# GCN_circulars

GRB_name: GRB100713A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10955
SUBJECT: GRB 100713A: optical upper limit
DATE:    10/07/13 23:33:31 GMT
FROM:    Giuseppe Greco at U Bologna  <giuseppe.greco2@studio.unibo.it>

G. Greco (INAF-Astronomical Observatory of BOLOGNA), C. Bartolini, A. Guarnieri, A. Piccioni
(University of Bologna), G. Pizzichini (INAF/IASF-Bologna), F. Giovannelli (INAF/IASF-Roma)
and A. Deblasi (INAF-Astronomical Observatory of BOLOGNA) report:

We observed the location of the  GRB GRB 100713A (Mereghetti et al. 2010, GCN 10951)
with the 152 cm Cassini Telescope located in Loiano under clear sky conditions
(seeing approximately 2 arcsec).

One R-band observation (1x2400 sec) was done on 2010 July at 13.891 UT middle exposure time.

Comparison to the DSS (second epoch) reveals no new sources within the
INTEGRAL/IBAS error circle or the Swift/XRT error circle (D'Elia et al. 2010, GCN 10952).

Our 3-sigma limiting magnitude is R = 21 calibrated against the
USNO-B1.0 catalog stars and not corrected for the Galactic extinction.

This message can be cited.


GRB_name: GRB100713A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10956
SUBJECT: GRB 100713A: GROND upper limits
DATE:    10/07/14 10:11:51 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

M. Nardini, T. Kruehler, and J. Greiner  (all MPE Garching) report on behalf
of the GROND team:
  
We observed the field of GRB 100713A (INTEGRAL trigger 6041; Mereghetti et
al., GCN #10951) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla
Observatory (Chile).
  
Observations started at 23:46 UT on 2010 July 13th, 9.3 h after the GRB
trigger. They were performed at an average seeing of 2.6" and at an
average airmass of 2.5. With a total integration time of 13.2 min (12 min 
for the IR), we do not detect any source within the Swift-XRT error circle 
reported by D'Elia et al. (GCN #10952) down to

g' > 23.8,
r' > 22.9,
i' > 22.0,
z' > 21.5,
J  > 18.8,
H  > 17.4 and
K  > 16.8

The given limits are derived based on calibrating the images against USNO
B1 catalogue and 2MASS field stars and are not corrected for the Galactic
foreground extinction corresponding to a reddening of E_(B-V)= 0.056 in  
the direction of the burst (Schlegel et al. 1998). 

We  confirm the presence of a faint source close to the border of the XRT
error circle at the coordinates reported by D'Avanzo et al. (GCN 10954). 


GRB_name: GRB100713A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10957
SUBJECT: GRB100713A: Swift/UVOT observations
DATE:    10/07/14 12:38:05 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

M. De Pasquale (MSSL-UCL) and V. D'Elia (ASDC) on behalf of the Swift/UVOT 
team report:

Swift/UVOT began settled observations of the INTEGRAL burst GRB100713A 
(Mereghetti et al., GCN 10951) 6247s after the trigger.
At the position of the X-ray counterpart (D'Elia et al., GCN 10952), we do 
not detect any optical afterglow in the exposures in UVOT filters down to 
the following 3 sigma upper limits.


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

v          6403           6603       197        >19.6

wh         6247          12351       518        >21.8

b         11065          11965       880        >21.4

u         10152          11059       885        >20.7

uvw1       6813           6963       148        >19.8

uvm2       6608           6808       197        >19.6


The values quoted above are calculated using the UVOT photometric system
(Poole et al 2008, MNRAS, 383, 627) and are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.06 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB100713A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10959
SUBJECT: GRB 100713A : IRSF/SIRIUS NIR upper limits
DATE:    10/07/14 18:52:29 GMT
FROM:    Hiroyuki Naito at Nagoya U  <naito@stelab.nagoya-u.ac.jp>

H. Naito, T. Sako, D. Suzuki, S. Kobara and K. Omori (Nagoya Univ.) on  
behalf of the MOA Collaboration, T. Nagayama, M. Kurita (Nagoya  
Univ.), S. Crawford and S. Randriamampandry (South African  
Astronomical Observatory) on behalf of the IRSF Collaboration report:

We searched for a NIR afterglow of the GRB 100713A detected by  
INTEGRAL (Mereghetti et al., GCN 10951) starting from 19:42:07 UT on  
2010 July 13 (5.1 hours after the burst) with the SIRIUS on the IRSF  
1.4m telescope at SAAO in South Africa. In images of a 30 min exposure  
with J, H and Ks filter, we did not find any object within the error  
circle of the Swift XRT source position (V. D'Elia et al., GCN 10952).

A 3 sigma upper limits are the followings.

J > 18.9
H > 18.0
K > 17.4

This photometry was done by using the DoPHOT and calibrated against  
the 2MASS cataloged stars. The Galactic extinction was not corrected.


GRB_name: GRB100713A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10960
SUBJECT: GRB 100713A: Swift XRT refined analysis
DATE:    10/07/14 21:57:32 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

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

We have analysed 6.0 ks of XRT data for GRB100713A (D'Elia et al. GCN
Circ. 10952), from 6.23 to 52.3 ks after the  INTEGRAL trigger  
(Mereghetti et al. GCN Circ. 10951). The data
are entirely in Photon Counting (PC) mode. Using 1772 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 = 255.20133, +28.39434 which is equivalent to:

RA (J2000): 17 00 48.32
Dec(J2000): +28 23 39.6

with an uncertainty of 2.4 arcsec (radius, 90% confidence).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.25 (-0.8+0.9).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.50 (+0.78, -0.68). The
best-fitting absorption column is  2.2 (+2.0, -1.3) x 10^21 cm^-2, in
excess of the Galactic value of 5.0 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 3.5 x 10^-11 (7.6 x 10^-10) erg
cm^-2 count^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020143.

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

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GRB_name: GRB100713A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10961
SUBJECT: GRB 100713A: further inspection of TNG images
DATE:    10/07/15 08:05:32 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), L. A. Antonelli (INAF-OAR), V. D'Elia (ASDC), D.
Fugazza (INAF-OAB), A. de Ugarte Postigo (INAF-OAB), D. Malesani
(DARK/NBI) on behalf of the CIBO collaboration report:

Further inspection of our R and I-band TNG images of GRB 100713A (D'Avanzo
et al., GCN 10954) does not reveal any afterglow candidate at the refined
XRT position (D'Elia et al., GCN 10960). We note that the SDSS object
reported by D'Avanzo et al. (GCN 10954) and Nardini et al. (GCN 10956) is
significantly outside the XRT error circle.


GRB_name: GRB100713A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10962
SUBJECT: GRB 100713A: optical observation in Maidanak
DATE:    10/07/16 19:33:40 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), A. Volnova (SAI MSU),  B. Satovski (Astrotel),  M. 
Ibrahimov (MAO) report on behalf of  larger GRB  follow-up collaboration:

We observed the field of the INTEGRAL GRB 100713A (Mereghetti et al. GCN 
10951) with AZT-22 telescope of Maidanak observatory in R band between  July 
13 (UT) 18:21 -- 18:56 under photometric conditions and seeing ~0.7".

A possible faint source (S/N = 2.2) was detected at coordinates (J2000) 
RA=17 00 48.12 Dec = +28 23 40.2 with uncertainties 0.15" in both 
coordinates. The source is at the edge of enhanced XRT error circle (D'Elia 
et al.  GCN 10960).  At this time we cannot confirm the nature of the source 
and comparison with TNG observation (D'Avanzo et al. GCN 10954) and/or 
additional observation is necessary. The SDSS object reported by D'Avanzo et 
al. (GCN 10954) and Nardini et al. (GCN 10956) is also clearly detected.

The photometry is based on several SDSS field stars and Lupton ugriz -> R 
transformations :

T0+      Filter,   Exposure,  mag.          Upper limit (3 sigma)
(mid, d)              (s)
0.16830  R       300*6      24.4+/-0.5  24.0

The finding chart can be found at
http://grb.rssi.ru/GRB100713A/GRB100713A_AZT22.png

We thank Alexander Gusev for performing the observations and for his 
support.
 


GRB_name: GRB100719A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10963
SUBJECT: GRB 100719A: Swift detection of a burst
DATE:    10/07/19 03:47:15 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

R. Margutti (INAF-OAB), W. H. Baumgartner (GSFC/UMBC),
J. M. Gelbord (PSU), E. A. Hoversten (PSU), J. Mao (INAF-OAB),
C. B. Markwardt (CRESST/GSFC/UMD), D. M. Palmer (LANL),
T. Sakamoto (NASA/UMBC), M. H. Siegel (PSU), T. N. Ukwatta (GSFC/GWU)
and L. Vetere (PSU) report on behalf of the Swift Team:

At 03:30:57 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100719A (trigger=429357).  Swift did not slew to the burst
due to a sun observing constraint. The BAT on-board calculated location is 
RA, Dec 112.263, -5.837 which is 
   RA(J2000) = 07h 29m 03s
   Dec(J2000) = -05d 50' 12"
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 25 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The source will remain in Sun constraint until August 27,
and therefore there will be no XRT or UVOT observations. 

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


GRB_name: GRB100719A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10964
SUBJECT: GRB 100719A: Swift-BAT refined analysis
DATE:    10/07/19 14:49:02 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), R. Margutti (INAF-OAB),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+242 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100719A (trigger #429357)
(Margutti, et al., GCN Circ. 10963).  The BAT ground-calculated position is
RA, Dec = 112.319, -5.857 deg which is 
   RA(J2000)  =  07h 29m 16.6s 
   Dec(J2000) = -05d 51' 24.4" 
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 57%.
 
The mask-weighted light curve shows a few overlapping peaks starting
at ~T-5 sec, peaking at ~T+2 sec, and ending at ~T+80 sec.
T90 (15-350 keV) is 36.0 +- 9.2 sec (estimated error including systematics).
 
The time-averaged spectrum from T-3.9 to T+35.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.69 +- 0.25.  The fluence in the 15-150 keV band is 5.3 +- 0.9 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+2.06 sec in the 15-150 keV band
is 0.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/429357/BA/


GRB_name: GRB100718A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10965
SUBJECT: GRB 100718A: MASTER-Net  optical prompt and alert observations
DATE:    10/07/19 18:51:05 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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


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


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

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

Four MASTER   robotic systems (MASTER-Net: http://observ.pereplet.ru, 6 
Very Wide Field cameras and 3 Wide Field Telescopes ) 
located  near Kislovodsk and Tunka (near Baykal Lake)   was pointed to the 
GRB 100718A (Fermi trigger Number 301172784).
Initially all Very Wide Field Cameras are closed to Fermi GBM error box.
So we have next table of the observations:

-------------------------------------------------------------------------
t-t_GRB     r.a.     dec   FOW*      m_lim   Exp   Coadd   Camera   Where
  (s)        (center FOW) (degrees)            s   (number)(Diam.mm)

  0          269.6   22.6   18x24      14     25     25       61     Kislo

  0          251.9   23.0   18x24      14     25     25       61     Kislo

  0          270.4   20.9   18x24      14     25      5       61     Kislo

  0          276.0   22.7   18x24      14     25      5       61     Kislo

  0          259.5   24.1   18x24      14     25      5       61     Kislo

  0          253.5   22.7   18x24      14     25      5       61     Kislo

  0          324.1   11.6   40x24      11     25     25       35     Tunka

47          311.6   15.6   18x24      14     25      5       61     Kislo

47          295.3   16.9   18x24      14     25      5       61     Kislo

49          278.1   36.2   18x24      14     25     25       61     Kislo

49          298.4   36.7   18x24      14     25     25       61     Kislo

79          292.1   38.1    2x2      17.1    20      1      400     Kislo

51          290.4   38.6   40x24     11.2    25     25       35     Tunka


------------------------------------------------------------------------
* FOV axb, a - along r.a.

The weather was not very good at both sites.
We wait the more accurate error box.
The map of observations are available at 
http://observ.pereplet.ru/images/GRB100718A/
The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100722A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10966
SUBJECT: GRB 100722A: Fermi GBM detection
DATE:    10/07/23 08:12:08 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

Elisabetta Bissaldi (MPE) 
reports on behalf of the Fermi GBM Team: 


"At 02:18:37.24 UT on 22 July 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100722A (trigger 301457919 / 100722096).
The on-ground calculated location, using the GBM trigger
data, is RA = 238.8, DEC = -15.6 (J2000 degrees,
equivalent to 15h 55m, -15d 36), 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 Fermi Observatory executed a maneuver following this trigger and
tracked the burst location for the next 5 hours, subject to
Earth-angle constraints.

The angle from the Fermi LAT boresight is 33 degrees.

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

The GBM light curve consists of several peaks
with a duration (T90) of 6.6 +/- 0.2 s (50-300 keV).
The time-averaged spectrum from T0 to T0+6.7 s is
best fit by a Band function with Epeak = 68.1 (-3.5/+3.4) keV,
alpha = -1.01 (-0.06/+0.07), beta = -2.54 (-0.10/+0.08)
(Castor C-STAT 627 for 479 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(9.5 +/- 0.09) erg/cm^2. The 1-sec peak photon flux measured
starting from T0 in the 8-1000 keV band
is 26.9 +/- 0.4 ph/s/cm^2.


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


GRB_name: GRB100614A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10967
SUBJECT: GRB 100614A: 10.4-m GTC deep-optical limit  
DATE:    10/07/23 15:00:20 GMT
FROM:    Sergey Guziy at IAA CSIC  <gss@iaa.es>

S. Guziy, M. JelÃ­nek, J. Gorosabel (IAA-CSIC Granada), P. KubÃ¡nek (U.
Valencia), A. de Ugarte Postigo (INAF-OAB), D. PÃ©rez-RamÃ­rez (U, JaÃ©n),
G. GÃ³mez (GTC La Palma) and A. J. Castro-Tirado (IAA-CSIC), on behalf of
a larger collaboration, report:

"We observed the field of GRB 100614A  (G.Stratta et al., GCN #10837)
in ugriz bands with the 10.4-m Gran Telescopio Canarias (GTC)
at the Observatorio del Roque de los Muchachos on the island of La Palma.

Observations started at 01:55 UT on 2010 June 15th, 4.3 h after the GRB
trigger. Images were obtained at an average seeing of 0."6 and an
average airmass of 1.1 with the OSIRIS instrument (Cepa et al. 2010,
HSA5,conf.) and a total integration time of 180-s for each band. We do
not detect any source within the Swift-XRT error circle reported by
Osborne et al. (GCN #10849) with the following 3-sigma limiting magnitudes
(Vega
system):

u > 25.2,
g > 27.1,
r > 26.4,
i > 25.9,
z > 24.9.

The given limits were obtained by observation of standard stars and
compared with
the SSDS catalog and are not corrected for the Galactic foreground
extinction."

This message can be quoted.


GRB_name: GRB100724A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10968
SUBJECT: GRB 100724A: Swift detection of a burst
DATE:    10/07/24 01:04:32 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

C. B. Markwardt (CRESST/GSFC/UMD), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), J. M. Gelbord (PSU),
S. T. Holland (CRESST/USRA/GSFC), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU),
M. Stamatikos (OSU/NASA/GSFC), C. A. Swenson (PSU),
E. Troja (NASA/GSFC/ORAU) and T. N. Ukwatta (GSFC/GWU) report on
behalf of the Swift Team:

At 00:42:19 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100724A (trigger=429868).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA, Dec 194.566, -11.121 which is 
   RA(J2000)  =  12h 58m 16s
   Dec(J2000) = -11d 07' 16"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double peak structure
with a duration of about 70 sec.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~0.5 sec after the trigger. 

The XRT began observing the field at 00:43:48.1 UT, 88.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 194.5434, -11.1027
which is equivalent to:
   RA(J2000)  = 12h 58m 10.41s
   Dec(J2000) = -11d 06' 09.7"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 104 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.35e+20
cm^-2, Kalberla et al. 2005), with an excess column of 9.7
(+13.63/-5.98) x 10^20 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of nominal 250 seconds with the U filter
starting 304 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. Data from the 2.7'x2.7' sub-image are
not available at this time. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18.0 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.04. 

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: GRB100724A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10969
SUBJECT: GRB 100724A, GROND detection of an afterglow candidate
DATE:    10/07/24 01:21:28 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>

F. Olivares E., J. Greiner, P. Afonso (all MPE Garching), 
and S. Klose (TLS Tautenburg) report on behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405), the 7-channel imager mounted 
at the 2.2m ESO/MPI telescope on La Silla, started follow-up observations 
of GRB 100724A (Swift trigger 429868; Markwardt et al. 2010, GCN 10968) on 
July 24 at 0:45 UT (about 3 min after the trigger).

Within the revised 2.4 arcsec XRT error circle we find an afterglow 
candidate at position RA, Dec (J2000) = 12:58:10.4, -11:06:09, visible 
in all bands. We conclude that the redshift is less than 3.5.

Observations are ongoing.


GRB_name: GRB100724A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10970
SUBJECT: GRB 100724A: fading afterglow seen with GROND
DATE:    10/07/24 02:16:21 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>

F. Olivares E., J. Greiner, P. Afonso (all MPE Garching), and S. Klose 
(TLS Tautenburg), report on behalf of the GROND team:

The afterglow candidate reported by Olivares et al. (GCN 10969) is clearly 
fading. Between mid-times of 00:49 UT and 01:14 UT the object faded by 1.3 
magnitudes, corresponding to a power-law decay index of about 0.7. We 
therefore confirm this object to be the afterglow of GRB 100724A.


GRB_name: GRB100724A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10971
SUBJECT: GRB 100724A: X-shooter redshift
DATE:    10/07/24 06:55:35 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

C. C. Thoene, A. de Ugarte Postigo (INAF-OAB), P. Vreeswijk (Univ.
Iceland), P. D'Avanzo, S. Covino (INAF-OAB), J. P. U. Fynbo (DARK/NBI) and
N. Tanvir (Univ. Leicester) report on behalf of the X-shooter
collaboration

We observed the optical afterglow of GRB 100724A (Markwardt et al., GCN
10968, Olivares et al., GCN 10969, 10970) with X-shooter at the VLT in RRM
mode on July 24, 2010, starting at 00:53 UT (11 min after the burst).

We detect several absorption lines including Fe II 2344, 2383, 2586, 2600,
the Mg II doublet (2796, 2803) and Mg I 2852 at a common redshift of 1.288
which we suggest to be the redshift of the GRB. The wavelength calibration
was obtained from archival files and is therefore considered preliminary.

We thank the Paranal staff for performing the observations, in particular
Lorenzo Monaco and Andres Pino.


GRB_name: GRB100724A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10972
SUBJECT: GRB 100724A: Swift-BAT refined analysis
DATE:    10/07/24 15:12:20 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

C. B. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+644 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100724A (trigger #429868)
(Markwardt, et al., GCN Circ. 10968).  The BAT ground-calculated position is
RA, Dec = 194.569, -11.095 deg, which is 
   RA(J2000)  =  12h 58m 16.5s 
   Dec(J2000) = -11d 05' 41.7" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 43%.
 
The mask-weighted light curve shows several overlapping peaks starting
at T+0.0 sec and ending at T+4.0 sec.  There is a weak roughly exponential tail
extending out to ~T+20 sec.  T90 (15-350 keV) is 1.4 +- 0.2 sec (estimated error
including systematics).  The initial description of the lightcurve given
in GCN Circ 10968 as being 70 sec long was confused by the nearly simultaneous,
but different burst detected by Fermi.  The BAT mask-weighted lightcurve
clearly shows that the 100724A burst is only single episode around T_zero.
There is nothing in the mask-weighted lightcurve in the T+40 to T+70sec range.
 
The time-averaged spectrum from T+0.1 to T+1.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.92 +- 0.21.  The fluence in the 15-150 keV band is 1.6 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.09 sec in the 15-150 keV band
is 1.9 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/429868/BA/


GRB_name: GRB100724A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10973
SUBJECT: GRB 100724A:  Swift/UVOT observations
DATE:    10/07/24 15:21:51 GMT
FROM:    Craig Swenson at PSU/Swift  <cswenson@astro.psu.edu>

C. A. Swenson (PSU) and C. B. Markwardt (CRESST/GSFC/UMD) report
on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 100724A 
74s after the BAT trigger (Markwardt et al., GCN 10968).  We detect a 
source at the position of the detected X-ray source (Markwardt et al., 
GCN 10968) and the location reported by GROND (Olivares et al., GCN 
10969).  The source is clearly fading in the UVOT white filter between 
the first finding chart and a later observation.

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

Filter      T_start    T_stop    Exp(s)    Magnitude/3-sigma upper limit
----------------------------------------------------------------------
white (FC)      92       242      147            18.46  0.11
white          584       775       39            > 19.71
u     (FC)     304       554      246            18.54  0.15
u              706       726       19            18.17  0.37
v               74      1050       60            > 18.31
b              559       751       39            > 18.99
uvw1           682       702       19            > 17.96
uvm2           658       850       39            > 18.19
uvw2           609      1034       58            > 18.97

The quoted upper limits have not been corrected for the expected 
Galactic extinction along the line of sight of E_(B-V) = 0.043 mag 
(Schlegel, et al., 1998, ApJS, 500, 525).


