >22.2
 uvm2     &    1235 &    58,357 &    3732 &   >22.3
 uvw2     &     782 &    64,122 &    3530 &   >22.4
white     &      91 &    30,997 &    3107 &   >23.0
---------------------------------------------------

     We find weak evidence for variability at the location of the
USNO-B1.0 source 3.5 arcsec WNW of the XRT position at the time of the
second BAT trigger (Barthelmy et al. 2011, GCNC 12124).  Preliminary
photometry is

Filter       TSTART       TSTOP  EXPOSURE       Mag   Err  Sigma
----------------------------------------------------------------
white &          91 &       241 &     147 &   >21.1   3-sigma UL
white &         583 &       776 &      39 &    20.08 0.35    3.3
white &         858 &      1008 &     147 &   >21.3   3-sigma UL
white &        1161 &      2047 &     117 &    20.96 0.36    3.1
white &        6245 &      6444 &     197 &   >21.4   3-sigma UL
white &        7679 &    11,397 &     340 &    21.07 0.37    3.1
white &       11401 &    12,005 &     590 &   >21.9   3-sigma UL
white &       17893 &    18,800 &     885 &    20.98 0.16    7.8
white &       30335 &    30,997 &     644 &    21.39 0.23    5.2
----------------------------------------------------------------

We note that both the USNO-B1.0 source and the XRT position are
located in the coincidence loss halo of a bright star, which makes
precision photometry difficult.  It is not clear if the apparent
variability seen at the location of the USNO-B1.0 source is real or
not.

     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} = 0.05 mag, Schlegel et al. 1998, ApJS,
500, 525).


GRB_name: GRB110715A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12158
SUBJECT: GRB 110715A: Swift detection of a bright burst with an optical counterpart
DATE:    11/07/15 13:26:17 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

E. Sonbas (GSFC/USRA/Adiyaman Univ.), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), V. D'Elia (ASDC), M. De Pasquale (UCL-MSSL),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
C. Guidorzi (U Ferrara), 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),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
S. R. Oates (UCL-MSSL), C. Pagani (U Leicester),
K. L. Page (U Leicester), P. Romano (INAF-IASFPA),
A. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC),
M. H. Siegel (PSU), G. Stratta (ASDC), C. A. Swenson (PSU) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 13:13:50 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110715A (trigger=457330).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 237.660, -46.233 which is 
   RA(J2000) = 15h 50m 38s
   Dec(J2000) = -46d 13' 59"
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 15 sec.  The peak count rate
was ~70,000 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 13:15:21.9 UT, 90.9 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 237.6832, -46.2326 which is equivalent to:
   RA(J2000)  = 15h 50m 43.96s
   Dec(J2000) = -46d 13' 57.3"
with an uncertainty of 5.8 arcseconds (radius, 90% containment). This
location is 57 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 99 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 15:50:44.09 = 237.68370
  DEC(J2000) = -46:14:06.5  = -46.23513
with a 90%-confidence error radius of about 0.62 arc sec. This position is 9.2
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.34 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.59. 

Burst Advocate for this burst is E. Sonbas (eda.sonbas 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: GRB110715A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12160
SUBJECT: GRB 110715A: Swift-BAT refined analysis
DATE:    11/07/15 18:25:58 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),
E. Sonbas (GSFC/USRA/Adiyaman Univ.), M. Stamatikos (OSU), J. Tueller (GSFC),
(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 110715A (trigger #457330)
(Sonbas, et al., GCN Circ. 12158).  The BAT ground-calculated position is
RA, Dec = 237.665, -46.237 deg, which is 
   RA(J2000)  =  15h 50m 39.7s 
   Dec(J2000) = -46d 14' 13.9" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 69%.
 
The mask-weighted light curve shows a bright first peak, which is composed
of at least 2 overlapping peaks (at the lower energies), starting at ~T-10 sec
and peaking at ~T+2.5 sec.  the first peak never returns to basline before
the second and much weaker peak goes from ~T+12 to T+17 sec.
T90 (15-350 keV) is 13.0 +- 4.0 sec (estimated error including systematics).
 
The time-averaged spectrum from T-3.1 to T+20.9 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.25 +- 0.12, 
and Epeak of 120 +- 21 keV (chi squared 49.6 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.18 +- 0.02 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T+1.86 sec in the 15-150 keV band is
53.9 +- 1.1 ph/cm2/sec.  To within the calibration limits, the Band model
fits equally well.  A fit to a simple power law gives a photon index
of 1.63 +- 0.03 (chi squared 81.5 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/457330/BA/


GRB_name: GRB110715A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12161
SUBJECT: GRB 110715A: Enhanced Swift-XRT position
DATE:    11/07/15 18:40:34 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 120 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110715A, 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 = 237.68361, -46.23583 which is equivalent
to:

RA (J2000): 15h 50m 44.07s
Dec (J2000): -46d 14' 09.0"

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

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

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


GRB_name: GRB110715A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12162
SUBJECT: GRB 110715A: Swift/UVOT Detection
DATE:    11/07/15 22:32:12 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N.P.M. Kuin (MSSL-UCL) and E. Sonbas (GSFC/USRA/Adiyaman Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110715A
100 s after the BAT trigger (Sonbas et al., GCN Circ. 12158).

The preliminary UVOT position is:
  RA  (J2000) =  15:50:44.09 = 237.68369 (deg.)
  Dec (J2000) = -46:14:06.53 = -46.23515 (deg.)
with an estimated uncertainty of 0.56 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits 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              100          249          147         17.37 +/- 0.06
u                  312          501          187         17.86 +/- 0.09
b                 3734         3857          121         19.5  +/- 0.3
white             3960         4160          197         19.92 +/- 0.16
uvw2              4166         4366          197        >20.1
v                 4371         4571          197         19.3  +/- 0.3
uvm2              4576         6211          393        >20.3
uvw1              4781         6280          259        >20.1
u                 4986         5186          197         20.1  +/- 0.4
b                 5192         5391          197         19.9  +/- 0.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.59 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110715A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12164
SUBJECT: GRB110715A: VLT redshift
DATE:    11/07/16 05:19:25 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

S. Piranomonte (OAR/INAF), S. D. Vergani (OAB/INAF), D. Malesani, J. P. U.
Fynbo (DARK/NBI), K. Wiersema (Leicester), L. Kaper (Amsterdam) report on
behalf of the X-shooter GRB GTO collaboration:

We observed the optical afterglow of GRB 110715A (Sonbas et al., GCN Circ.
12158) with the ESO VLT equipped with the X-shooter spectrograph.

The optical afterglow is well detected in the R-band acquisition image
(taken on Jul 16.06 UT, i.e. 12.3 hr after the GRB), and has a magnitude
of R = 18.45 assuming R=15.21 for the USNO-B1 star at RA = 15:50:41.62,
Dec = -46:14:25.91.

Spectroscopic observations lasted for about 10 minutes, with a mean time
2011 Jul 16.08 UT (12.7 hr after the GRB). The seeing was about 0.9". We
then had to interrupt our observations due to strong wind.

We detect Ca II and Ca I absorption lines at a common redshift of z=0.82.
The wavelength calibration is based on archival calibration files.

We acknowledge excellent support from the night astronomer at the VLT,
Christophe Martayan, the telescope operator, Claudia Cid, and the shift
leader, Jonathan Smoker.

----------------------------------------------------------------
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GRB_name: GRB110715A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12165
SUBJECT: GRB 110715A: Swift-XRT refined Analysis
DATE:    11/07/16 06:54:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester) and E. Sonbas (GSFC/USRA/Adiyaman Univ.)
report on behalf of the Swift-XRT team:

We have analysed 4.2 ks of XRT data for GRB 110715A (Sonbas  et al. GCN
Circ. 12158), from 79 s to 29.4 ks after the  BAT trigger. The data
comprise 400 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 12161).

The light curve can be modelled with an initial power-law decay with an
index of alpha=0.57 (+/-0.05), followed by a break at T+2415 s to an
alpha of 1.78 (+/-0.13).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.91 (+/-0.07). The
best-fitting absorption column is  4.7 (+0.4, -0.3) x 10^21 cm^-2, in
excess of the Galactic value of 2.9 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.85 (+/-0.13) and a
best-fitting absorption column of 6.0 (+/-0.8) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 5.3 x 10^-11 (8.7 x 10^-11) erg cm^-2
count^-1.

A summary of the PC-mode spectrum is thus:
Total column:      6.0 (+/-0.8) x 10^21 cm^-2
Galactic foreground: 2.9 x 10^21 cm^-2
Excess significance: 12.6 sigma
Photon index:      1.85 (+/-0.13)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00457330.

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


GRB_name: GRB110715A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12166
SUBJECT: Konus-Wind observation of GRB 110715A
DATE:    11/07/16 10:11:53 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 bright GRB 110715A (Swift-BAT trigger #457330:
Sonbas et al., GCN 12158; Ukwatta et al., GCN 12160)
triggered Konus-Wind at T0=47635.304s UT (13:13:55.304)

The burst light curve shows a bright pulse, which peaked at T0+2s,
and a much weaker pulse at ~T0+11s.
A total burst duration is ~20 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/GRB110715_T47635/

As observed by Konus-Wind the burst
had a fluence of (2.3  0.2)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.984 s,
of (1.1  0.1)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+18.432 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.23 (-0.08, +0.09),
the high energy photon index beta = -2.7 (-0.5, +0.2),
the peak energy Ep = 120(-11, +12) keV,
chi2 = 85.8/84 dof.

The spectrum at the maximum count rate
(measured from T0+0.256 to T0+2.048 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 (-0.11, +0.11),
the high energy photon index beta = -3.6 (<-3.0),
the peak energy Ep = 148(-10, +11) keV,
chi2 = 51.5/55 dof.

Assuming the VLT redshift z = 0.82 (Piranomonte et al., GCN 12164)
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 (4.1  0.4)x10^52 erg,
the peak luminosity L_iso_max is (3.9  0.2)x10^52 erg/s,
and Ep_rest is 220  20 keV.

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


GRB_name: GRB110715A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12168
SUBJECT: GRB 110715A: APEX detection of the submm counterpart
DATE:    11/07/17 02:08:00 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI), A. Lundgren, F. Mac-Auliffe,
F.M. Montenegro, D.A. Garca-Appadoo, I. de Gregorio-Monsalvo,
S. Martin, C. De Breuk (ESO), P. Bergman, M. Hajigholi (OSO),
C.C. Thoene, J. Gorosabel, A.J. Castro-Tirado (IAA-CSIC),
J.P.U. Fynbo (DARK/NBI) and S. Covino (INAF-OAB) report on
behalf of a larger collaboration:

We have observed the field of GRB 110715A (Sonbas et al. GCN 12158)
using LABOCA/APEX at Chajnantor (Chile) in the 870 micrometer band.
The weather conditions were good, with a precipitable water vapor
of 0.62mm. Observations began on July 16 at 23:21 UT (1.42 days after
the burst) and were performed using the photometric mode, centred at
the position of the optical counterpart (Kuin et al. GCN 12162,
Piranomonte et al. GCN 12164).

On a preliminary analysis of 88 minutes on source we detect a flux at
the position of the afterglow of 11.0+/-2.3 mJy.

Further observations are foreseen. We encourage follow-up in other
wavelengths.


GRB_name: GRB110715A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12169
SUBJECT: GRB110715A: GROND Detection of the Optical/NIR Afterglow
DATE:    11/07/18 17:16:47 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

A. C. Updike (NASA/GSFC), P. Schady, J. Greiner (both MPE Garching),  
T. Kruehler (DARK/NBI), D. A. Kann, S. Klose and A. Rossi (all TLS  
Tautenburg) report on behalf of the GROND team:

We observed the field of GRB 110715A (Swift trigger 457330; Sonbas et  
al., GCN #12158) 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 00:35 UT on 18th July, lasting just under 2hrs  
and with a midtime ~3dys after the GRB trigger. They were performed at  
an average seeing of 1.1" and at an average airmass of 1.

We found a single point source within the 2.2" Swift-XRT error circle  
reported by Evans et al. (GCN #12161), consistent with the UVOT  
position (Kuin et al., GCN #12162).

Based on 4136s of total exposures in g'r'i'z' and 4320s in JHK, we  
estimate preliminary magnitudes (all AB system) of

g' = 22.59 +/- 0.09
r' = 21.22 +/- 0.02
i' = 20.53 +/- 0.02
z' = 19.93 +/- 0.02
J = 19.56 +/- 0.24
H = 18.79 +/- 0.17
K = 18.86 +/- 0.31

Given optical and NIR magnitudes are calibrated against GROND  
zeropoints and 2MASS field stars, respectively, and are not corrected  
for the expected Galactic foreground extinction corresponding to a  
reddening of E(B-V)=0.60 mag in the direction of the burst (Schlegel  
et al. 1998).


GRB_name: GRB110715A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12171
SUBJECT: GRB 110715A: ATCA detection of the radio counterpart
DATE:    11/07/19 00:27:05 GMT
FROM:    Tara Murphy at U.Sydney  <tara@physics.usyd.edu.au>

Paul J. Hancock, Tara Murphy (U of Sydney) and Brian P. Schmidt (ANU)

We observed GRB 110715A (GCN 12158) with the Australian Telescope
Compact Array (ATCA) on July 18 at 12.2 UT (~3 days after the GRB trigger).

We find a single unresolved radio source consistent with the UVOT
position (GCN 12162). The source has a measured flux density of
2.4 +/- 0.1 mJy/beam at 44.00 GHz.

Further observations are planned. We thank the observatory staff for
scheduling and supporting these observations.


GRB_name: GRB110709B
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12172
SUBJECT: GRB 110709B : Suzaku WAM observation of the prompt emission
DATE:    11/07/19 01:12:55 GMT
FROM:    Norisuke Ohmori at Miyazaki U  <ohmori@astro.miyazaki-u.ac.jp>

N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), M. Ohno,
Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, Y. Fukazawa (Hiroshima U.), 
K. Yamaoka (Aoyama Gakuin U.), S. Sugita (Nagoya U.), T. Yasuda, Y. Terada, 
M. Tashiro, W. Iwakiri, K. Takahara (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 long GRB110709B (Swift/BAT trigger #456967, GCN 12122 ; Cummings et al.,) 
triggered the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 21:32:44.453 UT (=T0).

The observed light curve shows multiple peaks starting at T0-10 s, ending
at T0+40 s, with a duration (T90) of about 48 seconds. The fluence in
100 - 1000 keV was 1.53 (-0.16, +0.29) x 10^-5 erg/cm^2. The 1-s peak
flux measured from T0+25.5 s was 1.70 (-0.43, +0.30) photons/cm^2/s in the
same range.

Preliminary result shows that the time-averaged spectrum from
T0-12 s to T0+40 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha       0.61 (-1.16, +0.95), and
 Epeak       286 (-80, +41) keV (chi^2/d.o.f. = 12.6/14).

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: GRB110719A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12173
SUBJECT: GRB 110719A: Swift detection of a burst
DATE:    11/07/19 06:22:14 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

T. Sakamoto (NASA/UMBC), A. P. Beardmore (U Leicester),
J. R. Cummings (NASA/UMBC), M. De Pasquale (UCL-MSSL),
C. Guidorzi (U Ferrara), O. M. Littlejohns (U Leicester),
C. B. Markwardt (NASA/GSFC), S. R. Oates (UCL-MSSL),
C. Pagani (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. Rowlinson (U Leicester),
C. J. Saxton (UCL-MSSL) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 06:09:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110719A (trigger=457553).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 24.564, +34.572 which is 
   RA(J2000) = 01h 38m 15s
   Dec(J2000) = +34d 34' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single noisy
FRED structure with a duration of about 50 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~T-1 sec after the trigger. 

The XRT began observing the field at 06:11:03.1 UT, 111.3 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 24.5799, +34.5869 which is equivalent to:
   RA(J2000)  = 01h 38m 19.17s
   Dec(J2000) = +34d 35' 12.8"
with an uncertainty of 5.6 arcseconds (radius, 90% containment). This
location is 71 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 121 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
0.04. 

Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto 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: GRB110715A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12174
SUBJECT: GRB 110715A optical observations
DATE:    11/07/19 12:16:46 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Peter Nelson (Ellinbank, Victoria, Australia) reported to the AAVSO 
International High Energy Network the following optical observations of 
GRB 110715A (Sonbas et al., GCN #12158):

P. Nelson (Ellinbank Observatory, Ellinbank, VIC, Australia) reports a 
detection of GRB 110715A from fifteen frames of 30-seconds exposure each 
taken with a clear filter through a 0.32-cm PlaneWave f/8 CDK and SBIG 
ST8XE camera. The magnitude derived from all frames is m(CR) = 18.0 +/- 
0.2 at the mid-point exposure time of 2011 July 15 14:05:01 UT. 
Magnitudes were measured relative to the USNO-B1.0 comparison star at RA: 
15:50:41.62, Decl: -46:14:25.91 with magnitude R=15.21 (see Piranomonte et 
al., GCN #12164).

Nelson reports that time-series was obtained by averaging the 15 frames 
into three consecutive groups of five frames, yielding the following 
magnitudes:

Time (UT) Mag (Clear, R zeropoint)
13:54:23 18.01 +/- 0.18
14:05:28 17.93 +/- 0.15
14:15:12 18.47 +/- 0.25

The position derived from these images is RA: 15:50:44.07, Decl: 
-46:14:06.5, which is fully consistent with the optical position given by 
Kuin et al. (GCN #12162).

The AAVSO International High Energy Network was made possible through 
grants from the Charles Curry Foundation and from NASA.


GRB_name: GRB110719A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12175
SUBJECT: GRB 110719A: Swift-BAT refined analysis
DATE:    11/07/19 14:59:21 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), 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 the recent telemetry downlink,
we report further analysis of BAT GRB 110719A (trigger #457553)
(Sakamoto, et al., GCN Circ. 12173).  The BAT ground-calculated position is
RA, Dec = 24.570, 34.578 deg, which is 
   RA(J2000)  =  01h 38m 16.8s 
   Dec(J2000) = +34d 34' 39.0" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.
 
The mask-weighted light curve shows a FRED-like peak starting at ~T-5 sec,
peaking at ~T+1 sec, and returning to background around T+95 sec.
T90 (15-350 keV) is 41.0 +- 7.4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-2.0 to T+42.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.63 +- 0.15.  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+2.02 sec in the 15-150 keV band
is 1.3 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/457553/BA/


GRB_name: GRB110719A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12176
SUBJECT: GRB 110719A: Enhanced Swift-XRT position
DATE:    11/07/19 15:43:09 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 1852 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110719A, 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 = 24.58085, +34.58616 which is equivalent
to:

RA (J2000): 01h 38m 19.40s
Dec (J2000): +34d 35' 10.2"

with an uncertainty of 2.5 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: GRB110719A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12177
SUBJECT: GRB 110719A: optical upper limit
DATE:    11/07/19 15:54:18 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (SAI MSU), L. Elenin (ISON), I. Molotov (ISON), A. Pozanenko 
(IKI) report on behalf of larger GRB  follow-up collaboration:

We observed the field of  GRB 110719A (Sakamoto  et al. GCN 12173) with 
0.45-m telescope f ISON-NM observatory  on  July 19 starting (UT) 06:54:39. 
We took 30 unfiltered images.  In a stacked image we do not detect any 
source within enhanced XRT error circle (Goad et al., GCN 12176) up to 
19.7m.  The photometry is based on the USNO-B1.0  1245-0023215 star 
(RA=01:38:11.95, Dec=+34:35:52.6) assuming R=13.72.

T0+         Filter,   Exposure, OT,   Upper Limit
(mid, d)               (s)

0.04370  none     30x60s     n/d    19.7


GRB_name: GRB110719A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12178
SUBJECT: GRB 110719A: Swift-XRT refined Analysis
DATE:    11/07/19 15:57:30 GMT
FROM:    Claudio Pagani at U of Leicester  <cp232@star.le.ac.uk>

C. Pagani (U. Leicester) and T. Sakamoto (NASA/UMBC) report on behalf
of the Swift-XRT team:

We have analysed 4.5 ks of XRT data for GRB 110719A (Sakamoto  et al.
GCN Circ. 12173), from 117 s to 12.1 ks after the  BAT trigger. The
data comprise 258 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN. Circ 12176).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=0.59 (+0.26, -0.30). At T+219 s  the decay
steepens to an alpha of 2.6 (+/-0.4) before breaking again at T+1393 s
to a final decay with index alpha=0.7 (+0.7, -0.6).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.39 (+0.13, -0.12). The
best-fitting absorption column is  9.0 (+3.8, -3.4) x 10^20 cm^-2, in
excess of the Galactic value of 4.0 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.58 (+0.26, -0.15)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.6 x 10^-11 (4.9 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.0 (+5.9, -0) x 10^20 cm^-2
Galactic foreground: 4.0 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.58 (+0.26, -0.15)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00457553.

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


GRB_name: GRB110719A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12180
SUBJECT: Swift/UVOT observations of GRB110719A
DATE:    11/07/19 18:18:06 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

M. De Pasquale, C.J. Saxton (MSSL-UCL) and T. Sakamoto (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110719A
121 s after the BAT trigger (Sakamoto et al., GCN Circ. 12173).
No optical afterglow consistent with the XRT position (Pagani et al., GCN 
Circ. 12173) is detected in the initial UVOT exposures and in the 
summed exposures taken in all filters.
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           121          271          147  >20.2
u_FC               279          529          246  >19.2
white              121        17904         1080  >21.3
v                 4848        10563         1143  >20.2
b                  535        17151         1101  >21.1
u                  279        16239         1328  >20.5
w1                5258        12124          836  >20.4
m2                5053        11468         1082  >20.8
w2                4643         6280          393  >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110719A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12181
SUBJECT: GRB 110719A: z-band upper limit
DATE:    11/07/19 18:51:56 GMT
FROM:    Stefano Covino at Brera Astronomical Observatory  <stefano.covino@gmail.com>

Andrew J. Levan (Univ. Warwick), Stefano Covino, Andrea Melandri (INAF/ 
OABr), Daniele Malesani, Antonio de Ugarte Postigo, Johan P.U.
Fynbo (DARK/NBI), report on behalf of the X-shooter GRB GTO  
collaboration:

We observed the field of GRB 110719A (Sakamoto et al., GCN 12173) with  
the ESO VLT equipped with X-shooter. We could only take a short
acquisition image, with mean time 2011 July 19.42 UT (3.95 hr after  
the GRB). No new object is detected within the refined XRT error circle
(Goad et al., GCN 12176), down to a limiting magnitude z > 22.5 (AB),  
calibrated against SDSS stars in the field.

We note that the inferred limit on the broad-band spectral slope is  
beta_OX < 0.64 (computed between the z band and 1 keV). Given the hard
X-ray spectral slope beta_X = 0.58 (Pagani et al., GCN 12178), our non  
detection is consistent with the extrapolation of the X-ray spectrum.
Our data do not allow to classify GRB 110719A as dark.


GRB_name: GRB110719A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12182
SUBJECT: GRB 110719A: optical limit by "Pi of the Sky"
DATE:    11/07/19 20:08:19 GMT
FROM:    Marcin Sokolowski at Soltan Inst. Nuc Studies,Warsaw  <marcin.sokolowski@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 ).

The wide field "Pi of the Sky South" apparatus, installed in the private
observatory of Alain Maury in San Pedro de Atacama
( http://grb.fuw.edu.pl/pi/index.html#spda_site.htm ) has observed
the position of GRB 110719A 105s after the GRB.
No new object has been found within the Swift-XRT error box.

t_start - t0    start (UT)   end (UT)     3-sigma limit
   105sec        06:10:56   06:11:06 UT      11.0 mag

The field was observed until 06:29:34 UT, no new object brighter then 11.0
mag was observed. The limit on 20 coadded images is 11.5 mag.

We acknowladge great support received from Alain Maury at SPdA Observatory.


GRB_name: GRB110719A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12183
SUBJECT: GRB 110719A: GRT Optical Observation
DATE:    11/07/19 21:39:46 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori@milkyway.gsfc.nasa.gov>

T. Sakamoto (UMBC/GSFC), D. Donato (UMD/GSFC), N. Gehrels (GSFC),
T. Okajima (GSFC), Y. Urata (NCU)

We observed the field of GRB 110719A detected by Swift (trigger #457553; 
Sakamoto et al., GCN Circ. 12173) with the 14-inch Goddard Robotic 
Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).

A total 127 images of 5 sec exposures were taken in the R filter 
starting from July 19 06:11:29 (UT), about 137 seconds after the trigger 
(92 seconds after the BAT position notice), and stopped on July 19 
06:31:01 (UT).  We do not detect the optical afterglow both in the 
individual images and the stacked image inside the XRT error circle 
(Goad et al., GCN #12176).  The estimated five sigma upper limit of 
the combined image (total exposure of 635 sec) is ~18.2 mag using 
the USNO-B1 catalog.


GRB_name: GRB110715A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12184
SUBJECT: GRB 110715A : Suzaku WAM observation of the prompt emission
DATE:    11/07/20 02:05:47 GMT
FROM:    Norisuke Ohmori at Miyazaki U  <ohmori@astro.miyazaki-u.ac.jp>

N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), 
K. Yamaoka (Aoyama Gakuin U.), M. Ohno, Y. Hanabata, T. Uehara, 
T. Takahashi, M. Mizuno, Y. Fukazawa (Hiroshima U.), S. Sugita (Nagoya U.), 
T. Yasuda, Y. Terada, W. Iwakiri, K. Takahara, M. Asahina, S. Kobayashi, 
M. Tashiro (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 long GRB 110715A (Swift/BAT trigger #457330 ; Sonbas et al., GCN 12158) 
triggered the Suzaku Wide-band  All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 13:13:49.914 UT (=T0).

The observed light curve shows a multi-peaked structure starting at T0,
ending at T0+4s, followed by a weaker emission seen up to T0+20s 
with a duration (T90) of 8 seconds.
The fluence in 100 - 1000 keV was 1.28 (-0.06, +0.07) x10^-5 erg/cm^2.
The 1-s peak flux measured from T0+3s was 20.3 (-1.1, +1.0) photons/cm^2/s 
in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-3s to
T0+20s is well fitted by a single power-law with a photon index
of 2.67 (-0.18, +0.19) (chi^2/d.o.f = 24.0/15).
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: GRB110715A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12185
SUBJECT: GRB110715A: spectral lag analysis
DATE:    11/07/20 13:34:29 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

D. Xu (WIS) reports:

GRB 110715A was detected by Swift/BAT (Sonbas et al., GCN 12158;
Ukwatta et al., GCN 12160),  Konus-Wind (Golenetskii et al., GCN
12166), and Suzaku/WAM (Ohmori et al., GCN 12184). The prompt emission
of this burst has a high photon count rate. And the lightcurve shows a
multi-peaked structure lasting ~5s (i.e., T0+5s, where T0 is the
trigger time), followed by a much weaker emission up to ~T0+20s.
Therefore, the overall T90 duration is ~10s or even a bit longer. On
the other hand, such a lightcurve feature is reminiscent of previous
short bursts with extended tail emissions.

With the redshift z = 0.82 (Piranomonte et al., GCN 12164) and the
cosmological parameters H_0 = 71 km/s/Mpc, Omega_M = 0.27,
Omega_Lambda = 0.73, the isotropic energy release E_iso is (4.1 
0.4)x10^52 erg, the isotropic peak luminosity L_iso,p is (3.9 
0.2)x10^52 erg/s, and the rest-frame \nu_F\nu peak energy Ep_rest is
220  20 keV (Golenetskii et al., GCN 12166). Thus, the values of Eiso
and Ep_rest are well consistent with the Eiso-Ep_rest relation (i.e.,
Amati relation) for long GRBs (or collapsar bursts).

The Swift/BAT data were reduced in a standard way and a CCF method was
used to derive spectral lags upon the lightcurves with 0.064s binning
(Xu et al., ApJ, 696, 971). We found lags of 0.04+/-0.01s (1sigma) for
15-25 V.S. 25-50 keV and 0.04+/-0.01 (1sigma) for 50-75 V.S. 75-350
keV. Thus, this event also fits the Liso-spectral lag relation for
long GRBs.

At z=0.82, searching for an accompanying SN is doable but requires
very deep photometric follow-ups (ref. Tanvir et al., ApJ, 725, 625).


GRB_name: GRB110721A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12187
SUBJECT: GRB 110721A: Fermi GBM detection
DATE:    11/07/21 11:17:24 GMT
FROM:    David Tierney at UCD  <david.tierney@ucd.ie>

D. Tierney (UCD) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team: 

"At 04:47:43.75 UT on 21 July 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110721A (trigger 332916465 / 110721200).

The on-ground calculated location, using the GBM trigger 
data, is RA = 331.42, DEC = -36.42 (J2000 degrees, 
equivalent to 22h 05m, -36d 25'), with an uncertainty 
of 1.00 degree (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 43.00 degrees.

The GBM light curve consists of a fast rise, exponential decay (FRED)
with a duration (T90) of  24.45 s (50-300 keV). 
The time-averaged spectrum from T0-0.32 s to T0+11.97 s is 
best fit by a Band function with Epeak = 372.50 (+26.50/-23.60) keV, 
alpha = -0.94 (+/-0.02), and beta = -1.77 (+/-0.02)
(C-Stat 945.78 for 591 d.o.f.).

The event fluence (10-1000 keV) in this time interval is 
(3.52 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured 
starting from T0+1.98 s in the 10-1000 keV band 
is 31.35 +/- 0.38 ph/s/cm^2.

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


GRB_name: GRB110721A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12188
SUBJECT: GRB 110721A: Fermi-LAT detection
DATE:    11/07/21 15:09:33 GMT
FROM:    Vlasios Vasileiou at LUPM/Fermi-LAT  <Vlasios.Vasileiou@lupm.in2p3.fr>

V. Vasileiou (CNRS/IN2P3/LUPM), F. Piron (CNRS/IN2P3/LUPM), D. Tierney (UCD), A. 
von Kienlin (MPE), S. Guiriec (UAH), and J. L. Racusin (NASA/GSFC) report on 
behalf of the Fermi-LAT team:

At 04:47:45 on July 21, 2011, Fermi-LAT detected high energy
emission from GRB 110721A, which was also detected by Fermi-GBM (trigger 
332916465, Tierney et al. (GCN 12187)), and Integral (SPI ACS
trigger 6326).

The best preliminary LAT on-ground location is found to be (RA, DEC)=
(333.4,-39.0) (J2000; deg) with an error radius of 0.75 (0.51) deg
at 90% (68%) containment (statistical error only), which was 40 deg from the LAT 
boresight at the time of the trigger. We further report that
the Fermi Observatory executed an autonomous repoint maneuver
to follow this trigger for the next 2.5 hours, subject to
Earth-angle constraints.

The data from the Fermi-LAT show a significant increase in the
event rate that is spatially and temporally correlated with the
GBM emission with high significance. This detection was independently
confirmed by the blind on-ground GRB search of the LAT data. More
than 20 (1) photons above 100 MeV (1 GeV) using a standard event
selection and about 1000 photons using a non-standard event
selection sensitive mostly to tens-of-MeV energies are observed
within 20 sec. The lightcurve at tens-of-MeV energies has a Fast Rise 
Exponential Decay (FRED) profile with an ~16 sec duration
similar to the GBM results. The highest energy event has an 1.7 GeV
energy, was observed about 0.7 sec after the trigger, and was
associated to the GRB with a high (>0.9) probability.

Preliminary spectral analyses on the LAT data taken during the
first 20 sec after the trigger resulted in a -2.9+-0.4 spectral index
and a 3.3+-0.8 x 10^-4 ph/cm^2/sec average flux integrated over E>100 MeV. This
spectral index is considerably softer than the extrapolation of the GBM spectral 
index at E>100 MeV energies (Tierney et al. (GCN 12187)), which suggests a 
spectral cutoff or softening of the spectrum.