GRB_name: GRB100724A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10974
SUBJECT: GRB 100724A: Enhanced Swift-XRT position
DATE:    10/07/24 16:03:15 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 6782 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 100724A, 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 = 194.54312, -11.10263 which is equivalent
to:

RA (J2000): 12h 58m 10.35s
Dec (J2000): -11d 06' 09.5"

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

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

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


GRB_name: GRB100724A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10975
SUBJECT: GRB 100724A: Swift XRT refined analysis 
DATE:    10/07/24 18:32:29 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

V. Mangano (INAF IASF-PA), B. Sbarufatti (INAF OAB/INAF IASF-PA) and
C. B. Markwardt (CRESST/GSFC/UMD) report on behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 100724A (Markwardt  et al.
GCN Circ. 10968), from 96 s to 25.1 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The light curve can be
modelled with  a broken power-law decay with an initial decay index of
alpha1=0.3 (+/-0.1) , a break at T+525 (+/-90) s and a final decay index of
alpha2=1.07 (+/-0.03).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.98 (+0.20, -0.19).
The best-fitting absorption column is consistent with the Galactic value
of 3.4 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 (5.6 x 10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
1.1, the count rate at T+24 hours will be 2.4e-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of
1.1 x 10^-13 (1.3 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00429868.

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


GRB_name: GRB100724A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10976
SUBJECT: GRB 100724A: Swift/BAT spectral lag results
DATE:    10/07/24 22:31:45 GMT
FROM:    Tilan Ukwatta at GSFC/GWU  <tilan.ukwatta@gmail.com>

T. N. Ukwatta (GWU/GSFC), S. D. Barthelmy (GSFC), N. Gehrels (GSFC),
C. B. Markwardt (CRESST/GSFC/UMD), J. Norris (U. Denver),
and T. Sakamoto (GSFC/UMBC) (for the Swift-BAT team):

For GRB 100724A (Markwardt et al GCN 10968), the spectral lag analysis
of the mask-weighted data from T-0.5 sec to T+2 sec yields a lag
of 316 +/- 82 msec for the 25-50 to 50-100 keV bands using light
curve binning of 64 msec. This relatively large observed lag value
puts this burst in the long burst category.

The observed T90 (1.4 +/- 0.2 sec; Swift/BAT 15-350 keV,
Markwardt et al., GCN 10972) value is in the middle of the
the soft/long bimodal distribution. The power-law fit to the
BAT spectrum gives index (PLI) of 1.92 +/- 0.21 (Markwardt et al.,
GCN 10972), which is in the middle of the Long GRB PLI distribution
and in the soft side tail of the Short GRB PLI distribution.

In summary, the observed T90 value for GRB 100724A is inconclusive.
The relatively large spectral lag value and soft spectrum points
towards long soft burst. Our conclusion is that this burst
is likely to be in the long burst category. Further observations
are encouraged to characterize the host galaxy.


GRB_name: GRB100724B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10977
SUBJECT: GRB 100724B: Fermi GBM detection
DATE:    10/07/24 23:28:20 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

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

"At 00:42:05.98 UT on 24 July 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100724B (trigger 301624927 / 100724029).

The on-ground calculated location, using the GBM trigger
data, is RA = 124.16, DEC = 74.42 (J2000 degrees,
equivalent to 08 h 16.6 m, 74 d 25.2 '), with an uncertainty
of 1.0 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 52 degrees.

GBM triggered an automatic repoint request to the Fermi
Observatory to execute a maneuver following this trigger
and track the burst location for the next 5 hours.
However due to spacecraft constraints, the slew did not
commence until 2733 s after the trigger.

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

The GBM light curve consists of several pulses
with a duration (T90) of about 111.6 s (50-300 keV).
The time-averaged spectrum from T0-5.12 s to T0+140.29 s is
best fit by a Band function with Epeak = 467.8 +15.3/-13.1 keV,
alpha = 0.84 +/- 0.01, and beta = -1.84 +/- 0.01
(Cstat 18069 for 736 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(2.44 +/- 0.006)E-04 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+52 s in the 8-1000 keV band
is 7.06 +/- 0.01 ph/s/cm^2.

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


GRB_name: GRB100724B
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10978
SUBJECT: GRB 100724B: Fermi LAT and GBM analysis
DATE:    10/07/25 04:32:20 GMT
FROM:    James Chiang at SLAC  <jchiang@slac.stanford.edu>

Yasuyuki Tanaka, Masanori Ohno (ISAS/JAXA), Hiromitsu Takahashi,
Takeshi Uehara (Hiroshima University), Nicola Omodei (Stanford Univ.),
James Chiang (SLAC) and Sylvain Guiriec (UAH) report on behalf of the
Fermi LAT and GBM teams:

At 00:42:06 UT on 24 July 2010, the Fermi Large Area Telescope (LAT)
detected gamma-rays from the long GRB 100724B. This burst was detected
and localized by the Fermi Gamma-Ray Burst Monitor (GBM) (trigger
301624927 / 100724029, GCN 10977).

The best LAT on-ground localization for this burst is RA, Dec =
120.04, 76.74 (08h 00m 09.6s, 76d 44' 24", J2000) with a 90%
containment radius of 1.1 degrees (statistical; 68% containment radius
0.6 degrees). At the GBM trigger time, this location was at angle of
49 degrees from the LAT boresight and approximately 18 degrees from
the Earth's limb. The GBM trigger caused an Autonomous Repoint
Request.  However, owing to the proximity of the burst location to the
Earth horizon and constraints on the spacecraft pointing, the angle of
the source with respect to the boresight remained greater than 40
degrees for the first 2700 seconds after trigger.

Using a non-standard data selection designed to maximize the low
energy acceptance, the LAT light curve shows two distinct peaks at ~20
and ~64 s after the GBM trigger and a smaller sub-peak at ~77 s
post-trigger. A joint spectral fit with the GBM data yields a photon
index in the LAT band (> 20 MeV) of -2.48 +/- 0.01 (stat). This is
consistent with an extrapolation of the high energy part of the
spectrum in the GBM band. This result differs somewhat from the fit
reported in GCN 10977. In order to account for a spectral feature
below 100 keV, we have included a low energy spectral component in
addition to the usual Band function model; this accounts for the
difference found in the high energy photon index.

Further analysis is ongoing.

The Fermi LAT point of contact for this burst is Yasuyuki Tanaka
(tanaka@astro.isas.jaxa.jp).

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.

[GCN OPS NOTE(24aug10):  Per author's request, the date in the first line
was changed from "25 July" to "24 July".]


GRB_name: GRB100725A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10979
SUBJECT: GRB 100725A: Swift detection of a burst
DATE:    10/07/25 07:23:01 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

C. B. Markwardt (CRESST/GSFC/UMD), J. M. Gelbord (PSU),
V. Mangano (INAF-IASFPA), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. A. Pritchard (PSU) and
B. Sbarufatti (INAF-OAB/IASFPA) report on behalf of the Swift Team:

At 07:12:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100725A (trigger=429954).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA, Dec 166.515, -26.688 which is 
   RA(J2000) = 11h 06m 04s
   Dec(J2000) = -26d 41' 14"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of at least 40 sec.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 07:14:09.1 UT, 76.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 166.4839, -26.6716 which is equivalent to:
   RA(J2000)  = 11h 05m 56.13s
   Dec(J2000) = -26d 40' 17.7"
with an uncertainty of 5.4 arcseconds (radius, 90% containment). This
location is 115 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. 

The initial flux in the 2.5 s image was 1.32e-09 erg cm^-2 s^-1 (0.2-10
keV). 


UVOT took a finding chart exposure of nominal 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. Data from the 2.7'x2.7' sub-image are
not available at this time. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.05. 




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: GRB100725A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10980
SUBJECT: GRB 100725A: Prompt enhanced Swift-XRT position
DATE:    10/07/25 08:02:01 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 100725A, we find an
enhanced XRT position of the afterglow: RA, Dec: 166.4815, -26.6703
which is equivalent to:
   RA (J2000)  = 11 05 55.57
   Dec (J2000) = -26 40 12.9
with an uncertainty of 2.2 arc sec (radius, 90% confidence). Analysis
of the promptly available data is online at
http://www.swift.ac.uk/sper/429954.

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: GRB100724B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10981
SUBJECT: Konus-Wind observation of GRB 100724B
DATE:    10/07/25 09:34:14 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 long hard GRB 100724B
(Fermi/GBM trigger 301624927: Bhat, GCN 10977;
localized by Fermi/LAT: Tanaka et al., GCN 10978)
triggered Konus-Wind at T0=2526.266s UT (00:42:06.266)

The burst light curve shows a complex structure with
a total duration of ~240 s. It consists of an initial harder part,
~90 s in duration, followed by a softer one, lasting to T0 + 230 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/GRB100724_T02526/

As observed by Konus-Wind the burst
had a fluence of 4.1(+/-0.3)x10-4 erg/cm2,
and a 256-ms peak flux, measured from T0+59.648s,
of 1.0(+/- 0.1)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+228.608 s) is best fit
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.87 (-0.06, +0.06),
the high energy photon index beta = -2.0 (-0.09, +0.07),
the peak energy Ep = 369(-37, +42)keV (chi2 = 86/87 dof).

The spectrum at the maximum count rate
(measured from T0+57.856 to T0+61.952 s) is best fit
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.8 (+/-0.1),
the high energy photon index beta = -2.1 (+/-0.15),
the peak energy Ep = 418(-58, +66)keV (chi2 = 84/87 dof).

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


GRB_name: GRB100725A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10982
SUBJECT: GRB100725A Faulkes Telescope South observations
DATE:    10/07/25 10:01:24 GMT
FROM:    David Bersier at Liverpool John Moores U  <dfb@astro.livjm.ac.uk>

D. Bersier, C. Guidorzi, Z. Cano, S. Kobayashi report on behalf of a 
larger collaboration:

We observed the location of GRB100725A (GCN 10979) with the Faulkes 
Telescope South,
starting at the beginning of the night (1.7 hour after trigger). In a 5 
minutes R-band
exposure, we do not detect any source not present on the DSS inside the 
enhanced XRT error
circle (GCN 10980). Any source at m=20.0 would have been clearly 
detected. The same holds
for a 6x5minutes exposure at a magnitude m=21.3.


GRB_name: GRB100725B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10983
SUBJECT: GRB 100725B: Swift detection of a burst
DATE:    10/07/25 11:39:50 GMT
FROM:    Wayne Baumgartner at GSFC  <wayne@milkyway.gsfc.nasa.gov>

W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU), V. D'Elia (ASDC),
J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC),
N. P. M. Kuin (UCL-MSSL), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
T. A. Pritchard (PSU), J. L. Racusin (NASA/GSFC),
B. Sbarufatti (INAF-OAB/IASFPA) and T. N. Ukwatta (GSFC/GWU) report on
behalf of the Swift Team:

At 11:24:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100725B (trigger=429969).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 290.026, +76.955 which is 
   RA(J2000) = 19h 20m 06s
   Dec(J2000) = +76d 57' 17"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 160 sec.  The peak count rate
was ~3500 counts/sec (15-350 keV), at ~140 sec after the trigger. 

The XRT began observing the field at 11:25:52.4 UT, 77.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 290.03471, 76.95639 which
is equivalent to:
   RA(J2000)  = 19h 20m 8.33s
   Dec(J2000) = +76d 57' 23.0"
with an uncertainty of 4.3 arcseconds (radius, 90% containment). This
location is 9.1 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 (5.43e+20
cm^-2, Kalberla et al. 2005), with an excess column of 2.7
(+3.09/-2.62) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 8.20e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 87 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.09. 

Burst Advocate for this burst is 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: GRB100725B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10984
SUBJECT: GRB100725B: Faulkes Telescope North observations
DATE:    10/07/25 12:50:26 GMT
FROM:    David Bersier at Liverpool John Moores U  <dfb@astro.livjm.ac.uk>

D. Bersier, Z. Cano report on behalf of a larger collaboration:

The Faulkes Telescope North located in Hawaii automatically
responded to Swift trigger 429969 (GCN 10983) 104 seconds
after trigger, in poor seeing conditions. We do not detect
any source inside the XRT error circle to the following limits:

delta_T    exp time  lim mag   filter
1.75 min   10 sec    17.5      R
11 min     30 sec    18.0      R
17 min     60 sec    18.5      R
27 min     120 sec   18.0      i


GRB_name: GRB100725A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10985
SUBJECT: GRB 100725A: Enhanced Swift-XRT position
DATE:    10/07/25 13:00:55 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 1441 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100725A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 166.48153, -26.67025 which is equivalent
to:

RA (J2000): 11h 05m 55.57s
Dec (J2000): -26d 40' 12.9"

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: GRB100725B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10986
SUBJECT: GRB 100725B: Enhanced Swift-XRT position
DATE:    10/07/25 14:30:45 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 702 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100725B, 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 = 290.03298, +76.95643 which is equivalent
to:

RA (J2000): 19h 20m 7.92s
Dec (J2000): +76d 57' 23.1"

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

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

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


GRB_name: GRB100725A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10987
SUBJECT: GRB 100725A: Swift XRT refined analysis
DATE:    10/07/25 15:02:01 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF OAB/INAF IASF-PA) , V. Mangano (INAF/IASF_PA)
and C. B. Markwardt (CRESST/GSFC/UMD) report on behalf of the
Swift-XRT team:

We have analysed 4.3 ks of XRT data for GRB 100725A (Markwardt et al.
GCN Circ. 10979), from 82 s to 11.0 ks after the  BAT trigger. The data
comprise 177 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The light curve can be modelled with an
initial power-law decay with an index of alpha=1.1 (+/-0.1), followed
by a break at T+270 s to an alpha of 6.5 (+/-0.5). After a second break
at T+590 s the decay follows an index of alpha=0.9 (+0.3 -0.4).

The spectrum formed from the WT mode data can be fitted with an
absorbed power-law with a photon spectral index of 1.18 (+/-0.08).
The best-fitting absorption column is  1.2 (+/-0.3) x 10^21 cm^-2,
in excess of the Galactic value of 4.6 x 10^20 cm^-2 (Kalberla et al.
2005). The spectrum formed from the PC mode data can be fitted with
an absorbed power-law with a photon spectral index of 1.20 (+/-0.09).
The best-fitting absorption column is 8.9 (+10.0 -0.8) x 10^20 cm^-2,
marginally in excess of the Galactic value. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor is 6.2 x 10^-11
(6.7 x 10^-11) ergcm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
0.9, the count rate at T+24 hours will be 2.4 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.4 x
10^-14 (1.6 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00429954.

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


GRB_name: GRB100725A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10988
SUBJECT: GRB 100725A: Swift-BAT refined analysis
DATE:    10/07/25 22:55:30 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/UMD), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+903 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100725A (trigger #429954)
(Markwardt, et al., GCN Circ. 10979).  The BAT ground-calculated position is
RA, Dec = 166.468, -26.667 deg, which is 
   RA(J2000)  =  11h 05m 52.2s 
   Dec(J2000) = -26d 39' 59.9" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.
 
The mask-weighted light curve shows many overlapping peaks starting
at ~T-3 sec, with the highest peak at ~T+9 sec, and ending at ~T+200 sec.
T90 (15-350 keV) is 141 +- 27 sec (estimated error including systematics).
 
The time-averaged spectrum from T-4.8 to T+172.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.23 +- 0.12.  The fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+8.58 sec in the 15-150 keV band
is 0.7 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/429954/BA/


GRB_name: GRB100725A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10989
SUBJECT: GRB 100725A: Swift/UVOT Upper Limits
DATE:    10/07/25 23:00:31 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard@astro.psu.edu>

GRB 100725A: Swift/UVOT Upper Limits

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

The Swift/UVOT began settled observations of the field of GRB 100725A
85 s after the BAT trigger (Markwardt et al., GCN Circ. 10979).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 10985) 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            85          234          147 >20.7
u_FC               297          547          246 >20.3
white               85        11646         1486 >21.8
v                  626        13269         1202 >20.2
b                  552         7488          440 >20.6
u                  297         7353          736 >20.5
w1                 675         7148          510 >20.4
m2                 651         6942          510 >20.3
w2                 602        12552         1396 >21.2

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB100725B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10990
SUBJECT: GRB 100725B: Swift/UVOT Upper Limits
DATE:    10/07/25 23:00:52 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard@astro.psu.edu>

GRB 100725B: Swift/UVOT Upper Limits

T. A. Pritchard (PSU) 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 100725B
87 s after the BAT trigger (Baumgartner et al., GCN Circ. 10983).
No optical afterglow consistent with the XRT position
(Goad et al., GCN Circ. 10986) 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)           87          237          147 >20.8
u(FC)              300          549          246 >20.4
white               87         6844          664 >21.4
v                  629         5882          244 >19.6
b                  555         6703          432 >20.5
u                  300         6498          659 >20.2
w1                 678         6293          432 >20.3
m2                 653         6088          432 >20.1
w2                 605         5677          255 >20.1

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.09 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB100725A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10991
SUBJECT: GRB 100725A: GROND upper limits
DATE:    10/07/26 02:05:22 GMT
FROM:    Felipe Olivares Estay at MPE  <felipe@mpe.mpg.de>

F. Olivares E. (MPE Garching), S. Klose (Tautenburg), and J. Greiner
(MPE Garching) report on behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405), the 7-channel imager
mounted at the 2.2m ESO/MPI telescope on La Silla, started follow-up
observations of GRB 100725A (Markwardt et al. 2010, GCN 10979) on July
25 at 23:05 UT (about 16 hrs after the trigger).

With a total integration time of 24.4 min in the optical and 20 min in
the nIR, we do not detect any source within the 1.8-arcsec XRT error
circle (Evans et al. 2010, GCN 10985) down to the following upper
limits (AB system):

g' > 22.8
r' > 23.3
i' > 23.1
z' > 22.9
J > 21.7
H > 21.1
K > 20.4,

The given limits are calibrated againt GROND zeropoints and 2MASS
field stars and are not corrected for the Galactic foreground
extinction corresponding to a reddening of E(B-V)= 0.052 in the
direction of the burst (Schlegel et al. 1998).


GRB_name: GRB100725B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10992
SUBJECT: GRB 100725B: refined XRT analysis 
DATE:    10/07/26 11:41:00 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

V. Mangano (INAF IASF-PA), B. Sbarufatti (INAF OAB/INAF IASF-PA)
and W. H. Baumgartner (GSFC/UMBC) report on behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 100725B (Baumgartner et al.
GCN Circ. 10983), from 68 s to 58.8 ks after the BAT trigger. The data
comprise 288 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 light curve shows flaring activity for the initial 300 s (i.e. the
WT observation), then can be modeled with a series of power-law decays
and a small Gaussian flare.
The initial decay index is alpha=4.66 (+0.4 -0.2). The Gaussian flare peaks
at T+780 (+/-37) s with a sigma of 145 (+/- 30) s.
At T+770 s the decay change in a possible slow rise with an alpha of
0.30 (+/- 0.27) before breaking again at T+8660 s to a final
decay with index alpha=1.3 (+/- 0.2).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index    of 1.75 (+/-0.06). The
best-fitting absorption column is  4.7 (+0.4, -0.3) x 10^21 cm^-2,
in excess of the Galactic value of 5.4 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum (extracted from T+359 s to T+6761 s, 2.9 ks
exposure) has a photon index of 2.5 (+/-0.2) and a best-fitting absorption
column of 5.1 (+0.7, -0.6) x 10^21 cm^-2. The counts to observed (unabsorbed)
0.3-10 keV flux conversion factor deduced from this spectrum is
4.1 x 10^-11 (1.1 x 10^-10) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
1.3, the count rate at T+48 hours will be 4.3 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of
1.8 x 10-13 (4.7 x 10-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00429969.

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


GRB_name: GRB100725B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10993
SUBJECT: GRB 100725B: Swift-BAT refined analysis
DATE:    10/07/26 12:37:13 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+609 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100725B (trigger #429969)
(Baumgartner, et al., GCN Circ. 10983).  The BAT ground-calculated position is
RA, Dec = 290.029, 76.955 deg, which is 
   RA(J2000)  =  19h 20m 07.0s 
   Dec(J2000) = +76d 57' 17.6" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 28%.
 
The mask-weighted light curve shows several peaks starting at ~T-10 sec, peaking
at ~T+10, T+60, T+90, T+130, and T+220 sec, and ending at ~T+240 sec.
T90 (15-350 keV) is 200 +- 30 sec (estimated error including systematics).
 