A Swift Target of Opportunity observation has been requested and tiling 
observations are 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: GRB110719A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12189
SUBJECT: GRB 110719A / SMA 345 GHz upper limits
DATE:    11/07/21 20:55:07 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

A. Zauderer, G. Petitpas and E. Berger (Harvard/CfA) report on behalf of 
a larger collaboration:

"We observed GRB 110719A (GCN #12173) with the SMA at 345 GHz starting 
on 2011 July 19.6 (7.5 hours after the burst) for a total integration 
time on source of 4.6 hours.  No counterpart is detected within the XRT 
error circle (GCN #12176) to a 3-sigma upper limit of 2.1 mJy/bm.

We acknowledge and thank the SMA observatory staff for their support
of these rapid response observations."


GRB_name: GRB110709B
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12190
SUBJECT: GRB 110709B / EVLA detection of radio counterpart
DATE:    11/07/21 22:04:14 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

A. Zauderer and E. Berger (Harvard/CfA) report on behalf of a larger 
collaboration:

"We observed GRB 110709B (GCN 12122) with the EVLA on several occasions 
between 2011 July 11 and 16 UT at a frequency of 5.8 GHz.  Within the 
XRT error circle (GCN 12136) we find a single unresolved radio source 
which brightened by about a factor of 1.6 between 2.1 and 7.0 days after 
the burst.  The source is located at (J2000):

RA =   10:58:37.114
Dec = -23:27:16.760

The coincidence with the XRT position and the rising flux indicate that 
this source is the radio afterglow of GRB 110709B.  No optical 
counterpart is detected at this position in our Gemini r-band 
observations (GCNs 12132, 12155) to a limit of >23.8 mag at 3.2 hours 
and >25.1 mag at 4.1 days.  Along with the bright X-ray counterpart, the 
radio source provides additional support that GRB 110709B is a dark burst.

We thank the EVLA staff for their support of these observations."


GRB_name: GRB110721A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12191
SUBJECT: Konus-Wind observation of GRB 110721A
DATE:    11/07/22 09:48:51 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 bright hard long GRB 110721A
(Fermi-GBM detection: Tierney and von Kienlin, GCN 12187;
Fermi-LAT detection: Vasileiou et al., GCN 12188)
triggered Konus-Wind at T0=17266.887s UT (04:47:46.887)

The burst light curve shows a single FRED-like pulse
with a total duration of ~25 s.
The emission is seen up to ~10 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/GRB110721_T17266/

As observed by Konus-Wind the burst
had a fluence of (8.8  0.9)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.984 s,
of (2.3  0.2)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+26.624 s) can be fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.02 (-0.14, +0.16),
the high energy photon index beta = -1.77 (-0.13, +0.07),
the peak energy Ep = 393(-104, +199) keV,
chi2 = 109.8/84 dof.

The spectrum at the maximum count rate
(measured from T0+0.256 to T0+2.304 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.0 (-0.2, +0.2),
the high energy photon index beta = -2.0 (-0.5, +0.2),
the peak energy Ep = 1130(-490, +550) keV,
chi2 = 74.1/74 dof.

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


GRB_name: GRB110721A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12192
SUBJECT: GRB 110721A: potential counterpart candidate
DATE:    11/07/23 20:37:50 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

J. Greiner (MPE), A.C. Updike (NASA/GSFC), T. Kruehler (DARK/NBI),
V. Sudilovsky (MPE) report:

We have analyzed the first 4 tiles of the Swift/XRT observations on the 
0.75 deg Fermi/LAT radius error box (Vasileiou et al., GCN 12188) of
the bright Fermi/GBM GRB 110721A (Tierney and von Kienlin, GCN 12187).
In the pointing with OBS-ID 00020169 we find a single X-ray source 
at RA(2000.0)=22h14m38.27s, Decl(2000.0)= -38:35:36.3 (+-6.8 arcsec).

We observed this position 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 
06:33 UT on July 22, about 26 hrs after the GRB trigger. They were 
performed at an average seeing of 1.0" and at an average airmass of 1.

We found a single point source within the 6.8" Swift-XRT error circle,
at coordinates

    RA(2000.0)   = 22h 14m 38.19s, 
    Decl(2000.0) = -38d 35' 35.7"

with an uncertainty of +-0.3".

Based on 1840 s of total exposures in g'r'i'z' and 1920 s in JHK, we  
estimate preliminary magnitudes (all AB system) of

g = 24.3 +/- 0.2 
r = 22.9 +/- 0.1
i = 22.3 +/- 0.1
z = 21.8 +/- 0.1
J = 21.0 +/- 0.2
H = 20.5 +/- 0.2
K > 18.8

These optical and NIR magnitudes are calibrated against GROND zeropoints 
and 2MASS field stars, respectively, and are not corrected for the 
expected Galactic foreground extinction corresponding to a reddening of 
E(B-V)=0.016 mag in the direction of the burst (Schlegel et al. 1998).

The spectral energy distribution (SED) is well fit by a powerlaw, typical 
for GRB afterglows. The low-level g'-band flux can either be fit with 
Ly-alpha at a redshift of z~3.2, or host-intrinsic extinction.

We obtained another epoch of observations starting at 6:21 UT on Jul 23,
at an average seeing of 1.4". Within the errors (+-0.2 mag), the object
exhibits the same brightness in both observations.

We note that the chance coincidence to find 1 X-ray source in 4 Swift/XRT
pointings of the given exposure is nearly 100%. Also, the 4 tiles only 
cover 30% of the area of the Fermi/LAT error circle. However, the powerlaw
shape of the SED of the optical/NIR source make this a good candidate
for the counterpart of GRB 110721A. Our second observation is inconclusive,
unfortunately - the non-fading behaviour could either be due to a plateau 
of the emission from the afterglow, or indicate a non-GRB nature.

We suggest spectroscopic observations of this object to reveal its nature.


GRB_name: GRB110721A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12193
SUBJECT: GRB 110721A: Gemini-South spectroscopy of the potential optical counterpart
DATE:    11/07/24 15:11:38 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger (Harvard) reports on behalf of a larger collaboration:

"We obtained spectroscopic observations of the candidate optical counterpart
(GCN 12192) of the LAT burst GRB110721A (GCN 12188) with GMOS on the
Gemini-South 8-m telescope starting on 2011 July 24.20 UT.  A total of 3600
sec was obtained on source with a wavelength coverage of about 4000-8100
ang.  We find two clear absorption features at 5487 and 5436 ang, with a
significant decline in flux at shorter wavelengths, but to a non-zero
level.  The two features match CaII H&K at a redshift of z=0.382, or could
alternatively represent Ly-alpha absorption with the highest redshift being
z=3.512.  No other features are detected at wavelengths corresponding to
other typical lines at either redshift.  Given the detectable flux blueward
of 5430 ang (down to at least 4600 ang), and the fact that the source
appears to be extended in our i-band acquisition image (with seeing of about
0.7"), we consider the possibility that the object is an early-type galaxy
at z=0.382 to be more likely.

We thank Jochen Greiner for sharing a finding chart of GRB110721A from GROND
data."


GRB_name: GRB110721A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12194
SUBJECT: GRB 110721A: Preliminary Swift/UVOT Upper Limits 
DATE:    11/07/25 15:13:56 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/USRA/GSFC), and
C. A. Swenson (PSU)
report on behalf of the Swift/UVOT team:

Swift/UVOT began observations of the field of the weak X-ray source
that may be associated with GRB 110721A (Greiner et al., 2011, GCNC
12192) 54,869 s after the Fermi/GBM trigger (Tierney & von Kienlin,
2011, GCNC 12187).  We do not detect the GROND optical source in the
UVOT images.  Our preliminary upper limits are consistent with the
faint nature of the GROND source.  The 3-sigma UVOT upper limits are

Filter   T_start(s)   T_stop(s)      Exp(s)    Upper Limit
----------------------------------------------------------
v            56,146      56,853         672          >20.8
u            54,867      55,509         632          >21.4
white        55,516      56,158         632          >22.4
----------------------------------------------------------

These upper limits are on the UVOT photometric system of Poole et al.,
2008, MNRAS, 383, 627).  The upper limits are not corrected for the
Galactic extinction due to the reddening of E_{B-V} = 0.02 mag in the
direction of the burst (Schlegel et al., 1998, ApJS, 500, 525).


GRB_name: GRB110721A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12195
SUBJECT: IPN triangulation of GRB 110721A
DATE:    11/07/25 23:50:25 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

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,

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

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

E. Costa, E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci,
I. Lapshov, F. Lazzarotto, L. Pacciani, M. Rapisarda, P. Soffitta, 
for the SuperAGILE team, report:

The Fermi GRB 110721A (GCN 12187, 12188) was also observed by
AGILE MCAL and SuperAGILE (but outside the coded field of view 
of SuperAGILE), INTEGRAL SPI-ACS, Konus-Wind, and MESSENGER GRNS.
We have triangulated it to a preliminary 3 sigma error box whose 
area is 2250 square arcminutes, and whose coordinates are:

Center: RA=332.456 o = 22 h 09 m 49 s  DEC=-38.628 o = -38 o 37 ' 40 "
Corners:  333.674=22 h 14 m 42 s    -38.570=-38 o 34 '  13 "     
          331.191=22 h 04 m 46 s    -38.964=-38 o 57 '  49 "     
          333.709=22 h 14 m 50 s    -38.241=-38 o 14 '  26 "     
          331.240=22 h 04 m 58 s    -38.641=-38 o 38 '  28 "

This error box intersects the LAT error circle to form a joint
error box whose area is approximately 1200 square arcminutes.
A map is posted at ssl.berkeley.edu/ipn3/110721.

The counterpart candidate reported by Greiner et al. (GCN 12192)
lies just outside the IPN error box, making it unlikely that it is
related to the GRB.


GRB_name: GRB110726A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12196
SUBJECT: GRB 110726A: Swift detection of a burst
DATE:    11/07/26 01:48:27 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. A. Wolf (PSU), S. D. Barthelmy (GSFC),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
O. M. Littlejohns (U Leicester), C. B. Markwardt (NASA/GSFC),
A. Melandri (INAF-OAB), C. J. Mountford (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC), C. J. Saxton (UCL-MSSL),
M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.),
M. Stamatikos (OSU/NASA/GSFC), C. A. Swenson (PSU) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 01:30:40 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110726A (trigger=458059).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 286.751, +56.053 which is 
   RA(J2000)  =  19h 07m 00s
   Dec(J2000) = +56d 03' 12"
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 10 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 01:31:38.7 UT, 58.2 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 286.7161,
56.0712 which is equivalent to:
   RA(J2000)  = 19h 06m 51.87s
   Dec(J2000) = +56d 04' 16.3"
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This
location is 95 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (5.60 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 1.8
(+1.73/-1.55) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 59 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 0.08. 

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


GRB_name: GRB110726A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12197
SUBJECT: GRB 110726: ROTSE-III Detection of Optical Counterpart
DATE:    11/07/26 01:53:46 GMT
FROM:    Heather Flewelling at IfA/Hawaii  <flewelling.heather@gmail.com>

GRB 110726A: ROTSE-III Detection of Optical Counterpart

B. E. Schaefer (Louisiana State), W. Zheng (U Mich), H. Flewelling
(IfA/Hawaii), report on behalf of the ROTSE collaboration:

ROTSE-IIId, located at the Turkish National Observatory at
Bakirlitepe, Turkey, responded to GRB 110726 (Swift trigger 458059).
The first image was at 01:31:01.6 UT, 13.8 s after the burst (8.6 s
after the GCN notice time). The unfiltered images are calibrated
relative to USNO A2.0. We detect a new object, not visible in the DSS
(second epoch), with coordinates:

19:06:51.98 +56:04:15.03 (J2000), with positional uncertainty of 1' or better

start UT mag mlim(of image)
----------------------------------
01:31:01.6 16.1 16.9


A jpeg image is available at http://www.rotse.net/images/gsq458059_3d00_img.jpg

This object is very fast fading. Continuing observations are in progress.


GRB_name: GRB110726A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12198
SUBJECT: GRB 110726A: Liverpool Telescope observations
DATE:    11/07/26 03:37:41 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri (INAF-OAB), D. Bersier  and R. Smith (Liverpool JMU)  
report on behalf of a large collaboration:

The 2-m Liverpool Telescope robotically followed up GRB110726A (SWIFT  
trigger 458059; Wolf et al. GCN 12196) starting 190 seconds after the  
GRB trigger time. Initial RINGO2 polarimeter frames detected no  
candidate optical transient. Switching to broad band imaging, we do  
detect an uncatalogued source inside the XRT error circle, consistent  
wih the proposed optical counterpart of Schaefer et al. (GCN Circ.  
12197), in all three SDSS-gri filters. Our preliminary photometry gives:

Mid time from    Total Exp   Filter    Magnitude
trigger (min)    (s)
------------------------------------------------
14.7              10        R      19.0 +/- 0.1
30.0              60        R      19.6 +/- 0.1

20.1              30        I      18.6 +/- 0.1
33.0              60        I      19.1 +/- 0.1
------------------------------------------------

The observed decay is rather shallow (power law index ~0.4) for the  
next 45 minutes, unlike the initial behavior observed by ROTSE.

Magnitudes have been calibrated from the nearby USNOB-1 stars.  
Observations still ongoing.


GRB_name: GRB110726A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12199
SUBJECT: GRB 110726A: Swift/UVOT Detection
DATE:    11/07/26 04:02:40 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@astro.psu.edu>

M.H. Siegel (PSU) and C. A. Wolf (PSU) report on behalf
of the Swift/UVOT team:

Swift/UVOT began observations of the field of GRB 110726A (Wolf et al. 2011,
GCN 12196) 59 seconds after the BAT trigger.  The 150 second finding chart
in the White filter reveals a candidate afterglow in the rapidly available
2.7'x2.7' sub-image at:

 RA(J2000) =     19:06:52.06 = 286.71693
 DEC(J2000) = +56:04:16.6  = 56.0713

with a 90%-confidence error radius of about 0.6 arc sec. This is consistent
with the afterglow reported by both the XRT (Wolf et al.) and ROTSE (Schaefer
et al., 2011, GCN 12197).  The estimated magnitude is 17.80 with a 1-sigma
error of about  0.06. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.08.


GRB_name: GRB110726A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12200
SUBJECT: GRB 110726A: Enhanced Swift-XRT position
DATE:    11/07/26 10:30:39 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 629 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110726A, 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 = 286.71752, +56.07123 which is equivalent
to:

RA (J2000): 19h 06m 52.21s
Dec (J2000): +56d 04' 16.4"

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: GRB110726A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12201
SUBJECT: GRB 110726A: Swift-BAT refined analysis
DATE:    11/07/26 11:38:19 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),
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), T. N. Ukwatta (MSU), C. A. Wolf (PSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+572 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110726A (trigger #458059)
(Wolf, et al., GCN Circ. 12196).  The BAT ground-calculated position is
RA, Dec = 286.713, 56.070 deg which is 
   RA(J2000)  =  19h 06m 51.2s 
   Dec(J2000) = +56d 04' 11.0" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows a single peak starting at ~T-1 sec,
peaking at ~T+2 sec, and ending at ~T+5 sec.  T90 (15-350 keV) is
5.2 +- 1.1 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.9 to T+5.0 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.64 +- 0.87, 
and Epeak of 46.5 +- 11.8 keV (chi squared 79.8 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 2.2 +- 0.3 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+0.61 sec in the 15-150 keV band is
1.0 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.86 +- 0.18 (chi squared 87.7 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/458059/BA/


GRB_name: GRB110726A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12202
SUBJECT: GRB110726A: Gemini-N tentative redshift
DATE:    11/07/26 17:19:31 GMT
FROM:    Antonino Cucchiara at LBNL  <acucchiara@lbl.gov>

A. Cucchiara (UC Santa Cruz), J. S. Bloom and S. B. Cenko (UC Berkeley) 
report on behalf of a larger collaboration:

"We observed the field of GRB 110726A at 06:14 UT (~0.19 days 
after the burst) with the GMOS camera mounted on the 
Gemini-North telescope.

We obtained a sequence of 2x900 seconds spectra centered at 
6000 Angstrom and covering 4000-8100A wavelength range.
The object is well detected and present a featureless continuum 
except for a weak double line which we interpret as a signature 
of MgII 2796,2803 at redshift z = 1.036. 

No other clear features are detected.
Therefore, we suggest 1.036 < z < 2.7 as redshift range for 
GRB 110726A.

We thank the Gemini-N staff for performing this observation,
in particular J. Holt."


GRB_name: GRB110726A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12203
SUBJECT: GRB 110726A: Further Swift/UVOT Observations
DATE:    11/07/26 19:00:16 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@astro.psu.edu>

B.L. Porterfield (PSU), M.H. Siegel (PSU) and C.A. Wolf (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB
110726A 60 s after the BAT trigger (Wolf et al., GCN Circ. 12196).
A fading source consistent with the XRT position is detected in
the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  19:06:52.08 = 286.71700 (deg.)
    Dec (J2000) = +56:04:16.5  =  56.07126 (deg.)
with an estimated uncertainty of 0.51 arc sec. (radius, 90%
confidence).

Preliminary detections and 3-sigma upper limits using the UVOT
photometric system (Poole et al. 2008, MNRAS, 383, 627) for the
early exposures are listed below.

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

white fc          60          210        147      17.84 +/- 0.04
white           6348         6520        169     >20.85
v                602        11374        806      20.61 +/- 0.27
b                528         6344        235      20.44 +/- 0.22
u fc             272          522        246      18.41 +/- 0.08
u               5938        17370       1081     >21.25
w1               653         5934        216     >20.5
m2               628        12301        825     >21.1
w2               578        10448        649     >21.5

The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.08 in the direction
of the burst (Schlegel et al. 1998).


GRB_name: GRB110726A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12204
SUBJECT: GRB110726A: MITSuME Ishigakijima Optical Observation
DATE:    11/07/27 00:03:12 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 110726A (Wolf et al., GCN 12196)
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 12:56:13 UT (~11.4 h after the burst). We
detected the previously reported afterglow (Schaefer et al., GCN 12197;
Melandri et al., GCN 12198) in Rc bands.

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
----------------------------------------------------------------------
0.53142    14:15:55    7020.0   >22.3  21.8  0.2   >20.7
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110726A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12205
SUBJECT: GRB 110726A: ROTSE-III refined analysis, fast decay in early phase
DATE:    11/07/27 00:49:50 GMT
FROM:    Weikang Zheng at U.of Michigan  <zwk@umich.edu>

W. Zheng (U Mich), B. E. Schaefer (Louisiana State), H. Flewelling
(IfA/Hawaii), report on behalf of the ROTSE collaboration:

Further analysis to the early optical observations of GRB 110726A from
ROTSE-IIId (Schaefer et al. GCN 12197) shows that, the OT decayed
quickly in early time after ~140s. The OT is detected in our first
co-added of 10 images (14s -142s) with magnitude ~16.1 +/- 0.2. However,
in our second co-added of 10 images (150s - 429s), and afterward
observations, the OT had faded to below our limiting magnitude of ~18.0,
this gives a decay index larger than -1.7, which is much steeper than
the later decay index reported by Melandri et al. (GCN 12198) of ~-0.4
15 minutes after the burst. We summarize the result below:

t_start t_stop mag    err detection?     number of co-added images

 14.0    74.0  16.1   0.3 Yes            5
 82.0   142.0  16.1   0.3 Yes            5
150.0   285.0  17.8   -   Upper limit    5
293.0   429.0  17.8   -   Upper limit    5


GRB_name: GRB110726A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12206
SUBJECT: GRB 110726A: IAC80 R-band observations
DATE:    11/07/27 02:09:41 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

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

"We carried out R-band observations of the GRB 110726A XRT error circle (Osborne et al., GCNC 12200) with the 0.82m IAC80 telescope at the Observatorio del Teide, Tenerife. A single exposure of 600s taken on July 26.19673-26.20367 UT (3.21-3.38 hours post GRB) shows the optical afterglow (Schaefer et al., GCNC 12197) at a preliminary magnitude of R~20.8. We used as photometric reference the R=18.06 USNO B1.0 star 1460-0295684, located at RA(J2000)=19:06:51.534, DEC(J2000)=+56:04:41.20."


GRB_name: GRB110726A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12207
SUBJECT: GRB 110726A:  EVLA observations
DATE:    11/07/27 03:30:03 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

A. Zauderer, E. Berger (Harvard/CfA), and D. A. Frail (NRAO) report on 
behalf of a larger collaboration:

"We observed GRB 110726A (GCN 12196) with the EVLA beginning on 2011 
July 26.19 UT (3.1 hours after the burst) at 5.8 GHz.  No source is 
detected in coincidence with the optical counterpart (GCNs 12197,12199) 
to a 3-sigma limit of about 60 microJy."


GRB_name: GRB110726A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12210
SUBJECT: GRB 110726A: optical upper limit in CrAO
DATE:    11/07/29 14:38:54 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed  the field of the Swift GRB 110726A  (Wolf et al., GCN 12196) 
with AZT-11 telescope of CrAO between  Jul. 26 (UT) 18:48 - 20:13. We do not
detect the afterglow (Schaefer  et al., GCN 12197; Melandri et al., GCN 
12198) . The photometry is based on the star used in GCN  12206 (Gorosabel 
et al.) USNO B1.0 1460-02955684   (19 06 51.53 +56 04 41.2 ) assuming 
R=18.06:

T0+      Filter,   Exposure, OT,           Upper Limit (3 sigma)
(mid, d)              (s)

0.7511   R        29x180       n/d           21.5


GRB_name: GRB110721A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12212
SUBJECT: GRB 110721A: Swift observations of afterglow candidate
DATE:    11/07/30 03:01:49 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <grupe@astro.psu.edu>

D. Grupe (PSU), C.A. Swenson (PSU), J.L. Racusin (NASA/GSFC),
& C. Wolf (PSU) report on behalf of the Swift team.


We report on the Swift follow-up observations of the field of the
afterglow candidate reported by Greiner et al. (GCN Circ. 12192) of
the FERMI GBM/LAT detected burst GRB 110721A (Tierney & v. Kienlin,
GCN Circ. 12187; Vasileiou et al., GCN Circ. 12188). Greiner et al.
found a faint X-ray source in one of the tiling Swift observations
(Obs ID 20169, 1.8 ks) which was also detected by GROND.  This
field was observed by Swift again approximately 150 hours after
the FERMI trigger for 4.9  ks with the XRT in photon counting mode
(Obs ID 20174). We did not detect any  source in the 0.3-10 keV
band at the position reported by Greiner  et al. (GCN Circ. 12192).
We determined a 3 sigma upper limit of  2.5 e-3 counts/s. The
comparison of this new observation to the X-ray afterglow
candidate with a count  rate of (3.8+6.14-3.16)e-3 counts/s (in the
1.8 ks observation 20169) is inconclusive as it could be
consistent with either a constant source or fading.

Based on the source detection in Obs ID 20169, if we assume a
standard X-ray spectrum with Galactic foreground absorption and
the standard cosmology for a source at a redshift of z=0.382 as
reported by  Berger (GCN Circ. 12193) the luminosity in the
0.3-10 keV band is 2e43 ergs/s. This luminosity is consistent
with that of a low luminosity AGN.


Note that some of the Swift observations of the fields around
GRB 110721A were unusable because this region was difficult for
the star trackers to achieve lock. Therefore, no further
observations are planned.


GRB_name: GRB110731A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12215
SUBJECT: GRB 110731A: Swift detection of a burst with an optical counterpart
DATE:    11/07/31 11:23:28 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. R. Oates (UCL-MSSL), A. P. Beardmore (U Leicester),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
A. Melandri (INAF-OAB), C. J. Mountford (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL), C. J. Saxton (UCL-MSSL)
and T. N. Ukwatta (MSU) report on behalf of the Swift Team:

At 11:09:30 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110731A (trigger=458448).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 280.521, -28.546 which is 
   RA(J2000) = 18h 42m 05s
   Dec(J2000) = -28d 32' 44"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multiple-peaked
structure with a duration of about 20 sec.  The peak count rate
was ~20000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 11:10:36.9 UT, 66.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 280.5042, -28.5363 which is equivalent to:
   RA(J2000)  = 18h 42m 01.00s
   Dec(J2000) = -28d 32' 10.6"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 63 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 75 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 18:42:01.01 = 280.50419
  DEC(J2000) = -28:32:13.7  = -28.53713
with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.0
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.80 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.17. 

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: GRB110731A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12216
SUBJECT: GRB 110731A: FTN+FTS  afterglow observations
DATE:    11/07/31 12:17:39 GMT
FROM:    David Bersier at Liverpool John Moores U  <dfb@astro.livjm.ac.uk>

David Bersier (LJMU) report on behalf of a larger collaboration:

The Faulkes Telescopes North (Hawaii) and South (Australia) both started 
automatically (110 and 182 seconds after trigger)  to observe GRB 
110731A, in response to the Swift trigger 458448.  The software detected 
a uncatalogued decaying source that coincides with the position of the 
UVOT candidate afterglow (GCN 12215).
We measure a magnitude mR=16.4 at 28 minutes after the trigger time. 
Assuming a  power law decay, the decay index is about -1.

Observations have been obtained with the BVR filters and are continuing 
on both telescopes.


GRB_name: GRB110731A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12217
SUBJECT: GRB 110731A: Swift-BAT refined analysis
DATE:    11/07/31 13:58:26 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),
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-240 to T+402 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110731A (trigger #458448)
(Oates, et al., GCN Circ. 12215).  The BAT ground-calculated position is
RA, Dec = 280.513, -28.536 deg, which is 
   RA(J2000)  =  18h 42m 03.1s 
   Dec(J2000) = -28d 32' 10.0" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 98%.
 
The mask-weighted light curve shows many overlapping peaks starting at ~T-1.5 sec,
peaking at +T_zero, and ending at ~T+8 sec with a long exponential decay
lasting out to ~T+80 sec.  T90 (15-350 keV) is 38.8 +- 13.0 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-1.3 to T+80.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.15 +- 0.05.  The fluence in the 15-150 keV band is 6.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.26 sec in the 15-150 keV band
is 11.0 +- 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/458448/BA/


GRB_name: GRB110731A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12218
SUBJECT: Fermi-LAT Detection of GRB110731A
DATE:    11/07/31 18:13:26 GMT
FROM:    Julie McEnery at NASA/GSFC  <julie.e.mcenery@nasa.gov>

Johan Bregeon, Julie McEnery and Masanori Ohno report on
behalf of the Fermi Large Area Telescope (LAT) collaboration.

Based on an on-ground analysis, the Large Area Telescope (LAT),
on-board the Fermi Gamma-ray Space Telescope, detected high energy
emission above 100 MeV, with greater than 10 sigma significance, from
the Swift detected burst GRB 110731A (Oates et al, GCN 12215).

The preliminary LAT location of the ground automated analysis
is (Ra,Dec) = (280.39,-28.53)+/-0.20 d (68% cont.) which is consistent
with the Swift localization and within 0.1d  from the optical
counterpart position.

Further analysis is ongoing.

The Fermi LAT point of contact for this burst is Johan Bregeon
(johan.bregeon@pi.infn.it).

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


GRB_name: GRB110731A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12219
SUBJECT: GRB 110731A: Enhanced Swift-XRT position
DATE:    11/07/31 18:18:07 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 1566 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 110731A, 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 = 280.50417, -28.53748 which is equivalent
to:

RA (J2000): 18h 42m 1.00s
Dec (J2000): -28d 32' 14.9"

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

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

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


GRB_name: GRB110731A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12220
SUBJECT: GRB 110731A: NOT photometry
DATE:    11/07/31 23:11:39 GMT
FROM:    Giorgos Leloudas at Dark Cosmology Centre  <giorgos@dark-cosmology.dk>

D. Malesani, G. Leloudas (DARK/NBI), Dong Xu (WIS), A. de Ugarte Postigo, J. Hjorth (DARK/NBI), P. Jakobsson (U. Iceland), and M. B. Nielsen (NOT), report on behalf of a larger collaboration.

We used the Nordic Optical Telescope (La Palma, Spain) equipped with ALFOSC to observe the field of GRB 110731A (Oates et al., GCN 12215).  Observations started at 21:22 UT, i.e. 10.22 hr after the trigger. We obtained 3x300 s in R under bad (1.7") seeing conditions.

The afterglow has faded considerably with respect to the report by Bersier (GCN 12216). Photometry is made difficult by the crowding of the field, and we estimate a tentative magnitude for the transient R = 22.2 +- 0.3 mag.


GRB_name: GRB110731A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12221
SUBJECT: GRB 110731A: Fermi GBM observation
DATE:    11/08/01 06:29:38 GMT
FROM:    David Gruber at MPE  <dgruber@mpe.mpg.de>

David Gruber (MPE) reports on behalf of the Fermi GBM Team: 

"At 11:09:29.94 UT on 31 July 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110731A (trigger 333803371 / 110731465)
which which was also detected by Fermi LAT (Bregeon et al. 2011, GCN 12218)
and Swift (Oates et al. 2011, GCN 12215).

The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 6 degrees.
Moreover, this burst was bright enough to result in a Fermi spacecraft 
autonomous rapid repoint (ARR) maneuver.

The GBM light curve consists of one pulse
with a duration (T90) of about 7.3 +/- 0.3 s (50-300 keV). 
The time-averaged spectrum from T0 s to T0+7.3 s is 
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.82 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 317 +/- 10 keV.

The event fluence (10-1000 keV) in this time interval is 
(2.218 +/- 0.006)E-05 erg/cm^2. The 1-sec peak photon flux measured 
starting from T0+0.128 s in the 10-1000 keV band 
is 20.9 +/- 0.5 ph/s/cm^2.

A Band function fits the spectrum equally well 
with Epeak= 304 +/- 13 keV, alpha = -0.80 +/- 0.03 and beta = -2.98 +/- 0.30. 


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


GRB_name: GRB110731A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12222
SUBJECT: GRB110731A: Swift/UVOT Observations
DATE:    11/08/01 12:17:25 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 110731A 75s 
after the trigger (Oates et al., GCN Circ. 12215). We detect a fading 
source in the white, v, b and u filters at a refined position of 
RA(J2000), DEC(J2000)= 280.50413 deg, -28.537167 deg. This is equivalent to:

    RA (J2000)  18:42:00.99
   Dec (J2000) -28:32:13.8

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence).
This is consistent with the UVOT position reported in Oates et al. 
(GCN Circ. 12215) and with the enhanced position of the X-ray afterglow 
(Beardmore et al., GCN Circ. 12219). The non-detection in the uv filters is 
consistent with a redshift of between 2 and 3.

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)     75         225       147    15.85+/-0.02
wh          567        587       19     17.64+/-0.11
v           790        810       19     16.90+/-0.23
b           542        562       19     17.87+/-0.23 
u (FC)      287        537       246    17.71+/-0.08
u           1118       1138      19     18.37+/-0.44
uvw1        666        1286      78     >18.88   
uvm2        642        1261      78     >18.77   
uvw2        592        1385      97     >19.24   
#####################################################

We note that photometry is difficult due to the field being crowded and the presence of a faint 
contaminating source in the source region. The values quoted above are not 
corrected for the non-negliable Galactic extinction due to the reddening 
of E(B-V) = 0.18 in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB110731A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12223
SUBJECT: Konus-Wind observation of GRB 110731A
DATE:    11/08/01 12:53:47 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 GRB 110731A (Swift-BAT trigger #458448: Oates, et al., GCN 
12215; Krimm et al., GCN 12217; also detected by Fermi-LAT: McEnery, GCN 
12218, and Fermi-GBM: Gruber, GCN 12221) triggered Konus-Wind at 
T0=40174.604 s UT (11:09:34.604).

The burst light curve shows a multipeaked structure with a duration of 
~7 s. There is a low-level emission seen in the G2 band (~80-360 keV) up 
to ~T0+40 s.