The time-averaged spectrum from T-4.8 to T+226.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.89 +- 0.06.  The fluence in the 15-150 keV band is 6.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+132.41 sec in the 15-150 keV band
is 2.4 +- 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/429969/BA/


GRB_name: GRB100724B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10994
SUBJECT: GRB 100724B: gamma-ray detection by AGILE
DATE:    10/07/26 14:36:30 GMT
FROM:    Martino Marisaldi at INAF-IASF  <marisaldi@iasfbo.inaf.it>

M. Marisaldi, F. Fuschino, C. Labanti, M. Galli, A. Bulgarelli, F. 
Gianotti, M. Trifoglio, G. Di Cocco (INAF/IASF Bologna), 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. Giuliani, A. Chen, 
S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF Milan), M. Tavani, 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:

"The AGILE Gamma-Ray Imaging Detector (GRID) and Mini-Calorimeter (MCAL) 
detected at gamma-ray energies the long bright GRB 100724B (Bhat, GCN 
10977; Tanaka et al., GCN 10978; Golenetskii et al., GCN 10981).

The GRB triggered AGILE-MCAL, sensitive in the energy range 330 keV - 
100 MeV,  on 24 July 2010 at 00:42:00 UT (T0).
As seen by MCAL the burst has a duration (T90) of ~96 s, with observable 
emission up to ~T0+150 s. The GRB emission has significant detection in 
MCAL up to an energy of about 80 MeV.

The time integrated spectrum in the time interval [T0, T0+150.0 s]
can be fit in the energy range 500 keV - 80 MeV with a single powerlaw
with photon index -2.09 (-0.06, +0.08) (reduced chi2 = 0.94 with 39 
d.o.f.). The estimated fluence is (2.7  0.2)x10-4 erg/cm2 in the same 
energy range. All reported errors are at the 90% confidence level.

AGILE-GRID shows a definite detection above 100 MeV. Further analysis 
are in progress.

This message may be cited."


GRB_name: GRB100724B
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10995
SUBJECT: GRB 100724B: Suzaku WAM observation of the prompt emission
DATE:    10/07/26 15:09:31 GMT
FROM:    Takeshi Uehara at Hiroshima U  <uehara@hirax7.hepl.hiroshima-u.ac.jp>

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


The bright long GRB 100724B (Fermi/GBM trigger #301624927 ; P. N. Bhat et al., GCN 10977) 
triggered the Suzaku Wide-band  All-sky Monitor (WAM) which covers an 
energy range of 50 keV - 5 MeV at 00:42:04.70 UT (=T0). 

The observed light curve shows a multi-peaked structure starting at T0-7s, ending 
at T0+143s with a duration (T90) of about 103 seconds. 
The fluence in 100 - 1000 keV was 1.63(+0.03/-0.07) x 10^-4 erg/cm^2.  
The 1-s peak flux measured from T0+65s was 9.3 photons/cm^2/s in the same 
energy range.

Preliminary result shows that the time-averaged spectrum from
T0-4.1s to T0+141.3s is well fitted by a power-law with exponential cutoff model:
  dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
  alpha       1.09  (+0.18/-0.19), and
  Epeak       666  (+107/-67) keV (chi^2/d.o.f. = 22.8/22).

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

The light curves with 1-sec time resolution for this burst will be appeared at:
 http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html


GRB_name: GRB100724B
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10996
SUBJECT: GRB 100724B: AGILE/GRID analysis
DATE:    10/07/26 16:21:05 GMT
FROM:    Marco Feroci at IASF/INAF  <sa.grb@iasf-roma.inaf.it>

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


The Gamma-Ray Imaging Detector (GRID) on board AGILE detected the long
bright GRB 100724B (Bhat, GCN 10977; Tanaka et al., GCN 10978;
Golenetskii et al., GCN 10981, Marisaldi et al., GCN 10994)
in the energy range 25 - 500 MeV with a statistical significance
larger than 9 sigma.

The gamma-ray emission observed by the AGILE-GRID instrument lasted
about  100 seconds, and two peaks are evident in the lightcurve
consistent with the behaviour reported by Fermi LAT
(the MCAL and GRID preliminary lightcurves are available at
http://www.asdc.asi.it/images/GRB100724B_lc.gif  ).

The total fluence above 25 MeV during this time interval is
F = 0.2+/-0.1 ph/cm2 .
A preliminary estimate of the gamma-ray spectral photon index is
alpha= 2.2 +/-0.3.

GRB 100724B turns out to be the brightest GRB detected by AGILE
above 100 MeV during its operations in space.

A plot showing the distance between the GRB position and the AGILE
boresight as a function of time can be retrieved at
http://www.asdc.asi.it/images/GRB_100724B_distance2.png .

This message may be cited.


GRB_name: GRB100725B
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10997
SUBJECT: GRB100725B: MITSuME optical upper limits
DATE:    10/07/27 00:28:17 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 100725B (Baumgartner et al. GCNC 10983)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2010-07-25 14:05:46 UT (~2.7 h after
the burst). We did not find any new point source within the XRT
error circle (Goad et al., GCNC 10986) 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
------------------------------------------------------
0.13892    14:44:37  7620.0     >19.7  >19.3  >18.7
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100727A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10998
SUBJECT: GRB 100727A: Swift detection of a burst
DATE:    10/07/27 05:56:00 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

D. C. Morris (GWU/GSFC), M. M. Chester (PSU), J. M. Gelbord (PSU),
C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),
H. A. Krimm (CRESST/GSFC/USRA), V. Mangano (INAF-IASFPA),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC) and
R. L. C. Starling (U Leicester) report on behalf of the Swift Team:

At 05:42:17 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100727A (trigger=430094).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 154.166, -21.364 which is 
   RA(J2000) = 10h 16m 40s
   Dec(J2000) = -21d 21' 51"
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 50 sec, with possible additional
activity around T+175.  The peak count rate
was ~3300 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 05:43:14.4 UT, 56.6 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 154.17823, -21.39002 which
is equivalent to:
   RA(J2000)  = 10h 16m 42.78s
   Dec(J2000) = -21d 23' 24.1"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 100 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.  We cannot determine whether the source is
fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
5.09e+20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 1.29e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 65 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. 
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 0.05. 

Burst Advocate for this burst is D. C. Morris (david.c.morris 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: GRB100727A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  10999
SUBJECT: GRB100727A: MOA optical upper limit
DATE:    10/07/27 09:53:01 GMT
FROM:    Shuhei Kobara at U.Nagoya/MOA-II  <kobara@stelab.nagoya-u.ac.jp>

S. Kobara, K. Omori, T. Sumi, D. Suzuki, H.Naito and T. Sako (STE Lab. , Nagoya Univ.)
on behalf of the MOA Collaboration report :

We searched for an optical afterglow of GRB100727A (GCN 10998, D. C. Morris et al.)
starting from 07:12:3 UT on 2010 July 27 ( 90 minutes after the burst) 
with the MOA-II 1.8m telescope at Mt.John observatory in New Zealand.
In a single image of a 300 sec exposure with a wideband Red filter (center 
wavelength ~ 750nm and FWHM ~ 250nm), we did not find any object
within the error circle of the Swift XRT source position (GCN 10998, D. C. Morris et al.
).
A 3 sigma upper limit is set in the I magnitude at 21.6 mag.   

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


GRB_name: GRB100727A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11000
SUBJECT: GRB 100727A: Enhanced Swift-XRT position
DATE:    10/07/27 12:49:07 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 4198 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 100727A, 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 = 154.17739, -21.39042 which is equivalent
to:

RA (J2000): 10h 16m 42.57s
Dec (J2000): -21d 23' 25.5"

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: GRB100727A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11001
SUBJECT: GRB 100727A, Swift-BAT refined analysis
DATE:    10/07/27 14:00:16 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

M. Stamatikos (GSFC/ORAU), 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/UMD), D. C. Morris (GWU/GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), J. Tueller (GSFC),
T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+617 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 100727A (trigger #430094)
(Morris, et al., GCN Circ. 10998).  The BAT ground-calculated position is
RA, Dec = 154.187, -21.417 deg which is
    RA(J2000)  =  10h 16m 44.8s
    Dec(J2000) = -21d 25' 02.7"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 98%.

The burst began with weak precursor activity starting at T-80 sec
and peaking at T-40 sec.  The main pulse, a mostly featureless
FRED profile, began at T-2 sec and continued to approximately
T+50 sec. T90 (15-350 keV) is 84 +- 14 sec (estimated error
including systematics).

The time-averaged spectrum from T-82.0 to T+29.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.81 +- 0.13.  The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.33 sec in the 15-150 keV band
is 1.2 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/430094/BA/


GRB_name: GRB100727A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11002
SUBJECT: GRB 100727A: Fermi GBM observation
DATE:    10/07/27 14:57:12 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 05:42:22.00 UT on 27 July 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100727A (trigger 301902143 / 100727238),
which was also detected by the SWIFT-BAT (Morris et al. 2010, GCN 10998)
The GBM on-ground location is consistent with the Swift position.
 
The angle from the Fermi LAT boresight is 95.1 degrees.

The GBM light curve consists of single peak
with a duration (T90) of about 24 +/- 3 s (50-300 keV). 
The time-averaged spectrum from T0-6.144 s to T0+12.288 s is 
best fit by a simple power law function with 
index -1.71 +/- 0.04 (Castor C-STAT 785 for 473 d.o.f.).

The event fluence (8-1000 keV) in this time interval is 
(2.03 +/- 0.14)E-06 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0-4.096 s in the 8-1000 keV band 
is  1.6 +/- 0.2  ph/s/cm^2.

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


GRB_name: GRB100727A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11003
SUBJECT: GRB 100727A: Swift XRT refined analysis
DATE:    10/07/27 21:07:26 GMT
FROM:    Boris Sbarufatti at INAF-OAB/IASFPA  <boris.sbarufatti@brera.inaf.it>

B. Sbarufatti (INAF OAB/IASF PA), V. Mangano (INAF/IASF PA)
and D. C. Morris (GWU/GSFC) report on behalf of the Swift-XRT
team:

We have analysed 9.8 ks of XRT data for GRB 100727A (Morris et al.
GCN Circ. 10998), from 48 s to 39.8 ks after the BAT trigger.
The data comprise 185 s in Windowed Timing (WT) mode (the first
7 s were taken while Swift was slewing) with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst
was given by Osborne et al. (GCN. Circ 11000). The light curve can
be modeled with a doubly broken power-law decay. The initial decay
index is alpha=2.6 (+/-0.1). A bright flare starts at T+190 s and
peaks at T+247 s. The light curve breaks at T+450 s entering a
plateau phase with alpha=0.0 (+0.06 -0.08). The second break is
observed at T+6.5 ks, followed by a decay index
alpha=0.64 (+0.12-0.09)

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.8 (+/-0.14). The
best-fitting absorption column is  4.2 (+/-0.3) x 10^21 cm^-2, in
excess of the Galactic value of 5.1 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.6 (+/-0.2)
and a best-fitting absorption column of 3.1 (+/-0.5) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 9.7 x 10^-11 (2.3 x 10^-10) erg cm^-2
count^-1.

If the light curve continues to decay with a power-law decay index of
0.64, the count rate at T+24 hours will be 2.8 x 10^-2 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of
2.7 x 10-12 (6.4 x 10-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00430094.

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


GRB_name: GRB100728A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11004
SUBJECT: GRB 100728A: Swift detection of a burst
DATE:    10/07/28 02:30:01 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. K. Cannizzo (NASA/UMBC), W. H. Baumgartner (GSFC/UMBC),
P. A. Evans (U Leicester), J. M. Gelbord (PSU),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA),
O. M. Littlejohns (U Leicester), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
A. Rowlinson (U Leicester), M. H. Siegel (PSU),
M. Stamatikos (OSU/NASA/GSFC) and R. L. C. Starling (U Leicester)
report on behalf of the Swift Team:

At 02:18:24 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100728A (trigger=430151).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 88.743, -15.262 which is 
   RA(J2000) = 05h 54m 58s
   Dec(J2000) = -15d 15' 42"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of at least 200 sec, although the burst was
already in progress when the spacecraft slewed to the original position.  
The peak count rate was ~11,000 counts/sec (15-350 keV), at ~25 sec after
the trigger. 

The XRT began observing the field at 02:19:41.0 UT, 76.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 88.7610, -15.2561 which is equivalent to:
   RA(J2000)  = 05h 55m 02.63s
   Dec(J2000) = -15d 15' 21.9"
with an uncertainty of 5.8 arcseconds (radius, 90% containment). This
location is 64 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. 

The initial flux in the 0.1 s image was 2.01e-08 erg cm-2 s-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 86 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
0.18. 

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


GRB_name: GRB100728A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11005
SUBJECT: GRB 100728A: Enhanced Swift-XRT position
DATE:    10/07/28 09:33:08 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 5085 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 100728A, 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 = 88.75839, -15.25531 which is equivalent
to:

RA (J2000): 05h 55m 2.01s
Dec (J2000): -15d 15' 19.1"

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: GRB100728A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11006
SUBJECT: GRB 100728A: Fermi GBM observation
DATE:    10/07/28 10:06:01 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 02:17:30.61 UT on 28 July 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100728A (trigger 301976252 / 100728095), 
which was also detected by the Swift-BAT (Cannizzo et al. 2008, GCN 11004)

The GBM on-ground location is consistent with the Swift position.
 
The angle from the Fermi LAT boresight is 58.6 degrees.

The GBM light curve shows a multi-peaked structure 
with a duration (T90) of about  162.9 +/- 0.9 s (50 - 300 keV). 
The time-averaged spectrum from T0-8.192 s to T0+191.491 s is 
well fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.76 +/- 0.01 and
the cutoff energy, parameterized as Epeak, is 353.7 +/- 6.7 keV
(Castor C-STAT 3540 for 727 d.o.f.) .

The event fluence (8-1000 keV) in this time interval is 
(1.291 +/- 0.008)E-04 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0+80.2 s in the 8-1000 keV band is 10.8 +/- 0.2 ph/s/cm^2.

A Band function fits the spectrum equally well (Castor C-STAT 3537 for 726
d.o.f.) with Epeak= 344.3 +9.1/-7.9 keV, alpha = -0.75 +/- 0.01 and 
beta = -3.04 +0.23/-0.57. 

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


GRB_name: GRB100728A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11007
SUBJECT: GRB 100728A: KAIT optical afterglow detection
DATE:    10/07/28 11:30:36 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley, C. R. Klein, A. N. Morgan, and W. Li (UC Berkeley) report 
on behalf of the KAIT follow-up team:

The Katzman Automatic Imaging Telescope (KAIT) responded to GRB 100728A 
and began taking data starting less than one minute after the trigger. 
A moderately bright optical transient not present in DSS survey imaging 
is visible in the initial set of exposures at the following position:

RA  =  02:56:13.48
dec = +00:16:51.8
(J2000)

We measure I = 18.7 +/- 0.3 mag at 10:33:51 UT (t = 95 secs after the 
BAT trigger)

In addition, we also manually slewed the 1.0 meter Nickel telescope and 
began taking data starting at 6.6 minutes after the trigger; the 
afterglow is also well-detected and is seen to fade in subsequent 
exposures.  Follow-up is continuing.


GRB_name: GRB100728A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11008
SUBJECT: GRB 100728A: Skynet/PROMPT Detections
DATE:    10/07/28 11:31:35 GMT
FROM:    Kevin Ivarsen at UNC/PROMPT  <kmi@physics.unc.edu>

K. Ivarsen, J. Haislip, D. Reichart, A. LaCluyze, J. Moore, A. Foster, R.
Egger, A. Oza, M. Schubel, A. Trotter, J. A. Crain, and M. Nysewander
report:

Skynet observed the Swift/BAT localization of GRB 100728A (Swift trigger
#430172) with four of the 16" PROMPT telescopes at CTIO beginning 45
seconds after the trigger in BVRI. We detect the afterglow in all filters.

At 50 seconds after the trigger, its magnitude is I = 14.62 +0.08 -0.07
(calibrated to 10 SDSS stars), R = 15.24 +0.07, -0.06 (calibrated to 7
SDSS stars), V = 15.78, +0.08, -0.07 (calibrated to 8 SDSS stars), B =
16.54 +0.21, -0.17 (calibrated to 2 SDSS stars). SDSS transformations were
applied using Jester et al., 2005, ApJ, 130, 873.

PROMPT's BVRI light curve of the first 4.3 minutes after the trigger,
calibrated to SDSS stars, can be found here:
http://skynet.unc.edu/grb/grb100728a.png. Further observations were
limited by morning twilight at PROMPT.


GRB_name: GRB100728B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11009
SUBJECT: GRB 100728B: Swift detection of a burst with an optical counterpart
DATE:    10/07/28 11:42:40 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

D. C. Morris (GWU/GSFC), A. P. Beardmore (U Leicester),
V. D'Elia (ASDC), P. A. Evans (U Leicester), J. M. Gelbord (PSU),
C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),
H. A. Krimm (CRESST/GSFC/USRA), O. M. Littlejohns (U Leicester),
C. B. Markwardt (CRESST/GSFC/UMD), J. P. Osborne (U Leicester),
C. Pagani (U Leicester), K. L. Page (U Leicester),
A. Rowlinson (U Leicester), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC) and
R. L. C. Starling (U Leicester) report on behalf of the Swift Team:

At 10:31:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100728B (trigger=430172).  Swift slewed immediately to the 
burst. The BAT on-board calculated location is RA, Dec 44.053, +0.280 
which is
    RA(J2000) = 02h 56m 13s
    Dec(J2000) = +00d 16' 46"
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 plus some possible precursor
activity.  The peak count rate was ~2000 counts/sec (15-350 keV),
at ~0 sec after the trigger.

The XRT began observing the field at 10:33:32.9 UT, 97.0 seconds after
the BAT trigger. No source was detected in the first 2.5 seconds image.
The XRT observed the field for approximately 80 seconds in WT mode.
The prompt spectrum from the WT data shows evidence of a source.
Due to an observing constraint no additional PC data were taken to allow
XRT to centroid on the afterglow and derive a position.
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 100 seconds after the BAT trigger. There is a candidate afterglow 
in the rapidly available 2.7'x2.7' sub-image at
   RA(J2000)  = 02:56:13.46 = 44.05607
   DEC(J2000) = +00:16:51.9  =  0.28109
with a 90%-confidence error radius of about 0.75 arc sec. This position is 
11.7 arc sec. from the center of the BAT error circle. The estimated 
magnitude is 17.30 with a 1-sigma error of about 0.14. No correction has 
been made for the expected extinction corresponding to E(B-V) of 0.07.

Burst Advocate for this burst is D. C. Morris (david.c.morris 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: GRB100728B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11010
SUBJECT: GRB 100728B: KAIT optical afterglow detection (correction)
DATE:    10/07/28 11:45:27 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley, A. N. Morgan, and C. R. Klein (UC Berkeley) report:

The burst observed in our previous circular was in fact 100728B (Swift 
trigger #430172), and not 100728A (#430151, Cannizzo et al., GCN 11004). 
    We apologize for any confusion this may have caused.


GRB_name: GRB100728B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11011
SUBJECT: GRB 100728B: Skynet/PROMPT Detections (correction)
DATE:    10/07/28 12:00:18 GMT
FROM:    Kevin Ivarsen at UNC/PROMPT  <kmi@physics.unc.edu>

K. Ivarsen, J. Haislip, D. Reichart, A. LaCluyze, J. Moore, A. Foster, R.
Egger, A. Oza, M. Schubel, A. Trotter, J. A. Crain, and M. Nysewander

The observations reported in GCN #11008 (Swift trigger #430172) should
refer to GRB 100728B rather than GRB 100728A.

We observed the optical transient at the following position:

RA  = 02:56:13.51
Dec = +00:16:52.16

We apologize for any inconvenience this may have caused.


GRB_name: GRB100728B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11012
SUBJECT: GRB 100728B: optical detection
DATE:    10/07/28 12:13:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 100728B (Page et al. GCN  11009) with 
0.45-m astrograph f/2.8 f ISON-NM observatory (32d 54' 11.64'',  105d 31' 
42. 34'' ) starting July 28 (UT) 10:56:08, i.e. 24 minutes after burst 
onset.  A few unfiltered 300s exposures were taken before down. In a first 
exposures we clearly detect the afterglow at the position (J2000) RA= 02 56 
13.48 Dec= +00 16 51.4 which  coincides with early afterglow detection 
(Perley et al. GCN  11007; Page et al. GCN  11009).

A preliminary photometry of unfiltered exposures against USNO-B1.0 field 
stars (R-filter) at 29.3 minutes after burst is 19m. 


GRB_name: GRB100728B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11013
SUBJECT: GRB 100728B: GROND Detection of the NIR Afterglow
DATE:    10/07/28 13:28:07 GMT
FROM:    Robert Filgas at MPI  <filgas@mpe.mpg.de>

F. Olivares, R. Filgas and J. Greiner (all MPE Garching) report on behalf of
the GROND team:

We observed the field of GRB 100728B (Swift trigger 430172; Morris et al.,
GCN #11009) simultaneously in 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 10:34 UT, 2 minutes after the GRB trigger. They
were performed during astronomical twilight at an average airmass of 1.2.

We detect a single point source at position reported by Perley et al. (GCN
#11007), Morris et al. (GCN #11009), Ivarsen et al. (GCN #11011) and
Elenin et al. (GCN #11012).

Based on the first 4 min of total exposures in JHK, we estimate
preliminary magnitudes (all in AB system) of

J = 16.4 +- 0.1 mag,

H = 16.2 +- 0.1 mag and

K = 16.0 +- 0.1 mag

Given magnitudes are calibrated against 2MASS field stars and are not
corrected for the expected Galactic foreground extinction corresponding to
a reddening of E_(B-V)=0.07 mag in the direction of the burst (Schlegel et
al. 1998).


GRB_name: GRB100728A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11014
SUBJECT: GRB 100728A: Swift-XRT refined analysis
DATE:    10/07/28 13:35:53 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P. A. Evans (U. Leicester) and J. K. Cannizzo (NASA/UMBC) report on
behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 100728A (Cannizzo et al. GCN
Circ. 11004), from 66 s to 23.4 ks after the BAT trigger. The data
comprise 1.3 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 11005).

The light curve can be modeled with a broken power-law decay, with a
series of flares superimposed during the first kilosecond. The
underlying decay begins with a decay index of 1.6 (+/-0.1), breaking at
T+410 sec to a decay index of 1.07 (+0.03, -0.04). The decay then breaks
again at T+11600 sec to a final decay of 1.82 (+/-0.2). Nine discrete
flares can clearly be identified, with peak times of T+ 88, 111, 189,
252, 296, 383, 445, 516, 659 sec. These all occurred while the XRT was 
in Windowed Timing mode.

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.022 (+/-0.022). The
best-fitting absorption column is 3.69 (+0.09, -0.08) 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 2.05 (+/-0.09) and a
best-fitting absorption column of 3.7 (+/-0.3) x 10^21 cm^-2. The counts
to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from
this spectrum is 4.5 x 10^-11 (7.6 x 10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
1.82, the count rate at T+24 hours will be 0.024 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-12 (1.8 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00430151.

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


GRB_name: GRB100728B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11015
SUBJECT: GRB 100728B: Fermi GBM observation
DATE:    10/07/28 13:47:40 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 10:31:54.97 UT on 28 July 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100728B (trigger 302005916 / 100728439),
which was also detected by the Swift-BAT (Morris et al. 2008, GCN 11009)
The GBM on-ground location is consistent with the Swift position.
 
The angle from the Fermi LAT boresight is 57.1 degrees.

The GBM light curve shows a single pulse
with a duration (T90) of about 11.8 +/- 2.4 s (50-300 keV). 
The time-averaged spectrum from T0-1.024 s to T0+5.632 s is 
well fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.9 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 131 +/- 15 keV
(chi squared 1043 for 599 d.o.f.).

The event fluence (8-1000 keV) in this time interval is 
(2.4 +/- 0.1)E-06 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0+1.22 s in the 8-1000 keV band 
is 6.2  +/- 0.2 ph/s/cm^2.

A Band function fits the spectrum equally well (chi squared 1037 
for 598 d.o.f.) with Epeak= 104 +/- 14 keV, alpha = -0.8 +/- 0.2 
and beta = -2.2 +/-0.2. 

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


GRB_name: GRB100728A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11016
SUBJECT: GRB 100728A: Swift/UVOT Upper Limits
DATE:    10/07/28 14:01:25 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) and J. K. Cannizzo (NASA/UMBC) report on behalf  
of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 100728A 86s after the BAT trigger (Cannizzo et al., GCN 11004).
We do not detect a new source at the enhanced Swift XRT position
(Evans et al. GCN 11005).

The preliminary 3-sigma upper limits for the finding chart exposures  
(FC)
and summed images are:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white (FC)  86      236      147        >20.54
white       578     7432     657        >21.16
u     (FC)  299     548      246        >19.82
u           702     7021     490        >20.04
v           628     11695    1218       >20.06
b           554     7226     510        >20.37
uvw1        677     13337    1228       >20.62
uvm2        1255    12600    1337       >20.69
uvw2        604     7554     447        >20.19
-------------------------------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction corresponding to a reddening along the line of
sight of E_(B-V) = 0.18 mag. All photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB100728B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11017
SUBJECT: GRB 100728B:  Enhanced Swift-XRT position
DATE:    10/07/28 14:29:45 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 820 s of XRT Photon Counting mode data and 2 UVOT
images, we find an astrometrically corrected X-ray position (using the
XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 44.05620, 0.28120 which is equivalent to:

RA (J2000):  02 56 13.48
Dec (J2000): +00 16 52.5

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

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

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


GRB_name: GRB100728A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11018
SUBJECT: GRB 100728A, Swift-BAT refined analysis 
DATE:    10/07/28 15:22:22 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

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

Using the data set from T-130 to T+963 sec from the recent telemetry 
downlink,
we report further analysis of BAT GRB 100728A (trigger #430151)
(Cannizzo, et al., GCN Circ. 11004).  The BAT ground-calculated position is
RA, Dec = 88.753, -15.259 deg which is
  RA(J2000)  =  05h 55m 00.7s
  Dec(J2000) = -15d 15' 33.0"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 81%.

The BAT light curve is quite complex with a long series of peaks and flares
extending from approximately T-100 sec to T+750 sec.  Detected emission
began around T-100 sec, rising to a first peak at T-40 sec.  The burst
continued as a series of at least ten overlapping peaks with the strongest
peak centered at T+30 sec.  There was a strong set of BAT peaks centered
at T+120 sec, corresponding with the second flare detected by the XRT
(Evans & Cannizzo, GCN Circ 11014).  This was followed by a series of 
weaker
flares out to T+750 sec, at times which appear to correspond to flares
detected by the XRT. The burst triggered just after the spacecraft settled
following a slew to a pre-planned target, so it is possible that there was
some very early emission (before T-120 sec) which was not detected. T90
(15-350 keV) is 198.5 +- 12.7 sec (estimated error including systematics).

The time-averaged spectrum from T-84.3 to T+334.0 sec is best fit by a
simple power-law model.  The power law index of the time-averaged spectrum
is 1.18 +- 0.02.  The fluence in the 15-150 keV band is 3.8 +- 0.0 x 10^-5
erg/cm2. The 1-sec peak photon flux measured from T+28.26 sec in the 15-150
keV band is 5.1 +- 0.2 ph/cm^2/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/430151/BA/


GRB_name: GRB100727A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11019
SUBJECT: GRB 100727A: Swift/UVOT Upper Limits
DATE:    10/07/28 16:14:12 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

S. T. Holland (CRESST/GSFC/USRA) and
D. C. Morris (GWU/GSFC)
report on the behalf of the Swift UVOT team:

    The Swift/UVOT observed the field of GRB 100727A starting 47 s
after the BAT trigger (Morris, et al., 2010, GCN Circ. 10998).
Settled observations started at 65 s.  We do not find any new source,
relative to the DSS, USNO-B1.0, or 2MASS at the position of the XRT
afterglow (Osborne, et al. 2010, GCN Circ. 11000).  Preliminary
3-sigma upper limits for detecting a source in the finding charts, and
in the co-added images, using a 2.5 arcsecond radius circular
aperture, are

Filter      T_start    T_stop    Exp(s)      Mag
------------------------------------------------
white (fc)       65       215       147    >20.8
                856      1006       147    >21.2
    u (fc)      278       527       246    >20.5

    v           609    18,409      1414    >20.9
    b           533    24,918      1215    >21.7
    u           278    24,189      2335    >21.7
 uvw1           658    29,885      2289    >21.9
 uvm2           633    28,542      2390    >21.8
 uvw2           584    17,496      1415    >21.8
white            65      7075       805    >22.1
------------------------------------------------

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight corresponding to a
reddening of E_{B-V} = 0.05 mag (Schlegel, et al., 1998, ApJS, 500,
525).  All photometry is on the UVOT photometry system described in
Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB100728A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11020
SUBJECT: GRB 100728A: GROND Detection of the NIR Afterglow Candidate
DATE:    10/07/28 16:55:50 GMT
FROM:    Robert Filgas at MPI  <filgas@mpe.mpg.de>

F. Olivares, T. Kruehler, R. Filgas, J. Greiner, M. Nardini (all MPE
Garching) and A. Nicuesa (TLS Tautenburg) report on behalf of the GROND
team:

We observed the field of GRB 100728A (Swift trigger 430151; Cannizzo et
al., GCN #11004; A. von Kienlin, GCN #11006) simultaneously in
g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at
the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile).

Observations started at 09:26 UT, 7 hours after the GRB trigger and were
terminated at 10:32 UT by the GRB 100728B trigger. They
were performed at an average seeing of 1.3" and at an average airmass of
2.5.

We found a single, very faint point source in the H band within the
enhanced Swift-XRT error circle reported by Beardmore et al. (GCN #11005) at

RA (J2000) = 05:55:02.01
DEC (J2000) = -15:15:20.4

with an uncertainty of 0.5" in each coordinate.

Based on 24 min of total exposures in g'r'i'z' JHK, we
estimate preliminary magnitudes and upper limits (all in AB system) of

g' > 23.3
r' > 23.9
i' > 23.5
z' > 23.5
J > 22.0
H = 21.2 +- 0.3
K > 20.3

Given magnitudes and upper limits are obtained by calibrating the images
against GROND zeropoints as well as 2MASS field stars and are not
corrected for the expected Galactic foreground extinction corresponding
to a reddening of E_(B-V)=0.18 mag in the direction of the burst
(Schlegel et al. 1998).

These magnitudes imply very red colors of the afterglow of J-H > 0.8
and r-H > 2.7. Together with the significant excess absorption seen by
the XRT (Evans & Cannizzo, GCN 11014), and the lack of prompt detections
in the optical and UV filters (Oates & Cannizzo, GCN 11016), these values
are suggestive of a highly extinguished optical/NIR afterglow. The K band
upper limit is not constraining even for the steepest SED slopes and
consistent with this hypothesis.


GRB_name: GRB100728A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11021
SUBJECT: Konus-Wind observation of GRB 100728A
DATE:    10/07/28 18:02:30 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 GRB 100728A
(Swift/BAT trigger 430151: Canizzo et.al, GCN 11004)
triggered Konus-Wind at T0=8300.008s UT (02:18:20.008)

The burst light curve shows a complex structure with
a total duration of ~200 s. There is a hint of a weaker
emission lasting at least to T0+290 s.
The emission is seen up to several MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB100728_T08300/

As observed by Konus-Wind the burst
had a fluence of 1.95(+/-0.35)x10-4 erg/cm2,
and a 256-ms peak flux, measured from T0+27.392s,
of 4.2(+/-0.7)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+137.216 s) is best fit
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.65 (-0.09, +0.09),
the high energy photon index beta = -2.5 (-0.3, +0.2),
the peak energy Ep = 305(-25, +27)keV (chi2 = 88/84 dof).

The spectrum at the maximum count rate
(measured from T0+24.832 to T0+31.488 s) is best fit
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.47 (+/-0.15),
the high energy photon index beta = -2.6 (-0.3, +0.2),
the peak energy Ep = 390(-48, +63)keV (chi2 = 84/84 dof).

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


GRB_name: GRB100728B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11022
SUBJECT: GRB 100728B: Swift-XRT Refined Analysis
DATE:    10/07/28 20:26:38 GMT
FROM:    Claudio Pagani at U of Leicester  <cp232@star.le.ac.uk>

C. Pagani (U. Leicester) and D. C. Morris (GWU/GSFC) report on behalf of
the Swift-XRT team:

We have analysed 6.8 ks of XRT data for GRB 100728B (Morris et al. GCN
Circ. 11009), from 81 s to 17.4 ks after the BAT trigger. The data
comprise 86 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et al.
(GCN. Circ 11017).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.109 (+0.029, -0.030).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.20 (+/-0.20). The
best-fitting absorption column is 1.2 (+0.4, -0.5) x 10^21 cm^-2, in
excess of the Galactic value of 6.2 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 3.5 x 10^-11 (5.0 x 10^-11) erg
cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
1.109, the count rate at T+24 hours will be 5.0 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x
10^-13 (2.5 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00430172.

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


GRB_name: GRB100728B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11023
SUBJECT: GRB 100728B, Swift-BAT refined analysis 
DATE:    10/07/28 21:31:46 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.krimm@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/UMD), D. C. Morris (GWU/GSFC),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+350 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 100728B (trigger #430172)
(Morris, et al., GCN Circ. 11009).  The BAT ground-calculated position is
RA, Dec = 44.051, 0.296 deg which is
    RA(J2000)  =  02h 56m 12.2s
    Dec(J2000) = +00d 17' 45.9"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 11%.

The mask-weighted light curve shows a single peak of duration 10 seconds,
starting at T-2 sec and continuing at a low level to about T+20 sec. An
observing constraint moved the burst out of the BAT field of view at T+350
sec, but there is no sign of extended emission from this burst.
T90 (15-350 keV) is 12.1 +- 2.4 sec (estimated error including systematics).

The time-averaged spectrum from T-1.7 to T+13.2 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.55 +- 0.14.  The fluence in the 15-150 keV band is 1.7 +- 0.1 x 10-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.18 sec in the 15-150 keV band
is 3.5 +- 0.5 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/430172/BA/


GRB_name: GRB100728B
Detection_method: KAIT
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11024
SUBJECT: GRB 100728B: Continued KAIT observations
DATE:    10/07/29 05:56:35 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley, W. Li, and A. V. Filippenko (UC Berkeley) report on behalf 
of the KAIT GRB follow-up team:

The Katzman Automatic Imaging Telescope (KAIT) began observations of GRB 
100728B (Morris et al., GCN 11009) at 30 sec after the trigger time (10 
sec after the GCN notice), and continued to track the afterglow in a 
combination of V, I, and unfiltered exposures until shut down by morning 
twilight.  The afterglow remains detected throughout this period.

An series of 2-second frames taken between 30-64 sec clearly shows a 
rapid rise from an initial mag of ~16.5 (calibrated to USNO B1.0) to a 
peak of 16.1 mag at ~50 seconds.  The afterglow decays as an unbroken 
power-law with decay index alpha=0.97 after that time through the end of 
our observations at 5700 s.

A subset of the unfiltered photometry is presented below:

tstart(s) exp(s) mag      unc
149       20    17.02 +/- 0.02
249       20    17.61 +/- 0.03
446       20    18.21 +/- 0.05
643       20    18.51 +/- 0.07
846       20    18.90 +/- 0.07
1141      60    19.15 +/- 0.07
1440      60    19.40 +/- 0.07
1668      60    19.76 +/- 0.10
2264     100    19.81 +/- 0.10
3326     100    19.86 +/- 0.08
4186     140    20.33 +/- 0.10
5115     140    20.58 +/- 0.14
5544     200    20.88 +/- 0.19

All times are referenced to the BAT trigger at 10:31:55 UT.  Magnitudes 
are calibrated relative to USNO B1.0 standards in the field.

Further analysis is in progress.  We note that the I-band magnitude in 
our previous circular (GCN 11007) was calibrated to USNO R-band 
standards and should not be relied upon for detailed analysis.  In 
addition, the time from burst specified in that circular is relative to 
the BAT position notice time, rather than the trigger time as specified. 
  (The UT time given is correct as stated.)


GRB_name: GRB100728B
Detection_method: KAIT
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11025
SUBJECT: GRB 100728B: Lick Observations
DATE:    10/07/29 05:59:34 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley@astro.berkeley.edu>

D. A. Perley, C. R. Klein, and A. N. Morgan (UC Berkeley) report:

We began observations of the afterglow of GRB 100728B (Morris et al., 
GCN 11009; Perley et al., GCN 11007) with the Nickel 40-inch telescope 
at Lick Observatory starting at 10:38:32 UT, 397 sec after the Swift 
trigger.  A series of frames in R-band (as well as one V-band and one 
U-band exposure) was acquired.  The resulting light curve shows a 
gradual, unbroken power-law decay with a decay index consistent with 
that seen in the KAIT observations (Perley et al., GCN 11024). 
Photometry from our first seven R-band exposures is as follows:

tstart(s) exp(s) filt  mag    unc
397        60    R = 17.38 +/- 0.06
830       300    R = 18.33 +/- 0.05
1162      300    R = 18.53 +/- 0.06
1497      200    R = 18.71 +/- 0.07
1888      160    R = 18.88 +/- 0.09
2062      120    R = 18.80 +/- 0.09
2197      120    R = 18.99 +/- 0.11

Calibration is relative to a single bright star at RA=44.041108, 
dec=+0.242409 (SDSS DR6 magnitudes g=15.61, r=14.52, i=14.57; the 
equivalent Cousins R magnitude is R=14.3 using the average of the two 
SDSS Lupton transformations.)  As this star may be weakly blended with a 
faint neighbor and its USNO magnitude (R2=13.94) differs from this SDSS 
value, caution is advised in interpreting the absolute calibration.


GRB_name: GRB100728B
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11026
SUBJECT: GRB 100728B: Swift/UVOT Observations
DATE:    10/07/29 08:52:21 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) and D. C. Morris (GWU/GSFC) report on behalf of  
the Swift/UVOT team:

The Swift/UVOT began observerving the field of GRB 100728B 101s
after the BAT trigger (Morris et al., GCN Circ. 11009). We detect the
optical afterglow in the white, v, b and u filters only.

The refined UVOT position is RA (J2000)= 163.48809, DEC  
(J2000)=-45.47265,
which is equivalent to:

      RA (J2000) = 02:56:13.467
     Dec (J2000) = +00:16:52.18

with an estimated uncertainty of 0.52 arcsec (radius, 90% confidence).

This position is consistent with the XRT refined position (Evans et  
al., GCN Circ 11017)
and with the optical afterglow positions reported by KAIT (Perley et  
al., GCN Circ 11007, 11010 & 11024),
PROMPT (Ivarsen et al., GCN Circ 11008, 11011) & the SON-NM  
observatory (Elenin et al., GCN Circ 11012).
The non-detection in the UV filters suggests a photometric redshift of  
z~2.8.

Preliminary magnitudes and the 3 sigma upper limits are reported below  
for
individual optical images and summed UV images.

Filter    T_start(s)  T_stop(s)  Exposure    Mag/3SigUL
###########################################################
white     101          251         147        17.43 +/- 0.08
white     4713         4913    197       20.62 +/- 0.22
v         3687         3887        197       20.19 +/- 0.56
b         4509         4709    197       20.47 +/- 0.33
u   4303         4503    197       19.90 +/- 0.28
uvw1   4098         6050    294       > 20.50
uvm2      3892         5529    393       > 20.52
uvw2      3482         5119    393       > 20.93
###########################################################

The above magnitudes are not corrected for the Galactic extinction
corresponding to a non-negligible reddening of E_{B-V} = 0.07 mag  
(Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric system
described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB100728B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11027
SUBJECT: GRB 100728B - NOT optical observation
DATE:    10/07/29 10:51:33 GMT
FROM:    Annalisa De Cia at U of Reykjavik,Science Inst.  <annalisa@raunvis.hi.is>

A. De Cia (University of Iceland), D. Malesani (DARK/NBI), P.M.
Vreeswijk, S. Schulze and P. Jakobsson (University of Iceland)
report:


We observed the field of GRB 100728B (Morris et al., GCN 11009)
with the NOT equipped with StanCam, under poor seeing
conditions. Observations were carried out in the R filter for 40
minutes, with mean time 18.36 hours after the GRB trigger. The
seeing was 1.3".

At the position of the optical afterglow (Perley et al., GCN
11007; Morris et al., GCN 11009) we do not detect any clear
source, down to a limiting mag R > 22.2. By smoothing the image,
a weak source can be marginally detected with magnitude R = 22.5
+/- 0.5 mag, calibrated against SDSS stars converted to Vega.

We acknowledge the careful assistence of the NOT staff, in
particular Anders Thygesen.


GRB_name: GRB100728B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11028
SUBJECT: GRB 100728B: Swift/UVOT Observations (correction)
DATE:    10/07/30 15:10:48 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

The coordinates in circular 11026 should be

RA (J2000)= 0.28116, DEC (J2000)=44.05611,
which is equivalent to:

RA (J2000) = 02:56:13.467
Dec (J2000) = +00:16:52.18

The coordinates in the degree format in circular 11026 were  
accidentally taken from a different GRB.


GRB_name: GRB100728B
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11029
SUBJECT: GRB 100728B: Swift/UVOT Observations (correction to GCN 11028)
DATE:    10/07/30 15:27:55 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

Apologies, the coordinates in circular 11028 should be RA (J2000)=  
44.05611, DEC (J2000)=0.28116


GRB_name: GRB100725B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11030
SUBJECT: GRB 100725B: TELMA optical observation
DATE:    10/07/30 16:26:49 GMT
FROM:    Sergey Guziy at IAA CSIC  <gss@iaa.es>

J. C. Tello, R. SÃ¡nchez, M. JelÃ­nek, P. KubÃ¡nek, S. Guziy,
A. J. Castro-Tirado (IAA-CSIC Granada) on behalf of a
larger collaboration report:

"Following the detection of GRB 100725B by Swift (Baumgartner et al.
GCNC 10983), we have obtained optical images with the 0.6m TELMA robotic
telescope at the BOOTES-2 station located in Southern Spain.