As observed by Konus-Wind the burst
had a fluence of 1.63(-0.10,+0.11)x10^-5 erg/cm2,
and a 64-ms peak flux measured from T0+4.304 s
of (6.0 +/- 1.3)x10^-6 erg/cm2/s
(both in the 20 keV - 6 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+8.448 s) can be fitted (in the 20 keV - 6 MeV
range) by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with
alpha = -0.74(-0.15, +0.16),  and
Ep = 288(-25, +30) keV (chi2 = 98.2/76 dof).
Fitting by GRB (Band) model yields the same alpha and Ep,
and only an upper limit on the high energy
photon index: beta < -2.92 (chi2 = 98.1/75 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/GRB110731_T40174/


GRB_name: GRB110731A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12224
SUBJECT: GRB 110731A: Swift-XRT refined Analysis
DATE:    11/08/01 12:54:32 GMT
FROM:    Owen Littlejohns at U of Leicester  <oml2@le.ac.uk>

O. M. Littlejohns, P. A. Evans, A. P. Beardmore (U. Leicester) and S.
R. Oates (UCL-MSSL) report on behalf of the Swift-XRT team:

We have analysed 8.1 ks of XRT data for GRB 110731A (Oates  et al. GCN
Circ. 12215), from 56 s to 36.0 ks after the  BAT trigger. The data
comprise 607 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 12219).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.04 (+0.05, -0.10). At T+502 s  the decay
steepens to an alpha of 1.183 (+0.027, -0.024) before breaking again at
T+29.0 ks to a final decay with index alpha=4.2 (+5.8, -2.0). We note
that the uncertainty in this final decay is large due to the small
number of data points after the final break.

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.08 (+/-0.05). The
best-fitting absorption column is  2.05 (+0.14, -0.13) x 10^21 cm^-2,
in excess of the Galactic value of 1.0 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.92 (+/-0.12) and a
best-fitting absorption column of 1.7 (+0.4, -0.3) 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 (5.5 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.7 (+0.4, -0.3) x 10^21 cm^-2
Galactic foreground: 1.0 x 10^21 cm^-2
Excess significance: 8.4 sigma
Photon index:      1.92 (+/-0.12)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00458448.

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


GRB_name: GRB110731A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12225
SUBJECT: GRB 110731A Gemini-N redshift
DATE:    11/08/01 13:23:44 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir, K. Wiersema (U. Leicester), A. J. Levan (U. Warwick), S. B. Cenko (U. Berkeley)
and T. Geballe (Gemini) report on behalf of a larger collaboration:

We observed the location of GRB 110731A (Oates et al. GCN12215) with
the GMOS-N instrument on Gemini-North (Mauna Kea), beginning at 1 Aug 2011
09:07 UT.  Spectroscopic observations totalling 3600s were obtained in good
conditions using the B600 grating (spanning approximately 3800 A to 6650 A). 
We identify a broad Ly-alpha absorption feature and several absorption lines of
O, C, Si and Al at a common redshift of z=2.83.  This includes fine structure lines
of O, C and Si, as seen in other GRB sight-lines, confirming that this is the
redshift of the burst.

Provisional calibration of the acquisition image gives a magnitude of R=22.0 for
the afterglow (uncorrected for foreground extinction of A_R ~ 0.5),  suggesting
a fairly shallow rate of decay since the NOT epoch (Malesani et al. GCN12220).


GRB_name: GRB110731A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12226
SUBJECT: GRB110731A: MITSuME Ishigakijima Optical Upper Limits
DATE:    11/08/01 14:10:02 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 110731A (Oates et al., GCNC 12215)
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 13:02:23 UT (~1.9 h after the burst).
We did not find any new point source within the enhanced XRT error
circle (Beardmore et al., GCNC 12219) in all the three bands. We
could not detect the previously reported afterglow
(Bersier, GCNC 12216; Malesani et al., GCNC 12220).


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
----------------------------------------------------
0.12025    14:02:40    6180.0   >21.8 >20.6 >20.1
----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110731A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12227
SUBJECT: GRB 110731A / EVLA upper limits
DATE:    11/08/01 19:02:55 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

A. Zauderer, E. Berger (Harvard), and D.A. Frail (NRAO) report on
behalf of a larger collaboration:

"We observed the Swift burst GRB 110731A (GCN 12215) with the EVLA
beginning on 2011 Aug 1.15 UT (0.68 days after the burst).
Observations were performed at 5.75 and 22 GHz for about 30 min
at each frequency.  No radio source is detected in coincidence
with the optical afterglow (GCN 12215), to a 3-sigma limit of
~50 microJy at 5.75 GHz.  Additional observations are planned."


GRB_name: GRB110801A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12228
SUBJECT: GRB 110801A: Swift detection of a burst with an optical counterpart
DATE:    11/08/01 20:01:04 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),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), A. Melandri (INAF-OAB),
C. J. Mountford (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU),
E. Sonbas (GSFC/USRA/Adiyaman Univ.), C. A. Swenson (PSU),
E. Troja (NASA/GSFC/ORAU) and T. N. Ukwatta (MSU) report on behalf of
the Swift Team:

At 19:49:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110801A (trigger=458521).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 89.285, +80.988 which is 
   RA(J2000)  =  05h 57m 08s
   Dec(J2000) = +80d 59' 18"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a few weak peaks
with a duration of about 70 sec.  The peak count rate
was ~700 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 19:51:21.9 UT, 98.9 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 89.4307, +80.9548 which is equivalent to:
    RA(J2000)  = 05h 57m 43.36s
    Dec(J2000) = +80d 57' 17.2"
with an uncertainty of 4.9 arcseconds (radius, 90% containment). This
location is 146 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 108 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 05:57:44.73 =  89.43637
  DEC(J2000) = +80:57:21.6  =  80.95600
with a 90%-confidence error radius of about 0.62 arc sec. This position is 5.4
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.03 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.08. 

Burst Advocate for this burst is 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: GRB110801A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12229
SUBJECT: GRB 110801A: ROTSE-III Detection of re-brightening from OT
DATE:    11/08/01 21:15:02 GMT
FROM:    Weikang Zheng at U.of Michigan  <zwk@umich.edu>

GRB 110801A: ROTSE-III Detection of re-brightening from OT

W. Zheng (U Mich), T. Guver (U Arizona), report on behalf of the ROTSE
collaboration: 


ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe,
Turkey, responded to GRB 110801A (Swift trigger 458521; Pasquale et al.
GCN 12228). The first image was at 19:52:57.7 UT, 194.7 s after the
burst. The unfiltered images are calibrated relative to USNO A2.0.
We detect the OT at UVOT location (GCN 12228), the OT appeared
to be re-brightening to ~15.0 mag at ~1400s after the burst.
Continuing observations are in progress.

[GCN OPS NOTE(01aug11): Per author's request (at GCN's request),
the language was changed to remove the implication that the delay
in observing was tied to the Notice arrival time.  The delay was due
to weather and dome operations.  The "(8.7 s after the GCN notice time)"
was removed from the text.]


GRB_name: GRB110801A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12230
SUBJECT: GRB 110801A: TLS Optical afterglow confirmation
DATE:    11/08/01 21:22:52 GMT
FROM:    Ana Nicuesa at TLS Tautenburg  <ana@tls-tautenburg.de>

GRB 110801A: TLS Optical afterglow Confirmation

A. Nicuesa Guelbenzu, X. Luo, S. Klose, U. Laux, B. Stecklum (all
at TLS Tautenburg) report:

We observed the afterglow of GRB 110801A (M. De Pasquale et al., GCN 12228)
with the 2m/1.34m Schmidt telescope of the Thueringer
Landessternwarte Tautenburg starting about 20 min after the GRB trigger.

The afterglow is clearly detected in the R band images at the position
of the UVOT detection.

We confirm the re-brightening of the afterglow as reported by
ROTSE III (Zheng et al. 2011, GCN 12229).


GRB_name: GRB110801A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12232
SUBJECT: GRB 110801A: Enhanced Swift-XRT position
DATE:    11/08/02 02:01:09 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 1989 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 110801A, 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 = 89.43603, +80.95615 which is equivalent
to:

RA (J2000): 05h 57m 44.65s
Dec (J2000): +80d 57' 22.2"

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: GRB110801A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12233
SUBJECT: GRB110801A: MITSuME Ishigakijima Optical Observation
DATE:    11/08/02 05:13:46 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 110801A (Pasquale et al., GCNC 12228)
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 2011-08-01 19:53:51 UT (~4 min after the burst).
We detected the previously reported afterglow (Pasquale et al.,
GCNC 12228; Zheng and Guver, GCNC 12229; Guelbenzu et al., GCNC 12230)
in all the three bands.

Photometric results of the OT are listed below. We used GSC2.3 catalog
for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'  g'_err   Rc  Rc_err   Ic  Ic_err
----------------------------------------------------------------------
0.00323    19:54:21     60.0    16.16  0.07  15.14  0.04  14.44  0.04
0.00404    19:55:31     60.0    15.35  0.06  14.29  0.04  13.57  0.04
0.00485    19:56:41     60.0    15.38  0.06  14.28  0.04  13.56  0.04
0.00731    20:00:14     60.0    15.54  0.06  14.51  0.04  13.79  0.04
0.00976    20:03:45     60.0    15.71  0.07  14.67  0.04  13.98  0.04
0.01222    20:07:18     60.0    15.77  0.07  14.79  0.04  14.12  0.04
0.01466    20:10:48     60.0    15.89  0.07  14.91  0.04  14.24  0.04
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110801A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12234
SUBJECT: GRB 110801A: Afterglow redshift from 10.4m GTC
DATE:    11/08/02 06:33:02 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. Cabrera Lavers (GTC), A. de Ugarte Postigo (DARK/NBI), A.J.
Castro-Tirado, J. Gorosabel, C.C. Thoene (IAA-CSIC), R. Domnguez (GTC)
report on behalf of a larger collaboration:

We have observed the afterglow of GRB 110801A (De Pasquale et al. GCNC
12228) using OSIRIS at the 10.4m GTC telescope (La Palma, Spain).
Observations consisted on 2x900s + 1x600s exposures using the R1000B
grating (resolution ~1000) with coverage between 3600 and 7500 Angstrom.
Observations started at 3:30 UT (7.7h after the burst). In a preliminary
analysis, using archival calibrations, we detect a high signal to noise
ratio continuum with absorption features that include CII, SiIV, SiII,
CIV, FeII, AlII, AlIII, NiII, ZnII, and MnII, as well as fine structure
FeII* and NiII* at a common redshift of z=1.858, which we identify as the
redshift of the afterglow. We also identify two intervening systems at
z=1.246 and z=0.745 through the presence of the MgII doublet.


GRB_name: GRB110801A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12235
SUBJECT: GRB 110801A: Swift-XRT refined Analysis
DATE:    11/08/02 09:00:16 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 9.9 ks of XRT data for GRB 110801A (De Pasquale  et
al. GCN Circ. 12228), from 89 s to 24.0 ks after the  BAT trigger. The
data comprise 566 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 Evans
et al. (GCN. Circ 12232).

The light curve initially shows a number of flares, the largest peaking
at 500-600 count/s  between T+355 s and T+390 s after the trigger. Once
this flare has decayed, the light curve after T+800 s can be modelled
by a power-law with a slope of 1.12 +/- 0.06.

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.754 (+0.025, -0.026). The
best-fitting absorption column is  6.4 (+/-0.6) x 10^21 cm^-2, at a
redshift of 1.858, in addition to the Galactic value of 6.2 x 10^20
cm^-2 (Kalberla et al. 2005). We note this spectrum includes strong
spectral evolution through the flare. The PC mode spectrum has a photon
index of 2.04 (+/-0.09) and a best-fitting absorption column of 1.6
(+1.6, -1.4) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10
keV flux conversion factor deduced from this spectrum  is 3.6 x 10^-11
(4.5 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 6.2 x 10^20 cm^-2
Intrinsic column:    1.6 (+1.6, -1.4) x 10^21 cm^-2 at z=1.858
Photon index:      2.04 (+/-0.09)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00458521.

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


GRB_name: GRB110801A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12236
SUBJECT: Swift/UVOT observations of GRB110801A
DATE:    11/08/02 12:52:23 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 110801A
109 s after the BAT trigger (De Pasquale et al., GCN Circ. 12228).
A source consistent with the XRT position (Evans et al., GCN Circ. 12232)
is detected in the initial and summed UVOT exposures, except in um2 
filter and a detection in uw2, at 2 sigma confidence level. Since
the redshift of this event is 1.86 (Cabrera Lavers, GCN Circ. 12234),
we think the weak detection in uw2 is due to flux in the reddest part
of this filter.

The refined UVOT position is:
     RA  (J2000) =  05:57:44.87 =  89.43695 (deg.)
     Dec (J2000) = +80:57:21.1  =  80.95592 (deg.)
with an estimated uncertainty of 0.51 arc sec. (radius, 90% confidence).

The afterglow shows a quick rise from the first exposure up to ~300s.

Preliminary detections and 3-sigma upper limits 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 (fc)         109        259          147         18.06  0.07
white              109       6337          727         17.23  0.05
v                  598       6747          451         17.07  0.06
b                  523       6132          432         17.47  0.05
u (fc)             267        517          246         15.89  0.05
u                  267       5927          488         15.68  0.04
w1                 647       5722          255         17.92  0.11
m2                 622       6904          404         >20.2
w2                 573       6543          452         20.48  0.41

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110801A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12237
SUBJECT: GRB 110801A: Swift-BAT refined analysis
DATE:    11/08/02 14:06:06 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),
M. De Pasquale (UCL-MSSL), 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-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110801A (trigger #458521)
(De Pasquale, et al., GCN Circ. 12228).  The BAT ground-calculated position is
RA, Dec = 89.415, 80.958 deg, which is 
   RA(J2000)  =  05h 57m 39.6s 
   Dec(J2000) = +80d 57' 28.5" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%.
 
The mask-weighted light curve shows two main clusters of peaks.  The first
starts at ~T-30 sec, with a maximum at ~T+2 sec, and a long exponental decay
almost down to background before the second cluster.  The second cluster
starts ~T+310 sec, peaks at ~T+340 sec, and ending at ~T+550 sec.
T90 (15-350 keV) is 385 +- 10 sec (estimated error including systematics).
 
The time-averaged spectrum from T-24.2 to T+385.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.84 +- 0.10.  The fluence in the 15-150 keV band is 4.7 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+341.78 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/458521/BA/


GRB_name: GRB110801A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12238
SUBJECT: GRB 110801A: MASTER OT observations 
DATE:    11/08/02 17:32:35 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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


  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


  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 GRB110801A 101 sec after GRB 
time at  2011-08-01 19:51:23 UT. Unfortunatelly the objects was not in 
focus  because recently photometer modification.  On our first (20s
exposure) set we haven't found optical transient within SWIFT error-box
(De Pasquale et al., GCN 12228).
The 3-sigma upper limit has been about 14.0 mag (white+polarizator).


MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located 
near Kislovodsk (Caucasus Mountains)  closed roof 20 min before 
trigger due to cloudy condidtions. The telescope was repointed to the
GRB110901A  only 47 min 40 sec after trigger time at 2011-08-01 20:37:22 UT.
We found OT at UVOT postion (De Pasquale et al., GCN 12228).
The results of our photometry are:

Time_Start    T_mean-T_trig  exp time       m        error      Band 
UT                  s          s 
20:37:22          2950        180         16.13       0.06        R
20:44:29          3377        180         16.12       0.06        R 
20:48:01          3589        180         16.29       0.08        R
20:48:01          3589        180         16.03       0.06     White 
20:51:24          3792        180         16.43       0.06        R
20:51:24          3792        180         16.19       0.06     White
23:20:14         12722        180         17.75       0.10        R

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).

The power low index (F~t^-aplha) apha ~1.0+-0.1     during this 
observations in R-band.

The message may be cited.


GRB_name: GRB110801A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12239
SUBJECT: GRB 110801A: Evidence for a jet break
DATE:    11/08/02 21:38:15 GMT
FROM:    Ana Nicuesa at TLS Tautenburg  <ana@tls-tautenburg.de>

A. Nicuesa Guelbenzu, S. Klose, S. Schmidl, A. Rossi, U. Laux, B. Stecklum
(all at TLS Tautenburg) report:

We re-observed the afterglow of GRB 110801A (M. De Pasquale et al., GCN
12228)
with the 2m/1.34m Schmidt telescope of the Thueringer Landessternwarte
Tautenburg starting about 24 hours after the GRB trigger.

A stacking of the first 15 minutes of the second epoch data does not show
the afterglow in the R band down to 21 mag (Vega system). We conclude that
a jet break has occurred within the last 24 hours.


GRB_name: GRB110801A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12240
SUBJECT: GRB110801A: MITSuME Ishigakijima Optical Observation at 1 day after the burst
DATE:    11/08/03 04:58:24 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 110801A (De Pasquale et al., GCNC 12228)
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 2011-08-02 17:38:02 UT (~21.8 h after the burst).
We detected the previously reported afterglow (Pasquale et al.,
GCNC 12228; Zheng and Guver, GCNC 12229; Guelbenzu et al., GCNC 12230;
Kuroda et al., GCNC 12233) in all the three bands.

Photometric results of the OT are listed below. We used GSC2.3 catalog
for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'  g'_err   Rc  Rc_err   Ic  Ic_err
----------------------------------------------------------------------
0.95038    18:38:15   5760.0     21.5  0.3    20.3  0.2   19.1   0.2
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110801A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12241
SUBJECT: GRB 110801A: SAO RAS optical observations
DATE:    11/08/03 08:08:25 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

V. V. Sokolov, A. S. Moskvitin, T. A. Fatkhullun, (SAO RAS) report on
behalf of a larger collaboration:

We observed the field of GRB 110801A (De Pasquale et al., GCN 12228)
with the 6-m BTA of SAO RAS (Russia) equipped with the Scorpio.
The observations were carried out in the B and Rc bands
at 00:07:36 -- 00:13:36 UT, August, 02 (since 4.35 hours after the trigger).
The weather conditions were tolerable, seeing around 2".5.

Magnitudes of optical transient are as follows:
B = 19.02 +/- 0.02
R = 18.10 +/- 0.01
Calibration were done against the magnitudes B2 = 16.74 and R2 = 15.73
of the USNO-B.1 star 1709-0023450 (R.A. = 05:57:24.91 Dec.= +80:57:39.8,
Epoch = 2000). The magnitudes of OT were not corrected for the Galactic
extinction E(B-V) = 0.08 in the direction of the burst (Schlegel et al.
1998).

Also we obtained 2 x 600 sec. spectrum (range = 4000 -- 8400A, resolution
FWHM = 10A) at 00:19:54 -- 00:41:24 UT. At the noisy relatively blue
continuum we marginally detected only the C IV absorption line
corresponding to the red shift reported by Cabrera Lavers et al.
(GCN 12234).

The message may be cited.


GRB_name: GRB110731A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12242
SUBJECT: GRB110731A: MOA optical observations of the steeply fading afterglow
DATE:    11/08/03 11:49:40 GMT
FROM:    Akihiko Fukui at Nagoya U/MOA  <afukui@stelab.nagoya-u.ac.jp>

P. J. Tristram (MJUO), A. Fukui (Nagoya U.), K. Ohnishi (Nagano NCT) and T. Sako (Nagoya U.) 
report on behalf of the MOA collaboration.

We began prompt observations of the afterglow of GRB110731A (Oates et al., GCN 12215)
at July 31 11:12:47 UT responding to the Swift trigger 458448 (3.3 min after the trigger)  
using the 61 cm B&C telescope at the Mt John University Observatory in New Zealand.
We obtained a series of I and V band images with 60 sec exposure times followed by some 
120 sec exposures until 12:56 UT (105 min after the trigger). 
The total number of I and V images are 39 and 35, respectively. 
Although the first image had a poor psf, the following images had well-shaped psf's and 
we confirmed the steeply fading afterglow, which is consistent with the previous reports 
(e.g. Bersier et al. GCN 12216), on these images in both the I and V bands. 
The afterglow is located within the error circle reported by Oates et al. GCN 12222.
The magnitude of the afterglow on the second and on the last images in the I band obtained 
by psf-fitting photometry with the DoPHOT package 
(Schechter et al. 1993) and calibrated to the USNO-B1.0 N magnitude (similar to I magnitude) 
follow.

------------------------------------------
Filter mid_JD-2450000 exptime[sec] dT[min] Nmag error 
I  5773.96831  60  4.86  14.75  0.20
I  5774.03807  120  105.31  20.2  2.7
------------------------------------------

Here dT denotes the difference between the mid_JD (mid time of exposure) and the trigger 
time. The large error in the magnitude of the last image resulted from the calibration relying on extrapolation.  


GRB_name: GRB110726A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12243
SUBJECT: GRB 110726A: Swift-XRT refined Analysis
DATE:    11/08/03 12:34:39 GMT
FROM:    Chris Wolf at PSU  <cwolf@swift.psu.edu>

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

We have analysed 50 ks of XRT data for GRB 110726A (Wolf  et al. GCN
Circ. 12196), from 47 s to 421.3 ks after the  BAT trigger. The data
comprise 1.3 ks in Windowed Timing (WT) mode (the first 4 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 12200).

The late-time light curve (from T0+4.1 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.26 (+0.16, -0.15).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.12 (+0.22, -0.21). The
best-fitting absorption column is  1.6 (+/-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 PC mode spectrum has a photon index of 2.15 (+0.12, -0.28)
and a best-fitting absorption column of 9.6 (+3.9, -4.0) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.4 x 10^-11 (4.5 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.6 (+3.9, -4.0) x 10^20 cm^-2
Galactic foreground: 5.6 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.15 (+0.12, -0.28)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00458059.

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


GRB_name: GRB110731A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12244
SUBJECT: GRB 110731A : Suzaku WAM observation of the prompt emission
DATE:    11/08/04 02:12:35 GMT
FROM:    Yoshitaka Hanabata at Hiroshima U  <hanabata@hep01.hepl.hiroshima-u.ac.jp>

Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, M. Ohno, Y. Fukazawa
(Hiroshima U.), T. Yasuda, Y. Terada, M. Tashiro, W. Iwakiri,
K. Takahara (Saitama 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 bright long GRB110731A (Swift/BAT trigger #458448: Oates et al.
GCN 12215, also detected by Fermi-LAT: Bregeon et al. GCN 12218)
triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers
an energy range of 50 keV - 5 MeV at 11:09:30.211 UT (=T0).

The observed light curve shows multiple peaks starting at T0-1.5 s, ending
at T0+7.5 s, with a duration (T90) of about 6.56 seconds. The fluence in
100 - 1000 keV was 1.31 (-0.12, +0.08) x 10^-5 erg/cm^2. The 1-s peak
flux measured from T0+3.5 s was 5.20 (-0.70, +0.57) photons/cm^2/s in the
same range.

Preliminary result shows that the time-averaged spectrum from T0-1.5 s to
T0+7.5 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha       0.93 (-0.66, +0.57), and
 Epeak       339 (-51, +40) keV (chi^2/d.o.f. = 11.2/12).

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: GRB110721A
Detection_method: VLA Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12245
SUBJECT: EVLA observation for Fermi burst GRB 110721A
DATE:    11/08/04 02:22:23 GMT
FROM:    Poonam Chandra at Royal Mil. College Canada  <Poonam.Chandra@rmc.ca>

Poonam Chandra (RMC), S. Bradley Cenko (UC Berkeley),
 and Dale A. Frail (NRAO)report on behalf of a larger collaboration:

We observed the field of the potential X-ray afterglow (GCN 12192,
12212) of the Fermi GBM (GCN 12187) and LAT (12188) GRB 110721A
with the EVLA on 2011 July 26.29 UT at 4.5 and 7.9 GHz.  The field of view
is dominated by the radio bright AGN PKS 2211-388, located 9" from the
XRT localization.  PKS 2211-388 has 7.9 GHz flux of 0.35 Jy and
 4.5 GHz flux of 0.75 Jy in our EVLA observations. We suggest that
the proposed X-ray counterpart is instead associated with PKS 2211-388.

The potential optical counterpart (GCN 12192), likely to be an
early-type galaxy at z=0.382 (GCN 12193), is located ~ 10" from
PKS 2211-388.  Given the large offset and the spectral type,
we consider it unlikely to be related to either PKS 2211-388 or GRB 110721A.


GRB_name: GRB110801A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12246
SUBJECT: GRB 110801A: optical observations in CrAO
DATE:    11/08/04 15:56:39 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of GRB 110801A (Pasquale  et al. GCN 12228) with Shajn 
telescope of CrAO  observatory  on  between Aug. 2 (UT) 22:03 and Aug. 3 
(UT) 00:27 under variable weather conditions and a mean  seeing of  2.1 
arsces. We took several frames with exposure of 60 s in R-band. On a stacked 
image we detected the optical counterpart (Pasquale  et al. GCN 12228, Zheng 
et al. GCN 12229). A  photometry is based on the USNO B1.0 star 1709-0023450 
(05 57 24.91 +80 57 39.8) assuming R=15.73.

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

1.1428    R         74x60       21.60 +/- 0.09   23.2 


GRB_name: GRB110802A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12247
SUBJECT: IPN triangulation of GRB110802A (short/hard burst)
DATE:    11/08/04 16:50:23 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley and J. Goldsten, on behalf of the MESSENGER GRNS 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,

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

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

GRB 110802A, a short-duration, hard spectrum burst, was detected by
Konus-Wind, MESSENGER GRNS, Odyssey HEND, Swift BAT (outside the coded
field of view), and Suzaku WAM at 55157 s UT.  We have triangulated it to
a preliminary 3 sigma error box whose area is 55 sq. arcmin. and whose
coordinates are

CENTER:  RA=44.455 o =  02h57m49s , DEC= +32.593 o = 32 o 35' 34"
CORNERS:    44.448 o=   02h57m48s        +32.932 o = 32 o 55' 54"
            44.476 o =  02h57m54s        +32.851 o = 32 o 51' 03"
            44.436 o =  02h57m45s        +32.329 o = 32 o 19' 45"
            44.465 o =  02h57m51s        +32.244 o = 32 o 14' 40"

Some improvement to this error box is possible.

A Swift ToO has been requested.  The spectrum and time history will
be reported in a forthcoming GCN Circular.


GRB_name: GRB110802A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12249
SUBJECT: Konus-Wind observation of GRB 110802A
DATE:    11/08/04 17:48:43 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 extremely hard GRB 110802A
(localized by IPN: Hurley et al., GCN 12247)
triggered Konus-Wind at T0=55156.191s UT (15:19:16.191)

The burst light curve shows a single double-peaked pulse,
the total duration of the burst is ~0.6 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/GRB110802_T55156/

As observed by Konus-Wind the burst
had a fluence of (1.3  0.3)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0-0.032 s,
of (5.0  1.6)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.256 s)
is best fitted in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -0.63 (-0.25, +0.31),
and Ep = 3451(-1086, +2256) keV,
chi2 = 24.0/24 dof.

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


GRB_name: GRB110726A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12251
SUBJECT: GRB 110726A: two epochs of SAO RAS optical observations
DATE:    11/08/06 07:04:37 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A.S.Moskvitin, V.V.Sokolov
report on behalf of the SAO RAS GRB follow-up team:

We observed the field of GRB 110726A (Wolf et al., GCN 12196) with two
optical telescopes of SAO RAS: the 1-m Zeiss-1000 on July, 26/27 in B
and Rc bands and the 6-m BTA + Scorpio on July, 29/30 in Rc band.
We clearly detected an optical transient at the place reported by
Schaefer, Zheng & Flewelling (GCN Circ. 12197, ROTSE-III) and
Siegel & Wolf (GCN Circ. 12199, Swift/UVOT). Results of SAO RAS
observations of OT are presented in the following table.
_______________________________________________________________________
date of July, UT   filter   exp.            magnitude        telescope
_______________________________________________________________________
26.833 -- 27.017   Rc       17 x 300 sec.   22.17 +/- 0.12   Zeiss-1000
26.856 -- 27.022   B        16 x 300 sec.   23.47 +/- 0.17   Zeiss-1000
29.819 -- 29.861   Rc       15 x 180 sec.   23.34 +/- 0.09   BTA
_______________________________________________________________________

We use USNO-B.1 1460-0295684 (R. A. = 19:06:51.53, Dec. =  +56:04:41.2,
Epoch = 2000.0) with the magnitudes B2 = 20.39, R2 = 18.06
(Gorosabel et al. GCN Circ. 12206) as the reference star.

At the BTA image (ftp://ftp.sao.ru/pub/grb/GRB110726A/GRB110726A_BTA.jpeg)
we detected one more faint object with R = 25.21 +/- 0.30, located 3.5"
North-East from the Swift/UVOT position. According to the Gemini-N redshift
range 1.036 < z < 2.7 reported by Cucchiara Bloom & Cenko (GCN Circ. 12202)
this angle size corresponds to (110 -- 370) +/- 20 kpc.

The message may be cited.


GRB_name: GRB110807A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12253
SUBJECT: GRB 110807A: Swift detection of a burst or a posible new SGR
DATE:    11/08/07 20:22:17 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

V. D'Elia (ASDC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
M. M. Chester (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), N. P. M. Kuin (UCL-MSSL),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), D. M. Palmer (LANL), C. J. Saxton (UCL-MSSL),
G. Stratta (ASDC), C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report
on behalf of the Swift Team:

At 19:57:46 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110807A (trigger=458907).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 278.696, -8.760 which is 
   RA(J2000)  =  18h 34m 47s
   Dec(J2000) = -08d 45' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single timebin spike
structure with a duration of less than 0.064 sec.  The peak count rate
was ~3500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 20:03:13.2 UT, 326.8 seconds after
the BAT trigger. Using promptly downlinked data we find an X-ray source
located at RA, Dec 278.71751, -8.76597 which is equivalent to:
   RA(J2000)  = 18h 34m 52.20s
   Dec(J2000) = -08d 45' 57.5"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 79 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. This
position is 6.6 arcseconds from that of a known X-ray source: 2XMM
J183452.4-084603 in the XMM-NEWTON XMMSSC catalogue. 

A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 332 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 large, but uncertain extinction expected. 

Due to the short, soft nature of the burst, and the proximity
of the source to the Galactic plane (0.3 degrees) we suggest
that this source may be a previously unknown Soft Gamma Repeater. 
Verification of this could come if a second burst is seen or
the XRT counterpart shows periodicity. 

Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB110807A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12254
SUBJECT: GRB 110807A: SAO RAS observations
DATE:    11/08/08 01:05:50 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin, V. V. Sokolov and R. I. Uklein,
report on behalf of the SAO RAS GRB follow-up team:

We observed the field of GRB 110807A (D'Elia et al, GCN 12253)
with the 6-meter BTA + Scorpio on August 7.843 -- 7.857 UT
(observations were started since 16 minutes after the BAT trigger).

We obtained 21 x 30 sec. exposures in Rc band. At our stacked image
(seeing = 1".9), inside the XRT error circle we clearly detected
only one object with the following coordinates:
R. A. = 18:34:52.42
Dec. = -08:45:57.08,
with approximately error 1" (all coordinates for Epoch = 2000).

The brightness of the object were measured as R = 23.44 +/- 0.34
(no extinction correction were made). Calibration were done against
the magnitude R2 = 17.85 of the USNO-B.1 star 0812-0420010
(R.A. = 18:34:51.24, Dec. = -08:45:40.1).

We also noted presence of the other object just outside from the XRT
error circle to the North-West which is marked as USNO-B.1 star
0812-0420027 (R.A. = 18:34:51.86, Dec. = -08:45:52.3).
At our image this object is extended along the South-East direction
and probably may be two or more objects.

Zoomed image from BTA can be found at
ftp://ftp.sao.ru/pub/grb/GRB110807A/GRB110807A_BTA.jpeg

The message may be cited.