At the position of the X-ray afterglow detected by SWIFT/XRT (Goad et
al. GCNC 10986) we do not detect any optical source down to i' < 19 in
the co-added 187 images (60-s each, using an i' band filter, at 20:41 UT,
i.e. 9.3-hr after the onset of the burst).

This message can be quoted.


GRB_name: GRB100802A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11031
SUBJECT: GRB 100802A: Swift detection of a burst
DATE:    10/08/02 05:56:25 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

E. Troja (NASA/GSFC/ORAU), J. M. Gelbord (PSU),
C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),
O. M. Littlejohns (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. Rowlinson (U Leicester),
T. Sakamoto (NASA/UMBC), M. H. Siegel (PSU),
M. Stamatikos (OSU/NASA/GSFC), R. L. C. Starling (U Leicester) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 05:45:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100802A (trigger=430603).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 2.457, +47.752 which is 
   RA(J2000) = 00h 09m 50s
   Dec(J2000) = +47d 45' 06"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single FRED peak
structure with a duration of about 30 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 05:46:55.8 UT, 79.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 2.4673, +47.7545 which is equivalent to:
   RA(J2000)  = 00h 09m 52.15s
   Dec(J2000) = +47d 45' 16.2"
with an uncertainty of 5.1 arcseconds (radius, 90% containment). This
location is 26 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. 

The initial flux in the 2.5 s image was 2.09e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 88 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
0.12. 

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: GRB100802A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11032
SUBJECT: GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
DATE:    10/08/02 06:21:36 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@astro.psu.edu>

M. H. Siegel (PSU) and E. Troya (NASA/GSFC/ORAU) report on behalf of the
Swift/UVOT team:

UVOT took a finding chart exposure of 250 seconds with the U filter  
starting
301 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 00:09:52.47 =  2.46862
  DEC(J2000) = +47:45:19.1  = 47.75531
with a 90%-confidence error radius of about 0.78 arc sec. This  
position is 4.3
arc sec. from the center of the XRT error circle. The estimated  
magnitude is
19.56 with a 1-sigma error of about 0.21. No correction has been made  
for the
expected extinction corresponding to E(B-V) of 0.12. 


GRB_name: GRB100802A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11033
SUBJECT: GRB 100802A: ROTSE-III Optical Limits
DATE:    10/08/02 06:29:52 GMT
FROM:    Shashi Bhushan Pandey at ROTSE  <shaship@umich.edu>

S. B. Pandey (U Mich), H. Flewelling (IfA/Hawaii), W. Zheng (U Mich),
report on behalf of the ROTSE collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
100802A (Swift trigger 430603; Troja, E., GCN 11031), producing images
beginning 9.1 s after the GCN notice time. An automated response took the
first image at 05:46:10.1 UT, 27.9 s after the burst, and during the
gamma-ray emission, under fair 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 or the XRT error circle, for both single
images and coadding into sets of 10. Individual images have limiting
magnitudes ranging from 15.3-17.6; we set the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
05:46:10.1   05:46:15.1         5     15.3           27.9       N
05:47:30.9   05:52:12.0       281     18.2          108.7       Y


GRB_name: GRB100802A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11034
SUBJECT: GRB 100802A: Liverpool Telescope observations
DATE:    10/08/02 07:11:05 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), A. Gomboc (U. Ljubljana),
report on behalf of a large collaboration:

On 2010 August 02 at 05:51:53 UT the 2-m Liverpool
Telescope automatically began observing the Swift GRB 100802A
(Troja et al., GCN Circ. 11031) using the r' filter,
corresponding to 6.3 minutes after the burst trigger time.

We do not detect any uncatalogued source within the XRT
error circle. We do not detect the possible afterglow
candidate reported by UVOT either (Siegel and Troja,
GCN Circ. 11032) with the following upper limit:

Mid time from  Total Exp   Filter    Magnitude
trigger (s)    (s)
-------------------------------------------------
530            6x10        r' > 18.8
-------------------------------------------------

Magnitude has been calibrated from nearby USNOB1.0
R2 stars.


GRB_name: GRB100802A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11035
SUBJECT: GRB 100802A: Swift-BAT refined analysis
DATE:    10/08/02 12:53:03 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/UMD),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(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 100802A (trigger #430603)
(Troja, et al., GCN Circ. 11031).  The BAT ground-calculated position is
RA, Dec = 2.482, 47.752 deg, which is 
   RA(J2000)  =  00h 09m 55.6s 
   Dec(J2000) = +47d 45' 05.5" 
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 84%.
 
The mask-weighted light curve shows a FRED peak starting at ~T-7 sec and
peaking at ~T+1sec.  There is a second peak on the tail of the first 
at ~T+90 sec.  There is also a long peak starting around T+250, peaking
at ~T+450 sec, and ending at ~T+700 sec.  T90 (15-350 keV) is 487 +- 30 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-3.3 to T+531.7 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.85 +- 0.10.  The fluence in the 15-150 keV band is 3.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.08 sec in the 15-150 keV band
is 0.9 +- 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/430603/BA/


GRB_name: GRB100802A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11036
SUBJECT: GRB 100802A: Enhanced Swift-XRT position
DATE:    10/08/02 13:49:26 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 794 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 100802A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 2.46849, +47.75479 which is equivalent
to:

RA (J2000): 00h 09m 52.44s
Dec (J2000): +47d 45' 17.3"

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

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

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


GRB_name: GRB100728A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11037
SUBJECT: GRB 100728A: Suzaku WAM observation of the prompt emission
DATE:    10/08/02 15:27:24 GMT
FROM:    Yuji Urata at Nat. Central U.  <urata@astro.ncu.edu.tw>

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


The long GRB 100728A (Fermi/GBM trigger #301976252; von Kienlin et al., GCN
#11006; Swift/BAT trigger #430151; Cannizzo et al., GCN 11004) triggered the
Suzaku Wide-band  All-sky Monitor (WAM) which covers an energy range of 50
keV - 5 MeV at 2010-07-28 02:17:32.68 UT (=T0).

The observed light curve shows a multi-peaked structure starting at T0-5s,
ending at T0+198s, with a duration (T90) of about 162 seconds. The fluence
in 100 - 1000 keV was 9.09 (-1.55, +0.07) x 10^-5 ergs/cm^2. The 1-s peak
flux measured from T0+80s was 4.66 (-0.78, +0.03) photons/cm^2/s in the same
energy range.

Preliminary result shows that the time-averaged spectrum from
T0-2s to T0+180s is well fitted by a power-law with exponential cutoff
model:
  dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
  alpha       0.76 (+/-0.11), and
  Epeak       378 (-14, +13) keV (chi^2/d.o.f. = 34.4/22).

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: GRB100802A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11038
SUBJECT: GRB 100802A: Swift/UVOT Possible Optical Afterglow
DATE:    10/08/02 15:59:42 GMT
FROM:    Alice Breeveld at MSSL-UCL  <aab@mssl.ucl.ac.uk>

A. Breeveld (MSSL/UCL) 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 100802A 
89 s after the BAT trigger (Troja et al., GCN Circ. 11031). Using the 
data from the most recent telemetry, there is a tentative detection of 
an optical afterglow at the position given by Siegel et al., GCN Circ. 
11032, in the early white and u exposures.
Preliminary detections and later 3-sigma upper limits using the UVOT 
photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first 
finding chart (FC) exposures and subsequent summed exposures are:

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

white_FC            89          238          147         20.7  0.24
u_FC               301          551          246         19.57  0.22
white              581         5566          327         21.85  0.48 
(2.4 sigma sig)
v                  632         5977          432         >20.6
b                  557         6754          388         >21.2
u                  706         6593          412         >20.92
w1                 682         6388          432         >20.9
m2                 657         6183          432         >20.6
w2                 608         5772          432         >21.0

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.12 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB100802A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11039
SUBJECT: GRB 100802A: XRT refined analysis
DATE:    10/08/02 17:37:31 GMT
FROM:    Antonia Rowlinson at U.of Leicester  <bar7@star.le.ac.uk>

A. Rowlinson (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 100802A (Troja et al. GCN
Circ. 11031), from 69 s to 24.0 ks after the BAT trigger. The data
comprise 804 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et al.
(GCN. Circ 11036).

The light curve can be modelled with an initial power-law decay with an
index of alpha=1.64 (+0.03, -0.03) and a flare peaking at 515 s which is
consistent with a BAT peak (Baumgartner et al. GCN Circ. 11035). At
T+11500 s, the light curve breaks to a decay with alpha=0.06 (+0.26,
-0.21).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.88 (+/-0.03). The
best-fitting absorption column is 1.93 (+/-0.09) x 10^21 cm^-2, in
excess of the Galactic value of 9.7 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 4.0 x 10^-11 (5.4 x 10^-11) erg
cm^-2 count^-1. The PC mode spectrum can be fitted with an absorbed
power-law with a photon spectral index of 2.21 (+0.23, -0.33). The
best-fitting absorption column is 1.39 (+0.82, -0.42) x 10^21 cm^-2, in
excess of the Galactic value. The counts to observed (unabsorbed) 0.3-10
keV flux conversion factor deduced from this spectrum is 3.5 x 10^-11
(5.2 x 10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
0.06, the count rate at T+24 hours will be 1.6 x 10^-2 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.6 x
10^-13 (8.3 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00430603.

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


GRB_name: GRB100802A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11040
SUBJECT: GRB 100802A: P60 Observations
DATE:    10/08/02 18:23:13 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 GRB100802A (Troja et al., GCN 11031) with the
automated Palomar 60 inch telescope.  Observations were taken in the Sloan
r', i', and z' filters beginning at 05:51 UT on 2 August (~ 6 minutes
after the BAT trigger).

In a co-added r'-band image (mid-point 06:02 UT, or ~ 17 minutes after
the burst trigger), we detect a marginal source at the location of the
candidate UVOT afterglow (Siegel and Troja, GCN 11032; Breeveld and Troja,
GCN 11038).  Calibrating with respect to several USNO-B1 catalog objects,
we measure R = 21.3 +/- 0.3 mag.  No object is detected at this location
in a co-added i'-band image (mid-point 06:04 UT, or ~ 18.5 minutes after
the burst trigger) to a limiting magnitude of I > 20.6.

The values quoted above are not corrected for Galactic extinction.


GRB_name: GRB100802A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11041
SUBJECT: GRB100802A: MITSuME optical upper limits
DATE:    10/08/03 05:46:22 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 100802A (Troja et al., GCNC 11031)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2010-08-02 11:43:26 UT (~6 h after
the burst). We did not find any new point source within the XRT
error circle and the enhanced XRT error circle (Evans et al.,
GCNC 11036) in all the three bands. Also, we could not detect the
previously reported afterglow (Siegel and Troya, GCN 11032).

Three sigma upper limits of the OT are listed below. We used
GSC 2.3 catalog for flux calibration.


T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.29658    12:52:41  9480.0     >19.9  >19.8  >19.3
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100802A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11042
SUBJECT: GRB 100802A: NOT optical observation
DATE:    10/08/03 10:09:43 GMT
FROM:    Dong Xu at DARK,NBI  <dong@astro.ku.dk>

D. Xu (Weizmann Inst.), D. Malesani (DARK/NBI), P. Jakobsson (Univ. of
Iceland), P. A. Wilson, R. Nilsson (NOT), report on behalf of a larger
collaboration:

We have imaged the field of GRB100802A (Troja et al., GCN #11031) with
the Nordic Optical Telescope equipped with ALFOSC. Observations
started at 02:49 UT, 3rd August (~21.06 hrs after the BAT trigger) and
four 900 s frames in the R band were obtained.

We detect an optical source localised at

RA(J2000) = 00:09:52.38
Dec(J2000) = +47:45:18.8

with an error radius of 0.4". This position is 0.96" +/- 0.85" S-W of
the UVOT position (Siegel & Troja, GCN #11032). We therefore identify
this source as the afterglow of GRB100802A. A finding chart is visible
at the following URL:

http://www.astro.ku.dk/~malesani/GRB/100802A/GRB100802A_NOT.jpg.

Based on the USNO-B1 catalog (R1 magnitudes), we find R=22.9+/-0.3 at
a mean epoch of 21.6 hr after the BAT trigger. Compared with the P60
detection (Cenko, GCN #11040), our measurement confirms a clear
fading, and implies a rather shallow decay of the afterglow light
curve with alpha = 0.34 +/- 0.08 assuming an unbroken power-law decay
F(t) propto t^-alpha. This might suggest some contribution from an
underlying host galaxy.


GRB_name: GRB100713A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11043
SUBJECT: GRB 100713A: CrAO optical limits
DATE:    10/08/03 20:53:22 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the INTEGRAL GRB 100713A (Mereghetti et al. GCN 
10951) with  Shajn telescope of  CrAO in VRI-filters starting  July, 13 (UT)
21:56, i.e. 7.4 hours after burst.

We do not detect any sources in enhanced XRT error circle (D'Elia et al. GCN 
10960). The photometry of  stacked images based on SDSS star 
J170053.83+282355.1  assuming  R=16.46, I=16.24 and V=16.78 (the magnitudes 
obtained from  Lupton's SDSS ugriz -> VRI transformations).

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

0.3539  V          43x60           24.0
0.3546   R         43x60           24.0
0.3553   I          43x60           23.2

Since we do not detect the source observed at 3.75 hours after burst (GCN 
10962)  we can suggest the source reported in GCN 10962 as the afterglow 
candidate.


GRB_name: GRB100713A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11044
SUBJECT: GRB 100713A: second epoch Maidanak optical observation 
DATE:    10/08/03 21:06:36 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), A. Volnova (SAI MSU),  B. Satovski (Astrotel),  M. 
Ibrahimov (MAO) report on behalf of  larger GRB  follow-up collaboration:

We observed the field of the INTEGRAL GRB 100713A (Mereghetti et al. GCN 
10951) with AZT-22 telescope of Maidanak observatory in second epoch on July 
17-19 under mean seeing of about 1.0".

We do not detect any sources in enhanced XRT error circle (D'Elia et al. GCN 
10960).

The photometry of stacked image is based on five SDSS field stars and Lupton 
ugriz -> R transformations :

T0+      Filter,   Exposure,  mag.          Upper limit (3 sigma)
(mid, d)              (s)
5.157   R       300*23        n/d            23.8

We thank Alexander Gusev for performing the observations and for his 
support. 


GRB_name: GRB100728B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11045
SUBJECT: GRB 100728B: optical photometry of ISON-NM 
DATE:    10/08/03 21:25:21 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 100728B (Morris et al. GCN  11009)
with 0.45-m telescope f ISON-NM observatory  on  July 28 (Elenin at al.,
GCN 11012).

The afterglow ( Perley et al. GCN 11007; Morris et al. GCN 11009; Ivarsen et
al. GCN 11011)  is detectable on each of four images taken between July 28
(UT) 10:45:49 - 11:01:14.

A photometry of unfiltered images against SDSS field stars and R-mag 
obtained with Lupton transformations is following

t-t0,  filter, exposure,  OT
(sec)

 984   W     300            18.36+/-0.17
1294  W     300            18.93+/-0.22
1603  W     300            18.80+/-0.18
1909  W     300            19.00+/-0.30

Finding chart and SDSS calibration stars can be found at
http://grb.rssi.ru/GRB100728B/100728b-refstars.png


GRB_name: GRB100802A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11046
SUBJECT: GRB 100802A: Fermi GBM observation
DATE:    10/08/04 08:54:53 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

Elisabetta Bissaldi (MPE) reports on behalf of the Fermi GBM Team:


"At 05:45:35.68 UT on 2 August 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100802A (trigger 302420737 / 100802240),
which was also detected by the Swift-BAT (Troja et al. 2010, GCN 11031).
The GBM on-ground location is consistent with the Swift position.
 
The angle from the Fermi LAT boresight is 76 degrees.

The GBM light curve consists of an initial peak
followed by a softer tail with a duration (T90) of about 100 s (50-300 keV).
The time-averaged spectrum from T0 to T0+40 s is
adequately fit by a power law function with an exponential
high energy cutoff.  The power law index is -1.17 (+0.21/-0.25) and
the cutoff energy, parameterized as Epeak, is 149 (+41/-96) keV
(Castor C-STAT 669 for 479 d.o.f.).

The event fluence (10-1000 keV) in this time interval is
(2.24 +/- 0.28)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+62 s in the 10-1000 keV band
is 3.2 +/- 0.6 ph/s/cm^2.


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


GRB_name: GRB100805A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11047
SUBJECT: GRB 100805A: Swift detection of a burst with an optical counterpart
DATE:    10/08/05 04:27:27 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

E. A. Hoversten (PSU), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. M. Gelbord (PSU), C. Gronwall (PSU),
S. T. Holland (CRESST/USRA/GSFC), D. M. Palmer (LANL),
M. H. Siegel (PSU), M. C. Stroh (PSU) and T. N. Ukwatta (GSFC/GWU)
report on behalf of the Swift Team:

At 04:12:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100805A (trigger=430957).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 299.874, +52.614 which is 
   RA(J2000) = 19h 59m 30s
   Dec(J2000) = +52d 36' 52"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a peak with a
duration of about 20 sec.  The peak count rate
was ~600 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 04:14:48.7 UT, 126.4 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 299.87559, 52.62758 which
is equivalent to:
   RA(J2000)  = 19h 59m 30.14s
   Dec(J2000) = +52d 37' 39.3"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 47 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.69e+21 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 129 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 19:59:30.52 = 299.87716
  DEC(J2000) = +52:37:40.3  = 52.62787
with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.00 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.19. 

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: GRB100805A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11048
SUBJECT: GRB 100805A: ROTSE-III Optical Limits
DATE:    10/08/05 04:56:08 GMT
FROM:    Shashi Bhushan Pandey at ROTSE  <shaship@umich.edu>

S. B. Pandey (U Mich) and W. Zheng (U Mich), report on behalf of the ROTSE
collaboration:

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB
100805A (Swift trigger 430957; Hoversten , E. A., GCN 11047), producing
images beginning 6.2 s after the GCN notice time. An automated response
took the first image at 04:13:39.2 UT, 50.9 s after the burst, under fair
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 or at the Swift/UVOT position, for both
single images and coadding into sets of 10. Individual images have limiting
magnitudes ranging from 16.1-17.3; we set the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
04:13:39.2   04:13:44.2         5     16.1           50.9       N
04:14:59.3   04:19:41.7       282     18.0          131.0       Y


GRB_name: GRB100805A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11049
SUBJECT: GRB 100805A: Enhanced Swift-XRT position
DATE:    10/08/05 04:57:18 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M. C. Stroh and E. A. Hoversten (PSU) report on behalf of the Swift-XRT team:

Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA,Dec = 299.8760, 52.6279 (degrees) which is equivalent to:

RA  (J2000) = 19 59 30.23
DEC (J2000) = +52 37 40.3

with an uncertainty of 2.3 arcsec (radius, 90% containment). This location is 48.4 arcseconds from the BAT onboard position, inside the BAT error circle.

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: GRB100805A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11050
SUBJECT: GRB 100805A: P60 Optical Afterglow Candidate
DATE:    10/08/05 04:59:00 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 100805A (Swift trigger #430957) with the
robotic Palomar 60 inch telescope.  Images were obtained in the Sloan r',
i', and z' filters beginning at 04:15 UT on 5 August (~ 3 minutes after
the Swift trigger time).

At the edge of the XRT error circle we detect a bright point source not
present in the Digital Sky Survey imaging of the field at coordinates
(J2000):

 RA: 19:59:30.53   Dec: +52:37:40.0

Calibrating with respect to the USNO-B1 catalog, we measure a preliminary
magnitude or R = 17.3.

Observations to confirm the transient nature of this source are ongoing.


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11051
SUBJECT: GRB 100805A: Further P60 Monitoring
DATE:    10/08/05 05:18:42 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 continued to image the field of GRB 100805A with the automated
Palomar 60 inch telescope (see GCN 11050).  The object we identified as a
candidate afterglow (first noted by Hoversten at al., GCN 11047) has faded
significantly over the last hour, and we can therefore confirm this source
is the optical afterglow of GRB 100805A.  Using field stars from the
USNO-B1 catalog for reference, we measure a magnitude of R = 19.5 at 04:56
UT on 5 August.  Comparing with our previous measurement, we infer a
power-law decay index of alpha ~ 0.8.