GRB_name: GRB110808A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12256
SUBJECT: GRB 110808A: Swift detection of a burst with optical counterpart
DATE:    11/08/08 06:36:32 GMT
FROM:    Giulia Stratta at ASDC  <stratta@asdc.asi.it>

G. Stratta (ASDC), W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU),
V. D'Elia (ASDC), N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
A. Melandri (INAF-OAB), K. L. Page (U Leicester) and
C. J. Saxton (UCL-MSSL) report on behalf of the Swift Team:

At 06:18:54 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110808A (trigger=458918).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 57.264, -44.179 which is 
   RA(J2000) = 03h 49m 03s
   Dec(J2000) = -44d 10' 42"
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 10 sec.  The peak count rate
was ~400 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 06:20:45.1 UT, 110.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
57.2666, -44.1944 which is equivalent to:
   RA(J2000)  = 03h 49m 3.97s
   Dec(J2000) = -44d 11' 40.0"
with an uncertainty of 2.6 arcseconds (radius, 90% containment). This
location is 55 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 (1.04 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 3
(+3.41/-2.82) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 5.42e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 120 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 03:49:04.28 =  57.26782
  DEC(J2000) = -44:11:40.3  = -44.19452
with a 90%-confidence error radius of about 0.83 arc sec. This position is 5.1
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.93 with a 1-sigma error of about  0.19. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01. 

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


GRB_name: GRB110808A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12257
SUBJECT: GRB 110808A: Enhanced Swift-XRT position
DATE:    11/08/08 10:56:19 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 304 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110808A, 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 = 57.26664, -44.19536 which is equivalent
to:

RA (J2000): 03h 49m 3.99s
Dec (J2000): -44d 11' 43.3"

with an uncertainty of 3.2 arcsec (radius, 90% confidence).

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

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


GRB_name: GRB110808A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12258
SUBJECT: GRB 110808A: VLT/X-shooter spectroscopy
DATE:    11/08/08 11:04:03 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo, J. P. U. Fynbo (DARK/NBI), P. Jakobsson (U.
Iceland), B. Milvang-Jensen (ESO, DARK/NBI), A. Melandri (INAF-OABr), D.
Malesani (DARK/NBI), S. Schulze (U. Iceland), P. Goldoni (APC/Univ. Paris
7 and SAp/CEA), N. R. Tanvir (U. Leicester), H. Flores (Paris Obs.), K.
Wiersema (U. Leicester), S. Covino (INAF-OABr), L. Lovisi, B. Lanzoni (U.
Bologna) report on behalf of the X-shooter GRB collaboration:

We observed the afterglow of GRB 110808A (Stratta et al. GCN 12256) with
the ESO VLT equipped with the X-shooter spectrograph on 8 August 2011,
beginning 09:19 UT (3 hr after the GRB). The acquisition image shows the
UVOT optical afterglow candidate to have R ~ 21.2 mag.

We detect several emission lines, including [O II], [O III] and H-alpha at
a  common redshift of z = 1.348 (based on archival calibration frames). At
the same redshift we detect the Mg II doublet and Fe transitions in
absorption.

We acknowledge the support of the VLT staff, in particular Claudio Melo.


GRB_name: GRB110807A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12259
SUBJECT: Swift SGR 1834.9-0846: Swift-BAT refined analysis
DATE:    11/08/08 11:40:09 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),
V. D'Elia (ASDC), 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-240 to T+963 sec from recent telemetry downlinks,
we report further analysis of Swift SGR 1834.9-0846 (trigger #458907)
(which we reported as GRB 110807A in D'Elia, et al., GCN Circ. 12253).
The BAT ground-calculated position is RA, Dec = 278.709, -8.758 deg, which is 
   RA(J2000)  =  18h 34m 50.1s 
   Dec(J2000) = -08d 45' 28.4" 
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.
 
The mask-weighted light curve shows a single spike starting at T_zero and
ending at ~T+0.04 sec.  T90 (15-350 keV) is 0.032 +- 0.008 sec
(estimated error including systematics).
 
The time-averaged spectrum from T+0.0 to T+0.040 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index -0.70 +- 2.57, 
and Epeak of 40.5 +- 8.0 keV (chi squared 51.9 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.2 +- 0.3 x 10^-8 erg/cm2
and the 1-sec peak flux measured from T-0.48 sec in the 15-150 keV band is
0.3 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.13 +- 0.30 (chi squared 59.7 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 

Given the soft nature of this event, the Fermi-GBM event consistant
with this location (Guiriec, 12255), and that the Swift location does not match
any of the known SGRs, we classify this event as a new SGR source.  The digits
in the name are derived from the Swift-XRT location (Circ 12253).
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/458907/BA/


GRB_name: GRB110808A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12261
SUBJECT: GRB 110808A: Swift-XRT refined Analysis
DATE:    11/08/08 14:49:07 GMT
FROM:    Giulia Stratta at ASDC  <stratta@asdc.asi.it>

G. Stratta and V. D'Elia (ASDC) report on behalf of the Swift-XRT team:


We have analysed 3.8 ks of XRT data for GRB 110808A (Stratta  et al.
GCN Circ. 12256), from 100 s to 18.0 ks after the  BAT trigger. The
data comprise 91 s in Windowed Timing (WT) mode (the first 9 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode. The enhanced XRT position for this burst was given by Goad
et al. (GCN. Circ 12257).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.79 (+0.22, -0.20), followed by a break at T+459 s to
an alpha of 0.57 (+0.18, -0.23).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.07 (+0.29, -0.25). The
best-fitting absorption column is  2.9 (+1.4, -1.3) x 10^21 cm^-2, at a
redshift of 1.348 (de Ugarte Postigo et al. GCN Circ. 12258), in
addition to the Galactic value of 1.0 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 2.2 x 10^-11 (3.5 x 10^-11) erg
cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Galactic foreground: 1.0 x 10^20 cm^-2
Intrinsic column:    2.9 (+1.4, -1.3) x 10^21 cm^-2 at z=1.348
Photon index:      3.07 (+0.29, -0.25)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00458918.

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


GRB_name: GRB110808A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12262
SUBJECT: GRB 110808A: Swift-BAT refined analysis
DATE:    11/08/08 14:51:05 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), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
G. Sato (ISAS), M. Stamatikos (OSU), G. Stratta (ASDC),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-471 to T+639 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110808A (trigger #458918)
(Stratta, et al., GCN Circ. 12256).  The BAT ground-calculated position is
RA, Dec = 57.322, -44.177 deg which is 
   RA(J2000)  =  03h 49m 17.2s 
   Dec(J2000) = -44d 10' 35.4" 
with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 76%.
 
The mask-weighted light curve shows a FRED pulse shape starting at ~T+0 sec,
peaking at ~T+1 sec, and returning the baseline at ~T+50 sec.
T90 (15-350 keV) is 48 +- 23 sec (estimated error including systematics).
 
The time-averaged spectrum from T-7.4 to T+40.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.32 +- 0.43.  The fluence in the 15-150 keV band is 3.3 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.06 sec in the 15-150 keV band
is 0.4 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/458918/BA/


GRB_name: GRB110808A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12264
SUBJECT: GRB 110808A: Swift/UVOT Detection
DATE:    11/08/08 19:04:03 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard@astro.psu.edu>

T. A. Pritchard (PSU) and G. Stratta (ASDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110808A
120 s after the BAT trigger (Stratta et al., GCN Circ. 12256).
A source consistent with the Enhanced Swift-XRT position
(Goad et al., GCN Circ. 12257) is detected in the initial UVOT exposures.

The preliminary UVOT position is:
     RA  (J2000) =  03:49:04.27 =  57.26780 (deg.)
     Dec (J2000) = -44:11:40.1  = -44.19448 (deg.)
with an estimated uncertainty of 0.64 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits 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              120          270          147         19.88  0.14
white              57           559           19         18.48  0.23
white              3996         4196         200         20.17  0.16
v                  609          629           19 >18.7
b                  535          555           20         18.64  0.32
u                  279          528          246         18.28  0.09
u                  683          703           19         17.48  0.25
u                  6062         6262         196 >20.62
w1                 658          678           19 >17.8
w2                 585          605           19 >18.3

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


GRB_name: GRB110807A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12266
SUBJECT: SGR 1834.9-0846/ GRB 110807A: archival IR observations 
DATE:    11/08/10 12:58:34 GMT
FROM:    Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>

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

"The region around the newly discovered SGR 1834.9-0846 (D'Elia et
al. GCN 12253; Barthelmy et al. GCN 12259) has been imaged as part
of the UKIDSS Galactic Plane Survey (Lucas et al. 2008 MNRAS 391
136) in the J, H and K-bands on May 10, 2007. Close to the refined
XRT location (current 90% error radius 1.8") we find two sources.
One at:

RA(J2000) 18:34:52.17 
DEC(J2000) -08:45:54.0

which is also in 2MASS, and has catalogue magnitudes of J=16.41 +/-
0.01, H=14.96 +/- 0.01, K= 14.13 +/- 0.01. We however note that
this source appears marginally extended in the K-band imaging, and
may be the result of the superposition of two sources within this
crowded region.

The second source is at location:

RA(J2000) 18:34:52.02 
DEC(J2000) -08:45:54.5

and has magnitudes of J=17.73 +/- 0.03, H=16.67 /- 0.02, K=16.07+/-
0.04. There are also numerous faint sources at larger offsets from
the refined XRT position. Further observations will be needed to
ascertain if any of these sources exhibit photometric variability."


GRB_name: GRB110808B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12269
SUBJECT: IPN triangulation of GRB 110808B (short/hard/intense)
DATE:    11/08/10 21:29:44 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley and 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,

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

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

GRB 110808B, a very intense short-duration, hard spectrum GRB,
was observed by Konus-Wind, Mars Odyssey, MESSENGER, and RHESSI at
56693 s UT.  We have triangulated it to a preliminary, 3 sigma error
box whose area is about 108 square arcminutes, whose maximum dimension
is ~22 arcminutes, and whose coordinates are:
             RA(2000)                         Dec(2000)
CENTER:   266.1808=17 h 44 m 43.4 s    -37.7463=-37 o 44 '  47 "
CORNERS:  266.0492=17 h 44 m 11.8 s    -37.7586=-37 o 45 '  31 "   
          266.3453=17 h 45 m 22.9 s    -37.8732=-37 o 52 '  24 "     
          266.0166=17 h 44 m 04.0 s    -37.6169=-37 o 37 '  01 "     
          266.3123=17 h 45 m 14.9 s    -37.7332=-37 o 44 '  00 "

Although this error box lies at Galactic latitude -5 degrees, it does
not include any of the known magnetars.  A Swift ToO has been requested.
Further details of the spectrum and time history will appear in a
forthcoming GCN Circular.  A map is posted at
ssl.berkeley.edu/ipn3/110808B.  This error box can be improved.


GRB_name: GRB110808A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12270
SUBJECT: Konus-Wind observation of GRB 110808A
DATE:    11/08/11 10:30:42 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-duration extremely hard GRB 110808A
(localized by IPN: Hurley et al., GCN 12269)
triggered Konus-Wind at T0=56695.237s UT (15:44:55.237)

The burst light curve shows a single bright hard pulse,
with a duration of ~0.5 s and much weaker tail of
the emission which is detectable till T0+8 s.
The emission is seen up to 13 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110808_T56695/

As observed by Konus-Wind the burst
had a fluence of (1.6  0.2)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.112 s,
of (1.1  0.2)x10-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.256 s)
is best fitted in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -1.13 (-0.08, +0.08),
and Ep = 2960(-796, +1217) keV,
chi2 = 53.2/45 dof.
Fitting this spectrum by the GRB (Band) function yields
the following model parameters:
the low-energy photon index alpha = -1.13 (-0.08, +0.07),
the high energy photon index beta = -2.5 (<-1.9),
the peak energy Ep = 2630(-744, +836) keV,
chi2 = 54.3/44 dof.

The spectrum at the maximum count rate
(measured from T0+0.064 to T0+0.128 s)
is best fitted in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -1.07 (-0.11, +0.12),
and Ep = 4238(-1530, +3270) keV,
chi2 = 12.5/16 dof.

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


GRB_name: GRB110808B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12271
SUBJECT: Konus-Wind observation of GRB 110808B
DATE:    11/08/11 11:15:57 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-duration extremely hard GRB 110808B
(localized by IPN: Hurley et al., GCN 12269)
triggered Konus-Wind at T0=56695.237s UT (15:44:55.237)

The burst light curve shows a single bright hard pulse,
with a duration of ~0.5 s and much weaker tail of
the emission which is detectable till T0+8 s.
The emission is seen up to 13 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110808_T56695/

As observed by Konus-Wind the burst
had a fluence of (1.6  0.2)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.112 s,
of (1.1  0.2)x10-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.256 s)
is best fitted in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -1.13 (-0.08, +0.08),
and Ep = 2960(-796, +1217) keV,
chi2 = 53.2/45 dof.
Fitting this spectrum by the GRB (Band) function yields
the following model parameters:
the low-energy photon index alpha = -1.13 (-0.08, +0.07),
the high energy photon index beta = -2.5 (<-1.9),
the peak energy Ep = 2630(-744, +836) keV,
chi2 = 54.3/44 dof.

The spectrum at the maximum count rate
(measured from T0+0.064 to T0+0.128 s)
is best fitted in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -1.07 (-0.11, +0.12),
and Ep = 4238(-1530, +3270) keV,
chi2 = 12.5/16 dof.

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


GRB_name: GRB110807A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12272
SUBJECT: SGR 1834.9-0846/ GRB 110807A, I-band observations
DATE:    11/08/11 11:59:50 GMT
FROM:    Juan Carlos Tello at IAA-CSIC  <jtello@iaa.es>

J. C. Tello, A. Sota and A. J. Castro-Tirado (IAA-CSIC Granada), on behalf
of a larger collaboration, report:

"We observed SGR 1834.9-0846/ GRB 110807A detected by Swift/BAT (D'Elia et
al., GCNC 12253, Barthelmy, GCN 12259) with the OSN 1.5m telescope. I-band
frames were obtained on 7 Aug, starting 16 min after the gamma-ray detection
(i.e. simultaneously to the BTA Rc-band observations, Moskvitin et al., GCNC
12254). Neither on the single I-band images (10s exposure time each) nor on
the co-added frames, taken between 20:14 and 21:48 UT, with total exposure
4820 sec, an object is detected within the Swift/XRT error box. The limiting
magnitude for the combined image is I = 21.6 (calibrated against USNO
B1.0)."

This message may be cited.


GRB_name: GRB110812A
Detection_method: superAGILE
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12274
SUBJECT: GRB 110812A: SuperAGILE localization of a long GRB.
DATE:    11/08/12 07:38:41 GMT
FROM:    Marco Feroci at IASF/INAF  <sa.grb@iasf-roma.inaf.it>

E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, F. Lazzarotto,
L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), G. Barbiellini, F. Longo, E. Moretti (INFN Trieste),
A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti,
F. Fuschino, M. Marisaldi, M. Galli (INAF/IASF Bologna),
A. Giuliani, A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF
Milan), M. Tavani, G. Pucella, V. Vittorini, A. Argan, A. Trois,
M. Cardillo, G. Piano, S. Sabatini (INAF/IASF Rome), A. Pellizzoni, M. Pilia
(INAF/OA Cagliari), S. Vercellone, F. D'Ammando (INAF/IASF Palermo),
P. W. Cattaneo, A. Rappoldi (INFN Pavia), P. Picozza, A. Morselli,
E. Striani, (INFN Roma-2), M. Prest, E. Vallazza (Universita'
dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1),
P. Giommi, C. Pittori, F. Lucarelli, P. Santolamazza, F. Verrecchia
(ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report:

"SuperAGILE detected a gamma ray burst on 12 August 2011, at 00:20:08 UT.
The event had a duration of about 30 s in the 20-60 keV energy range,
with a multi peak structure. Assuming a crab-like energy spectrum, the  
peak flux on 1-s timescale was 8.91E-08 erg/cm2/s.
The burst position was reconstructed as (RA, Dec)
(358.409, 72.206) deg, which is:

RA(J2000)  = 23h 53m 38.15s
Dec(J2000) = 72d 12' 23.32"

with an uncertainty of 3' radius. The given uncertainty accounts
for both the statistical and systematic errors.

An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."

This message may be cited.


GRB_name: GRB110801A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12275
SUBJECT: GRB 110801A: optical observations at Mt. Terskol observatory
DATE:    11/08/13 13:40:30 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, N. Parakhin, A. Sergeev (Terskol Branch of Institute of
Astronomy), A. Pozanenko (IKI) on behalf of larger GRB follow up
collaboration report:

We observed field of the Swift  GRB 110801A (Pasquale  et al. GCN 12228)
with Zeiss-600 telescope of Mt.Terskol observatory in R filter starting on
Aug. 02 (UT) 00:25.  In a stacked image we clearly detect optical afterglow
(Pasquale  et al. GCN 12228, Zheng et al. GCN 12229). A  photometry is based
on the USNO B1.0 star 1709-0023450 (05 57 24.91 +80 57 39.8) assuming
R=15.73.

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

0.1951   R         4x180       18.35 +/- 0.10


GRB_name: GRB110801A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12276
SUBJECT: GRB 110801A: Konus-Wind and Swift/BAT joint spectral analysis
DATE:    11/08/15 15:05:55 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori@milkyway.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), 
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), 
M. Stamatikos (OSU), J. Tueller (GSFC), and T. Ukwatta (MSU)

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

We performed the Konus-Wind and the Swift/BAT joint spectral analysis 
of GRB 110801A (Swift/BAT trigger #458521: De Pasquale et al., GCN Circ. 12228, 
Barthelmy et al. GCN Circ. 12237).  Since the Konus-Wind observed this GRB 
in the waiting mode, we only have 3 channel spectral data for the Konus-Wind 
which cover the energy range from 20 keV to 1.2 MeV.  The joint spectral 
analysis of the Konus-Wind and the Swift/BAT data allows us to derive 
the broad-band spectral parameters of this burst. 

The time interval of the spectral data is chosen from T0(BAT)-26.43 to 
T0(BAT)+64.83 sec and from T0(BAT)+332.74 to T0(BAT)+388.67 sec where T0(BAT) 
is the trigger time of BAT at 19:49.43 UTC to include two time-separated episodes.  
The energy ranges which we used in the joint spectral analysis are 20-1200 keV 
and 14-150 keV for the Konus-Wind and the Swift/BAT respectively.  The spectral 
data of two instruments are fitted with the spectral model multiplied by the 
constant factor to take into account the systematic effective area uncertainties 
in the response matrices of each instrument. 

The spectrum is well fitted with a power-law with exponential cutoff model: 
dN/dE ~ E^{alpha}*exp(-(2+alpha)*E/Epeak).  The constant factors of each 
instrument agree within 10%. No systematic residual from the best fit model is 
seen in the spectral data of each instrument (see Sakamoto et al. 2011, PASJ, 63, 
215 for the spectral cross-calibration).  The best fit spectral parameters are: 
alpha = -1.70 (-0.15/+0.12) and Epeak = 140 (-60/+900) keV (chi2/dof = 74/58).  
The best fit spectral parameters for the GRB (Band) model fixing beta = -2.5 are: 
alpha = -1.70 (-0.15/+0.22), and Epeak = 140 (-50/+1270) keV (chi2/dof = 74/58). 
The energy fluence in the 15-1200 keV band calculated by a power-law with 
exponential cutoff model for this 147.2 sec interval is 7.3 (-0.9/+ 1.7)x10^-6 erg/cm2.  

Assuming z=1.858 (Cabrera Lavers et al. GCN Circ. 12234) and a standard cosmology 
model with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73, the isotropic 
energy release is E_iso = 1.0 (-0.2/+0.3) x10^53 erg in 1 keV to 10 MeV at the 
GRB rest frame extrapolating the best Band function fit fixing beta = -2.5. 

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/GRB110801A/


GRB_name: GRB110815A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12277
SUBJECT: IPN triangulation of GRB110815A (long, intense)
DATE:    11/08/17 18:17:23 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, and W.
Hajdas, on behalf of the RHESSI 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,

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

E. Costa, E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci,
I. Lapshov, F. Lazzarotto, L. Pacciani, M. Rapisarda, P. Soffitta, 
for the SuperAGILE team, report:

GRB110815A at 34857 s UT was detected by SuperAGILE (outside the coded
FoV), Konus-Wind, MESSENGER GRNS, Odyssey HEND, RHESSI, Suzaku WAM, and
Swift BAT (also outside the coded FoV).  We have triangulated it to a
preliminary, 3 sigma error box whose area is 195 sq. arcmin and whose
coordinates are:

    RA(2000)                 DEC(2000)
85.297 o =  5 h 41 m 11.2 s  +32.442 = 32 o 26 '  31 "  (CENTER)
85.183 o =  5 h 40 m 43.9 s  +32.409 = 32 o 24 '  31 "  (CORNER)
85.464 o =  5 h 41 m 51.3 s  +32.753 = 32 o 45 '  12 "  (CORNER)
85.130 o =  5 h 40 m 31.1 s  +32.113 = 32 o 06 '  48 "  (CORNER)
85.411 o =  5 h 41 m 38.6 s  +32.474 = 32 o 28 '  26 "  (CORNER)

A map has been posted at ssl.berkeley.edu/ipn3/110815.  
This error box can be improved.  The time history and spectrum
will be given in a forthcoming GCN Circular.  A Swift ToO
has been requested.


GRB_name: GRB110815A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12278
SUBJECT: Konus-Wind observation of GRB 110815A
DATE:    11/08/18 09:15:30 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 intense GRB 110815A
(localized by IPN: Hurley et al., GCN 12277)
triggered Konus-Wind at T0=34855.971s UT (09:40:55.971)

The burst light curve shows two peaks separated by ~13 s.
The total duration of the burst is ~20s.
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/GRB110815_T34855/

As observed by Konus-Wind the burst
had a fluence of (5.0  0.5)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.920 s,
of (1.8  0.1)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+19.200 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.85 (-0.1, +0.1),
the high energy photon index beta = -2.5 (-0.3, +0.2),
the peak energy Ep = 251(-25, +25) keV,
chi2 = 73/87 dof.

The spectrum at the maximum count rate
(measured from T0 to T0+2.816 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.12 (-0.13, +0.14),
the high energy photon index beta = -2.8 (-0.3, +0.2),
the peak energy Ep = 300(-20, +22) keV,
chi2 = 99/87 dof.

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


GRB_name: GRB110818A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12279
SUBJECT: GRB 110818A: Swift detection of a burst
DATE:    11/08/18 21:00:09 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. B. Markwardt (NASA/GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
N. P. M. Kuin (UCL-MSSL), O. M. Littlejohns (U Leicester),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester),
T. A. Pritchard (PSU), A. Rowlinson (U Leicester),
T. Sakamoto (NASA/UMBC), C. J. Saxton (UCL-MSSL), M. H. Siegel (PSU)
and R. L. C. Starling (U Leicester) report on behalf of the Swift
Team:

At 20:37:49 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110818A (trigger=500914).  Because of an Earth-limb
observing constraint, the slew to the burst was delayed by ~4 min. 
The BAT on-board calculated location is 
RA, Dec 317.384, -63.970 which is 
   RA(J2000)  =  21h 09m 32s
   Dec(J2000) = -63d 58' 10"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows several peaks
with a total duration of about 60 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~7 sec after the trigger. 

The XRT began observing the field at 20:44:09.7 UT, 380.4 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 317.3382,
-63.9814 which is equivalent to:
   RA(J2000)  = 21h 09m 21.17s
   Dec(J2000) = -63d 58' 53.1"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 83 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 (2.62 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2
(+1.14/-1.05) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the U filter starting
856 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. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.04. 

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


GRB_name: GRB110815A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12280
SUBJECT: GRB 110815A : Suzaku WAM observation of the prompt emission
DATE:    11/08/19 02:39:31 GMT
FROM:    Norisuke Ohmori at Miyazaki U  <ohmori@astro.miyazaki-u.ac.jp>

N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki),
M. Ohno, Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, 
Y. Fukazawa (Hiroshima U.), K. Yamaoka (Aoyama Gakuin U.),
S. Sugita (Nagoya U.), T. Yasuda, Y. Terada, W. Iwakiri, 
K. Takahara, M. Asahina, S. Kobayashi, M. Tashiro (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 long GRB110815A (localized by IPN; Hurley et al., GCN12277) 
triggered the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 09:40:57.524 UT (=T0).

The observed light curve shows two peaks starting at T0 s, ending
at T0+17 s, with a duration (T90) of about 13 seconds. The fluence in
100 - 1000 keV was 2.84 (-0.04, +0.05) x 10^-5 erg/cm^2. The 1-s peak
flux measured from T0+2 s was 19.62 (-0.82, +0.92) photons/cm^2/s in the
same range.

Preliminary result shows that the time-averaged spectrum from
T0 s to T0+17 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha       1.45 (-0.13, +0.13), and
 Epeak       300 (-25, +20) keV (chi^2/d.o.f. = 102.1/88).

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: GRB110818A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12281
SUBJECT: GRB 110818A, Swift-BAT refined analysis
DATE:    11/08/19 03:02:20 GMT
FROM:    Craig Markwardt at NASA/GSFC  <craigm@milkyway.gsfc.nasa.gov>

C. B. Markwardt (GSFC), 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),
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-239 to T+963 sec from the recent telemetry 
downlink, we report further analysis of BAT GRB 110818A (trigger 
#500914) (Markwardt, et al., GCN Circ. 12279).  The BAT 
ground-calculated position is RA, Dec = 317.373, -63.981 deg which is
    RA(J2000)  =  21h 09m 29.6s
    Dec(J2000) = -63d 58' 52.7"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 29%.

The mask-weighted light curve consists of a single broad peak, with 
several sharper peaks superimposed.   T90 (15-350 keV) is 103 +- 18 sec 
(estimated error including systematics).

The time-averaged spectrum from T-14.2 to T+117.4 sec is best fit by a 
simple power-law model.  The power law index of the time-averaged 
spectrum is 1.58 +- 0.11.  The fluence in the 15-150 keV band is 4.0 +- 
0.2 x 10^-6 erg/cm2.  The 1-sec peak photon flux measured from T+27.3 
sec in the 15-150 keV band is 1.6 +- 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/500914/BA/


GRB_name: GRB110815A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12282
SUBJECT: GRB 110815A: Swift-XRT and UVOT refined Analysis
DATE:    11/08/19 07:04:37 GMT
FROM:    Antonia Rowlinson at U.of Leicester  <bar7@star.le.ac.uk>

A. Rowlinson (U Leicester), B.L. Porterfield; (PSU), M.H. Siegel (PSU), and C. B. Markwardt (GSFC) report on behalf of the Swift-XRT team:

We have analyzed 3.9 ks of XRT data for GRB 110815A (Hurley et al. GCN Circ. 12277), from 208 ks to 216 ks after the IPN trigger. The data are entirely in Photon Counting (PC) mode. The data are centred on RA, Dec = (85.297, 32.442). The XRT field of view therefore covers about 80% of the IPN error box. No source is detected in the XRT image with a 3 sigma upper limit of 2.4e-3 count s^-1.

Swift/UVOT observed the field of GRB 110815A (Hurley et al. GCN Circ. 12277) for 1.9 ks from 208 ks to 216 ks after the IPN trigger. Data were obtained entirely in the white filter. We do not detect any new source within the IPN error box down to a 3-sigma magnitude limit of 21.64 on the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627).  The magnitude limit is 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).

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


GRB_name: GRB110818A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12283
SUBJECT: GRB 110818A: Swift-XRT refined Analysis
DATE:    11/08/19 07:07:01 GMT
FROM:    Antonia Rowlinson at U.of Leicester  <bar7@star.le.ac.uk>

A. Rowlinson (U. Leicester) and C. B. Markwardt (NASA/GSFC) report on
behalf of the Swift-XRT team:

We have analysed 7.8 ks of XRT data for GRB 110818A (Markwardt et al.
GCN Circ. 12279), from 384 s to 18.3 ks after the  BAT trigger. The
data comprise 61 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The best available XRT position  (using the
promptly downlinked event data, the XRT-UVOT alignment and matching
UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 317.3378,
-63.9813 which is equivalent to:

RA (J2000): 21 09 21.07
Dec(J2000): -63 58 52.7

with an uncertainty of 2.0 arcsec (radius, 90% confidence).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=5.8 (+0.6, -0.7). At T+461 s  the decay
flattens to an alpha of 1.57 (+0.14, -0.11) before breaking again at
T+2167 s to a final decay with index alpha=0.95 (+0.10, -0.14).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.97 (+0.12, -0.11). The
best-fitting absorption column is  7.8 (+2.7, -2.4) x 10^20 cm^-2, in
excess of the Galactic value of 2.6 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 3.6 x 10^-11 (4.4 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7.8 (+2.7, -2.4) x 10^20 cm^-2
Galactic foreground: 2.6 x 10^20 cm^-2
Excess significance: 5.3 sigma
Photon index:      1.97 (+0.12, -0.11)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00500914.

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


GRB_name: GRB110818A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12284
SUBJECT: GRB 110818A: Optical afterglow and redshift from VLT/X-shooter
DATE:    11/08/19 07:49:47 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

P. D'Avanzo (INAF/Brera), M. Sparre, D. Watson, J. P. U. Fynbo, D. 
Malesani, B. Milvang-Jensen (DARK/NBI), P. Goldoni (APC/Univ. Paris 7 
and SAp/CEA), V. D'Elia (INAF/Rome), and N. R. Tanvir (U. Leicester), 
report on behalf of the X-shooter GTO GRB collaboration:

We observed the field of GRB 110818A (Markwardt et al. GCN 12279) with 
the ESO VLT equipped with X-shooter. Observations started on 2011-08-19 
at 02:47 UT (6.15 hr after the GRB).

The acquisition image shows an optical afterglow candidate inside the 
XRT error circle (Markwardt et al. GCN 12279) at the following 
coordinates (J2000):

RA = 21:09:21.04
Dec = -63:58:52.3

with an uncertainty of about 0.5". The object has a magnitude R ~ 22.3, 
calibrated assuming R = 19.2 for the USNO-B1 star 0260-0726657 (RA, Dec 
= 21:09:23.14, -63:58:33.0).

A total spectroscopic exposure of 4x1200 s was obtained, covering the 
spectral range from 300 to 2500 nm.

We report a redshift of z = 3.36 based on detection of absorption 
features from Si II, C IV, Al II, Ca H, Ca K and Mg I. Emission from the 
[O III] doublet is also observed.

We would like to thank the staff at the VLT, in particular, Alain 
Smette, Patricia Guajardo and Dimitri Gadotti for carrying out the 
observations.


GRB_name: GRB110818A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12285
SUBJECT: GRB 110818A: Enhanced Swift-XRT position
DATE:    11/08/19 08:28:06 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 4176 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 110818A, 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 = 317.33705, -63.98105 which is equivalent
to:

RA (J2000): 21h 09m 20.89s
Dec (J2000): -63d 58' 51.8"

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: GRB110818A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12286
SUBJECT: GRB 110818A: Swift/UVOT Upper Limits
DATE:    11/08/19 19:29:06 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard@astro.psu.edu>

T. A. Pritchard (PSU) and C. B. Markwardt (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110818A
379 s after the BAT trigger (Markwardt et al., GCN Circ. 12279).
No optical afterglow consistent with the Enhanced Swift-XRT position
(GCN Circ. 12285) 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

v                  379        14423         1513         >20.8
b                  477        18642         2455         >22.2
u                  452         8009          813         >20.4
w1                 428         7804          646         >20.9
m2                7399         7599          197         >20.9
w2                6989        13752         1082         >21.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110818A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12287
SUBJECT: GRB 110818A: Fermi GBM observation
DATE:    11/08/19 23:02:20 GMT
FROM:    Shaolin Xiong at UAH  <sx0002@uah.edu>

S. Xiong (UAH) reports on behalf of the Fermi GBM Team:

"At 20:37:54.221 UT on 18 August 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110818A (trigger 335392676 / 110818860 ),
which was also detected by the Swift (Markwardt et al. 2011, GCN 12279).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 96 degrees.
This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 75 s (50-300 keV).
The time-averaged spectrum from T0-16.4 s to T0+57.3 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.33 +/- 0.08 and
the cutoff energy, parameterized as Epeak, is 256.3 +/- 55.3 keV.