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11052
SUBJECT: GRB 100805A: Liverpool Telescope afterglow observations
DATE:    10/08/05 06:08:10 GMT
FROM:    Andreja Gomboc at LT,ARI,Liverpool JMU  <ag@astro.livjm.ac.uk>

A. Gomboc (U. Ljubljana), C. Guidorzi (U. Ferrara), D. Kopac (U. Ljubljana) 
report on behalf of a larger collaboration:

On 2010 August 05 at 04:14:32 UT the 2-m Liverpool
Telescope automatically began observing the Swift GRB 100805A
(Hoversten  et al., GCN Circ. 11047) with Ringo 2 instrument, continuing 
with multi-filter (g', r', i') observations at 6.7 min after the GRB trigger.

The LT-TRAP procedure automatically identified the optical afterglow 
at the UVOT position (Hoversten  et al., GCN Circ. 11047, Cenko, GCN Circ. 11050) 
with the following magnitudes:
------------------------------------------------------------------------
T-t0 (s) Exp. (s)   Filter     Mag             
------------------------------------------------------------------------
400        10                  r'                 17.92 +- 0.07
421             10                  r'                 17.93 +- 0.07
726              10                  r'                 18.36 +- 0.10
3386            60                  r'                 19.79 +- 0.12
------------------------------------------------
We confirm the power-law decay index of 0.8 found by P60 (Cenko, GCN Circ. 11051).

Magnitudes were calibrated from nearby USNOB1.0 R2 stars.
Observations are continuing.


GRB_name: GRB100805A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11053
SUBJECT: GRB 100805A: Enhanced Swift-XRT position
DATE:    10/08/05 06:40:33 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 734 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100805A, 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 = 299.87770, +52.62788 which is equivalent
to:

RA (J2000): 19h 59m 30.65s
Dec (J2000): +52d 37' 40.4"

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: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11054
SUBJECT: GRB 100805A: I-band detection from 1.23m CAHA telescope.
DATE:    10/08/05 06:46:49 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel, V. Terron, M. Jelinek, A.J. Castro-Tirado (IAA-CSIC),  
report on behalf of a larger collaboration:

"Following the detection of GRB 100805A by Swift (Hoversten et al.  
GCNC 11047) we carried out I-band observations with the 1.23m  
telescope at Observatory of  Calar Alto. The first exposure started on  
Aug 5.1824 UT (~10 minutes post burst) with an integration time of  
120s. The optical afterglow is well detected with a preliminary  
magnitude of I ~ 16.9, against USNO-B1.0 field stars."


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11056
SUBJECT: GRB 100805A: GRAS 002 optical observations
DATE:    10/08/05 08:40:39 GMT
FROM:    Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen@kassiopeia.net>

Markku Nissinen (Taurus Hill Observatory) and Veli-Pekka Hentunen (Taurus
Hill Observatory) report:

We used Global-rent-a-scope GRAS 002 Tak Mewlon 300 telescope with SBIG 
ST-8E CCD at RAS Observatory Mayhill H06 (New Mexico, USA) for follow-up 
observations of GRB 100805A (D. Palmer et al., GCN 11047). The observations
were started on August 05, at 04:56 UTC (44 min after the burst) and stopped 
on August 05, at 06:29 UTC. Four luminance 600 seconds images and three optical
R-band 600 seconds images were taken. We detected a very dim optical afterglow
object at the position of RA 19h 59min 30s.64 and DEC +52o 37' 40".5 with 
respect to POSSII F/USNO-B1.0 (J2000) which is in good correlation with
S.B. Cenko observations (GCN 11050). Upper limit for our luminance observations
is >20.8 mag (LR) and R-band observations is >20.1 (R). Quoted upper limit has 
been derived using POSSII F and USNO-B1.0 field stars as reference.
                
Filter              Tmid(s)        Exp(s)      OA Mag  USNO-B1.0
                
luminance        2949          600          19.6+/-0.5 (LR)
luminance        3614          600          19.6+/-0.5 (LR)
luminance        4276          600          19.8+/-0.5 (LR)
luminance        8177          600          >20.8
optical R         5299          600          >20.1
optical R         5986          600          >20.1
optical R         7501          600          >20.1

URL-link to our luminance image:
http://cutenews.kassiopeia.net/data/upimages/GRB100805A_web.jpg


GRB_name: GRB100805A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11057
SUBJECT: GRB 100805A: Swift-XRT Refined Analysis
DATE:    10/08/05 11:00:30 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M. C. Stroh and E. A. Hoversten (PSU) report on behalf of the Swift-XRT team: 

We have analysed 3.3 ks of XRT data for GRB 100805A (Hoversten et al. GCN Circ. 11047), from 111 s to 6.7 ks after the BAT trigger. The data comprise 48 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 11049). 

The light curve can be modelled with an initial power-law decay with an index of alpha=3.6 (+0.5, -0.4), followed by a break at T+294 s to an alpha of 0.45 (+0.12, -0.23). 

A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.97 (+0.17, -0.10). The best-fitting absorption column is 1.7 (+0.5, -0.0) x 10^21 cm^-2, in excess of the Galactic value of 1.7 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.1 x 10^-11 (5.7 x 10^-11) erg cm^-2 count^-1. 

If the light curve continues to decay with a power-law decay index of 0.45, the count rate at T+24 hours will be 0.032 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x 10^-12 (1.8 x 10^-12) erg cm^-2 s^-1. 

The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00430957.

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


GRB_name: GRB100805A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11058
SUBJECT: GRB 100805A: Swift-BAT refined analysis
DATE:    10/08/05 12:46:07 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), E. A. Hoversten (PSU),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100805A (trigger #430957)
(Hoversten, et al., GCN Circ. 11047).  The BAT ground-calculated position is
RA, Dec = 299.846, 52.618 deg, which is 
   RA(J2000)  =  19h 59m 23.0s 
   Dec(J2000) = +52d 37' 05.8" 
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.
 
The mask-weighted light curve shows a few overlapping weak peaks
starting at ~T-1 sec, peaking at ~T+2 sec, and ending at ~T+20 sec.
There is a possible 3-sigma peak at ~T+60 sec.  T90 (15-350 keV) is
15.0 +- 3.0 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.4 to T+17.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.76 +- 0.23.  The fluence in the 15-150 keV band is 5.1 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.97 sec in the 15-150 keV band
is 0.7 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/430957/BA/


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11060
SUBJECT: GRB 100805A: IAC80 BVR-band observations
DATE:    10/08/05 14:05:26 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (IAA-CSIC), M. Chioare Diaz-Martin (IAC), R. Iglesias Marzoa (Univ. of La Laguna), M. Jelinek (IAA-CSIC), report on behalf of a larger collaboration:

"We have acquired BVR-band images of the GRB 100805A (Hoversten et al. GCNC 11047) field with the 82-cm IAC80 telescope on the Observatory of Teide, Tenerife, Spain. The optical afterglow (Hoversten et al. GCNC 11047; Cenko et al. GCNC 11050, GCNC 11051; Gomboc et al. GCNC 11052; Gorosabel et al. GCNC 11054; Nissinen et al. GCNC 11056) is detected in the three optical bands with an approximate magnitude of R~19.3 on Aug. 5.2046 UT (mean observing time, ~42 minutes post burst). The calibration is based on USNO B1.0 field stars."


GRB_name: GRB100802A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11061
SUBJECT: GRB 100802A: WIYN observations
DATE:    10/08/05 16:13:08 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike@clemson.edu>

Adria C. Updike, Ginger Bryngelson, Dieter H. Hartmann (Clemson
University) and Peter A. Milne (Steward Observatory) report:

We observed the field of GRB 100802A (Troja et al., GCN 11031) with the
3.5m WIYN telescope at KPNO equipped with WHIRC on August 3, 2010
beginning 26 hours and 13 minutes after the trigger and continuing for 26
minutes in the K band under good conditions.  We do not detect the
afterglow (Siegel & Troja, GCN 11032; Cenko, GCN 11040) or any source
within the enhanced XRT position (Evans et al., GCN 11036) to limiting
magnitude of K > 18.8 upon comparison to the 2MASS catalog and field
stars.  No further observations are planned.


GRB_name: GRB100805A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11062
SUBJECT: GRB 100805A: Swift/UVOT Observations of the Optical Afterglow
DATE:    10/08/05 19:02:30 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

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

      The Swift/UVOT observed the field of GRB 100805A starting 112 s
after the BAT trigger (Hoversten, et al., 2010, GCN Circ. 11047).
Settled observations started at 130 s.  We detect the optical
afterglow (Hoversten, et al., 2010, GCN Circ, 11047) in all filters
except uvw2.  The refined UVOT position is

     RA (J2000) =  19:59:30.51  =  299.87713 (deg)
    Dec (J2000) = +52:37:40.1   =  +52.62783 (deg)

with an estimated uncertainty of 0.43 arcsec (radius, 90% confidence,
statistical + systematic).  This is 1.31 arcsec west of the
UVOT-enhanced XRT position (Goad, et al., 2010, GCN Circ. 11053).

     Preliminary magnitudes, and 3-sigma upper limits for detecting a
source in the finding charts and in the co-added images, are

Filter      T_start   T_stop    Exp(s)      Mag   Err
-----------------------------------------------------------
white (fc)      130      280       147     18.10 0.08
    u (fc)      288      538       246     18.32 0.11

    v           619     5984       432     19.80 0.23
    b           544   10,831      1213     21.22 0.20
    u           288     6600       659     18.55 0.09
 uvw1           668     6395       432     20.78 0.39
 uvm2           643     6189       432     20.68 0.45
 uvw2           594   12,479      1149    >21.6  3-sigma UL
white           130   11,744      1319     19.42 0.07
-----------------------------------------------------------

     The quoted magnitudes and upper limits have not been corrected
for the expected Galactic extinction along the line of sight
corresponding to a reddening of E_{B-V} = 0.19 mag (Schlegel, et al.,
1998, ApJS, 500, 525).  All photometry is on the UVOT photometry
system described in Poole et al. (2008, MNRAS, 383, 627).

     The non-detection in the UVOT uvw2 filter, and the observed UVOT
spectral energy distribution at 4895 s, is consistent with GRB 100805A
having a redshift of approximately z = 1.3, although we can not rule
out the non-detection in uvw2 being due to extinction in the host
galaxy.  The white light curve exhibits a power-law decay with an
index of alpha = -0.71 +/- 0.03, consistent with what was observed by
Cenko, et al. (2010, GCN Circ. 11051).


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11063
SUBJECT: GRB 100805A: ROTSE-III Optical detection
DATE:    10/08/05 20:48:46 GMT
FROM:    Shashi Bhushan Pandey at ROTSE  <shaship@umich.edu>

S. B. Pandey and W. Zheng (U Mich), report on behalf of the ROTSE
collaboration:

Further analysis of GRB 100805A data taken from ROTSE-IIIb clearly detects
the
optical afterglow candidate (Hoversten E. A. et al., GCN 11047) in the
images
taken ~50.9 s after the burst (Pandey S. B. & Zheng W., GCN 11048).

In the consecutive images taken by ROTSE, the optical afterglow show a
temporal
decay nature very similar to those reported by Cenko S. B. (GCN 11051) and
Holland S. T. et al (GCN 11062). The optical afterglow detection by ROTSE
was
not reported in the previous circular (GCN 11048) due to a problem in the
online data processing.


GRB_name: GRB100805A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11064
SUBJECT: GRB 100805A: Early RAPTOR Observations
DATE:    10/08/05 21:09:45 GMT
FROM:    James Wren at LANL  <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis,
of Los Alamos National Laboratory report:

The RAPTOR telescope system responded to Swift trigger
430957 (Hoversten et al., GCN 11047) under fair observing conditions.
Our narrow-field instruments began observing the location at
04:13:44.3 UTC, 62.2 seconds after the initial BAT trigger.
At 100 seconds after the trigger, we estimate the counterpart to
have magnitude R~16.7 +/- 0.3.  The object fades steadily
reaching R~17.4 +/- 0.3 at 200 seconds after the trigger.  It
appears to remain near this level for the next 150 seconds or so
before resuming the fading behavior.  Our unfiltered images were
calibrated against the USNO-B1 R-band. Further analysis is ongoing.


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11065
SUBJECT: GRB 100805A: Xinglong TNT optical observation
DATE:    10/08/06 05:36:45 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

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

We began to observe GRB100805A (Hoversten E. A. et al., GCN 11047 ) 
with Xinglong TNT telescope at 12:29:52 (UT), 8.28h after 
the burst. Nine R band images were obtained. The exposure time for
each frame is 600 sec. The afterglow (Hoversten E. A. et al., GCN 11047)
with a brightness of 21.3+/-0.2 mag was detected with the combined 
9*600s white-band data at the mean time of 8.95h after the burst.

The reference star is a nearby USNO-B1.0 star with a coordinates 
of 19:59:33.3, +52:37:54.0, and a brightness of R2=17.41 mag.

Combining TNT data and other data reported in the previous GCN circulars 
(Cenko, GCN 11050, GCN 11051;Gomboc et al. GCN11052; 
Nissinen et al. GCN 11056; Gorosabel et al. GCN 11060; Wren et al. GCN 11064 ), 
we infer that the brightness of OT was decaying with a power-law decay index of 
alpha~0.73 from 100sec to 8.9h after the burst, consistent with 
the reports of  Cenko, GCN Circ. 11051 and  Gomboc  et al. GCN 10052.


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: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11066
SUBJECT: GRB 100805A: IAC80 and 1.5m OSN optical observations
DATE:    10/08/06 17:24:14 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (IAA-CSIC, Granada), M. Chioare Diaz-Martin (IAC, Obs. del Teide, Tenerife), R. Iglesias Marzoa (Univ. of La Laguna, Tenerife), A. Sota (IAA-CSIC, Granada), A.J. Castro-Tirado (IAA-CSIC, Granada), J.M. Castro Cern (ESAC, Madrid), report on behalf of a larger collaboration:

"We observed the field of GRB 100805A (Hoversten et al., GCNC 11047) with the 0.82m IAC80 (Obs. of Teide, Tenerife, Spain) and 1.5m OSN (Obs. of Sierra Nevada, Granada, Spain) telescopes in VRI-bands. The observations were carried out on Aug 6.0515-6.1393 UT (IAC80) and Aug 6.1608-6.1875 UT (1.5m OSN), respectively. The optical afterglow is marginally detected in our images with a preliminary magnitude of R~21.5,  calibrated against USNO-B1.0 field stars."


GRB_name: GRB100807A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11067
SUBJECT: GRB 100807A: Swift detection of a burst
DATE:    10/08/07 09:24:29 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

D. Grupe (PSU), W. H. Baumgartner (GSFC/UMBC), J. M. Gelbord (PSU),
C. Gronwall (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA) and
D. M. Palmer (LANL) report on behalf of the Swift Team:

At 09:13:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100807A (trigger=431128).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 55.324, +67.679 which is 
   RA(J2000) = 03h 41m 18s
   Dec(J2000) = +67d 40' 43"
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 ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 09:14:34.4 UT, 80.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 55.30004, 67.67171
which is equivalent to:
   RA(J2000)  = 03h 41m 12.01s
   Dec(J2000) = +67d 40' 18.2"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 41 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.31e+21
cm^-2, Kalberla et al. 2005), with an excess column of 3.8
(+4.16/-3.25) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 9.12e-10 erg cm^-2 s^-1 (0.2-10
keV). 


UVOT took a finding chart exposure of 150 seconds with the White filter
starting 90 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
0.81. 




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


GRB_name: GRB100807A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11068
SUBJECT: GRB 100807A: ROTSE-III Optical Limits
DATE:    10/08/07 09:40:30 GMT
FROM:    Heather Flewelling at IfA/Hawaii  <flewelling.heather@gmail.com>

GRB 100807A: ROTSE-III Optical Limits

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

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 100807A
(Swift trigger 431128; Grupe et al., GCN 11067), producing images beginning
5.2 s after the GCN notice time. An automated response took the first image
at 09:13:35.2 UT, 21.6 s after the burst, and during the gamma-ray emission,
under fair conditions. We took 10 5-sec and 10 20-sec exposures. These
unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on
going.

Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle or the XRT error circle, for both single
images and coadding into sets of 10. Individual images have limiting
magnitudes ranging from 15.9-17.2; we set the following specific limits.

start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
09:13:35.2 09:13:40.2 5 16.2 21.6 N
09:13:35.2 09:14:42.2 67 16.7 21.6 Y
09:14:55.2 09:19:37.9 282 18.1 101.6 Y


GRB_name: GRB100807A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11069
SUBJECT: GRB 100807A: Swift-BAT refined analysis
DATE:    10/08/07 13:13:13 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), D. Grupe (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+233 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100807A (trigger #431128)
(Grupe, et al., GCN Circ. 11067).  The BAT ground-calculated position is
RA, Dec = 55.283, 67.665 deg, which is 
   RA(J2000)  =  03h 41m 07.9s 
   Dec(J2000) = +67d 39' 54.2" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 37%.
 
The mask-weighted light curve a single peak starting around T-20 sec,
peaking at ~T+0, and ending around T+20 sec.  T90 (15-350 keV) is
7.9 +- 1.6 sec (estimated error including systematics).
 
The time-averaged spectrum from T-6.1 to T+3.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.32 +- 0.23.  The fluence in the 15-150 keV band is 3.4 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T-0.35 sec in the 15-150 keV band
is 1.8 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/431128/BA/


GRB_name: GRB100807A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11070
SUBJECT: GRB 100807A: Enhanced Swift-XRT position
DATE:    10/08/07 13:25:45 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 960 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100807A, 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 = 55.30042, +67.67158 which is equivalent
to:

RA (J2000): 03h 41m 12.10s
Dec (J2000): +67d 40' 17.7"

with an uncertainty of 1.9 arcsec (radius, 90% confidence).

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

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


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11071
SUBJECT: GRB 100805A: SAO RAS optical observations
DATE:    10/08/07 13:47:19 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin, T. A. Fatkhullin, V. V. Sokolov, T. N. Sokolova &
V. N. Komarova (SAO RAS, Niznijh Arkhyz, Russia), report:

We observed the field of the GRB100805A (Hoversten E. A. et al., GCN 11047)
with the Zeiss-1000 telescope of SAO RAS, Russia. The observations were
carried out in the BVRc bands on  Aug. 5.843-6.033 UT. Assuming the
magnitudes of the reference USNO-B1.0 star (L.P. Xin et al., GCN 11065) as
B = 18.94 and R = 17.41 we estimated the brightness of the GRB100805A optical
transient as:

B = 22.85 +/- 0.11
R = 21.43 +/- 0.10

Errors are formal and do not include ones of USNO-B1.0 to Johnson-Cousins
photometric system transformation.

This message may be cited.


GRB_name: GRB100807A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11072
SUBJECT: GRB 100807A:  Swift/UVOT Upper Limits
DATE:    10/08/07 15:57:36 GMT
FROM:    Craig Swenson at PSU/Swift  <cswenson@astro.psu.edu>

C. A. Swenson and D. Grupe (PSU) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 100807A
91 s after the BAT trigger (Grupe et al., GCN Circ. 11067).  No optical
afterglow consistent with the enhanced XRT position (Osborne et al.,
GCN Circ. 11070) 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            91          240          147         >20.9
u_FC               304          553          246         >20.4
white               91         5947          530         >21.8
v                  634         6358          255         >19.6
b                  559         7063          319         >21.1
u                  304         6973          659         >21.1
w1                 683         6768          413         >20.8
m2                6363         6563          197         >20.7
w2                 609         6153          255         >20.8

The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.81 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB100807A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11073
SUBJECT: GRB 100807A: P60 Optical Afterglow Discovery
DATE:    10/08/07 20:55:56 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 100807A (Grupe et al., GCN 11067) with the
automated Palomar 60 inch telescope.  Observations were obtained in the
Sloan r', i', and z' filters beginning at 9:16 UT on 7 August (~ 3 min
after the Swift trigger).

At the edge of the enhanced XRT position (Osborne et al., GCN 11070), we
detect a fading point source with coordinates (J2000):

 RA: 03:41:12.43    Dec: +67:40:17.4

Using several nearby objects in the USNO-B1 catalog for reference, we
report the following photometry for this object:

UT (mid-point) t_burst (min) Filter  Magnitude
---------------------------------------------------------------
09:16:55 3.7  R  20.47 +/- 0.17
09:18:21 5.1  I  19.80 +/- 0.14
09:47:07 33.9  R  21.57 +/- 0.20
09:49:58 36.8  I  20.96 +/- 0.20

The above magnitudes have not been corrected for the large Galactic
extinction along the line of sight.

The fading behavior confirms this source is the optical afterglow of GRB
100807A.


GRB_name: GRB100807A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11074
SUBJECT: GRB 100807A: Swift XRT refined analysis
DATE:    10/08/08 00:29:22 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <grupe@astro.psu.edu>

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

We have analyzed 9.7 ks of XRT data for GRB 100807A (Grupe  et al.
GCN Circ. 11067), from 125 s to 24882 s after the  BAT trigger. The
data comprise 36 s in Windowed Timing (WT) mode with the remainder
in Photon Counting (PC) mode. The light curve can be modeled
with  a broken power-law model. After an initial flare the light
curve decays with a slope of 6.4+0.6-1.9. The light curve breaks at
173+/-10s followed by a flatter decay slope of 0.82+/-0.08.

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).
The best-fitting absorption column is consistent with the Galactic
value of 3.3 x 10^21 cm^-2 (Kalberla et al. 2005). A fit to the pc
mode data is also consistent with the Galactic absorption column
density, but the spectrum is slightly flatter with  a photon index
of 1.79+/-0.37. The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from the WT spectrum  is 4.38 x 10^-11
(7.54 x 10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index
of 0.8, the count rate at T+48 hours will be in the order of
1.3 x 10^-3 count s^-1, corresponding to an observed (unabsorbed)
0.3-10 keV flux of 5.7 x 10^-14 (9.8 x 10^-14) erg cm^-2 s^-1.
Note that we are currently in the plateau phase which is followed by
a steeper decay slope.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00431128.

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


GRB_name: GRB100807A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11075
SUBJECT: GRB100807A: MITSuME optical upper limits
DATE:    10/08/08 08:36:56 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 100807A (Grupe et al., GCN 11067)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2010-08-07 13:29:46 UT (~4.3 h after
the burst). We did not find any new point source within the
enhanced XRT error circle (Osborne et al., GCNC 11070) in all
the three bands. We could not detect the previously reported
afterglow (Cenko, GCN 11073).

Three sigma upper limits of the OT are listed below. We used
GSC 2.3 catalog for flux calibration.


T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.21418    14:21:39  4620.0     >20.1  >19.7  >19.1
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11076
SUBJECT: GRB 100805A: 2-nd epoch of SAO RAS optical observations
DATE:    10/08/08 15:40:35 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin, T. A. Fatkhullin, V. V. Sokolov, T. N. Sokolova &
V. N. Komarova (SAO RAS, Niznijh Arkhyz, Russia), report:

We observed the field of the GRB100805A (Hoversten E. A. et al., GCN 11047)
once again with the Zeiss-1000 telescope of SAO RAS, Russia.
The observations were carried out in the Rc band on Aug. 7.832 - 7.918 UT.
At the position of the OT we detected a faint object with R = 23.3 +/- 0.2.
We assume the magnitude of the reference USNO-B1.0 star (L. P. Xin et al.,
GCN 11065; A. S. Moskvitin et al., GCN 11071) as R = 17.41.

Error are formal and do not include one of USNO-B1.0 to Johnson-Cousins
photometric system transformation.

This message may be cited.


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11077
SUBJECT: GRB 100805A: optical observation in CrAO
DATE:    10/08/09 11:35:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 100805A  (Hoversten et al., GCN 
11047) with Shajn telescope of CrAO in filter R between (UT) July, 07 
18:57:40 - 20:10:19 under good weather conditions and mean seeing of about 
1.7". Within enhanced Swift-XRT position (Goad et al., GCN 11053) we do not 
detect the afterglow   (Cenko, GCN 11050). However we detect the object in 
coordinates  (J2000) RA:  19 59 30.11 Dec: +52 37 37.79. The object is 5.6" 
away from the center of enhanced XRT position (Goad et al., GCN 11053) and 
about 4.5" from afterglow position (Cenko, GCN 11050; Holland et al, GCN 
11062). The object could be a host galaxy of  GRB 100805A.


The photometry is based on USNO-B1.0 star 1426-0390273 (J2000) RA= 19 59 
29.55 +52 37 19.6  Dec= +52 37 19.6 and assuming  R=17.59  is following:

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

2.6401  R       68x60     22.5  +/- 0.1             24.0

The combined images can be found 
http://grb.rssi.ru/GRB100805A/GRB100805a_100807_R_ZTSh.gif

Our observation and photometry is in some contradiction with observation 
reported in GCN 11076 (Moskvitin et al.) 


GRB_name: GRB100807A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11078
SUBJECT: GRB100807A: optical observation in CrAO
DATE:    10/08/09 15:05:23 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 100807A (Grupe  et al., GCN 11067) 
with Shajn telescope of CrAO in filter R between (UT) Aug. 07 22:58:14 --  
Aug. 08 01:17:44 under descending seeing with mean value of ~ 2.1". We do 
not detect the afterglow (Cenko, GCN 11073). The extended object ~ 8" was 
detected in coordinates (J2000) center RA:  03 41 12.92 Dec: +67 40 19.4. 
The position of optical afterglow  (Cenko, GCN 11073) is in the edge of the 
extended object.

The photometry is based on USNO-B1.0 star 1576-0084708  (J2000) RA= 03 41 
11.50  Dec= +67 39 58.1  (assuming  R=16.37):

T0+      Filter,   Exposure, Ext. Object mag.           Upper Limit
(mid, d)              (s)

0.6214  R       97x60       23.0 +/- 0.2                    23.8

With upper limit of R=23.8 we confirm the fading nature of afterglow of  GRB 
100807A (Grupe  et al., GCN 11067). The extended object might be a host 
galaxy of GRB 100807A.

The combined images can be found 
http://grb.rssi.ru/GRB100807A/GRB100807a_100807_R_ZTSh.gif


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11079
SUBJECT: GRB 100805A: the 3-rd epoch of SAO RAS optical observations
DATE:    10/08/11 11:37:35 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin, T. A. Fatkhullin, V. V. Sokolov, T. N. Sokolova & V. N.
Komarova (SAO RAS, Niznijh Arkhyz, Russia), report:

We performed the third epoch of observations of the GRB 100805A (Hoversten
E. A. et al., GCN 11047) field with the Zeiss-1000 telescope of SAO RAS,
Russia. The observations were carried out in the Rc band on Aug. 9.882 -
10.043 UT under good weather conditions and the seeing 1".7.

At the position of OT we detected an object with R = 23.54 +/- 0.22.

We assume the magnitude of the reference USNO-B1.0 star (L. P. Xin et al.,
GCN 11065; A. S. Moskvitin et al., GCN 11071, A. S. Moskvitin et al.,
GCN 11076) as R = 17.41.

Also we estimate the magnitude of the source reported by V. Rumyantsev and
A. Pozanenko (GCN 11077) as R = 22.31 +/- 0.08 according to their standard
star with R=17.59. All errors are formal and they do not include errors of
the USNO-B1.0 to Johnson-Cousins photometric system transformation.

Images from all 3 epochs with the marked OT and nearby object (GCN 11077)
can be found in
ftp://ftp.sao.ru/pub/grb/GRB100805A/GRB100805A_Zeiss1000.jpeg

This message may be cited.


GRB_name: GRB100807A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11080
SUBJECT: GRB 100807A: P200 Infrared Observations
DATE:    10/08/11 15:01:54 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

R. Chary and J. Davies (Caltech) report:

We have imaged the field of GRB 100807A (Grupe et al., GCN 11067) with
the WIRC instrument on the Palomar 200 inch telescope in the J and H bands
beginning at 9:47 UT on 7 August (~ 35 mins after the Swift trigger). The
fading transient reported in Cenko et al. (GCN 11073) is clearly
detected.  Using 2MASS stars for relative photometry, we measure the
following photometry for the object:

UT (mid-point)  t_burst (min)   Filter          Magnitude
---------------------------------------------------------------
09:55           41              J               19.76 +/- 0.1
10:10           56              H               19.05 +/- 0.1
12:16           183             J               21.10 +/- 0.2

The red colors of the source compared to the optical photometry can be
attributed to the A_V=2.5 mag of Galactic extinction in this region.

A nearby object 3" to the SE is also quite red with H=18.75+/-0.1 and
J-H=1.5 mag and could potentially be the host galaxy.

All magnitudes are in the Vega system.


GRB_name: GRB100805A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11081
SUBJECT: GRB 100805A: Swift/UVOT Observations of a Possible Late-Time Brightening
DATE:    10/08/11 19:48:49 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <Stephen.T.Holland@nasa.gov>

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

     Swift/UVOT observations of the optical afterglow of GRB 100805A
(Hoversten, et al., 2010, GCN Circ, 11047) suggest that the afterglow
may have brightened in the UVOT white band between approximately 1 day
and 6 days after the BAT trigger.  This may indicate the presence of a
supernova component in the light curve.  Our analysis is complicated
by the presence of several bright stars near the optical afterglow.
Further observations are needed to confirm that this possible brightening
is real.  Follow-up observations of this source are strongly encouraged.


GRB_name: GRB100802A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11082
SUBJECT: GRB 100802A: further NOT observation
DATE:    10/08/12 10:37:13 GMT
FROM:    Dong Xu at DARK,NBI  <dong@astro.ku.dk>

Nis B. Andreasen, Maria Cavallius, Louise Dyregaard Nielsen,
Christopher Groenbech, Simone J. Jakobsen, Jonatan Selsing,
Lasse Oedegaard (Niels Bohr Inst.), Johan P.U. Fynbo,
Daniele Malesani (DARK/NBI), Dong Xu (Weizmann Inst.),
and Pall Jakobsson (Univ. Iceland), report on behalf
of a larger collaboration:

We observed the field of GRB 100802A (Troja et al., GCN 11031, Siegel
& Troja, GCN 11032) with the NOT equipped with ALFOSC. Observations
were carried out with mean time Aug 11.10 UT (212.7 hr after the GRB).

The object seen in our early-time NOT image (Xu et al., GCN 11042) is
barely detected in the new stacked image, and has decayed by 1.3 +/-
0.4 mag between the two epochs.

We note that the NOT object is slightly offset (by ~1.1" W) with
respect to the UVOT position (GCN 11032; also confirmed by P60
imaging; B. Cenko, priv. comm.). Coupled to the slow decay, this may
indicate the presence of an underlying constant source of light, which
could be the host galaxy or a foreground, unrelated object.

An image showing the two epochs is available at the following URL:

http://www.astro.ku.dk/~malesani/GRB/100802A/GRB100802A_epoch2.jpg

Given the relative brightness of the underlying source (R ~ 23.7), we
encourage further photometric and spectroscopic observations.

[GCN OPS NOTE (12aug10): Per author's request, MC was added to the author list.]


GRB_name: GRB100805A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11083
SUBJECT: GRB 100805A: optical observation in CrAO (correction to the GCN 11077 and second epoch)
DATE:    10/08/12 20:25:38 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 100805A  (Hoversten et al., GCN 
11047) with Shajn telescope of CrAO in filter R  in two epochs  Aug. 07 and 
Aug 08. After revision of our first epoch observation reported in GCN 11077 
(Rumyantsev et al.)   we do find the afterglow (Cenko, GCN 11050). Our 
photometry (see below) is compatible with photometry reported for 
approximately the same epoch observation (Moskvitin et al. GCN 11076). We 
thank to C.Guidorzi for mention of inconsistency of our results reported in 
GCN 11077.

Coordinates of the afterglow is following
Aug. 07 (J2000) RA:  19 59 30.49 Dec: +52 37 40.3
Aug. 08 (J2000) RA:  19 59 30.47 Dec: +52 37 39.6

The coordinates are compatible within error bars with afterglow coordinates 
(Cenko, GCN 11050; Holland et al, GCN 11062).

The photometry is based on USNO-B1.0 star 1426-0390273 (J2000) RA= 19 59 
29.55 +52 37 19.6  Dec= +52 37 19.6 and assuming  R=17.59  is following:

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

2.6401  R       68x60     23.6 +/- 0.25            24.0
3.6417  R      101x60    23.3 +/- 0.15            24.3

The combined images can be found
http://grb.rssi.ru/GRB100805A/GRB100805a_100808_R_ZTSh.gif

Taken together late time photometry above and (Moskvitin et al., GCN 11076; 
Moskvitin et al., GCN 11079) one can suggest flattening of the light curve 
in R-filter in 2.5 - 4.5 days after burst trigger. However some 
re-brightening suggested by  Holland & Hoversten (GCN 11081) could not be 
excluded in this period too.


GRB_name: GRB100805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11084
SUBJECT: GRB 100805A: the 4-th epoch of SAO RAS optical observations
DATE:    10/08/13 15:30:09 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin, T. A. Fatkhullin, V. V. Sokolov, T. N. Sokolova & V. N.
Komarova (SAO RAS, Niznijh Arkhyz, Russia), report:

We performed further observations of the GRB100805A (Hoversten
E. A. et al., GCN 11047) field with the Zeiss-1000 telescope of SAO RAS,
Russia. The observations were carried out in the Rc band on Aug.
12.821 - 13.046 UT under good transparency and seeing of 2".5. Total
integration time is 15600 sec.

We do not detect any objects at the position of the OT up to limiting
magnitude R = 24.2 (3-sigma limit for stellar-like object).

We assumed the magnitude of the reference USNO-B1.0 star (L. P. Xin et al.,
GCN 11065; A. S. Moskvitin et al., GCN 11071, A. S. Moskvitin et al.,
GCN 11076, A. S. Moskvitin et al., GCN 11079) as R = 17.41.

Also we confirm the magnitude of the source reported by V. Rumyantsev and
A. Pozanenko (GCN 11077) as  R = 22.47 +/- 0.06 according to their standard
star with R=17.59. All errors are formal and they do not include errors of
the USNO-B1.0 to Johnson-Cousins photometric system transformation.

Combining all data in the R-band we found that late-time light curve
(T-T_0 > 2.3 days) behaviour follows the one of the early stage (F ~
t^-0.77, t < 3000 sec). Thus one can conclude that possible re-brightening
(Holland & Hoversten (GCN 11081)) occurred within ~0.3-2.3 days after the
burst. The R-band light curve can be found at
ftp://ftp.sao.ru/pub/grb/GRB100805A/GRB100805A_lc_R.jpeg

This message may be cited.


GRB_name: GRB100814A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11086
SUBJECT: GRB 100814A: ROTSE-III Detection of Optical Counterpart 
DATE:    10/08/14 04:14:34 GMT
FROM:    Brad Schaefer at LSU  <schaefer@grb.phys.lsu.edu>

B. E. Schaefer (Louisiana State), E.S. Rykoff (UCSB), W. Rujopakarn 
(Steward), S. B. Pandey (U Mich), W. Zheng (U Mich), report on behalf of 
the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 100814A (Swift trigger 431605). The first image was at 
03:55:01.1 UT, 289.8 s after the burst (4.1 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), nor in our first set of 
observations with coordinates:

     01:29:53.67      -17:59:41.58    (J2000), with positional uncertainty 
of 1" or better

start UT     mag     mlim(of image)
----------------------------------
03:55:11.3     17.4     8.0 


A jpeg image is available at 
http://www.rotse.net/images/gsq431605_3c011-020_key.jpg Note that the 
object marked 29 is the candidate in question.

Continuing observations are in progress.


GRB_name: GRB100814A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11087
SUBJECT: GRB 100814A: Swift detection of a burst with an optical afterglow
DATE:    10/08/14 04:22:40 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), N. P. M. Kuin (UCL-MSSL),
O. M. Littlejohns (U Leicester), C. B. Markwardt (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
C. J. Saxton (UCL-MSSL), R. L. C. Starling (U Leicester),
E. Troja (NASA/GSFC/ORAU) and T. N. Ukwatta (GSFC/GWU) report on
behalf of the Swift Team:

At 03:50:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100814A (trigger=431605).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 22.481, -17.986 which is 
   RA(J2000) = 01h 29m 55s
   Dec(J2000) = -17d 59' 07"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed three separate
peaks over a total interval of at least 150 sec.  The peak count rate
was ~6000 counts/sec (15-350 keV), at ~6 sec after the trigger. 

The XRT began observing the field at 03:51:38.6 UT, 87.4 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 22.47220,
-17.99643 which is equivalent to:
   RA(J2000)  = 01h 29m 53.33s
   Dec(J2000) = -17d 59' 47.1"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 48 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.75e+20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 6.18e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter
starting 153 seconds after the BAT trigger.  A bright optical afterglow 
candidate was found at RA=22.4749, dec=-17.9932 which is
  RA = 01h 29m 53.98s
  Dec=-17d 59m 35.5s
(J2000).  The estimated magnitude is U=16.8 . 


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: GRB100814A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11088
SUBJECT: GRB 100814A: Swift UVOT observations of the optical afterglow
DATE:    10/08/14 04:49:29 GMT
FROM:    Caryl Gronwall at PSU/Swift-UVOT  <caryl@astro.psu.edu>

C. Gronwall (PSU) and C. J. Saxton (MSSL) report on behalf of the
Swift/UVOT team:

In response to GRB 100814A (Swift/BAT trigger 431605) at 03:50:11 UT,
UVOT took a finding chart exposure of 250 seconds with the U filter  
starting
153 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 01:29:53.54 = 22.47309
DEC(J2000) = -17:59:43.5 = -17.99541
with a 90%-confidence error radius of about 0.75 arc sec. This  
position is 4.7
arc sec. from the center of the XRT error circle.  This position  
supersedes
the position given in (Beardmore et al., GCN Circ. 11087) and is  
consistent
with the optical afterglow position from ROTSE (Schaefer et al., GCN  
Circ. 11086).
The estimated magnitude is 16.76 with a 1-sigma error of about 0.14.  
No correction
has been made for the expected extinction corresponding to E(B-V) of  
0.02. 
   


GRB_name: GRB100814A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11089
SUBJECT: GRB100814A: Magellan Echellette Observations
DATE:    10/08/14 05:09:50 GMT
FROM:    Hsiao-Wen Chen at U Chicago  <hchen@oddjob.uchicago.edu>

John O'Meara (Saint Michael's College), Hsiao-Wen Chen (UChicago), Jason 
X. Prochaska (UC Santa Cruz)  report on behalf of a larger collaboration:

"We observed the afterglow of GRB100814A reported by Schaefer et al. (GCN
11086) and confirmed by Gronwall et al. (GCN 11088) using the MagE
echellette spectrograph on the Magellan Clay Telescope.  The observations
started at UT 04:46 on August 14, 2010, ~ one hour after the inital 
trigger.  We obtained a 900s exposure.  Our preliminary reduction shows 
that the afterglow spectrum displays absorption transitions due to AlIII, 
FeII, and MgII at redshift z=1.44, which we tentatively identify as the 
host redsdhift of the GRB.

Further analysis is underway.

This message may be cited."


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11090
SUBJECT: GRB 100814A: IAC80 R-band observations
DATE:    10/08/14 05:52:08 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (IAA-CSIC), S.  Rodriguez LLano (IAC), A.J. Castro-Tirado  
(IAA-CSIC), report on behalf of a larger collaboration:

"Following  the detection  of GRB  100814A by  Swift (Beardmore  et  
al. GCNC 11087) we have acquired  a series of R-band images with the  
0.82-m IAC80  telescope at Observatory  of Teide, Tenerife,  Spain.  
The first exposure started on Aug  14.1788 UT (~27.3 minutes post  
burst). The optical afterglow (Schaefer  et al. GCNC 11086; Gronwall  
et al. GCN 11088) is detected with a preliminary  magnitude of R~18.7,  
assuming  a magnitude of R=16.87  for the  USNO-B1.0 star placed at  
RA(J2000)=01:29:43.606, DEC(J2000)=-18:00:38.61."


GRB_name: GRB100814A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11091
SUBJECT: GRB 100814A: GROND Detection of the Optical/NIR Afterglow 
DATE:    10/08/14 11:20:51 GMT
FROM:    Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>

R. Filgas, P. Schady and J. Greiner (MPE Garching) report on behalf of  
the GROND team:


We observed the field of GRB 100814A (Swift trigger 431605; Beardmore  
et al., GCN #11087) 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 03:57 UT, 7 minutes after the GRB trigger at  
03:50 UT, and are continuing. They were performed at an average seeing  
of 1.2" and at an average airmass of 2.

We detect a single point source in all GROND optical (g'r'i'z') and  
NIR bands (JHK) at a position consistent with the coordinates provided  
by Schaefer et al. (GCN #11086) and Gronwall et al. (GCN #11088), and  
consistent with the spectroscopic redshift of z=1.44 (O'Meara et al.  
GCN #11089).

The afterglow decays as a power law with a best-fit index of alpha ~  
0.5, decaying from r' = 18.0 +/- 0.1 at T+25 minutes down to r' = 19.5  
+/- 0.1 (all in AB system) by the end of our observations, at T+6  
hours. Analysis is on going.

Given magnitudes are calibrated against USNO zeropoints and are not  
corrected for the expected Galactic foreground extinction  
corresponding to a reddening of E(B-V)=0.02 in the direction of the  
burst (Schlegel et al. 1998).