The event fluence (10-1000 keV) in this time interval is
(8.2 +/- 0.6)E-6 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+22.66 s in the 10-1000 keV band
is 5.0 +/- 1.4 ph/s/cm^2.

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


GRB_name: GRB110820A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12288
SUBJECT: GRB 110820A: Swift detection of a burst
DATE:    11/08/20 17:55:18 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

E. Troja (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC),
J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU),
E. Sonbas (GSFC/USRA/Adiyaman Univ.) and T. N. Ukwatta (MSU) report on
behalf of the Swift Team:

At 17:38:27 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110820A (trigger=501095).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 343.335, +70.305 which is 
   RA(J2000) = 22h 53m 20s
   Dec(J2000) = +70d 18' 20"
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 10 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 17:39:46.8 UT, 79.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 343.1911, 70.2974 which
is equivalent to:
   RA(J2000)  = 22h 52m 45.86s
   Dec(J2000) = +70d 17' 50.5"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 177 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 3.34
x 10^21 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 250 seconds with the U filter
starting  139 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. Data from the list of
sources generated on-board are not  available at this time. No
correction has been made for the expected extinction  corresponding to
E(B-V) of 0.55. 

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


GRB_name: GRB110820A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12289
SUBJECT: GRB 110820A: MASTER-NET observations
DATE:    11/08/20 18:05:47 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.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  GRB110820A 45 sec after 
notice time and 133 sec after GRB time at 2011-08-20 17:40:40.275 UT in 
two polarizations. On  our first (30s exposure) set we haven't found 
optical transient  within SWIFT error-box.

The 5-sigma upper limit has been about 16.5 mag
  The message may be cited.


GRB_name: GRB110820A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12290
SUBJECT: GRB 110820A: CrAO optical upper limit
DATE:    11/08/20 22:17:57 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 110820A (Troja  et al., GCN 12288) 
with AZT-11 telescope of CrAO between  Aug. 20 (UT) 18:23
 - 19:21. Within the XRT error box  (Troja  et al., GCN 12288)  we do not 
detect any source. The photometry is based on the USNO B1.0 star 
1602-0161058    (22:52:45.06 +70:17:17.5) assuming R=18.23:

T0+      Filter,   Exposure, OT,           Upper Limit (3 sigma)
(mid, d)              (s)

0.0520   R        20x180       n/d           21.6


GRB_name: GRB110820A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12291
SUBJECT: GRB 110820A: Enhanced Swift-XRT position
DATE:    11/08/20 23:52:19 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 1200 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 110820A, 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 = 343.19224, +70.29848 which is equivalent
to:

RA (J2000): 22h 52m 46.14s
Dec (J2000): +70d 17' 54.5"

with an uncertainty of 2.3 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: GRB110820A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12292
SUBJECT: GRB 110820A: Swift-BAT refined analysis
DATE:    11/08/21 01:52:10 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), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-119 to T+296 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110820A (trigger #501095)
(Troja, et al., GCN Circ. 12288).  The BAT ground-calculated position is
RA, Dec = 343.203, 70.298 deg, which is 
   RA(J2000)  =  22h 52m 48.8s 
   Dec(J2000) = +70d 17' 51.2" 
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.
 
The mask-weighted light curve shows two main peaks.  The first started at ~T-5 sec,
peaking at ~T+2 sec, and ending at ~T+35 sec.  The second starts at ~T+195 sec,
peaking at ~T+230, and ending at ~T+285 sec.  T90 (15-350 keV) is 256 +- 50 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-7.07 to T+264.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.92 +- 0.28.  The fluence in the 15-150 keV band is 8.2 +- 1.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.43 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/501095/BA/


GRB_name: GRB110820A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12293
SUBJECT: GRB110820A: MITSuME Ishigakijima Optical Upper Limits
DATE:    11/08/21 02:32:56 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

$B3'MM(B

$B9uED$G$9!#(B
$B:rHU$N(BGRB110820A$B$N@P3@Eg$N7k2L$G$9!#(B
$B2V;3$5$s$,4QB,$r$7$F$/$l$^$7$?!#(B

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 110820A (Troja et al., GCNC 12288)
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 17:47:41 UT (~9 min after the burst).
We did not find any new point source within the enhanced XRT error
circle (Beardmore et al., GCNC 12291) 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
----------------------------------------------------
0.04719    18:46:24    5280.0   >20.6 >21.3 >19.9
----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110820A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12294
SUBJECT: GRB 110820A: Swift-XRT refined Analysis
DATE:    11/08/21 06:32:35 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) and E. Troja (NASA/GSFC/ORAU) report on behalf
of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 110820A (Troja  et al. GCN
Circ. 12288), from 82 s to 24.5 ks after the  BAT trigger. The data
comprise 121 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Beardmore et al. (GCN. Circ 12291).

The first snapshot of data is dominated by a large flare, also detected
by the BAT (Palmer et al. GCN Circ. 12292). After around 750 s, the
light curve decay can be fitted with index alpha=0.28 (+0.13, -0.15).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.32 (+0.07, -0.06). The
best-fitting absorption column is  6.1 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 3.3 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.80 (+0.20, -0.26)
and a best-fitting absorption column of 4.7 (+/-1.3) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 5.1 x 10^-11 (7.8 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.7 (+/-1.3) x 10^21 cm^-2
Galactic foreground: 3.3 x 10^21 cm^-2
Excess significance: 5.9 sigma
Photon index:      1.80 (+0.20, -0.26)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00501095.

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


GRB_name: GRB110820A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12295
SUBJECT: GRB 110820A: CQUEAN izY Observation
DATE:    11/08/21 08:14:40 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ), 
Soojong Pak, Giseon Baek, and Youngseok Oh (Kyunghee University)

We observed GRB 100820A (Troja et al. GCN 12288) with i,z,and 
Y-filters using CQUEAN camera (the Camera for QUasars in the Early uNiverse) 
on the 2.1m telescope at the McDonald observatory. The observation 
started at 2010 August 21, 05:12:48 UT, about 11.5 hrs after the 
BAT trigger.

In a stacked i-band image (3 x 300 sec), we identify a faint object
within the error circle of the enhanced XRT position (Beardmore et al.
GCN 12291).

The position of the i-band source is

  RA=22:52:49.49
  Dec=70:17:53.6
  with a positional error of ~0.5".

We are carrying our further observations to examine variability 
of the source.


GRB_name: GRB110820A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12296
SUBJECT: GRB 110820A: i-band finding chart + correction to 12295
DATE:    11/08/21 08:22:26 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ), 
Soojong Pak, Giseon Baek, and Youngseok Oh (Kyunghee University)

The finding chart of the i-band image reported in Im et al.
(GCN 12295) is available at

http://astro.snu.ac.kr/~mim/grb110820a.html

We also make a correction to the year of the observation
reported in GCN 12295. It should be 2011, not 2010.


GRB_name: GRB110820A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12297
SUBJECT: GRB 110820A: Position udpate + 2nd epoch data
DATE:    11/08/21 11:58:19 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ), 
Soojong Pak, Giseon Baek, and Youngseok Oh (Kyunghee University)

We revise the position of the afterglow candidate to be

   RA=22:52:46.49
   Dec=70:17:53.6
   with a positional error of ~0.5".

The 2nd set of i-band images were taken 3 hrs after
the 1st set (Im et al. GCN 12295). Our analysis of the data
shows no significant fading of the object (dm < 0.1  mag)
during that time span.


GRB_name: GRB110820A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12298
SUBJECT: GRB 110820A: Swift/UVOT Upper Limits
DATE:    11/08/22 14:20:06 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler@nasa.gov>

S. Immler (NASA/CRESST/GSFC) and E. Troja (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110820A
139 s after the BAT trigger (Troja et al., GCN Circ. 12288).
No optical afterglow consistent with the enhanced XRT position
(Beardmore et al., GCN Circ. 12291) and the position of the
optical afterglow candidate Myungshin et al., GCN Circ. 12297)
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

u_FC               139          389          246 >20.6
v                  445        24186         1395 >21.1
b                  394        12987          932 >22.0
u                  139        18761         2181 >21.8
w1                 494        18331         2155 >21.8
m2                 469        24536         1716 >20.6
w2                 420        23272         1396 >21.2

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: GRB110820B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12299
SUBJECT: IPN triangulation of GRB 110820B (very long duration, extremely intense)
DATE:    11/08/22 22:40:43 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

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,

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

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

On 2011 August 20 at about 21:27:50 UT, an extremely intense, very long
duration GRB was observed by Konus-Wind, MESSENGER, RHESSI, and Swift
(BAT) (outside the coded field of view).  We have triangulated it to a
preliminary, 3 sigma error box whose area is 0.212 sq. deg. and whose
coordinates are:
------------------------------------------------
      RA(2000), deg              Dec(2000), deg
------------------------------------------------
Center:
   157.583 (10h 30m 20s)   -54.605 (-54d 36' 16")
Corners:
   159.392 (10h 37m 34s)   -54.329 (-54d 19' 45")
   156.617 (10h 26m 28s)   -54.836 (-54d 50' 09")
   155.769 (10h 23m 05s)   -54.841 (-54d 50' 27")
   158.541 (10h 34m 10s)   -54.362 (-54d 21' 44")
------------------------------------------------

Some improvement to this error box is possible. The time history and
spectrum will be given in a forthcoming GCN Circular.


GRB_name: GRB110820A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12300
SUBJECT: GRB 110820A: MASTER-NET first hour observations
DATE:    11/08/23 06:09:31 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.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. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

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

E. Sinyakov, 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  GRB110820A 45 sec after notice time and 
133 sec after GRB time at 2011-08-20 17:40:40.275 UT in two polarizations 
on one in each tube. 
During the analysis of the data of the first hour of observation following 
results have been received:

T-T(GRB)  T-T(GRB)  T-T(GRB)  Exptime    Limit    Filter  Coadd
start[s]  stop[s]   mean [s]    [s]    (5-sigma) 
---------------------------------------------------------------
133        163       148         30      16.4      P_      no
133        163       148         30      16.5      P|      no
133       2797      1465       2040      19.3      P_      14
133       2797      1465       2040      19.6      P|      14
133       2797      1465       4080      19.9     P|+P_    28

Image in filter P_+P| available here
http://observ.pereplet.ru/images/evgeny/GRB110820A.jpg


  The message may be cited.


GRB_name: GRB110820B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12301
SUBJECT: Konus-Wind observation of GRB 110820B
DATE:    11/08/23 09:34:20 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 long hard extremely intense GRB 110820B
(localized by IPN: Hurley et al., GCN 12299)
triggered Konus-Wind at T0=77268.054s UT (21:27:48.054)

The event light curve shows two major bursting episodes
separated by ~100 s. A weaker and softer emission is
observed at the time between the two main pulses.
The total duration of the burst is ~200s.
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/GRB110820_T77268/

As observed by Konus-Wind the burst
had a fluence of (2.5  0.3)x10-4 erg/cm2,
and a 64-ms peak flux, measured from T0+3.136 s,
of (2.6  0.4)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+191.488 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.22 (-0.05, +0.06),
the high energy photon index beta = -2.1 (-0.3, +0.2),
the peak energy Ep = 481(-83, +90) keV,
chi2 = 69/84 dof.

The spectrum at the maximum count rate
(measured from T0+0.256 to T0+3.840 s) is best fitted
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.55 (-0.09, +0.09),
the high energy photon index beta = -2.5 (-0.4, +0.2),
the peak energy Ep = 483(-53, +60) keV,
chi2 = 81/84 dof.

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


GRB_name: GRB110820A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12306
SUBJECT: GRB 110820A, the review of the sky area in plate archives
DATE:    11/08/26 16:36:37 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 110820A (Beardmore GCN Circ.12091) 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 
19830903.220221 GUA040C000207 16.0 15.75 1575-05316204
19841020.183916 GUA040C000521A 16.0 15.75 1575-05316204

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 15 minutes area around 
       the location given in Beardmore et al. GCN Circ.12091: 
       RA(J2000): 22h 52m 46.14s, Dec(J2000): +70d 17' 54.5"
Star USNOA2 - Comparison star.
  The preview images of 2 areas together with  
the 15x15 min.of arc area from SkyMap can be found in  
http://gua.db.ukr-vo.org/img/grb/110820A/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: GRB110825A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12307
SUBJECT: IPN triangulation of GRB110825A (very intense, long-duration)
DATE:    11/08/26 17:53:40 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley, on behalf of the MESSENGER 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,

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,

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

G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, M. Marisaldi, 
on behalf of the AGILE MCAL team, and

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

GRB110825A (=Fermi GBM trigger 335932012) was observed by AGILE MCAL
(outside the coded field of view of SuperAGILE), Fermi GBM, MESSENGER
GRNS, Odyssey HEND, Suzaku WAM, and Swift BAT (outside the coded field 
of view).  We have triangulated it to a preliminary, 3 sigma error
box whose area is 252 square arcminutes and whose coordinates are:

           RA                               DEC                         

CENTER:   44.896 o= 2 h 59 m 35.1 s      15.407 o= 15 o 24' 25"
CORNERS:  45.160 o= 3 h 00 m 38.3 s      14.528 o= 14 o 31' 39"          
          44.959 o= 2 h 59 m 50.1 s      15.336 o= 15 o 20' 11"           
          44.834 o= 2 h 59 m 20.1 s      15.478 o= 15 o 28' 42"         
          44.595 o= 2 h 58 m 22.7 s      16.428 o= 16 o 25' 40"

This preliminary error box has been posted at ssl.berkeley.edu/ipn3/110825A;
it can be improved.

A Swift ToO has been carried out, and the results of that observation,
as well as the details of the burst, will be reported in forthcoming
GCN Circulars.


GRB_name: GRB110825A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12308
SUBJECT: GRB110825A: Swift target of opportunity observation
DATE:    11/08/26 21:29:20 GMT
FROM:    Binbin Zhang at PSU  <bbzhang@psu.edu>

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


Swift began a target of opportunity observation of the IPN-detected
burst: GRB110825A (Hurley et al. et al. GCN Circ. 12307) on August 26,
2011 at 01:05 UT, approximately 22.7 hours after the burst was detected
by IPN. Swift data for these observations utilize Target ID 20183.

We have analysed 2.9 ks of XRT data for this burst, from 81.3 ks to
94.0 ks after the IPN trigger. The data are entirely in Photon Counting
(PC) mode. An X-ray source is detected within the XRT field-of-view.
The refined XRT position is RA, Dec = 44.79846, +15.42733 which is
equivalent to:

RA (J2000): 02 59 11.63
Dec(J2000): +15 25 38.4

with an uncertainty of 3.9 arcsec (radius, 90% confidence). This
position is 346 arcsec from the IPN position and about 180 arcsec from
the edge of IPN error box (see
http://www.personal.psu.edu/buz12/IPN_ERRORBOX_VS_XRT_GRB110825A.png). 
We cannot determine at the present time whether the source is fading.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.8 (+0.8, -0.4). The
best-fitting absorption column is consistent with the Galactic value of
9.9 x 10^20 cm^-2 (Kalberla et al. 2005). The count rate for the X-ray
source is about 0.01 count/sec, which is relatively bright when
comparing to other GRB's X-ray afterglow at t-T0=10^5 seconds. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.9 x 10^-11 (4.7 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      0 (+1.7, -0) x 10^21 cm^-2
Galactic foreground: 9.9 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.8 (+0.8, -0.4)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020183.


No source was found from UVOT data within the XRT error circle.
Preliminary 3-sigma up-limits are : 

Filter      EXPOSURE     Mag
---------------------------------------------------
    v  &    579 &   >19.19  
    u  &    1365 &  >20.79 
white  &    895.63 &  >21.40
---------------------------------------------------


We notice that there is no known source at the X-ray source position in
Simbad or the NED. We also notice that the RASS data for this position
were not deep enough to detect a source of this flux (0.01 count/sec).

We have scheduled further Swift TOO for this target. 

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


Burst Advocate for this burst is B.-B. Zhang (bbzhang AT 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: GRB110825A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12309
SUBJECT: GRB 110825A: field inspection and possible host galaxy
DATE:    11/08/27 00:09:52 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

D. Xu reports on behalf of a larger collaboration:

We inspected the archival datasets of the XRT field (Zhang & Grupe,
GCN 12308) of GRB 110825A (Hurley et al., GCN 12307). We found an
extended (in the SE-NW direction) object centered at

RA (J2000): 02:59:11.966
Dec(J2000): +15:25:41.34

which is 5.7 arcsec to the center of the XRT error circle with a
radius of 3.9 arcsec (90% confidence; GCN 12308). Therefore, if the
XRT source is really the counterpart of IPN-triangulated GRB110825A or
even of a new burst (as the XRT position is outside the IPN error
box), the extended object could be the host galaxy of this event.

Inspection of the archives reveals the extended object: (1)  being
U1050_00797295 (USNO at ESO) with r=18.4 mag and b=19.2 mag; (2) being
02591193+1525410 (2MASS at CADC) with J=16.493+/-0.140 mag,
H=15.810+/-0.134 mag, and K=15.210+/-0.149 mag; and (3) being
1054-0031516 (USNO B1 at CDS) with R1=18.91 mag and B1=19.84 mag.

In addition, preliminary UVOT photometry (standard 5arcsec aperture
photometry) centered on the above location reveals

v(AB)>19.28
u(AB)>21.90
wh(AB)=21.55 +/- 0.21

More accurate UVOT photometry is required as the OT is extended and
relatively faint for the UVOT telescope.

Considering the above possible host galaxy is brighter than usual GRB
hosts, this source might be a low-redshift one.


GRB_name: GRB110827A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12310
SUBJECT: GRB 110827A: Swift detection of a burst
DATE:    11/08/27 00:11:29 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

B.-B. Zhang (PSU), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
C. Gronwall (PSU), D. Grupe (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) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 00:01:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110827A (trigger=501520).  Swift could not slew to this
burst due to the Sun constraint.  The BAT on-board calculated location is 
RA, Dec 164.095, +53.787 which is 
   RA(J2000) = 10h 56m 23s
   Dec(J2000) = +53d 47' 13"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 30 sec.  The peak count rate
was ~600 counts/sec (15-350 keV), at ~0 sec after the trigger. 

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

Burst Advocate for this burst is B.-B. Zhang (bbzhang AT 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: GRB110825A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12311
SUBJECT: GRB 110825A: optical afterglow candidate
DATE:    11/08/27 10:17:19 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.xu@weizmann.ac.il>

D. Xu (WIS), S. Schulze, P. Jakobsson (U. Iceland), and F. Faedi (QUB) report:

We observed the field (Zhang & Grupe, GCN 12308) of GRB 110825A
(Hurley et al., GCN 12307) with the Nordic Optical Telescope (NOT)
equipped with ALFOSC. We obtained 4x300s R-band imaging, starting at
05:07:08 UT on 27th August 2011. Only the first frame is useful due to
cloudy weather and relatively bright background towards the morning
twilight.

An optical object was weakly detected within the XRT error circle (GCN
12308), localised at

RA (J2000): 02:59:11.674
Dec(J2000): +15:25:39.84
Error circle radius: ~0.2 arcsec

which is about 3.9 arcsec to the extended object reported in our
previous GCN 12309. The source has R~23.6 mag calibrated to nearby
stars in the USNO B1 catalog.

No further observation with the NOT is planned.


GRB_name: GRB110827A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12312
SUBJECT: GRB 110827A, Swift-BAT refined analysis
DATE:    11/08/27 13:54:44 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

T. Sakamoto (GSFC/UMBC), 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),
G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC),
T. N. Ukwatta (MSU), B.-B. Zhang (PSU) (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 110827A (trigger #501520)
(Zhang, et al., GCN Circ. 12310).  The BAT ground-calculated position is
RA, Dec = 164.059, 53.817 deg which is
     RA(J2000)  =  10h 56m 14.2s
     Dec(J2000) = +53d 49' 01.2"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a single peak starting at ~T-15 sec,
peaking at T+5 sec and returning to background by T+35 sec.
At T+195 sec, a pre-planned slew moved the source out of the field of view.
T90 (15-350 keV) is 8.5 +- 1.1 sec (estimated error including systematics).

The time-averaged spectrum from T-2.9 to T+6.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.24 +- 0.27.  The fluence in the 15-150 keV band is 1.8 +- 0.3 x 10-07
erg/cm2. The 1-sec peak photon flux measured from T+2.12 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/501520/BA/


GRB_name: GRB110825A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12313
SUBJECT: GRB110825A: ROTSE early time optical limit
DATE:    11/08/27 15:36:56 GMT
FROM:    Weikang Zheng at U.of Michigan  <zwk@umich.edu>

W. Zheng & C. Akerlof (U Mich), report on behalf of the ROTSE collaboration:

ROTSE-IIId, located at the Turkish National Observatory at
Bakirlitepe, Turkey, responded to GRB 110801A (Hurley et al.
GCN 12307; GBM trigger 335932012) near dawn condition.
The first image started at Aug. 25 02:30:44 UT, ~ 242 seconds
after the GBM trigger. Observation was performed in 4x4 tiling
mode around the center of the GBM trigger with exposure time
of 20 seconds for each image. Useful image last up to ~1000
seconds after trigger due to bright dawn background after that.

The optical afterglow location (Xu et al. GCN 110825) within XRT
error (Zhang & Grupe GCN 12308) is covered in 8 ROTSE images.
We do not detecte the optical afterglow. We summarize the upper
limit result below (clear band data, calibrated to USNO A-1.0):

------------------------------------
t-t0(s)  exp(s)  3-sigma upper limit
301.3    20.0    15.6
418.8    20.0    15.3
448.2    20.0    15.3
477.5    20.0    15.3
771.1    20.0    14.6
888.2    20.0    14.5
917.4    20.0    14.5
946.7    20.0    14.4


GRB_name: GRB110825A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12314
SUBJECT: GRB 110825A: GMG optical observation
DATE:    11/08/28 12:03:44 GMT
FROM:    Xiao-hong Zhao at Nanjing University  <zhaoxiaohong78@gmail.com>

X. H. Zhao (YNAO), D. Xu (WIS), J. M. Bai (YNAO), report on behalf of a larger collaboration:

We observed the XRT field (Zhang & Grupe, GCN 12308) of GRB 110825A
(Hurley et al., GCN 12307) with the 2.4m Gao-Mei-Gu (GMG) telescope
equipped with YFOSC in Yunan, China. Observations started at 19:02:36
UT on 27th August 2011 and 3x1200s R-band images were obtained.
The possible optical afterglow candidate, derived from a weak
detection from a single frame (Xu et al., GCN 12311) is not detected
in our stacked R-band image, which gives rise to a 3sigma upper limit
of R~23.9 mag for the XRT error circle, calibrated with the same USNO
reference star in GCN 12311.

No further observation with the GMG telescope is planned.


GRB_name: GRB110825A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12315
SUBJECT: GRB 110825A: Suzaku WAM observation of the prompt emission
DATE:    11/08/29 20:41:15 GMT
FROM:    Kazutaka Yamaoka at Aoyama Gakuin U  <yamaoka@phys.aoyama.ac.jp>

K. Yamaoka (Aoyama Gakuin U.), N. Ohmori, M. Akiyama, 
M. Yamauchi (Univ. of Miyazaki), M. Ohno, Y. Hanabata, 
T. Uehara, T. Takahashi, M. Mizuno, Y. Fukazawa (Hiroshima U.), 
S. Sugita (Nagoya U.), T. Yasuda, Y. Terada, W. Iwakiri, 
K. Takahara, M. Asahina, S. Kobayashi, M. Tashiro (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, long GRB110825A (localized by IPN; Hurley et al. GCN 12307) 
triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an 
energy range of 50 keV - 5 MeV at 02:27:03.410 UT (=T0).

The observed light curve shows multiple peaks starting at T0-3 s, ending
at T0+8 s, with a duration (T90) of about 6.9 seconds. The fluence in
 the 100 - 1000 keV range was 1.88 +/- 0.14 x 10^-5 erg/cm^2. 
The 1-s peak flux measured from T0+3 s was 17.0 +/- 0.8 photons/cm^2/s
in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-3 s to
T0+8 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha :     1.28 (-0.40, +0.34), and
 Epeak :     248 (-47, +41) keV (chi^2/d.o.f. = 19.4/21).

All the quoted errors are at statistical 90% confidence level,
in which 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: GRB110825A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12318
SUBJECT: GRB110825A: Fermi GBM observation
DATE:    11/08/30 21:11:14 GMT
FROM:    Sinead McGlynn at Excellence Cluster/TUM  <smcglynn@tum.de>

S. McGlynn (MPE/Excellence Cluster) reports on behalf of the Fermi GBM Team:

"At 02:26:50.94 UT on 25 August 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110825A (trigger 335932012 / 110825102),
which was also localised by the IPN
(Hurley et al. 2011, GCN 12307).

The angle from the Fermi LAT boresight at trigger time was 65 degrees.
Approximately 100 s from trigger time, the Fermi spacecraft executed
an automatic maneuver in response to a command from GBM, in
order to place the burst closer to the LAT boresight.

The GBM light curve shows a soft precursor (~2s) followed by 2 bright
peaks from T0+10s to T0+25s, with a possible soft tail at T0+75 to
T0+85s. The duration (t90) is 62.5 +/- 0.2 s (50-300 keV).

The time-averaged spectrum from T0-0.64 s to T0+82.3 s is
best fit by a Band function with Epeak = 233.6 (+21.9/-19.9) keV,
alpha = -1.23 (+/-0.03), and beta = -2.04 (+0.06/-0.08)
(C-Stat 719.72 for 490 d.o.f.).

The event fluence (10-1000 keV) in this time interval is
(5.45 +/- 0.70)E-5 erg/cm^2. The 1 s peak photon flux measured
starting from T0+15.5 s in the 10-1000 keV band
is 53.7 +/- 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: GRB110820A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12321
SUBJECT: GRB 110820A: optical upper limit
DATE:    11/09/02 14:33:04 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss@gmail.com>

Volnova (SAI MSU), E. Litvinenko (UBAI), I. Molotov (Institute of
Applied Mathematics), A. Pozanenko (IKI)

We observed the field of the Swift GRB 110820A (Troja et al., GCN
12288) with 40-cm telescope ORI-40 of Kitab ISON observatory on Aug.
20 starting on 17:48:45 UT, i.e. 15.5 minutes after the BAT trigger.
On the stacked image we do not detect any source within the enhanced
XRT error box (Beardmore et al., GCN 12291). The photometry is based
on the USNO B1.0 star USNO-B1.0 1603-0160240, (J2000) RA = 22:52:56.89
Dec = +70:18:37.5, assuming  R 17.19:

 Tstart UT, T0+,        Filter, Exposure, OT, Upper Limit (3 sigma)
                 (mid, d)             (s)

 17:48:45   0.01072   R       5*120        n/d  19.2
 17:48:45   0.02734   R       28*120      n/d  19.6


GRB_name: GRB110903A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12322
SUBJECT: GRB 110903A: a long GRB detected by INTEGRAL
DATE:    11/09/03 03:54:34 GMT
FROM:    Sandro Mereghetti at IASF/CNR  <sandro@iasf-milano.inaf.it>

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

a long gamma ray burst lasting about 400 s has been detected by IBAS in 
the IBIS/ISGRI data at 02:39:55 UT of September 3.

Its refined coordinates (J2000) are:

  RA: 197.0614 [degrees]
  DEC: 58.9852 [degrees]

with an uncertainty of 2 arcmin (90% c.l.).

The light curve consists of three main peaks starting approximately at t0, 
t0+200 s, and t0+300 s. The high count rate of the burst saturated the 
ISGRI telemetry.

A plot of the light curve will be posted at

http://ibas.iasf-milano.inaf.it/IBAS_Results.html


GRB_name: GRB110903A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12323
SUBJECT: Konus-Wind observation of GRB 110903A
DATE:    11/09/03 14:21:13 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 very long GRB 110903A
(localized by INTEGRAL: Mereghetti et al., GCN 12322)
triggered Konus-Wind at T0=09573.115s UT (02:39:33.115)

The light curve shows two equally hard peaks started
at ~T0 and at ~T0+190s respectively, and a third,
softer peak, started at ~T0+320s.
A total duration of the burst is ~370 s.
The emission is seen up to ~7 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110903_T09573/

As observed by Konus-Wind the burst
had a fluence of 4.2(-0.7,+2.2)x10-5 erg/cm2,
and a 256-ms peak flux, measured from T0+196.352 s,
of 1.8(-0.4,+0.6)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+368.896 s)
is best fitted in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -0.96 (-0.29, +0.37),
and Ep = 301(-80, +185) keV,
chi2 = 77.8/88 dof.
Fitting this spectrum by the GRB (Band) function yields
the following model parameters:
the low-energy photon index alpha = -0.93 (-0.31, +0.41),
the high energy photon index beta = -2.7 (<-1.9),
the peak energy Ep = 287(-89, +191) keV,
chi2 = 77.6/87 dof.

The spectrum near the maximum count rate
(measured from T0+196.864 to T0+205.056 s)
is best fitted in the 20 keV - 10 MeV range
by the GRB (Band) model, for which:
the low-energy photon index alpha = -0.69 (-0.20, +0.24),
the high energy photon index beta = -2.7 (<-2.2),
the peak energy Ep = 295(-57, +77) keV,
chi2 = 95.3/87 dof.

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


GRB_name: GRB110903A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12324
SUBJECT: GRB 110903A: Swift-XRT observations
DATE:    11/09/03 19:34:19 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 3.9 ks of XRT data for the INTEGRAL-detected burst:
GRB 110903A (Mereghetti et al., GCN Circ. 12322), from 33.8 ks to 45.3
ks after the INTEGRAL trigger. This GRB was also detected by Konus-Wind
(Golenetskii et al., GCN Circ. 12323). The data are entirely in Photon
Counting (PC) mode.  An X-ray source is detected within the INTEGRAL
error circle. Using 2176 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 = 197.06570,
+58.98150 which is equivalent to:

RA (J2000): 13h 08m 15.77s
Dec(J2000): +58d 58' 53.5"

with an uncertainty of 1.8 arcsec (radius, 90% confidence). This
position is 15.5 arcsec from the INTEGRAL position.  The light curve is
consistent with a constant source of mean count rate 6.1e-02 ct/sec. A
power-law fit gives an index of 0.9 (+/-1.9).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.8 (+0.4, -0.5). The
best-fitting absorption column is  3.7 (+2.2, -1.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.8 x 10^-11 (7.2 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.7 (+2.2, -1.5) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^20 cm^-2
Excess significance: 4.0 sigma
Photon index:      1.8 (+0.4, -0.5)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020184.

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


GRB_name: GRB110903A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12325
SUBJECT: GRB 110903A: Swift/UVOT Upper Limits
DATE:    11/09/03 22:18:17 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) and K.L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110903A
33.8 ks after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 12322).
No optical afterglow consistent with the enhanced XRT position (Page,
GCN Circ. 12324) is detected in the initial UVOT exposures.  UVOT
magnitude 3-sigma upper limits are reported in the following table:

Filter  T_start  T_stop  Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white    38935   45300    1507        > 21.94
v        39664   40380     705        > 19.86
u        33776   44483    1589        > 20.73

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.01
(Schlegel et al. 1998). All photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB110903A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12326
SUBJECT: GRB 110903A: Fermi GBM observation
DATE:    11/09/04 01:59:26 GMT
FROM:    Sheila McBreen at MPE  <smcbreen@mpe.mpg.de>

S. McBreen (UCD/MPE) and G. Fitzpatrick (UCD)
report on behalf of the Fermi GBM Team:

"At 02:39:34.42 UT on 03 September 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110903A (trigger 336710376 / 110903111),
which was also detected by  INTEGRAL (Mereghetti et  al. 2011, GCN 12322)
and Konus-Wind (Golenetskii et al. 2011, GCN 12323).
The GBM on-ground location is consistent with the INTEGRAL position.
The angle from the Fermi LAT boresight is 44 degrees.

The GBM light curve shows/consists of 3 main emission phases
with a duration (T90) of about 339.9 (+/-2.3)s (50-300 keV).
The time-averaged spectrum from T0-0 s to T0+339 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.88 +/- 0.04 and
the cutoff energy, parameterized as Epeak, is 281.3 +/- 21.1 keV.

The event fluence (10-1000 keV) in this time interval is
(3.3E-05 +/- 0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+7.7 s in the 10-1000 keV band
is 5.24 +/- 0.22 ph/s/cm^2.

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


GRB_name: GRB110905A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12327
SUBJECT: GRB 110905A: Swift detection of a burst
DATE:    11/09/05 06:34:30 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. Pagani (U Leicester), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), V. D'Elia (ASDC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
C. Guidorzi (U Ferrara), C. J. Mountford (U Leicester),
K. L. Page (U Leicester), C. J. Saxton (UCL-MSSL) and
R. L. C. Starling (U Leicester) report on behalf of the Swift Team:

At 05:48:40 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110905A (trigger=502415).  Swift did not slew because
of the Moon observing constraint.  The BAT on-board calculated location is 
RA, Dec 278.954, -19.318, which is 
   RA(J2000) = 18h 35m 49s
   Dec(J2000) = -19d 19' 03"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve is not available at this time. 

Due to an observing constraint, Swift cannot slew to the BAT position,
before 12:33 UT on 2011 September 8. There will thus be no XRT or UVOT
data for this trigger. 

Burst Advocate for this burst is C. Pagani (cp232 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: GRB110905A
Detection_method: KAIT
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12328
SUBJECT: GRB 110905A: KAIT observations
DATE:    11/09/05 06:47:08 GMT
FROM:    Weidong Li at UC Berkeley KAIT/LOSS  <weidong@astron.berkeley.edu>

W. Li and A. V. Filippenko, University of California, Berkeley,
on behalf of the KAIT GRB team, report:

The robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT) at Lick
Observatory observed GRB 110905A (Pagani et al., GCN 12327). 
The automatic sequence started at 06:18:04 UT, ~ 30 minutes after
the BAT trigger.  Our image processing pipeline found a new
object within the BAT error circle, with the following position:

R. A. = 18:35:43.44
DEC.  = -19:19:10.5  (J2000), 

The object has a magnitude of R ~ 16 at 06:19:48 UT (
calibrated to USNO B1). Observations are still ongoing. 


GRB_name: GRB110905A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12329
SUBJECT: GRB 110905A: Potential BAT trigger on MAXI J1836-194
DATE:    11/09/05 08:04:30 GMT
FROM:    Derek Fox at PSU  <dfox@astro.psu.edu>

Derek B. Fox (Penn State) reports: 

"The new R~16 mag optical source identified by Li & Filippenko (GCN
12328) in their follow-on observations of the recent Swift BAT image
trigger 502415 / GRB 110905A (Pagani et al., GCN 12327), is almost
certainly the optical counterpart to the recently-discovered X-ray
transient MAXI J1836-194 (Negoro et al., ATel #3611).  This likely
black hole X-ray binary system has an associated optical (Kennea et
al., ATel #3613), NIR (Rau, Greiner & Sudilovsky, ATel #3619) and
radio (Miller-Jones et al., ATel #3628) counterpat with coordinate
position (most accurately known from EVLA observations) consistent to
<~1 arcsec with the optical source of Li & Fillippenko.

Given that BAT trigger #502415 is a BAT image trigger with
localization consistent with the position of the new transient, this
raises the question of whether BAT trigger #502415 was generated by
high-energy variability of MAXI J1836-194 itself rather than being due
to a bona fide gamma-ray burst.

If GRB 110905A is a genuine gamma-ray burst -- distinct from and
unrelated to MAXI J1836-194 -- the source reported by Li &
Fillippenko, being the optical counterpart of MAXI J1836-194, is
almost certainly not the burst's optical afterglow.

The author cites a private communication from J. Greiner as first to
point out this possible interpretation of events."


GRB_name: GRB110905A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12330
SUBJECT: GRB 110905A / X-ray transient MAXI J1836-194: TNT optical observation 
DATE:    11/09/05 14:32:48 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L.P. Xin, M,Zhai, 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 GRB110905A (Pagani et al., GCN 12327)
with Xinglong TNT telescope at 11:25:29 (UT), 5.6 hour after 
the burst.  Ten R-band images were obtained. 
The optical source reported by Li & Filippenko (GCN 12328) 
was clearly detected  in all images with a brightness of 
~15.5 mag in R band ( relative to USNO B1.0 R2 magntidue).

This message may be cited.

For more information about Xinglong GRBs Follow-up
observations, please visit the website:
http://www.xinglong-naoc.org/grb/ 


GRB_name: GRB110905A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12331
SUBJECT: MAXI J1836-194 (originally GRB 110905A): Swift-BAT refined analysis
DATE:    11/09/05 17:40:23 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)
(i.e. the Swift-BAT team):
 
Using the data set from T+592 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT trigger #502415 (Pagani, et al.,
GCN Circ. 12327).  The BAT ground-calculated position is
RA, Dec = 278.958, -19.269 deg, which is 
   RA(J2000)  =  18h 35m 49.9s 
   Dec(J2000) = -19d 16' 07.5" 
with an uncertainty of 3.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
Because this was a long image trigger (26 minutes), the event-by-event data
just before, during, and for 592 sec after the trigger time was overwritten
in the ring buffer,  and as such, it is not possible to construct a lightcurve
for the early phase of this event.  Starting at T+590, the lightcurve
shows a low-level persistant emission out to T+963 sec.
 
The time-averaged spectrum from T+590 to T+963 sec can be fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.53 +- 0.39.  The fluence in the 15-150 keV band is 7.8 +- 2.0 x 10^-7 erg/cm2.
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/502415/BA/

Given the (a) the long and constant hard x-ray emission (in the later phase)
of this event, (b) the proximity to the Galactic Bulge, (c) the proximity
to the MAXI J1836-194; we believe this trigger to be due to the MAXI source
and not due to a GRB (as has been pointed out by J.Greiner (pri.comm.) and
D.Fox (GCN 12329)).


GRB_name: GRB110731A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12333
SUBJECT: GRB 110731A: SAO RAS and Terskol observations
DATE:    11/09/09 08:30:16 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin, V. V. Sokolov, O. I. Spiridonova (SAO RAS, Russia),
M. V. Andreev, A. V. Sergeev, N. A. Parakhin (Terskol Branch of Institute of
Astronomy, Russia)

We observed the field of GRB 110731A (Oates et al., GCN 12215) on July, 31
with 0.6-m Zeiss-600 (Terskol Branch of Institute of Astronomy,  Russia)
equipped with the PixelVision Vienna CCD (1024 x 1024, bin 2 x 2)
+ R filter, and 1-m Zeiss-1000 (SAO RAS, Russia) equipped with the
E2V 42-40 CCD (2048 x 2048, bin 2 x 2) + B and Rc filters. In both cases
the observations carried out at a high airmass and with the seeing ~4".

At all stacked images we did not detect any source within the Swift/UVOT
error circle (Oates., GCN 12222). Close to the error circle are visible two
objects which are also present in the USNO-B.1 catalogue:
S1: USNO-B.1 0614-0802286 (R.A.=18:42:00.72, Dec.=-28:32:14.9, E.=2000.0) &
S2: USNO-B.1 0614-0802328 (R.A.=18:42:01.24, Dec.=-28:32:11.6, E.=2000.0).
Our astrometric calibration and photometry of S1 object showed
that it can contain flux from OT but due to large seeing we can not
distinguish bright S1 and faint OT.

All three co-added images are shown at
ftp://ftp.sao.ru/pub/grb/GRB110731A/GRB110731A.jpg
Upper limits are shown at the following table.
_________________________________________________________
mid. time, UT   filter exp., sec  3-sigma lim. telescope
_________________________________________________________
19:15           R      53 x 200   19.9        Zeiss-600
19:24           Rc     31 x 60    21.7        Zeiss-1000
19:38           B      22 x 60    20.8        Zeiss-1000
_________________________________________________________

We use USNO-B.1 star 0614-0802353 (R.A.=18:42:01.83, Dec.-28:32:23.9,
E.=2000.0,  B2 = 15.77, R2 = 14.29) as a standard, and did not apply Galaxy
extinction correction.

This message can be cited.


GRB_name: GRB110825A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12334
SUBJECT: GRB 110825A: Further Swift/XRT Observations
DATE:    11/09/12 20:59:08 GMT
FROM:    Binbin Zhang at PSU  <buz12@psu.edu>

B.-B. Zhang (PSU), D. Grupe (PSU), D. N. Burrows (PSU), J. Gelbord (PSU)

and S. D. Barthelmy (GSFC) report on behalf of the Swift-XRT team:



We report further observations of the possible X-ray counterpart

(Zhang & Grupe, GCN 12308) of the IPN-detected  burst GRB 110825A

(Hurley etal., GCN 12307). The Swift/XRT found a relatively bright

X-ray source located at



RA (J2000): 02 59 11.63

Dec(J2000): +15 25 38.4.



We performed follow-up XRT observations of this field at T0+1 day, 
T0+5 days,T0+12 days and T0+16 days (where T0 = 2011 Aug 25 at

02:26:48.0 UT ), in order to determine whether or not the X-ray source

had faded. The observed count rates in the 0.3-10 keV band are as follows :



T-T0                     Count Rate

(8.7+/-0.6)x10^3 s   0.0129+/-0.0025 count/s

(4.8+/-0.2)x10^5 s   0.0045+/-0.0011 count/s

(1.1+/-0.01)x10^6 s  0.0065+/-0.0025 count/s

(1.4+/-0.07)x10^6 s  0.0083+/-0.0018 count/s



We find that this source is now at a count rate consistent with

that of our first observation on T0+1 day at the 1.5 sigma level.

The chance probability for the source being steady is about 0.015,

indicating that it is variable, but it is not decaying as expected for

a GRB. We conclude that this source is not the afterglow of GRB 110825A.

Thus, no afterglow was detected by XRT for this burst.



We note that the variability of this X-ray counterpart in the last two weeks

suggests that it may be a background AGN.



The updated results of the XRT-team automatic analysis are available

at <http://www.swift.ac.uk/xrt_products/00020183>.


GRB_name: GRB110915A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12335
SUBJECT: GRB 110915A: Swift detection of a burst
DATE:    11/09/15 13:29:30 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC),
P. D'Avanzo (INAF-OAB), P. A. Evans (U Leicester), C. Gronwall (PSU),
E. A. Hoversten (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), P. T. O'Brien (U Leicester),
P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), C. A. Swenson (PSU) and G. Tagliaferri (INAF-OAB)
report on behalf of the Swift Team:

At 13:20:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110915A (trigger=503219).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 310.851, -0.709 which is 
   RA(J2000)  =  20h 43m 24s
   Dec(J2000) = -00d 42' 33"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multiple peaks
with a total duration of about 95 sec.  The peak count rate
was ~4000 counts/sec (15-350 keV), at ~68 sec after the trigger. 

The XRT began observing the field at 13:22:00.5 UT, 76.1 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 310.8242, -0.7231 which is equivalent to:
    RA(J2000)  = 20h 43m 17.80s
    Dec(J2000) = -00d 43' 23.1"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 108 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 84 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
0.06. 

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: GRB110915A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12336
SUBJECT: GRB 110915A: Prompt enhanced Swift-XRT position
DATE:    11/09/15 14:10:25 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 110915A, we find an
enhanced XRT position of the afterglow: RA, Dec: 310.8242, -0.7241
which is equivalent to:
   RA (J2000)  = 20 43 17.81
   Dec (J2000) = -00 43 26.7
with an uncertainty of 3.4 arc sec (radius, 90% confidence). Analysis
of the promptly available data is online at
http://www.swift.ac.uk/sper/503219.

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: GRB110915A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12337
SUBJECT: GRB 110915A: MASTER-Net early limit 
DATE:    11/09/15 16:30:29 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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.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


  MASTER   robotic telescope (MASTER-Net: http://observ.pereplet.ru) located 
at Blagoveschensk (Amur-site) was pointed to the  GRB110915A 15 sec after 
notice time and 31 sec after GRB time at 2011-09-15 13:21:15 UT. 
On our first (10s exposure) MASTER II telescope set we haven't found 
optical transient  within SWIFT error-box (Holland et al., GCN Circ 
12335).  Unfortunatelly the main telescopes was not in focus.

On our first (5s exposure) MASTER VWF (Very Wide Field Camera - FOV=420 
square degrees)   set we haven't found optical transient  within
SWIFT error-box (Holland et al., GCN Circ 12335).

       Date           T_start-T_trig     ExpTime   Limit  Coadd  Instrum
       (UT)                  (s)            (s)   (unfilt)
      13:21:15               31             10      12      No  MASTER II
      13:21:17               33              5      12      No  MASTER VWF
      13:21:17               33             60      14      12  MASTER VWF

  The message may be cited.


GRB_name: GRB110915A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12338
SUBJECT: GRB 110915A: MITSuME Akeno Optical upper limits
DATE:    11/09/15 16:32:13 GMT
FROM:    Yoichi Yatsu at Tokyo Tech.  <yatsu@hp.phys.titech.ac.jp>

K. Kawakami, K. Tokoyoda, Y. Yatsu, Y. Aoki, M. Hayashi, S. Song,
R. Usui, and N. Kawai (Tokyo Tech)  report on behalf of the MITSuME
collaboration:

We observed GRB 110915A (S. T. Holland et al, GCN12335)
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 14:29:30, ~69 min after the
BAT trigger.

We did not find any new point source within the enhanced XRT error
circle (P.A. Evans et al., GCNC 12336) in two bands.


Photometric results and are listed below. We used GSC2.3 catalog for
flux calibration.

T0+[s]      MID-UT     T-EXP[sec]      g'             Rc           Ic
---------------------------------------------------------------------------------
 +4126   14:34:59          1440           ---          >17.6     >17.6
---------------------------------------------------------------------------------
T0+ : Elapsed time after the burst [sec]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110915A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12339
SUBJECT: GRB 110915A: GMG optical upper limit
DATE:    11/09/15 17:05:38 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.dark@gmail.com>

X.-H. Zhao (YNAO), D. Xu (WIS), J.-R. Mao & J.-M. Bai (YNAO) report on
a larger collaboration:

We observed the XRT field (Evans, GCN 12336) of GRB 110915A (Holland
et al., GCN 12335) with the 2.4m GMG telescope in Yunnan, China
equipped with YFOSC. Observations started at 13:58:09 UT, 15th Sep.
2011 (i.e., 0.6236 hr after the burst), and 1x20 min R-band and 1x20
min V-band images were obtained under the cloudy weather.

No optical source was present within the XRT error circle in GCN
#12336, which sets a 3\sigma upper limit of R~21.6 mag, calibrated
with the USNO B1 catalog.


GRB_name: GRB110915A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12340
SUBJECT: GRB 110915A: Enhanced Swift-XRT position
DATE:    11/09/15 19:22:20 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 2062 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 110915A, 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 = 310.82447, -0.72312 which is equivalent
to:

RA (J2000): 20h 43m 17.87s
Dec (J2000): -00d 43' 23.2"

with an uncertainty of 1.6 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: GRB110915B
Detection_method: superAGILE
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12341
SUBJECT: GRB 110915B: SuperAGILE localization of a long GRB
DATE:    11/09/15 21:29:14 GMT
FROM:    Marco Feroci at IASF/INAF  <sa.grb@iasf-roma.inaf.it>

E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, F. Lazzarotto,
L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), G. Barbiellini, F. Longo, E. Moretti (INFN Trieste),
A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti,
F. Fuschino, M. Marisaldi, M. Galli (INAF/IASF Bologna),
A. Giuliani, A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF
Milan), M. Tavani, M. Cardillo, G. Pucella, V. Vittorini, A. Argan, A. Trois,
G. Piano, S. Sabatini (INAF/IASF Rome), A. Pellizzoni, M. Pilia
(INAF/OA Cagliari), S. Vercellone, F. D'Ammando (INAF/IASF Palermo),
P. W. Cattaneo, A. Rappoldi (INFN Pavia), P. Picozza, A. Morselli,
E. Striani, (INFN Roma-2), M. Prest, E. Vallazza (Universita'
dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1),
P. Giommi, C. Pittori, F. Lucarelli, P. Santolamazza, F. Verrecchia
(ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report:

"SuperAGILE detected a gamma ray burst on 15 September 2011, at 18:24:19 UT.
The event had a duration of about 18 s in the 20-60 keV energy range,
with a single peak structure. Assuming a crab-like energy spectrum,  
the peak flux on 1-s timescale was 7.73E-08 erg/cm2/s.
The burst position was reconstructed  as (RA, Dec)
(77.548, 1.925) deg, which is:

RA(J2000)  = 05h 10m 11.57s
Dec(J2000) = 1d 55' 30.98"

with an uncertainty of 4' radius. The given uncertainty accounts
for both the statistical and systematic errors.

An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."

This message may be cited.


GRB_name: GRB110915A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12342
SUBJECT: GRB 110915A: 1.23m CAHA I-band observations
DATE:    11/09/15 22:54:19 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

R. Sanchez-Ramirez (IAA-CSIC), N. Morales (IAA-CSIC), J. Gorosabel (IAA-CSIC), J.L. Ortiz (IAA-CSIC), P. Kubanek (U. Valencia & IAA-CSIC), A. de Ugarte Postigo (DARK/NBI), A.J. Castro-Tirado (IAA-CSIC), report on behalf of a larger collaboration:

"We imaged the field of the Swift GRB 110915A (Holland et al., GCN Circ 12335) with the 1.23m Calar Alto telescope. The observations were carried out in the I-band on Sep 15.7984-15.8500 UT (starting 5.81 hours after the GRB) with a total exposure time of 25 X 180 = 4500s.  No object brighter than I=21.5 is detected in the XRT error circle (Evans et al., GCN Circ 12340)."


GRB_name: GRB110915A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12343
SUBJECT: GRB 110915A: NOT observations
DATE:    11/09/16 00:26:36 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK, NBI), P. Jakobsson (U. Iceland), A. de Ugarte Postigo 
(DARK, NBI), J. Lykke (NOT), D. Xu (WIS), and N. R. Tanvir (U. 
Leicester) report on behalf of a larger collaboration:

Using ALFOSC on the Nordic Optical Telescope (NOT) we have obtained 
R-band (3 x 600 s) and z-band (18 x 300 s) imaging of the GRB 110915A 
field (Holland et al., GCN 12335) starting on 2011 September 15.87 UT 
(around 7.5 hr after the burst).

We do not detect any object within the refined XRT error circle (Evans 
et al., GCN 12340). The limiting magnitudes are R(Vega) = 24.3 and z(AB) 
= 23.5, calibrated against the USNO-B1 and SDSS catalogs, respectively.

Using our R-band limit and preliminary X-ray fluxes, we obtain a 
corresponding upper limit on beta_OX of around 0.1, rendering the burst 
dark according to the definition proposed by Jakobsson et al. (2004, 
ApJ, 617, L21). This burst may therefore be at high redshift, or suffer 
from significant dust extinction. The presence of significant excess 
absorption in the X-ray afterglow spectrum 
(http://www.swift.ac.uk/xrt_spectra/00503219/) makes the second option 
more likely.


GRB_name: GRB110915A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12344
SUBJECT: GRB 110915A: MITSuME Okayama and Ishigakijima Optical upper limits
DATE:    11/09/16 00:58:08 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 110915A (Holland et al., GCNC 12335)
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, GCNC 12336) in all the three bands.

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

Ishigakijima Astronomical Observatory:
The observation started on 2011-09-15 13:28:55 UT (~8.2 min after
the burst).
T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.07421    15:07:35    9360.0    >22.0  >21.8  >20.7
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


Okayama Astrophysical Observatory:
The observation started on 2011-09-15 14:58:17 UT (~1.6 h after
the burst).
T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.08645    15:25:12    3060.0    >19.8 >20.2  >19.34
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110915A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12345
SUBJECT: GRB110915A  MITSuME Okayama J-band upper-limit
DATE:    11/09/16 04:24:57 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

Kenshi Yanagisawa, Daisuke Kuroda, Yasuhiro Shimizu, Kiichi Okita
(OAO/NAOJ), Michitoshi Yoshida (Hiroshima-U), Kouji Ohta(Kyoto-U)
and Nobuyuki Kawai(Tokyo Tech.) report on behalf of the MITSuME
collaboration.

We observed the field of GRB110915A (Holland et al, GCN12355) in J-band
with a wide-field near infrared imager at Okayama Astrophysical
Observatory (Japan).  The imager has effective aperture of 0.91 m.

Observations started from 15:19 UT on 15th September, just 2 hours after
the BAT trigger, to 16:02 UT.  The total exposure of 35 min was
successfully obtained.

In our co-add image, we did not find any new point source within the
enhanced XRT error circle (P.A. Evans et al., GCNC 12340) down to
limiting magnitude of  J=17.3 (Vega, S/N=3) . The photometric
calibration was made against 2MASS field stars.

T0+[s]      MID-UT     T-EXP[sec]      J
---------------------------------------------------
 +8130      15:35          2110       >17.3
---------------------------------------------------
T0+ : Elapsed time after the burt [sec]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110915A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12346
SUBJECT: GRB 110915A: Deep Gemini-South i/z-band imaging
DATE:    11/09/16 04:40:32 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley (Caltech), A. Cucchiara (UC Santa Cruz), and N. R. Tanvir
(Leicester) report on behalf of a larger collaboration:

We imaged the field of GRB 110915A (Holland et al., GCN 12335) with 
GMOS-S on Gemini-South starting at 00:36 UT on 2011-09-16.  We acquired 
6x240 seconds in i-band, and 7x240 seconds in z-band. Conditions were 
clear with generally good seeing (0.7").

We find no significant sources within the XRT error circle in either 
filter.  We calculate the following 3-sigma limits:

   i > 26.0 mag  (t_mid = 11.49 hr)
   z > 24.9 mag  (t_mid = 12.03 hr)

Given the bright X-ray afterglow and and other optical limits reported 
to date, these results indicate that GRB 110915A is a very dark burst, 
as also noted by Malesani et al (GCN 12343).  Infrared and radio 
follow-up is encouraged.


GRB_name: GRB110903A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12347
SUBJECT: GRB 110903A: Suzaku WAM observation of the prompt emission
DATE:    11/09/16 11:59:17 GMT
FROM:    Yoshitaka Hanabata at Hiroshima U  <hanabata@hep01.hepl.hiroshima-u.ac.jp>

Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, M. Ohno, Y. Fukazawa
(Hiroshima U.), T. Yasuda, Y. Terada, M. Tashiro, W. Iwakiri,
K. Takahara, M. Asahina, S. Kobayashi, A. Sakamoto (Saitama 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 very long, bright GRB110903A (Mereghetti et al. GCN 12322)
was detected by the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy range of 50 keV - 5 MeV at 02:39:34.298 UT (=T0).

The observed light curve shows a multi-peaked structure starting at
T0-57 s, ending at T0+364 s with a duration (T90) of about 340 
secnds. There is a possible precursor at T0-57 s with a duration of
about 15 seconds. The fluence in 100 - 1000 keV was 2.18 (-0.47,
+0.22) x 10^-5 erg/cm^2. The 1-s peak flux measured from T0+198 s was
2.45 (-0.20, +0.17) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0 to
T0+364 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha : 1.19 (-0.44, +0.54), and
 Epeak : 281 (-78, +33) keV (chi^2/d.o.f. = 39.2/31).
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/untrig/grb_table.html


GRB_name: GRB110915B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12348
SUBJECT: GRB 110915B: XRT afterglow candidate
DATE:    11/09/16 12:05:21 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), J. K. Cannizzo (NASA/UMBC), P.A. Evans and M.R. Goad
(U. Leicester) report on behalf of the Swift-XRT team:

At 04:36:53 UT, September 16, 2011, Swift began a Target of Opportunity
observation of the AGILE discovered burst GRB 110915B (Del Monte et al. et
al. GCN Circ. 12341).

We have analysed 2.1 ks of XRT data, from 36.8 ks to 43.2 ks after the
AGILE trigger. The data are entirely in Photon Counting (PC) mode.  An
uncatalogued X-ray source is detected within the AGILE error circle. Using
2132 s of PC mode data and 3 UVOT images, we find an enhanced XRT position
(using the XRT-UVOT alignment and matching UVOT field sources to the
USNO-B1 catalogue): RA, Dec = 77.55470, +1.93280 which is equivalent to:

RA (J2000): 05h 10m 13.13s
Dec(J2000): +01d 55' 57.9"

with an uncertainty of 1.8 arcsec (radius, 90% confidence). This position
is 37 arcsec from the AGILE position. The light curve is consistent with a
constant source of mean count rate 7.1e-02 ct/sec. A power-law fit gives
an index of -0.3 (+2.3, -1.1).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.85 (+0.36, -0.27). The
best-fitting absorption column is  9 (+10, -1) x 10^20 cm^-2, consistent
with the Galactic value of 8.5 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 3.9 x 10^-11 (4.8 x 10^-11) erg cm^-2 count^-1.

A summary of the PC-mode spectrum is thus:
Total column:             9 (+10, -1) x 10^20 cm^-2
Galactic foreground: 8.5 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:             1.85 (+0.36, -0.27)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020185.

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


GRB_name: GRB110915A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12349
SUBJECT: GRB 110915A: Deep Near-IR Limits from Magellan
DATE:    11/09/16 12:27:01 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger, R. Chornock, J. Strader (Harvard) and L. Spitler (Swinburne)
report:

"We imaged the field of GRB 110915A (GCN 12335) with the FourStar near-IR
imager mounted on the Magellan/Baade 6.5-m telescope starting on 2011 Sep
16.155 UT (14.4 hr after the burst).  Observations were obtained in the J
and Ks filters in good seeing (0.6").  We do not detect any sources in
coincidence with the enhanced XRT position (GCN 12340) to a 3-sigma limit of
J>23.5 mag and Ks>23.0 mag (AB).  The X-ray flux on the same timescale
(extrapolated from the existing XRT light curve) is F_X ~ 4e-12 cgs,
indicating an expected near-IR brightness of J~19 mag and K~18.5 mag.  If
due to extinction, the required ~4.5 mag in J and Ks are suggestive of an
unusually large A_V."


GRB_name: GRB110915B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12350
SUBJECT: GRB 110915B: Afterglow candidate from OSN
DATE:    11/09/16 13:22:14 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI), J. C. Tello, V. Casanova, A. J.
Castro-Tirado, R. Sanchez-Ramirez, J. Gorosabel, S. Guziy (IAA-CSIC) D.
Malesani (DARK/NBI) report on behalf of a larger collaboration:

We have observed the field of the AGILE GRB 110915B (Del Monte et al. GCNC
12341) using the 1.5m OSN telescope at Sierra Nevada Observatory (Granada,
Spain). The observation consisted of 46 x 120s exposures in R-band. In the
combined exposure we detect an uncatalogued source inside the error box of
the XRT afterglow candidate (D'Avanzo et al. GCNC 12348) at the following
coordinates (J2000, +/- 0.5"):

R.A.: 05:10:13.14
Dec.: +01:55:59.1

The preliminary magnitude of the object at an average epoch of Sep. 16.166
UT (9.59 hr after the burst onset) is R = 22.8+/-0.30, as compared to the
USNO-B1.0 star at coordinates 05:10:09.720, +01:56:40.12, for which we
assume R = 17.61.

Further analysis is ongoing.


GRB_name: GRB110915A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12351
SUBJECT: GRB 110915A: Swift-XRT refined Analysis
DATE:    11/09/16 13:30:40 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF-OAB/IASFPA) and S. T. Holland (CRESST/USRA/GSFC)
report on behalf of the Swift-XRT team:

We have analysed 3.3 ks of XRT data for GRB 110915A (Holland  et al.
GCN Circ. 12335), from 82 s to 7.7 ks after the  BAT trigger. The data
comprise 1.6 ks 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 12336).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=5.6 (+0.6, -0.4). At T+120 s  the decay
flattens to an alpha of 0.49 (+0.15, -1.09) before breaking again at
T+309 s to a final decay with index alpha=0.84 (+0.04, -0.03).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.98 (+/-0.05). The
best-fitting absorption column is  2.69 (+0.18, -0.17) x 10^21 cm^-2,
in excess of the Galactic value of 5.3 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.04 (+0.21, -0.20)
and a best-fitting absorption column of 2.6 (+/-0.7) 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 (6.3 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.6 (+/-0.7) x 10^21 cm^-2
Galactic foreground: 5.3 x 10^20 cm^-2
Excess significance: 6.5 sigma
Photon index:      2.04 (+0.21, -0.20)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00503219.

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


GRB_name: GRB110915A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12352
SUBJECT: GRB 110915A, Swift-BAT refined analysis
DATE:    11/09/16 14:33:10 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.krimm@nasa.gov>

T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), S. T.
Holland (CRESST/USRA/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-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110915A (trigger #503219)
(Holland, et al., GCN Circ. 12335).  The BAT ground-calculated position is
RA, Dec = 310.830, -0.713 deg which is
     RA(J2000)  =  20h 43m 19.2s
     Dec(J2000) = -00d 42' 45.8"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 25%.

The light curve consists first of a group of multiple overlapping peaks lasting
from T0-5 sec to T0+45 sec.  This is followed by a second cluster from T0+55
sec to T0+85 sec, containing the brightest peak at ~T0+70 sec. T90 (15-350 keV)
is 78.76 +- 1.25 sec (estimated error including systematics).

The time-averaged spectrum from -2.74 to 92.1 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.94 +- 0.23,
and Epeak of 124.8 +- 41.4 keV (chi squared 58.07 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 5.7 +- 0.2 x 1006 erg/cm2
and the 1-sec peak flux measured from T+68.04 sec in the 15-150 keV band is
3.3 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.41 +- 0.05 (chi squared 72.11 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/503219/BA/


GRB_name: GRB110915A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12353
SUBJECT: GRB 110915A: GROND Upper limits
DATE:    11/09/16 18:32:42 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

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

We observed the field of GRB 110915A (Swift trigger 503219; Holland et
al., GCN 12335) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m MPI/ESO telescope at La Silla
Observatory (Chile).

Observations started at 23:26 UT on 15 September, 10.1 hours after the GRB
trigger. They were performed at an average seeing of 1.1 and at an average
airmass of 1.2.

We do not detect a source within the enhanced UVOT/Swift-XRT error circle
reported by Evans et al. (GCN 12340). For a total exposure time of 6003 s
in g'r'i'z' and 4800 s in JHK, we do not detect a source down to:

g' > 25.5,

r' > 25.4,

i' > 24.3,

z' > 23.8,

J > 21.2,

H > 20.0, and

K > 18.6

The given limits are derived based on calibrating the images against GROND
zeropoints (g'r'i'z' are AB mags) and 2MASS field stars (JHK are Vega
mags) and are not corrected for the Galactic foreground extinction
corresponding to a reddening of E(B-V) = 0.058 in the direction of the
burst (Schlegel et al. 1998).

These upper limits are in agreement with the i/z upper limits from Perley
et al. (GCN 12346) and the J/Ks upper limits from Berger et al. (GCN
12349).

[GCN OPS NOTE(16sep11): Per author's request, the date in the second paragraph
was corrected from "16 Sep" to "15 Sep", and Perley citation was changed
from "12345" to "12346".]


GRB_name: GRB110915B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12354
SUBJECT: GRB 110915B: Swift/UVOT Upper Limits
DATE:    11/09/16 21:12:10 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

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

The Swift/UVOT began settled observations of the field of GRB 110915B
36,747 s after the AGILE trigger (Del Monte et al., GCN Circ. 12341).
No optical afterglow consistent with the position of the X-ray 
(D'Avanzo et al. GCN Circ.12348) or optical (de Ugarte Postigo et al., 
GCN Circ. 12350) afterglow candidates 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            37077        48670         1468         >22.2
v                42882        48935          542         >20.1
u                36747        52898         1869         >22.0

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


GRB_name: GRB110915A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12355
SUBJECT: GRB 110915A: Swift/UVOT Upper Limits
DATE:    11/09/17 20:18:06 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) and S. T. Holland (CRESST/USRA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110915A  
84 ks after the BAT trigger (Holland et al., GCN Circ. 12335).  No  
optical afterglow consistent with the enhanced XRT position (Evans et  
al., GCN Circ. 12340) is detected in the initial UVOT exposures.   
UVOT magnitude 3-sigma upper limits are reported in the following table:

Filter  T_start  T_stop  Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white      84     1884    429       > 21.46
v         616     5316    203       > 19.35
b         540     1858    136       > 20.10
u         284     1834    362       > 20.36
uvw1      665     1809    136       > 19.59
uvm2      641     1784    136       > 19.46
uvw2      592     1897    144       > 19.82

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.06
(Schlegel et al. 1998). All photometry is on the UVOT photometric  
system described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB110915B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12356
SUBJECT: GRB 110915B: GROND Observations of the Optical/NIR Afterglow  Candidate
DATE:    11/09/19 16:23:34 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

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

We observed the field of the AGILE GRB 110915B (E. Del Monte et al., GCN
12341) 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 were taken starting at 06:59 UT on 18 September 2011 (2.5 days
after the GRB trigger). They were performed at an average seeing of 1".4
and at an airmass of 2, with the Moon only 22 degrees away.

We detect the afterglow candidate reported by A. de Ugarte Postigo et al.
(GCN 12350). Based on an exposure time of 4502 s in the optical, we estimate
an r' magnitude (in AB) of:

r' = 23.2 +/- 0.1.

Compared to the magnitudes reported by A. de Ugarte Postigo et al., the
candidate shows no decay over the past 2.1 days and so is likely not the
GRB
afterglow. We find a flux ratio between optical and X-rays of f_x/f_opt =
4500 which indicates an AGN nature if the X-ray emission (P. D'Avanzo et
al., GCN 12348) has not faded.

Given magnitudes are calibrated against GROND zeropoints and shifted based
on the USNO-B1.0 star used by A de Ugarte Postigo., RA = 05:10:09.720,
Dec. = +01:56:40.12, and are not corrected for the expected Galactic
foreground extinction corresponding to a reddening of E(B-V) = 0.07 in the
direction of the burst (Schlegel et al. 1998).

We are indebted to A. de Ugarte Postigo for providing us a finding chart.


GRB_name: GRB110918A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12357
SUBJECT: IPN triangulation of GRB 110918A (long duration, extremely intense)
DATE:    11/09/19 20:14:28 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,

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, V. Savchencko, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team, and

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

The long-duration, extremely intense GRB110918A was observed by
INTEGRAL (SPI-ACS), Konus-Wind, Mars Odyssey (HEND), and MESSENGER
(GRNS) at 21:26:57 UT.  Swift was in the SAA, and Fermi was
Earth-occulted.  We have triangulated it to a preliminary, 3 sigma
error box whose coordinates are:

-----------------------------------------------
    RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
   32.575 (02h 10m 18s)   -27.281 (-27d 16' 51")
Corners:
   32.587 (02h 10m 21s)   -27.114 (-27d 06' 51")
   32.636 (02h 10m 33s)   -27.237 (-27d 14' 14")
   32.561 (02h 10m 15s)   -27.447 (-27d 26' 48")
   32.513 (02h 10m 03s)   -27.324 (-27d 19' 27")
-----------------------------------------------

The error box area is about 62 sq. arcmin., and its maximum
dimension is about 20 arcmin.  This localization can be
improved.

We note that this is the most intense burst observed in at
least several years of IPN monitoring; details of the time
history and energy spectrum will be given in a forthcoming GCN
Circular.

A Swift ToO observation has been scheduled.


GRB_name: GRB110915A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12358
SUBJECT: GRB 110915A: Konus-Wind and Swift/BAT joint spectral analysis
DATE:    11/09/19 21:22:41 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

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

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), and T. Ukwatta (GWU)

report:

We performed the Konus-Wind and the Swift/BAT joint spectral analysis
of GRB 110915A (Swift/BAT trigger #503219: Holland et al., GCN Circ.
12335, Ukwatta et al. GCN Circ. 12352). Since the Konus-Wind observed
this GRB in the waiting mode, we only have 3 channel spectral data for
the Konus-Wind which cover the energy range from 20 keV to 1.2 MeV.  The
joint spectral analysis of the Konus-Wind and the Swift/BAT data
allows us to derive the broad-band spectral parameters of this burst.

The time interval of the spectral data for each instrument is chosen
from T0(BAT)-3.3 to T0(BAT)+82.1 s where T0(BAT) is the trigger time
of BAT at 13:20:44.40 UTC.  The energy ranges which we used in the joint
spectral analysis are 20-1200 keV and 14-150 keV for the Konus-Wind and
the Swift/BAT respectively.  The spectral data of two instruments are
fitted with the spectral model multiplied by the constant factor to take
into account the systematic effective area uncertainties in the response
matrices of each instrument.

The spectrum is well fitted with a power-law with exponential cutoff
model: dN/dE ~ E^{alpha}*exp(-(2+alpha)*E/Epeak). No systematic residual 
from the best fit model is seen in the spectral data of each instrument. 
The BAT constant factor is 0.76(-0.08,+0.09) (the KW constant factor is 
fixed to 1). The best fit spectral parameters are: alpha = -1.08 
(-0.14/+0.19) and Epeak = 183 (-48/+80) keV (chi2/dof = 62/58). The best 
fit spectral parameters for the GRB (Band) model are: alpha = 
-0.90(-0.21,+0.24), beta = -2.2(-0.8,+0.3), and Epeak = 132(-28,+57) keV 
(chi2/dof = 58/57). The derived alpha and Epeak are in agreement with 
those derived from analysis of the BAT data alone (Ukwatta et al. GCN 
Circ. 12352). The energy fluence in the 15-1200 keV band calculated by a 
power-law with exponential cutoff model for this 85.4 s interval is 
1.35(-0.20,+0.25)x10^-5 erg/cm2.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110915A/

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


GRB_name: GRB110918A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12361
SUBJECT: GRB110918A: BOOTES-1 optical limit
DATE:    11/09/20 11:10:50 GMT
FROM:    Martin Jelinek at Inst.Astrophys.Andalucia,Granada  <mates@iaa.es>

M. Jelinek and A. J. Castro-Tirado (IAA-CSIC, Granada), on behalf of a 
larger collaboration, report:

"We observed the error box of the extraordinarily intense GRB110918A 
detected by the IPN (Hurley et al. GCNC 12357) with the 0.3m BOOTES-1 
robotic telescope in southern Spain. A 270x20s unfiltered coadded 
exposure taken under non-optimal conditions (low position in the sky, 
moonlight and fog) reached a limiting magnitude of ~17.0 at an 
exposure mean time of Sep 20, 1.09 UT (i.e. 27.65 hr after the onset 
of the high-energy emission). No new object is present within the 
entire IPN error box when compared to the DSS. Deeper optical/nIR 
observations are encouraged."

This message can be quoted.


GRB_name: GRB110918A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12362
SUBJECT: Konus-Wind observation of GRB 110918A
DATE:    11/09/20 11:18:01 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 exceptionally intense GRB 110918A
(localized by IPN: Hurley et al., GCN 12357)
triggered Konus-Wind at T0=77222.856s UT (21:27:02.856)

The burst is the most intense long GRB event in the history
of Konus-Wind observations since November, 1994.

The light curve of event started with an extremely bright hard short
pulse followed by three weaker partly overlapping peaks in the next 25 seconds.
The emission during this part of the burst is seen up to ~12 MeV.
A spectral lag between hard G3(1400-300 keV) and soft G1(25-90 keV)
instrument's light curves of the initial bright phase of the event
is estimated to a moderate value of ~0.090 s.

A weak decaying emission in the soft energy channel G1(25-90 keV)
continues till at least T0+250s when the measurements stopped.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110918_T77222/

As observed by Konus-Wind the burst
had a fluence of 7.5(-0.2,+0.2)x10-4 erg/cm2,
and a 16-ms peak flux, measured from T0+0.368 s,
of 8.7(-0.4,+0.4)x10-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The best fit of the time-integrated spectrum of the burst
(measured from T0 to T0+69.376 s) is achieved
(in the 20 keV - 10 MeV range) with the GRB (Band) model, for which:
the low-energy photon index alpha = -1.2 (-0.1, +0.1),
the high energy photon index beta = -2.0 (-0.04, +0.03),
the peak energy Ep = 150(-17, +20) keV,
chi2 = 171/81 dof.

The spectrum near the maximum count rate
(measured from T0+0.256 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 = -0.34 (-0.02, +0.02),
the high energy photon index beta = -2.5 (-0.1, +0.1),
the peak energy Ep = 1150(-110, +120) keV,
chi2 = 102/83 dof.

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


GRB_name: GRB110918A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12363
SUBJECT: GRB 110918A: pseudo-z=  from prompt emission spectrum
DATE:    11/09/20 13:31:38 GMT
FROM:    Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse  <atteia@ast.obs-mip.fr>

J-L. Atteia (IRAP-UPS/CNRS)&  A. Pelangeon report:

We used the spectral parameters of GRB 110918A provided by Golenetskii et al. (GCNC 12362)
to compute the spectral pseudo-redshift(**) of this burst localized by IPN (Pal'shin et al., GCNC 12358).

We find a pseudo-redshift pz= 0.28 +/- .07


** cf.http://cosmos.ast.obs-mip.fr/projet/v2/calculation_pz.html

-- 
Jean-Luc Atteia                             atteia@ast.obs-mip.fr
IRAP
Observatoire Midi-Pyrenees                  Phone       0 561 332 884
14 Avenue E. Belin                          Internat. +33 561 332 884
31400 Toulouse - France                     Fax.        0 561 332 840


GRB_name: GRB110918A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12364
SUBJECT: GRB 110918A: Swift-XRT observations
DATE:    11/09/20 13:32:36 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA), P. A. Evans
(U Leicester), H. A. Krimm (GSFC/USRA) report on behalf of the
Swift-XRT team:

We have analysed 2.5 ks of XRT data for the IPN-detected burst: GRB
110918A (Hurley et al. et al. GCN Circ. 12357), from 107.4 ks to 113.6
ks after the  IPN trigger. The data are entirely in Photon Counting
(PC) mode.  An new X-ray source is detected close to the edge of the
XRT FoV. Using 2498 s of PC mode data and 6 UVOT images, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 32.53860, -27.10610
which is equivalent to:

RA (J2000): 02h 10m 9.27s
Dec(J2000): -27d 06' 22.0"

with an uncertainty of 1.5 arcsec (radius, 90% confidence). This
position is 640 arcsec from the IPN position, and outside the IPN error
box.  The light curve uses only the first 1.5 ks of data, since after
this the source is too near the edge of the field of view for the light
curve extraction tools to work. This light curve is consistent with a
constant source of mean count rate 2.7e-01 ct/sec. A power-law fit
gives an index of -1.320 (+3.525, -0.013). The source count rate is
definitely above the 3 sigma upper limit of 0.08 ct/sec obtained from
the analysis of RASS data.
We believe that such a bright uncatalogued X-ray source close to the
IPN error box is likely the afterglow of the GRB.

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.12 (+0.28, -0.23). The
best-fitting absorption column is  1.5 (+0.7, -0.6) x 10^21 cm^-2, in
excess of the Galactic value of 1.7 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 2.9 x 10^-11 (4.2 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.5 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 1.7 x 10^20 cm^-2
Excess significance: 3.9 sigma
Photon index:      2.12 (+0.28, -0.23)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020186.

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


GRB_name: GRB110918A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12365
SUBJECT: GRB 110918A: INT optical detection of Swift candidate afterglow
DATE:    11/09/20 13:53:36 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N.R. Tanvir, K. Wiersema (U. Leicester), A.J. Levan, S. Greiss, 
B. Gaensicke (U. Warwick) report on behalf of a larger collaboration: 


We observed the field of IPN burst GRB 110918A (Hurley et al. GCN
12357) with the Isaac Newton Telescope on La Palma, using the Wide
Field Camera starting at 20-Sep-2011 02:22 UT, roughly 29 hours
post-burst.  Close to the location of the X-ray source reported by Mangano
et al. (GCN 12364) we detect a bright optical point-source which is not
visible in the DSS2 images of the region.


Very provisional calibration gives a magnitude R~19.0-19.5 (well above the
DSS2 limit) and a position: 


RA(2000)=02 10 09.39 
dec(2000)=-27 06 19.6 


accurate to ~0.5" in each coordinate.  We cannot yet assess variability.


GRB_name: GRB110918A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12366
SUBJECT: GRB 110918A: GROND detection of the afterglow candidate
DATE:    11/09/20 14:54:05 GMT
FROM:    Arne Rau at MPE  <arau@mpe.mpg.de>

J. Elliott (MPE Garching), T. Kruehler (DARK/NBI), S. Klose, D. A. Kann 
(both TLS Tautenburg), A. Rau and J. Greiner (both MPE Garching) report 
on behalf of the GROND team:

We observed the field of the IPN GRB 110918A (Hurley et al., GCN 12357) 
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 
405) mounted at the 2.2m MPI/ESO telescope at La Silla Observatory (Chile).

Observations started at September 20, 2011, 02:37 which is roughly 29.2 
hr after the trigger. They consisted of a dithered mosaic of 5 tiles 
covering the full IPN error box. The X-ray and optical afterglow 
candidate reported by Mangano et al. (GCN #12364) and Tanvir et al. (GCN 
#12365) however is only covered by the larger field of view of the NIR 
channels.

We confirm the presence of a bright NIR source, and estimate a 
preliminary AB magnitude of J = 18.7 +/- 0.1 at a midtime of 08:04 UT, 
which has been derived by calibrating the field against stars from the 
2MASS catalog.


GRB_name: GRB110918A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12367
SUBJECT: GRB 110918A: Afterglow Confirmation from PTF
DATE:    11/09/20 15:08:34 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

S. B. Cenko (UC Berkeley), N. R. Tanvir (Leicester), E. O. Ofek (Caltech /
Weizmann Institute), K. Wiersema (Leicester), A. J. Levan (Warwick), and
P. E. Nugent (LBNL):

As part of the Palomar Transient Factory (PTF), we have imaged the
location of the afterglow candidate (GCN 12364, GCN 12365) of the IPN GRB
110918A (GCN 12357) with the robotic Palomar 48 inch telescope.  Images
began at 8:49 UT (dt ~ 35.4 hours after the burst trigger time) in the PTF
R-band.

Comparing our images with those obtained by the INT approximately six
hours earlier (GCN 12365), we find the optical candidate has faded by 0.45
+/- 0.13 mag.  The observed variability thus confirms that this object is
the afterglow of GRB 110918A.  Though with large uncertainties, the
inferred power-law decay slope (alpha ~ 2.1) is quite steep for this
period after the trigger.


GRB_name: GRB110918A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12368
SUBJECT: GRB 110918A: Gemini-N redshift
DATE:    11/09/20 15:30:29 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

A.J. Levan (U. Warwick), N.R. Tanvir, K. Wiersema (U. Leicester),
E. Berger (Harvard), D. Fox (Penn State) report on behalf of a larger
collaboration:


We observed the candidate optical afterglow of GRB 110918A reported by
Tanvir et al. (GCN12365) with the GMOS-N spectrograph on Gemini-N,
Mauna Kea.  Observations began at 20-Sep-2011 12:51 UT.  The trace is
well detected and consistent with being a power-law continuum,
confirming that this source is very likely the afterglow of the burst
detected by the IPN (Hurley et al. GCN12357, see also Cenko et
al. GCN12367).  We identify absorption features of MgII (2796A/2804A),
MgI (2853A) and CaII (3935A/3970A) at a common redshift of z=0.982 (based
on a provisional wavelength calibration).


We thank the Gemini staff, particularly Jen Holt, for obtaining
these observations.


GRB_name: GRB110918A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12369
SUBJECT: GRB 110918A optical observation
DATE:    11/09/20 16:36:08 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Arto Oksanen (Hankasalmi Obs., Hankasalmi, Finland), Caisey Harlingten 
(Harlingten Observatory, San Pedro de Atacama, Chile), Bradley Schaefer 
(LSU), and Matthew Templeton (AAVSO) report the following follow-up 
optical observation of the error box of GRB 110918A (Hurley et al., GCN 
Circ. #12357):

A. Oksanen (Hankasalmi Obs., Hankasalmi, Finland) reports an observation 
of the error box of the intense, long GRB 110918A (Hurley et al., GCNC 
#12357; Golonetskii, et al., GCNC #12362) using the Harlingten Observatory 
0.5-m Planewave telescope with Apogee Alta-U42D9 CCD located in San Pedro 
de Atacama, Chile.  Ten, 60-second unfiltered observations of the field 
containing the GRB error box were made; the coadded image has a midpoint 
time of 2011 Sep 20 07:33 UT (JD 2455824.8146), approximately 34 hours 
post burst.  We find the point source detected by Mangano et al. (GCNC 
#12364) and Tanvir et al. (GCNC #12365) at a preliminary magnitude of 
R=19.0 measured relative to the nearby USNO-A2.0 star 0600-00854967 
(B=18.8,R=17.7).

Coadded images of the field are available at the following links:

FITS: http://pilvi.dyndns.org/arto/GRB110918A_median.fit

JPEG: http://pilvi.dyndns.org/arto/GRB110918A_median.jpg


The AAVSO International High Energy Network was made possible through 
grants from the Charles Curry Foundation and from NASA, and is supported 
through the AAVSO Endowment.


GRB_name: GRB110918A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12370
SUBJECT: GRB 110918A: rest-frame energetics in gamma-gays
DATE:    11/09/20 17:43:34 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

D. Frederiks and V.Pal'shin on behalf of the Konus-WIND team, report:

Basing on the Konus-Wind detection of GRB 110918A
(Hurley et al., GCN 12357; Golenetskii et al. GCN 12362),
assuming Gemini-N redshift z=0.982 (Levan et al., GCN 12368),
and a standard cosmology model (H_0 = 71 km/s/Mpc, Omega_M = 0.27,
Omega_\Lambda = 0.73), we estimate the following rest-frame parameters
of the prompt gamma-ray emission:
   the isotropic equivalent energy release is E_iso ~1.9x10^54 erg,
   the peak luminosity is L_iso_max ~ 4.4x10^54 erg/s, and
   the peak energy of the time-integrated spectrum is Ep_rest ~300 keV.

This estimation of L_iso_max makes GRB 110918A the most luminous
gamma-ray burst (with known redshift) ever observed by Konus-Wind.


GRB_name: GRB110918A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12371
SUBJECT: GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
DATE:    11/09/21 03:56:54 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU), F. E. Marshall (NASA/GSFC), M. De Pasquale (UNLV),
and H. A. Krimm (GSFC/USRA) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110918A
153272 s after the IPN Trigger.  A source consistent with the XRT
position (Mangano et al., GCN 12364) is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  02:10:09.33 =  32.53887 (deg.)
   Dec (J2000) = -27:06:19.6  = -27.10545 (deg.)
with an estimated uncertainty of 0.55 arc sec. (radius, 90% confidence).

Over approximately 18 ks of observation, we do not detect any statistically
significant fading.  Additional Swift/UVOT observations are planned.

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           153272       154107          791     20.36+-0.13
white           158468       159889         1373     20.16+-0.08
white           163169       165670         2419     20.12+-0.05
white           168950       171166         2178     20.21+-0.06

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


GRB_name: GRB110915B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12372
SUBJECT: GRB 110915B : X-ray afterglow confirmation
DATE:    11/09/21 12:14:05 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), J. K. Cannizzo (NASA/UMBC), P.A. Evans and M.R. Goad
(U. Leicester) report on behalf of the Swift-XRT team:

Swift continued to monitor the field of the AGILE-detected GRB 110915B
(Del Monte et al. GCN Circ. 12341).
We have analysed 6.1 ks of XRT data, from 36.8 ks to 442.2 ks after the
AGILE trigger. The data comprise 148 s in Windowed Timing (WT) mode with
the remainder in Photon Counting (PC) mode.

The X-ray source reported in D'Avanzo et al. (GCN Circ. 12348) has faded
to a level of 5.8e-3 ct/sec. The light curve can be modelled with a
power-law decay with a decay index of alpha=1.05 (+0.57, -0.25).


The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020185.

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


GRB_name: GRB110921A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12373
SUBJECT: GRB 110921A: Swift detection of a burst
DATE:    11/09/21 14:01:54 GMT
FROM:    David Burrows at PSU/Swift  <burrows@astro.psu.edu>

W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), S. Campana (INAF-OAB),
J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC),
P. A. Evans (U Leicester), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
O. M. Littlejohns (U Leicester), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
P. T. O'Brien (U Leicester), C. Pagani (U Leicester),
K. L. Page (U Leicester), J. L. Racusin (NASA/GSFC),
T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.),
R. L. C. Starling (U Leicester) and B.-B. Zhang (PSU) report on behalf
of the Swift Team:

At 13:51:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110921A (trigger=503652).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 294.078, +36.377 which is 
   RA(J2000) = 19h 36m 19s
   Dec(J2000) = +36d 22' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a ragged, single-peaked
structure with a duration of about 10 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 13:53:22.5 UT, 122.4 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 294.09838, 36.32882 which is equivalent
to:
   RA(J2000)  = 19h 36m 23.61s
   Dec(J2000) = +36d 19' 43.8"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 182 arcseconds from the BAT onboard position, outside 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 (1.43 x
10^21 cm^-2, Kalberla et al. 2005), with an excess column of 3.1
(+2.28/-1.97) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 125 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 0.14. 

Burst Advocate for this burst is W. H. Baumgartner (wayne 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: GRB110921A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12374
SUBJECT: GRB 110921A: MASTER-Net early limit
DATE:    11/09/21 15:00:27 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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


  MASTER II  robotic telescopes (MASTER-Net: http://observ.pereplet.ru) 
located in Amur  and in Tunka (Siberia) was pointed to the  GRB110921A 7 
sec after notice time and 53 sec after GRB time at 2011-09-21 
13:52:13.432 UT. On our first (10s exposure) set we haven't found optical  transient  within SWIFT error-box (ra=19 36 19 dec=+36 22 48 r=0.050000). 
Observations were made in polarizing bands.
The 5-sigma upper limit has been about 17.2 in Amur and 17.5 
in Tunka.
Observations and data reduction is  continued.
The message may be cited.


GRB_name: GRB110918A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12375
SUBJECT: GRB 110918A: Spectroscopy from GTC
DATE:    11/09/21 15:46:02 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

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

We have obtained spectroscopy of the afterglow of GRB 110918A (Hurley et
al., GCN 12357, Mangano et al. GCN 12364, Tanvir et al., GCN 12365) using
OSIRIS at the 10.4m GTC telescope at Roque de los Muchachos Observatory
(Spain). Our data consisted of 3x900s exposures with the R500B grism, with
a resolution of ~500 obtained with an average epoch of Sep. 21.106 UT
(53.09 hr after the burst).

In a preliminary reduction we detect absorption features of ZnII, FeII,
MnII, MgII, MgI and CaII at a common redshift of 0.984+/-0.001, similar to
the one derived by Levan et al. (GCN 12368).

We acknowledge the excellent support of the GTC staff, in particular J.M.
Gonzalez Perez, A. Cabrera Lavers and B. Gerken.


GRB_name: GRB110918A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12376
SUBJECT: GRB 110918A: Swift-XRT refined Analysis
DATE:    11/09/21 16:04:56 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

V. Mangano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA),
P. A. Evans (U Leicester), H. A. Krimm (GSFC/USRA)
report on behalf of the Swift-XRT team:

We have analysed 13.1 ks of XRT data for GRB 110918A, from 107.4 ks
to 211.3 ks after the IPN trigger (Hurley et al. GCN Circ. 12357).
The data are in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Mangano et al. (GCN Circ. 12364).

The light curve can now be modeled with a single power-law decay
with index alpha=1.49 (+0.24, -0.25). This confirms the XRT
source is the afterglow of the GRB.

The PC mode spectrum has a photon index of 2.11 (+0.21, -0.19)
and a best-fitting absorption column at redshift z=0.982
(Levan et al. GCN Circ. 12368) of 6.3 (+2.8, -2.1) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is
3.0 x 10^-11 (4.3 x 10^-11) erg cm^-2 count^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020186.

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


GRB_name: GRB110921A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12377
SUBJECT: GRB 110921A : TNT optical counterpart candidate
DATE:    11/09/21 16:30:38 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

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

We began to observe GRB 110921A (Baumgartner et al., GCN 12373)
with Xinglong TNT telescope at 13:59:40 (UT), about 8 min  after 
the burst.  25 White-band images and a series of R-band data were obtained. 
A new source was detected in the combined white band image within 
the errorbox of XRT position. The brightness of this new source is estimated 
to be about 20.2 mag derived from USNO B1.0 R2mag. 

We propose that this source is the candidate of optical 
counterpart of GRB 110921A.
More deep observations are needed to confirm this.

This message may be cited.

For more information about Xinglong GRBs Follow-up
observations, please visit the website:
http://www.xinglong-naoc.org:8080/grb/index.html


GRB_name: GRB110921A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12378
SUBJECT: GRB 110921A: MITSuME Akeno Optical Observation
DATE:    11/09/21 16:38:54 GMT
FROM:    Yoichi Yatsu at Tokyo Tech.  <yatsu@hp.phys.titech.ac.jp>

K. Tokoyoda, M. Hayashi, Y. Yatsu, Y. Aoki, K. Kawakami, S. Song,
R. Usui, and N. Kawai (Tokyo Tech)  report on behalf of the MITSuME
collaboration:

We observed GRB 110921A (W. H. Baumgartner et al, GCN12373)
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 13:53:08, ~108 sec after the
BAT trigger.

We did not find optical counterpart in g'-band and R-band
within the enhanced XRT error circle (W. H. Baumgartner et al, GCN12373).

While, in I-band, we detected a very faint OT candidate in the error circle
only in the earliest data-set (T0+108s ~ T0 + 348s).
Further data analysis for the I-band data is now ongoing.

Photometric results are listed below. We used GSC2.3 catalog for
flux calibration.

T0+[s]      MID-UT     T-EXP[sec]      g'             Rc           Ic
---------------------------------------------------------------------------------
 +108     14:07:40         1530           >20.0       >19.5       ---
---------------------------------------------------------------------------------
T0+ : Elapsed time after the burst [sec]
T-EXP: Total Exposure time [sec]


GRB_name: GRB110921A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12379
SUBJECT: GRB 110921A: Enhanced Swift-XRT position
DATE:    11/09/21 20:01:29 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 1830 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 110921A, 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 = 294.09821, +36.32864 which is equivalent
to:

RA (J2000): 19h 36m 23.57s
Dec (J2000): +36d 19' 43.1"

with an uncertainty of 1.9 arcsec (radius, 90% confidence).

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

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


GRB_name: GRB110921A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12380
SUBJECT: GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
DATE:    11/09/21 20:40:56 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), M. Andreev, A. Sergeev (Terskol Branch of Institute of 
Astronomy),  M. Ibrahimov (MAO) on behalf of larger GRB follow up 
collaboration report:

We observed  the field of the Swift GRB 110921A (Baumgartner et al., GCN 
12373) with Zeiss-600 telescope of Mt. Terskol observatory and AZT-22 
telescope of Maidanak observatory on Sep. 21. Several images were taken in 
both observatories in R filter. Within the enhanced XRT error box  (Goad et 
al., GCN 12379)  we do not  detect the candidate of optical counterpart of 
GRB 110921A (Xin et al., GCN 12377).  Preliminary photometry of a combined 
image (Zeiss-600) and a single image of AZT-22 is based on the nearby USNO 
B1.0 stars:

UT                 Filter,   Exposure, OT,        Upper Limit (3 sigma) 
Telescope
(mid)                           (s)

Sep.21 16:50  R        1800       n/d           21.1 
Zeiss-600
Sep.21 17:48  R         300        n/d           21.2 
AZT-22

Since our photometry is somewhat deeper than photometry of the candidate 
(Xin et al., GCN 12377), we could suggest the candidate is a real afterglow 
of GRB 110921A. 


GRB_name: GRB110918A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12381
SUBJECT: GRB 110918A: submm observations from APEX
DATE:    11/09/21 21:30:55 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI), C. De Breuck (ESO), A. Lundgren
(ALMA/ESO) and M. Dumke (APEX/ESO) report on behalf of a larger
collaboration:

We have observed the afterglow candidate (Tanvir et al., GCN 12365) of the
bright IPN GRB110918A (Hurley et al., GCN 12357) using APEX/LABOCA at
Chajnantor (Chile). Observations where performed at 345GHz, using the
photometric mode, with mean epoch Sep. 21.184 UT (54.97 hr after the
burst) under good weather conditions (PWV ~ 0.25 mm). No flux is detected
at the position of the afterglow, with a 3-sigma upper limit of 15mJy.


GRB_name: GRB110918A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12382
SUBJECT: GRB 110918A: Liverpool Telescope optical observations
DATE:    11/09/21 22:18:29 GMT
FROM:    Drejc Kopac at Math Phys U,Slovenia  <drejc.kopac@fmf.uni-lj.si>

C. Guidorzi (U. Ferrara), D. Kopac (U. Ljubljana) and N. R. Tanvir (U.
Leicester), on behalf of a large collaboration report:

We observed the optical afterglow of GRB 110918A (Cenko et al., GCN 12367)
with the 2-m Liverpool Telescope, starting at 01:07 UT on 2011 September
21. We took 6 images in R band with exposure time 300s and we clearly
detect the optical afterglow. Our preliminary photometry yields:

Mid time from   Exp    Filter   Magnitude
trigger (days)  (sec)
-------------------------------------------
2.16            1800   R        19.7 +- 0.1
-------------------------------------------

The magnitude is calibrated against nearby USNO-B1.0 stars and is not
corrected for the Galactic extinction.


GRB_name: GRB110921A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12383
SUBJECT: GRB 110921A, Swift-BAT refined analysis
DATE:    11/09/22 01:08:38 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), 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-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110921A (trigger #503652)
(Baumgartner, et al., GCN Circ. 12373).  The BAT ground-calculated position is
RA, Dec = 294.094, 36.355 deg which is
    RA(J2000)  =  19h 36m 22.6s
    Dec(J2000) = +36d 21' 19.8"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 15%.

The mask-weighted light curve shows multiple weak peaks.  T90 (15-350 keV) was
48.00 +- 22.63 sec (estimated error including systematics).

The time-averaged spectrum from T-31.55 to T+16.45 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.57 +- 0.17.  The fluence in the 15-150 keV band is 2.4 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+7.95 sec in the 15-150 keV band
is 0.2 +- 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/503652/BA/


GRB_name: GRB110921A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12384
SUBJECT: GRB 110921A: Swift-XRT refined Analysis
DATE:    11/09/22 08:05:33 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester) and W. H. Baumgartner (GSFC/UMBC) report on
behalf of the Swift-XRT team:

We have analysed 9.7 ks of XRT data for GRB 110921A (Baumgartner  et
al. GCN Circ. 12373), from 134 s to 40.9 ks after the  BAT trigger. The
data comprise 47 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN. Circ 12379).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=0.90 (+/-0.05).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.00 (+0.15, -0.14). The
best-fitting absorption column is  2.0 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 1.4 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 3.9 x 10^-11 (5.6 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.0 (+0.5, -0.4) x 10^21 cm^-2
Galactic foreground: 1.4 x 10^21 cm^-2
Excess significance: 7.9 sigma
Photon index:      2.00 (+0.15, -0.14)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00503652.

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


GRB_name: GRB110921A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12385
SUBJECT: GRB 110921A: TNT astrometry
DATE:    11/09/22 10:16:28 GMT
FROM:    Dong Xu at Weizmann Inst  <dong.dark@gmail.com>

D. Xu (WIS), L.P. Xin, J.Y. Wei (NAOC) report on behalf of a larger
collaboration:

We performed astrometry to the TNT image (Xin et al., GCN 12377),
calibrated with the SDSS field of GRB 110921A (Baumgartner et al., GCN
12373). The optical afterglow is localised at

RA (J2000): 19h 36m 23.478s
Dec (J2000): +36d 19' 43.38"

with an uncertainty of 1.0 arcsec, in the northwestern part of the
enhanced XRT error circle (Goad et al., GCN 12379).

The SDSS field reveals a source at coordinates

RA (J2000): 19h 36m 23.382s
Dec (J2000): +36d 19' 42.03"

with an uncertainty of 1.0 arcsec and at the southwestern edge of the
XRT error circle, which is too faint to be present for the TNT image.

NIR follow-up observation is encouraged.


GRB_name: GRB110921A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12386
SUBJECT: GRB 110921A: Fermi GBM observation
DATE:    11/09/22 15:47:15 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick@ucdconnect.ie>

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

"At 13:51:22.57 UT on 21 September 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110921A (trigger 338305884 / 110921577),
which was detected by the Swift/BAT (Baumgartner et al. 2011, GCN 12373).
The GBM on-ground location is consistent with the Swift position.

The GBM light curve shows a single bright
peak with a duration (T90) of ~37 s (50-300 keV).
The time-averaged spectrum from T0-26 s to T0+9 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.39 +/- 0.12 and
the cutoff energy, parameterized as Epeak, is 139 +/- 32 keV.

The event fluence (10-1000 keV) in this time interval is
(4.2 +/- 0.4)E-06 erg/cm^2. The 1 s peak photon flux measured
starting from T0+0.5 s in the 10-1000 keV band
is 2.9 +/- 0.3 ph/s/cm^2.


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


GRB_name: GRB110921A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12387
SUBJECT: GRB 110921A: NOT observations
DATE:    11/09/22 16:11:30 GMT
FROM:    Paul Vreeswijk at U of Iceland  <pmv@raunvis.hi.is>

Paul Vreeswijk (U. Iceland), Daniele Malesani, Antonio de Ugarte
Postigo (DARK, NBI), Dong Xu (WIS), Pll Jakobsson, Steve Schulze
(U. Iceland) and Nial Tanvir (U. Leicester) report on behalf of a
larger collaboration:

Using ALFOSC on the Nordic Optical Telescope (NOT) we have obtained
Sloan r'- (3 x 600 s) and z'-band (6 x 300 s) imaging of the field of
GRB 110921A (Baumgartner et al., GCN 12373, Barthelmy et al., GCN
12383), starting on 2011 September 21.925 UT (roughly 8.3 hr after the
burst). The observations were performed through clouds, but under good
seeing conditions (~0.8").

We do not detect the optical afterglow reported by Xin et al. (GCN
12377, see also Xu et al., GCN 12385), or any other object within the
enhanced Swift-XRT error circle (Goad et al., GCN 12379), down to
limiting magnitudes of about r'=23.3 and z'=21.0 (calibrated against
the SDSS catalog).

Just outside the enhanced XRT error circle, at R.A.(J2000)
19:36:23.38, decl.(J2000) 36:19:42.1 (with an uncertainty of 0.23"),
we detect an r'=22.4+-0.2 source, also visible - albeit barely - in
the combined z'-band imaging. This apparent point source is
consistent, both in position and brightness, with the SDSS object
noted by Xu et al. (GCN 12385).

We are grateful for the NOT staff, particularly Fatemeh Sadat Kiaeerad
and Marjaana Lindborg, for obtaining these observations.


GRB_name: GRB110918A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12388
SUBJECT: GRB110918A: Lick Observations
DATE:    11/09/23 01:36:34 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley (Caltech), M. Ganeshalingam, P. Blanchard, and M. Mason (UC 
Berkeley) report:

We observed the location of bright IPN GRB 110918A (Hurley et al, GCN 
12357) starting at UT 2011-09-22 03:04:29 UT using the Nickel 40-inch 
telescope at Lick Observatory, under good seeing conditions at high 
airmass.  A series of five 180-second exposures in R-band were acquired 
in total.  The optical afterglow (Tanvir et al., GCN 12365) is 
well-detected in the combined stack.  Using five nearby USNOB1.0 stars, 
we calculate the following photometry:

   R = 20.68 +/- 0.13   (t_mid = 3.2406 day)

The uncertainty estimate does not include the uncertainty of the 
calibration to USNO (for convenience, our calibration stars are listed 
below).  The measurement indicates a decay slope of approximately 
alpha=2.2 since the report of Guidorzi et al. (GCN 12382) and may 
suggest a very early jet break for this burst (see also Cenko et al., 
GCN 12367).

USNO calibration stars:
RA        dec        R2
032.546809 -27.104117 19.38
032.549492 -27.121698 19.29
032.555214 -27.117650 19.38
032.558045 -27.100853 19.39
032.569403 -27.106270 19.40


GRB_name: GRB110921A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12389
SUBJECT: GRB 110921A: Swift/UVOT Observations
DATE:    11/09/23 14:23:26 GMT
FROM:    Alice Breeveld at MSSL-UCL  <aab@mssl.ucl.ac.uk>

A. A. Breeveld (MSSL-UCL) and W. H. Baumgartner (GSFC/UMBC) report on 
behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110921A 
126 s after the BAT trigger (Baumgartner et al., GCN Circ. 12373).

A source consistent with the optical position (Xin et al., GCN Circ. 
12377 and Xu et al., GCN Circ. 12385) is detected at 3.5 sigma in the 
summed white data, but is not seen in any of the other filters, nor in 
any of the white exposures individually.
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           126          276          147         >21.3
u_FC               284          534          246         >20.6
white              126         1704          411          21.4 Â± 0.3
v                  614         5307          308         >20.3
b                  540         1679          117         >20.7
u                  284         1654          343         >20.9
w1                 664         1629          117         >21.1
m2                 639         1604          117         >19.7
w2                 590         1725          132         >20.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.14 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB110921B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12390
SUBJECT: GCN for GRB 110921B
DATE:    11/09/23 21:34:05 GMT
FROM:    Peter Jenke at MSFC  <pjenke@aol.com>

Peter Jenke (MSFC)/ Sylvain Guiriec (UAH)
report on behalf of the Fermi GBM Team:

"At 21:52:45.09 UT on 21 09 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110921B (trigger 338334767 / 110921.912).

The on-ground calculated location, using the GBM trigger
data, is RA = 17.95, DEC = -27.74 (J2000 degrees,
equivalent to 01 h 11.8 m, -27 d 44.4 m'), with an uncertainty
of 1.0 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 36.00 degrees.

The GBM light curve shows two main peaks with the
first being double peaked.  Moreover, this burst was
bright enough to result in a Fermi spacecraft 
autonomous rapid repoint (ARR) maneuver.
The burst had a duration (T90) of about 17 s (50-300 keV).
The time-averaged spectrum from T0+0.003 s to T0+23.552 s is
adequately fit by a Band function with Epeak = 513.0 +/- 31.3 keV,
alpha = -0.95 +/- 0.02, and beta = -2.23 +/- 0.10
(Chi squared 695.1 for 494 d.o.f.).

The event fluence (10-1000 keV) in this time interval is
(3.881 +/- 0.054)E-05 erg/cm^2. The peak photon flux measured
starting from T0+0.003 s in the 10-1000 keV band
is 7.558 +/- 0.068 ph/s/cm^2.

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


GRB_name: GRB110924A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12391
SUBJECT: GRB 110924A: Swift detection of a possible burst
DATE:    11/09/24 09:26:59 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU), A. P. Beardmore (U Leicester),
P. A. Evans (U Leicester), O. M. Littlejohns (U Leicester),
C. Pagani (U Leicester), K. L. Page (U Leicester),
B. Sbarufatti (INAF-OAB/IASFPA), E. Sonbas (GSFC/USRA/Adiyaman Univ.)
and T. N. Ukwatta (MSU) report on behalf of the Swift Team:

At 09:03:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110924A (trigger=503926).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 234.748, -66.308 which is 
   RA(J2000) = 15h 39m 00s
   Dec(J2000) = -66d 18' 29"
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 10 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 09:05:10.5 UT, 109.8 seconds after
the BAT trigger. No source was detected in 729 s of promptly downlinked
data. We are waiting for the full dataset to detect and localise the
XRT counterpart. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 115 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 69% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.16. 

Burst Advocate for this burst is E. A. Hoversten (hoversten 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: GRB110928A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12394
SUBJECT: GRB 110928A: Swift detection of a burst
DATE:    11/09/28 02:03:46 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

E. A. Hoversten (PSU), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
M. M. Chester (PSU), N. Gehrels (NASA/GSFC),
H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and
E. Sonbas (GSFC/USRA/Adiyaman Univ.) report on behalf of the Swift
Team:

At 01:51:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110928A (trigger=504215).  Swift will slew after 52 minutes
after the Earth limb constraint is avoided. 
The BAT on-board calculated location is 
RA, Dec 257.755, +36.570, which is 
   RA(J2000)  =  17h 11m 01s
   Dec(J2000) = +36d 34' 13"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single FRED-like 
pulse with a duration of about 10 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until 
T0+52 minutes. There will be no XRT or UVOT data until
this time. 

Burst Advocate for this burst is E. A. Hoversten (hoversten 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: GRB110928A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12395
SUBJECT: GRB 110928A: ROTSE-III Optical Limits
DATE:    11/09/28 02:32:52 GMT
FROM:    Brad Schaefer at LSU  <schaefer@grb.phys.lsu.edu>

B. E. Schaefer (Louisiana State), W. Zheng (U Mich), H. Flewelling (IfA/Hawaii), report on behalf of the ROTSE collaboration: 

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 110928A (Swift trigger 504215; Hoversten et al., GCN 12394), producing images beginning 7.1 s after the GCN notice time. An automated response took the first image at 01:52:39.1 UT, 67.3 s after the burst, under excellent conditions. We took 10 5-sec, 10 20-sec and 10 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, for both single images and coadding into sets of 10; the field is not crowded. Individual images have limiting magnitudes ranging from 16.1-17.4; we set the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
01:52:39.1   01:52:44.1         5     16.1           67.3       N
01:52:39.1   01:54:26.8       107     17.5           67.3       Y


GRB_name: GRB110928A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12396
SUBJECT: GRB 110928A: PAIRITEL NIR Observations
DATE:    11/09/28 02:37:03 GMT
FROM:    Adam Morgan at U.C. Berkeley  <qmorgan@gmail.com>

C. R. Klein and A. N. Morgan (U. C. Berkeley) report:

We observed the field of GRBs 110928A (Hoverston et al., GCN 12394) with the
1.3m PAIRITEL located at Mt. Hopkins, AZ. Observations began at 2011-Sep-28
02h03m59s, 12.5 minutes after the GRB. In mosaics (effective exposure time
of 468s) taken simultaneously in the J, H, and Ks filters, we do not clearly
detect any new sources in the BAT error circle down to the limit of the
2mass catalog.


GRB_name: GRB110928A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12397
SUBJECT: GRB 110928A: Swift/UVOT finding chart observation
DATE:    11/09/28 03:09:54 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) reports on behalf of the Swift UVOT team:

UVOT took a finding chart exposure of 150 seconds with the white  
filter of the field of
GRB 110928A starting 3341 seconds after the BAT trigger (Hoversten et  
al., GCN 12394).
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.


GRB_name: GRB110928A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12398
SUBJECT: GRB 110928A: Swift-XRT observations
DATE:    11/09/28 03:51:12 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows
(PSU), J.A. Kennea (PSU), S. Campana (INAF-OAB) and G. Cusumano
(INAF-IASF PA) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 110928A at 02:47:09.1 UT,
3337.3 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 257.73360,
36.53636 which is equivalent to:
   RA(J2000)  = 17h 10m 56.06s
   Dec(J2000) = +36d 32' 10.9"
with an uncertainty of 4.3 arcseconds (radius, 90% containment). This
location is 136 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.  We cannot determine whether the source is
fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.14 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.1
(+2.44/-1.70) x 10^22 cm^-2 (90% confidence). 


GRB_name: GRB110928A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12399
SUBJECT: GRB 110928A: Swift-BAT refined analysis
DATE:    11/09/28 04:17:24 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), E. A. Hoversten (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 the recent telemetry downlink,
we report further analysis of BAT GRB 110928A (trigger #504215)
(Hoversten, et al., GCN Circ. 12394).  The BAT ground-calculated position is
RA, Dec = 257.745, 36.547 deg, which is 
   RA(J2000)  =  17h 10m 58.7s 
   Dec(J2000) = +36d 32' 49.3" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 37%.
 
The mask-weighted light curve shows a single FRED-like peak starting at ~T_zero
and ending at ~T+30 sec.  T90 (15-350 keV) is 26.7 +- 4.8 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-0.53 to T+27.88 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.09 +- 0.30.  The fluence in the 15-150 keV band is 6.9 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+6.84 sec in the 15-150 keV band
is 0.9 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/504215/BA/


GRB_name: GRB110928A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12400
SUBJECT: GRB 110928A: Further PAIRITEL NIR Observations
DATE:    11/09/28 04:28:47 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 110928A (Hoversten et al., GCN 12394)
with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations
began at 2011-Sep-28 02h03m59s UT, ~12.5 min after the Swift trigger.
In  mosaics (effective exposure time of 678.6 s) taken simultaneously
in the J, H, and Ks filters, we do not detect any source within the
XRT error circle (Evans et al. GCN 12398).

post burst
t_mid (hr) exp.(hr) filt  U. Limit (3 sig)
0.36      0.19     J     > 18.2
0.36      0.19     H     > 17.5
0.36      0.19     Ks    > 15.9


Deeper NIR observations are underway. 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: GRB110928A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12401
SUBJECT: GRB 110928A: P60 Observations
DATE:    11/09/28 05:59:37 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration:

We have imaged the field of GRB 110928A (Hoversten et al., GCN 12394) with
the automated Palomar 60 inch telescope.  Observations were obtained in
the Sloan r', i', and z' filters beginning at 4:11 UT on 2011 September 28
(~ 2.3 hours after the Swift trigger).

We do not detect any sources within the XRT error circle (Evans et al.,
GCN 12398).  Using nearby point sources from the Sloan Digital Sky Survey
for reference, we calculate the following upper limits (AB):

r' > 22.1
i' > 21.6
z' > 20.3

We note the presence on the northern edge of the XRT error circle of one
(possibly two) extended sources present in SDSS.  The large size of the
current X-ray localization precludes any firm association with GRB
110928A, however.


GRB_name: GRB110928A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12402
SUBJECT: GRB 110928A: Enhanced Swift-XRT position
DATE:    11/09/28 06:01:13 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 1477 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 110928A, 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 = 257.73295, +36.53571 which is equivalent
to:

RA (J2000): 17h 10m 55.91s
Dec (J2000): +36d 32' 08.5"

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

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

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


GRB_name: GRB110825A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12403
SUBJECT: GRB 110825A: GROND Observations
DATE:    11/09/28 13:13:39 GMT
FROM:    Vladimir Sudilovsky at MPE  <vsudilov@mpe.mpg.de>

V. Sudilovsky, J. Greiner, A. Rau (All MPE Garching), and S. Klose (TLS 
Tautenburg) report on behalf of the GROND team:

We observed the field of the IPN GRB 110825A (Hurley et al., GCN 12307) 
on 2011 August 29 at 08:55 UT (52hr post trigger) simultaneously in 
g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at 
the 2.2m MPI/ESO telescope at La Silla Observatory (Chile).

With an exposure time of 3000s we do not find any source within the XRT 
error circle (Zhang et al., GCN 12308). In particular, the object 
reported by Xu et al. (GCN 12311) is not detected with a 3-sigma 
limiting magnitude of r' ~ 24.5 calibrated against USNO B1. This is 
consistent with the non-detection reported by Zhao et al (GCN 12314) and 
suggests that the source must have faded by at least 0.9mag within the 
first 48hr after the trigger. The optical decline is in agreement with a 
similar decay by a factor of 3 seen in the XRT lightcurve between day 1 
and day 5 (Zhang et al., GCN 12334). While this could suggest the source 
detected by Xu et al. to be the afterglow of GRB110825A, the very late 
re-brightening observed in X-rays (Zhang et al., GCN 12334) makes this 
interpretation unlikely.

Further deep optical imaging and X-ray monitoring are encouraged to 
resolve the nature of this source.

We thank Kim Page and Phil Evans for providing helpful details 
concerning the XRT observations of GRB 110825A.


GRB_name: GRB110928A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12404
SUBJECT: GRB 110928A: Swift-XRT refined Analysis
DATE:    11/09/28 18:02:01 GMT
FROM:    Chris Wolf at PSU  <cwolf@swift.psu.edu>

C. A. Wolf (PSU), E. A. Hoversten (PSU), and K. L. Page (U Leicester)
report on behalf of the Swift-XRT team:

We have analysed 12 ks of XRT data for GRB 110928A (Hoversten  et al.
GCN Circ. 12394), from 3.3 ks to 44.3 ks after the  BAT trigger. The
data was collected in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Osborne et al. (GCN. Circ 12402).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.55 (+0.17, -0.19).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.07 (+0.34, -0.27). The
best-fitting absorption column is  4.8 (+2.5, -1.7) x 10^21 cm^-2, in
excess of the Galactic value of 3.1 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 4.4 x 10^-11 (8.1 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.8 (+2.5, -1.7) x 10^21 cm^-2
Galactic foreground: 3.1 x 10^20 cm^-2
Excess significance: 4.7 sigma
Photon index:      2.07 (+0.34, -0.27)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00504215.

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


GRB_name: GRB110928A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12406
SUBJECT: GRB 110928A: Swift/UVOT Upper Limits 
DATE:    11/09/28 20:38:28 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110928A
3342 s after the BAT trigger (Hoversten et al., GCN Circ. 12394).
No optical afterglow consistent with the XRT position (Osborne et al.,
GCN Circ. 12402) 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          3342         3492          147         >20.2
white             3342         4723          344         >21.0
v                 3499         3698          197         >19.1
b                 4319         4518          197         >21.0
u                 4114         4313          197         >20.8
w1                3909         4108          197         >20.3
m2                3704         3903          197         >19.9
w2                4729         4929          197         >21.6

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


GRB_name: GRB110928A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12407
SUBJECT: GRB 110928A: RAPTOR Limits During Gamma-ray Emitting Interval
DATE:    11/09/28 21:11:25 GMT
FROM:    James Wren at LANL  <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis,
of Los Alamos National Laboratory report:

The RAPTOR network of robotic optical telescopes made observations of Swift
trigger 504215 (Hoversten et al., GCN 12394).  The burst location was within
the field of our wide-field monitors which began a 10 s integration of the
location at 01:51:33.0 UT, 1.2 s after the Swift trigger time and during the
gamma-ray emitting interval.  The next wide-field 10 s integration begins at
01:51:52.1 UT, and is also within the gamma-ray emitting interval.  Neither
image shows a counterpart at the Swift XRT location (Evans et al., GCN 12398)
to an unfiltered 3-sigma limiting magnitude of 10.1 based on comparison to
the Tycho-2 V-band.  Our narrow-field instruments began imaging at
01:52:40.2 UT, 68.4 s after the Swift trigger.  The initial 5 s exposures
show no counterpart to a 3-sigma limiting magnitude of 16.1 when compared to
the USNO-B1 R-band.  The following table gives a sample of our observations.
The start time is given as the seconds between the start of the exposure and
the initial Swift trigger time.

start(s)   exp(s)    mag limit
------------------------------
1.22       10.0      > 10.1
20.32      10.0      > 10.1
68.44       5.0      > 16.1
153.55     10.0      > 16.5
413.45     30.0      > 17.2


GRB_name: GRB110928A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12408
SUBJECT: Skynet observations of GRB 110928A
DATE:    11/09/29 04:14:54 GMT
FROM:    Aaron LaCluyze at U.North Carolina  <lacluyze@email.unc.edu>

J. Haislip, K. Ivarsen, A. LaCluyze, K. McLin, D. Reichart, J. Moore, T. 
Cromartie, R. Egger, A. Foster, M. Nysewander, A. Oza, E. Speckhard, A. 
Trotter, and J. A. Crain report:

Skynet observed the field of GRB 110928A (Hoverston et al., GCN 12394) 
with the GLAST Optical Robotic Telescope (GORT) at the Hume observatory 
in California beginning roughly 75 minutes after the burst.   We do not 
detect any uncatalogued sources.  Stacking only images that increase the 
limiting magnitude yields:


mean            mean
time              
time                                                                3-sigma
since             
since                                                               limiting
trigger        trigger (days)  telescope   exposures     filter      mag

3.186 h         0.13277            GORT     19 x 80 s     Ic         20.0
3.400 h         0.14166            GORT     23 x 80 s     Rc        21.0

This message may be cited.


GRB_name: GRB110928A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12409
SUBJECT: Skynet/Dolomiti observations of GRB 110928A
DATE:    11/09/30 04:19:07 GMT
FROM:    Aaron LaCluyze at U.North Carolina  <lacluyze@email.unc.edu>

J. Haislip, K. Ivarsen, A. LaCluyze, M. Maturi, D. Reichart, J. Moore, T.
Cromartie, R. Egger, A. Foster, N. Frank, M. Nysewander, A. Oza, E.
Speckhard, A.Trotter, and J. A. Crain report:

Skynet observed the field of GRB 110928A (Hoverston et al., GCN 12394)
with the 16" Dolomites Astronomical Observatory telescope (DAO) in Italy
beginning roughly 16.3 hours after the burst.   We do not detect any
uncatalogued sources.  Stacking only images that increase the limiting
magnitude yields:


Mean Time                                       3-sigma limiting
Since trigger    Tel      Exposures    Filter    magnitude
17.244 h         DAO      37 x 160 s     g'         21.0
(0.71850 days)


This message may be cited.


GRB_name: GRB110921A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12410
SUBJECT: GRB 110921A: MITSuME-Akeno Optical photometry
DATE:    11/09/30 16:46:34 GMT
FROM:    Yoichi Yatsu at Tokyo Tech.  <yatsu@hp.phys.titech.ac.jp>

K. Tokoyoda, M. Hayashi, Y. Yatsu, Y. Aoki, K. Kawakami, S. Song,
R. Usui, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME
collaboration:

As reported in GCN12378 (Tokoyoda et al.), we detected a very faint object
within the XRT error circle of GRB 110921A (W. H. Baumgartner et al, GCN12373)
with the MITSuME-Akeno 50cm telescope.
Here we report the results of aperture photometry.

We started the follow-up observation at 13:53:08 (UT), ~108 sec after the BAT
trigger(W. H. Baumgartner et al, GCN12373).  The optical counterpart can be seen
both in R and I band only in the earliest data-set from T0+108s to T0 + 348s.

For zero-point calibration we used GSC2.3 catalog.
The g' magnitudes of the reference stars were estimated based on Sesar
et al. (2006).
For I-band data we could not find any usable catalog data, therefore we
performed a field photometry.
The Photometric results are summarized below.

Filter T0+[s] MID-UT T-EXP[sec]  Mag Mag_err  LimitMag
-----------------------------------------------------------------------------------
g'    +108  13:55:31    240    ---   ---      >19.4
Rc   +108  13:55:31    240    18.8  0.2       ---
Ic    +108  13:55:13    210    18.8  0.3      ---
-----------------------------------------------------------------------------------


GRB_name: GRB110905A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12411
SUBJECT: GRB 110905A /  MAXI J1836-194: optical monitoring
DATE:    11/10/01 16:31:58 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), A. Volnova (SAI MSU), M. Andreev  (Terskol Branch of 
Institute of Astronomy), V. Rumyantsev (CrAO),  D. Shakhovskoy  (CrAO),  V. 
Biryukov (SAI MSU & CrAO),  A. Sergeev (Terskol Branch of Institute of 
Astronomy) on behalf of larger GRB follow up collaboration report:

We started a monitoring campaign of  MAXI J1836-194 (Negoro et al., ATel 
3611) after Swift triggers #502415 (=GRB110905A, Pagani et al., GCN 12327). 
Till now observations were obtained with Zeiss-600 (Mt. Terskol), AZT-11 
(CrAO), Zeiss-600 and ZTE (SAI MSU) in the R and B filters. We clearly 
detect significant optical variability of the source of MAXI J1836-194, and 
at least one peak of our light curve (Sep. 19.80) coincides with a peak of 
radio light curve of MAXIJ1836-194 at 4.8 GHz (Trushkin et al., ATel. 3656).

The light curve (Sep. 5 - Sep. 26) can be found at
http://grb.rssi.ru/GRB110905A=MAXI_J1836-194/MAXIJ1836-194_lc_opt.png

Observations will be continued. 


GRB_name: GRB111003A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12412
SUBJECT: GRB 111003A: Fermi GBM detection
DATE:    11/10/04 19:04:14 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick@ucdconnect.ie>

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

At 11:10:00.23 UT on 03 October 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 111003A (trigger 339333002/111003465).

The on-ground calculated location, using the GBM trigger
data, is RA = 276.8 , DEC = -62.3   (J2000 degrees,
equivalent to 18 h 27 m, -62 d 18.0'), with an uncertainty
of 1.1 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 62.00 degrees.
Moreover, this burst was bright enough to result in
a Fermi spacecraft repointing maneuver.

The GBM light curve consists of two peaks
with a duration (T90) of 17 s (50-300 keV).
The time-averaged spectrum from T0-1.0 s to T0+17.9 s is
well fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.94 (+/- 0.02) and
the cutoff energy, parameterized as Epeak, is 231.5 (+/- 8.0) keV.

The event fluence (10-1000 keV) in this time interval is
(1.83 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.6 s in the 10-1000 keV band is 18.2 +/- 0.5 ph/s/cm^2.

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


GRB_name: GRB111005A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12413
SUBJECT: GRB 111005A: Swift detection of a burst
DATE:    11/10/05 08:23:36 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. J. Saxton (UCL-MSSL), S. D. Barthelmy (GSFC), V. D'Elia (ASDC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
C. Guidorzi (U Ferrara), J. A. Kennea (PSU),
O. M. Littlejohns (U Leicester), S. R. Oates (UCL-MSSL),
K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-IASFPA)
and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team:

At 08:05:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111005A (trigger=504779).  Swift did not slew because of
a Sun observing constraint.  The BAT on-board calculated location is 
RA, Dec 223.284, -19.730 which is 
   RA(J2000)  =  14h 53m 08s
   Dec(J2000) = -19d 43' 48"
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 ~1900 counts/sec (15-350 keV), at ~1 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 18:03 UT on 2011 December 25. There will thus be no XRT
or UVOT data for this trigger before this time. 

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: GRB111005A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12414
SUBJECT: GRB 111005A: bright galaxy in error circle
DATE:    11/10/05 08:54:07 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

A.J. Levan (U. Warwick), N.R. Tanvir, K. Wiersema, P.T. O'Brien
(U. Leicester), comment:

We note that the BAT error circle of GRB 111005A (Saxton et al. GCN 12413)
contains the bright, nearby galaxy ESO 580-49, at a redshift 0.01326
(~55 Mpc). If associated with GRB 111005A this would make it the closest
GRB identified since GRB980425/SN1998bw. Although the burst is extremely
close to the sun any follow-up observations are strongly encouraged.


GRB_name: GRB111005A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12415
SUBJECT: GRB 111005A: Swift-BAT refined analysis
DATE:    11/10/05 13:20:33 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), C. J. Saxton (UCL-MSSL)
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+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 111005A (trigger #504779)
(Saxton, et al., GCN Circ. 12413).  The BAT ground-calculated position is
RA, Dec = 223.315, -19.722 deg, which is 
   RA(J2000)  =  14h 53m 15.6s 
   Dec(J2000) = -19d 43' 19.1" 
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 42%.
 
The mask-weighted light curve shows a single peak starting roughly at T-20 sec,
peaking at ~T+1 sec, and ending at ~T+40 sec.  T90 (15-350 keV) is
26 +- 7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-5.23 to T+23.06 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.03 +- 0.27.  The fluence in the 15-150 keV band is 6.2 +- 1.1 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.70 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/504779/BA/


GRB_name: GRB111005A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12416
SUBJECT: GRB 111005A: VLT IR observations
DATE:    11/10/06 01:04:09 GMT
FROM:    Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>

A.J. Levan (Warwick), D. Malesani, J. Hjorth (DARK/NBI), N.R. Tanvir,
K. Wiersema (U. Leicester) report for a larger collaboration:

We observed the location of GRB 111005A (Saxton et al. GCN 12413)
with the VLT and the HAWKI IR instrument.  Images were taken in
twilight and with a high airmass, and began at 23:27 UT. We do not
identify any new sources in or around the z=0.013 galaxy ESO 580-49
(Levan et al. GCN 12414) in comparison with archival 2MASS images
(limiting magnitude approximately K~16). There are several fainter
sources lying on the field of the galaxy, but further observations
will be necessary to establish if any of these is variable, and
hence a plausible counterpart for GRB 111005A.

We thank the ESO directorate for the rapid approval of these
observations, and the VLT staff, in particular Christophe Martayan
and Retha Pretorius for their assistance with these challenging
observations."


GRB_name: GRB111005A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12417
SUBJECT: GRB 111005A: GROND NIR observations
DATE:    11/10/06 08:43:20 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

M. Nardini (Uni. Milano-Bicocca), J. Greiner (MPE Garching) and
T. Kruehler (DARK), report on behalf of the GROND team:

We observed the field of the GRB 111905A (Saxton et al., GCN 12413)
starting 2011 October 5 at 23:25 UT (15.3hr post trigger) simultaneously 
in JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at
the 2.2m MPI/ESO telescope at La Silla Observatory (Chile).
Observations were performed during twilight (with the Sun just 10 deg below
the horizon) before the target was going to set, at an average airmass
of 2.5 and seeing of 2".

With an exposure time of  240s seconds in JHKs we do not identify any 
new source within the BAT error circle (Barthelmy et al., GCN 12415)
relative to 2MASS.

In particular, we do not find any new point source within or near the 
galaxy ESO 580-49 mentioned by Levan et al. (GCN 12414).

Our 3 sigma limiting magntiudes (AB system) are:

J  < 19.8
H  < 19.3
Ks < 18.7

while the limits for an afterglow brighter than the corresponding
2MASS limits (transformed to AB mag) are

J < 16.7, 
H < 16.5 and 
Ks< 16.0 mag

in agreement with Levan et al. (GCN 12416).

The given GROND magnitudes are calibrated against 2MASS field stars.


GRB_name: GRB111005A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  12418
SUBJECT: GRB 111005A: VLT optical observations
DATE:    11/10/06 10:01:01 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), A.J. Levan (Univ. Warwick), N.R. Tanvir, K. 
Wiersema (Univ. Leicester), J. Hjorth, J. P. U. Fynbo (DARK/NBI), report 
on behalf of a larger collaboration.

We observed the surroundings of the galaxy ESO 580- G 049, which is 
overlapping the BAT error circle of GRB 111005A (Saxton et al., GCN 
12413; Barthelmy et al., GCN 12415; Levan et al., GCN 12414). 
Observations were carried out with the acquisition camera of the 
X-shooter spectrograph mounted on the ESO VLT. Images were taken in the 
z and I bands, and were carried out deep in twilight. We note that our 
data only cover a small fraction of the BAT error circle. The time of 
the observation is October 5, 23:40 UT (i.e., 15.6 hr after the GRB), 
and the exposure time was 30 s in both z and I.

Our data reach somewhat deeper than the DSS survey; our limiting 
magnitude is I ~ 20.5 (assuming I = 16.3 for the star at RA = 
14:53:07.299, Dec = -19:43:43.63). No new sources can be recognized in 
comparison to the DSS survey, in agreement with previous reports (Levan 
et al., GCN 12416; Nardini et al., GCN 12417). A few objects (fainter 
than the DSS limit) can be seen consistent with the galaxy disk, 
although their association with the GRB cannot be ascertained at this stage.

We acknowledge the excellent support of the ESO staff at Paranal in 
scheduling and executing such a challenging observation, in particular 
Christophe Martayan and Maja Vuckovic.