GRB_name: GRB100814A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11092
SUBJECT: GRB 100814A: Enhanced Swift-XRT position
DATE:    10/08/14 12:17:34 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 5031 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 100814A, 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 = 22.47308, -17.99503 which is equivalent
to:

RA (J2000): 01h 29m 53.54s
Dec (J2000): -17d 59' 42.1"

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: GRB100814A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11093
SUBJECT: GRB 100814A: CQUEAN r- and i-band Observation
DATE:    10/08/14 12:59:28 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ),
Soojong Pak, Hyeongju Jeong, Eunbin Kim, and Jinyoung Kim
(Kyunghee University)

  We observed GRB 100814A (Beardmore et al. GCN 11087) with the SDSS
r- and i-filters during the commissioning run of CQUEAN (the Camera for
QUasars in the Early uNiverse) on the 2.1m telescope at the McDonald
Observatory. The observation started at 2010 August 14, 08:57:54 UT,
about 5 hours after the BAT trigger.

  A series of 180 secs exposures were taken, and we confirm the afterglow
at the location reported by Schaefer et al. (GCN 11086) and Gorosabel et 
al.(GCN 11090). A preliminary photometry from a single frame with the
mid-point time of 09:00:24 UT is r ~ 19.10 +- 0.03 AB mag (subject to 
systematic error in the zero point determination), consistent with the 
value reported by Filgas et al. (GCN 11091). The photometric calibration 
is based on a standard star observation on the same night (BD+17 4708).

   We thank the staffs of the McDonalnd Observatory, Peter S. Odoms and 
John Kuehne for their assistance of the CQUEAN commissioning run.


GRB_name: GRB100814A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11094
SUBJECT: GRB 100814A, Swift-BAT refined analysis
DATE:    10/08/14 13:16:56 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori.sakamoto-1@nasa.gov>

H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL),
N. Gehrels (GSFC), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(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 100814A (trigger #431605)
(Beardmore, et al., GCN Circ. 11087).  The BAT ground-calculated position is
RA, Dec = 22.479, -17.990 deg which is 
   RA(J2000)  =  01h 29m 55.0s 
   Dec(J2000) = -17d 59' 25.7" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 90%.
 
The mask-weighted light curve shows three FRED-like spikes starting around 
T-4 sec, T+60 sec and T+140 sec.  Those spikes peak around T+5 sec, T+70 sec 
and T+145 sec.  The low level emission is visible up to T+235 sec.  
T90 (15-350 keV) is 174.5 +- 9.4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-3 to T+235 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.47 +- 0.04.  The fluence in the 15-150 keV band is 9.0 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band
is 2.5 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/431605/BA/


GRB_name: GRB100814A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11095
SUBJECT: Swift/UVOT observations of GRB100814A
DATE:    10/08/14 15:26:23 GMT
FROM:    Patricia Schady at MPE/Swift  <msslba@googlemail.com>

M. De Pasquale (MSSL-UCL) and C.J. Saxton (MSSL-UCL)
report on the behalf of the Swift UVOT team:

 The Swift/UVOT began settled observations of the field of
GRB 100814A 153 s after the BAT trigger  (Beardmore et
al. 2010, GCN Circ. 11087) with a finding chart in the u
filter. We detect the optical afterglow in all filters except
uvw2. The refined UVOT position is

 RA  (J2000) = 01h 29m 53.61s = 22.47338
 Dec (J2000) = -17d 59m 43.6s = -17.99545


with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence,
statistical + systematic). This is about 1.5 arcsec north of the
UVOT-enhanced XRT position (Beardmore et al. 2010, GCN Circ.
11092).

 Preliminary magnitudes, and 3-sigma upper limits for detecting a
source in the finding charts and in co-added images are

Filter      T_start   T_stop    Exp(s)      Mag   Err
---------------------------------------------------------------------
   u (fc)      153      403        246      16.80  0.06
   v            458      627         39       17.91  0.32
   b            408      721         53       21.22  0.20
   u            153      701       285       16.84  0.06
 uvw1        507      676         39       17.33  0.20
 uvm2       483       651         39       17.86  0.31
 uvw2        434      602          39    >18.52  3-sigma UL
 white      3858     4211        344      18.63  0.07
-----------------------------------------------------------

 The quoted magnitudes and upper limits have not been corrected
for the expected Galactic extinction along the line of sight
corresponding to a reddening of E_{B-V} = 0.02 mag (Schlegel, et al.,
1998, ApJS, 500, 525).  All photometry is on the UVOT photometry
system described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB100814A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11096
SUBJECT: GRB 100814A: Swift-XRT refined analysis
DATE:    10/08/14 20:34:14 GMT
FROM:    Andy Beardmore at U Leicester  <apb@star.le.ac.uk>

A. P. Beardmore (U Leicester) and C. J. Saxton (MSSL-UCL) report on
behalf of the Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 100814A (Beardmore et
al. GCN Circ. 11087), from 76 s to 28.6 ks after the BAT trigger. The
data comprise 721 s in Windowed Timing (WT) mode (the first 9 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode. The enhanced XRT position for this burst was given by
Beardmore et al. (GCN. Circ 11092).

The X-ray light curve initially rises by a factor of ~2 in count rate, 
reaching a broad peak at approximately T+160 s after the trigger, on top 
of which are superimposed three small flares at T+146, 176 and 220 s, 
respectively. At T+295 s the light curve falls with a steep decay of 
alpha=5.7 (+0.4, -0.3), then breaks to a shallow decay at T+517 s, after 
which it decays with an index of 0.47 (+0.03, -0.04).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.68 (+0.04, -0.03). The
best-fitting absorption column is 5.0 (+/-0.8) x 10^20 cm^-2, in
excess of the Galactic value of 1.8 x 10^20 cm^-2 (Kalberla et
al. 2005). The PC mode spectrum has a photon index of 1.90 (+0.11,
-0.10) and a best-fitting absorption column of 3.1 (+2.2, -1.4) x
10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum is 3.8 x 10^-11 (4.2 x
10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index 
of 0.47, the count rate at T+24 hours will be 0.18 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 
7.0 x 10^-12 (7.7 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00431605.

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


GRB_name: GRB100814A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11097
SUBJECT: Swift/UVOT Observations of GRB100814A - a clearer table.
DATE:    10/08/15 09:33:27 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

   M. De Pasquale (MSSL-UCL) and C.J. Saxton (MSSL-UCL)
report on the behalf of the Swift UVOT team:

In the GCN circ 11095 (Swift/UVOT observations of
GRB100814A) the table containing the information
on epochs and magnitudes could not be read well because
of a formatting problem. In the following, we rewrite
the table with a clearer look.

  We apologize for any inconvenience it might have caused.


Filter      T_start   T_stop    Exp(s)      Mag   Err
----------------------------------------------------------
    u (fc)    153      403        246      16.80  0.06
    v         458      627        39       17.91  0.32
    b         408      721        53       21.22  0.20
    u         153      701       285       16.84  0.06
  uvw1        507      676        39       17.33  0.20
  uvm2        483      651        39       17.86  0.31
  uvw2        434      602        39      >18.52  3-sigma UL
  white      3858     4211       344       18.63  0.07
----------------------------------------------------------


[GCN OPS NOTE(15aug10):  Per author's request, the "B" 
in the Subject line was changed to "A".]


GRB_name: GRB100814A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11098
SUBJECT: GRB 100814A: Submm observations from APEX
DATE:    10/08/15 12:02:52 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (INAF-OAB, DARK/NBI), C. de Breuck,
A.J. Castro-Tirado (IAA-CSIC), G. Siringo, F.M. Montenegro-Montes,
M. Martinez (APEX), A. Hacar (OAN), T. Stanke, A. Lundgren,
M. Dumke (ESO) report on behalf of a larger
collaboration:

"We have observed the field of GRB 100418A (Beardmore et al.
GCNC 11087) using LABOCA/APEX at Chajnantor (Chile) in the
345 GHz band. Observations began on 15th August at 05:39 UT
(25.8 hours after the burst onset). In a preliminary analysis
we do not detect any new source at the position of the afterglow
(Schaefer et al. GCNC 11086, De Pasquale et al. GCNC 11095)
down to a 3-sigma limit of 5.4 mJy. The formal flux density at
the position of the afterglow is 4.6+/-1.8 mJy."


GRB_name: GRB100814A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11099
SUBJECT: GRB 100814A: Fermi GBM observation
DATE:    10/08/15 12:23:54 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 03:50:08.81 UT on 14 August 2010, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 100814A (trigger 303450610 / 100814160),
which was also detected by the Swift-BAT (Beardmore et al. 2008, GCN 11087)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 87.2 degrees.

The GBM light curve consists of several pulses
with a duration (T90) of about 149 +/- 1 s (50-300 keV).
The time-averaged spectrum from T0+0.003 s to T0+157.57 s is
best fit by a Band function with Epeak = 106.4 +13.9/-12.6 keV,
alpha = -0.64 +0.14/-0.12, and beta = -2.02 +0.09/-0.12
(Castor C-STAT 807 for 484 d.o.f.).

The event fluence (10-1000 keV) in this time interval is
(1.98  +/- 0.06)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+6.784 s in the 10-1000 keV band
is 4.5 +/- 0.2 ph/s/cm^2.

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


GRB_name: GRB100814A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11100
SUBJECT: Swift/UVOT observations of GRB100814A - title correction to GCN 11097
DATE:    10/08/15 17:31:14 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

M. De Pasquale (MSSL/UCL) and C. J. Saxton (MSSL/UCL) on behalf of the 
Swift/UVOT team report:

  In the title of the GCN circular 11097 we mention "GRB100814B."
It should have been "GRB100814A". Apologies for the mistake.


GRB_name: GRB100816A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11102
SUBJECT: GRB 100816A: Swift detection of a possibly short burst with optical afterglow
DATE:    10/08/16 01:17:12 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), O. M. Littlejohns (U Leicester),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
C. J. Saxton (UCL-MSSL), M. Stamatikos (OSU/NASA/GSFC) and
R. L. C. Starling (U Leicester) report on behalf of the Swift Team:

At 00:37:51 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100816A (trigger=431764).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 351.740, +26.561 which is 
   RA(J2000) = 23h 26m 58s
   Dec(J2000) = +26d 33' 38"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single symmetric
peak structure with a duration of about 2 sec.  There is possible
further activity at around T+80s.  The peak count rate
was ~13000 counts/sec (15-350 keV), at ~0.5 sec after the trigger. 

The XRT began observing the field at 00:39:14.2 UT, 82.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 351.7381, +26.5785 which is equivalent to:
   RA(J2000)  = 23h 26m 57.15s
   Dec(J2000) = +26d 34' 42.6"
with an uncertainty of 5.5 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 91 seconds after the BAT trigger. The refined UVOT 
position is    
     RA (J2000)  23:26:57.56  
    Dec (J2000)  26:34:42.9      with an estimated uncertainty of 0.5
arcsec (radius, 90% confidence). This position is 5.5 arc sec. from
the  center of the XRT error circle. The estimated magnitude is 17.00
with  a 1-sigma error of about 0.03. No correction has been made for
the  expected extinction corresponding to E(B-V) of 0.09. 

There were no real-time GCN Notices on this burst because the block2world
filter was still in place due to the earlier episode of the startracker
loss-of-lock problem.  The MOC had just gotten the startracker back to lock
and BAT triggers restored when the trigger occurred.  But the block2world
had not yet been removed.  BAT_POSITION and XRT_POSITION notices were manually
generated and distributed. 

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: GRB100816A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11103
SUBJECT: GRB 100816A: ROTSE-III Optical Limits
DATE:    10/08/16 01:42:21 GMT
FROM:    Shashi Bhushan Pandey at ROTSE  <shaship@umich.edu>

S. B. Pandey (U Mich), report on behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded to GRB 100816A, possibly a short duration burst, (Swift trigger
431764; Oates, S. R., GCN 11102), producing images beginning 6.8 s after
the GCN notice time. An automated response took the first image at
01:00:05.7 UT, 1334.3 s after the burst, under fair 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 or the XRT error circle. Individual images
have limiting magnitudes ranging from 16.2-17.9; we set the following
specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
01:00:05.8   01:00:10.8         5     16.6         1334.4       N
01:01:37.27  01:05:58.67        180   18.5         1534.4       Y 


GRB_name: GRB100816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11104
SUBJECT: GRB100816A: TNG optical afterglow confirmation.
DATE:    10/08/16 06:28:22 GMT
FROM:    Angelo Antonelli at Obs. Astro. di Roma  <angelo.antonelli@oa-roma.inaf.it>

L. A. Antonelli (INAF-OAR), A. Fiorenzano (INAF-TNG), G. Tessicini  
(INAF-TNG), A. Stamerra (UniPisa) on behalf of the CIBO collaboration  
report:

We observed the field of the short hard GRB100816A (Swift trigger  
431764; Oates et al., GCN 11102) with the Italian 3.6m TNG telescope  
(La Palma, Canary Islands) equipped with the DOLORES camera.  
Observations started on Aug 16 at 03:22 UT (~2.8 hrs after the burst)  
under very poor weather conditions (high cloudiness and high  
humidity). We acquired a R band image of the GRB field for a total  
exposure time of 180s. We clearly detect a source consistent with the  
one reported by (Oates et al., GCN 11102). This souce, located at RA 
(J2000)=23:26:57.58; Dec(J2000)=+26:34:42.7 (+/-0.5''), showed a  
magnitude R~20.5 (calibrated against USNO B1.0) at the epoch of the  
observation. Due to its fading behavior with respect to the UVOT  
observation, we confirm that this source is the optical afterglow of  
GRB100816A.

This message can be cited."


GRB_name: GRB100816A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11105
SUBJECT: GRB 100816A: MASTER Optical Limits
DATE:    10/08/16 12:00:01 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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


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


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

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

MASTER   robotic telescopes (MASTER-Net: http://observ.pereplet.ru, 6 
Very Wide Field cameras and 2 Wide Field Telescopes ) located  near 
Kislovodsk  was pointed to the GRB 100816A (Oates et al., GCN Circ N 
11102)  21  sec  after Notice time and 1350 s after trigger time (before 
sunrise).


start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd? Filter
--------------------------------------------------------------------------
01:00:21.0   01:03:21.0       180     17.2         1350.0       N  Polarization


There are 6 very wide field cameras located at Kislovodsk with total FOV 
= 3 000 square degrees. Unfortunately, GRB was 4 degrees outside FOV.

The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11106
SUBJECT: GRB 100816A: TAROT Calern observatory optical detection
DATE:    10/08/16 14:38:10 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Klotz A. (CESR-OMP), Gendre B. (IASF),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 100816A detected by SWIFT
(trigger 431764) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 1339s after the GRB trigger
The elevation of the field increased from
72 degrees above horizon and weather conditions
were good.

We co-added a series of 30s unfiltered exposures.
We detect the OT mentioned by Oates et al. 2010 (GCNC 11102)
very close to the limiting magnitude of the image :

start exp. = 1339s
end exp. = 1601s
R ~ 19.2

Magnitudes were estimated with the nearby
star NOMAD-1 1165-0624306 and are not corrected
for galactic dust extinction.


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11107
SUBJECT: GRB100814A - interesting UVOT lightcurve.
DATE:    10/08/16 15:52:03 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <mdp@mssl.ucl.ac.uk>

M. De Pasquale, C. J. Saxton, and S. R. Oates (MSSL/UCL) report, on 
behalf of the Swift/UVOT team:

Swift GRB 100814A (Beardmore et al. GCN circ 11087) shows an interesting 
optical/UV lightcurve, with a flux rise detected by UVOT between 
approximately 10,000 and 100,000 seconds after the trigger. At about 40 
hours after the trigger, the afterglow was still of magnitude ~ 19 in 
the u and v filters.
Ground based observatories are encouraged to follow up this event.


GRB_name: GRB100816A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11108
SUBJECT: GRB 100816A: CQUEAN riz-band Detection, Host Galaxy?
DATE:    10/08/16 15:59:01 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

  Myungshin Im, Won-Kee Park (CEOU/Seoul National Univ),
  Soojong Pak, Hyeonju Jeong, Eunbin Kim, and Jinyoung Kim
  (Kyunghee University)

   We observed GRB 100816A (Palmer et al. GCN 11102) with the SDSS
  r,i,z-filters during the commissioning run of CQUEAN (the Camera for
  QUasars in the Early uNiverse)on the 2.1m telescope at the McDonald
  observatory. The observation started at 2010 August 16, 08:33:46 UT,
  about 8 hours after the BAT trigger. A series of 300 secs exposures
  were taken.

   We identify an object within the error circles reported by UVOT
  (Palmer et al. GCN 11102), and by Antonelli et al. (GCN 11104) which
  faded significantly, confirming its GRB afterglow nature.
   We also notice another extended object, about 1.3" to the South
  of the afterglow at RA=23:26:57.53 and Dec= +26:34:41.6 with ~0.4"
  error in position.
   The close proximity of the object to the afterglow suggests that
  this second object is possibly a host galaxy of GRB 100816A,
  although a chance projection cannot be ruled out.

         GRB      host    GRB+host     mid-point (UT)
   r      (unresolved)      21.4       08:39:36
   i     21.31    20.58      -         08:45:08

   The magnitudes are in AB, and the error of the photometry is
  about 0.1 mag. The photometry calibration is done with a standard
  star observation.
   The finding charts are available at
   http://astro.snu.ac.kr/~mim/grb/grb100816A/grb100816A_small.jpg
   http://astro.snu.ac.kr/~mim/grb/grb100816A/grb100816A_large.jpg
   N is up, and E is left. Further analysis of the data is
   ongoing.

   We thank the staffs of the McDonald observatory, David Doss,
  Peter S. Odoms, and John Kuehne for their assistance of
  the CQUEAN commissioning run.


GRB_name: GRB100816A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11109
SUBJECT: GRB 100816A: Gemini-N imaging
DATE:    10/08/16 16:03:01 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir, K. Wiersema (U. Leicester), A. J. Levan (U. Warwick),
D. Perley (UC Berkeley) report on behalf of a larger collaboration:

We imaged the field of possibly short GRB 100816A (Oates et al.
GCN 11102) with Gemini-N/GMOS, beginning about 11:33 (UT),
approximately 11 hours post-burst.

The afterglow detected by UVOT and confirmed to be fading
by the TNG (Antonelli et al. GCN 11104) is clearly detected at
a magnitude R~22.4, calibrated against USNO-B1 stars in the
field. We also detect a relatively bright galaxy centred about 1.2 arcsec
south of the afterglow, which may well be the host of the burst.
The magnitude of the galaxy is comparable to that of the
afterglow at this time.

Analysis of spectroscopic observations is ongoing.

We thank the Gemini observers, particularly Alexander
Fritz, for their assistance in obtaining these observations.


GRB_name: GRB100816A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11110
SUBJECT: GRB 100816A: Enhanced Swift-XRT position
DATE:    10/08/16 17:30:46 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 406 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100816A, 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 = 351.74010, +26.57887 which is equivalent
to:

RA (J2000): 23h 26m 57.62s
Dec (J2000): +26d 34' 43.9"

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: GRB100816A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11111
SUBJECT: GRB 100816A, Swift-BAT refined analysis
DATE:    10/08/16 17:33:20 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

C. B. Markwardt (GSFC/UMD), 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),
S. R. Oates (UCL-MSSL), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-119 to T+263 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 100816A (trigger #431764)
(Oates, et al., GCN Circ. 11102).  The BAT ground-calculated position is
RA, Dec = 351.738, 26.568 deg which is
    RA(J2000)  =  23h 26m 57.1s
    Dec(J2000) = +26d 34' 04.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 33%.

The mask-weighted light curve shows a single symmetric peak. There is
low-level ongoing emission out to about T+100 sec.  T90 (15-350 keV) is
2.9 +- 0.6 sec (estimated error including systematics).

The time-averaged spectrum from T-0.7 to T+4.5 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.73 +- 0.24,
and Epeak of 170.7 +- 79.7 keV (chi squared 50.79 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 2.0 +- 0.1 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+0.10 sec in the 15-150 keV band is
10.9 +- 0.4 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.16 +- 0.06 (chi squared 61.72 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/431764/BA/


GRB_name: GRB100816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11112
SUBJECT: GRB 100816A: 1.23m CAHA optical observations
DATE:    10/08/16 18:39:32 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

V. Terron, M. Fernandez, A.J. Castro-Tirado, J. Gorosabel (IAA-CSIC),  
report on behalf of a larger collaboration:

We carried out BVRI-band observations of the Swift GRB 100816A  (Oates  
et al., GCNC 11102) with the 1.23m Calar Alto telescope. The optical  
afterglow (Oates et al., GCNC 11102; Antonelli et al., GCNC 11104) is  
well detected in BVRI with a preliminary magnitude of I~19.9 on Aug  
16.0492 UT (~33 min post burst), calibrated using USNO-B1.0 field stars.


GRB_name: GRB100816A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11113
SUBJECT: GRB 100816A: Swift-BAT spectral lag results
DATE:    10/08/16 18:58:58 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. Norris (U. Denver), T. N. Ukwatta (GWU/GSFC), S. D. Barthelmy (GSFC),
N. Gehrels (GSFC), M. Stamatikos (OSU/NASA/GSFC), and T. Sakamoto (GSFC/UMBC)
for the Swift-BAT team:

For GRB 100816A (Oates et al GCN 11102), the BAT team has analyzed the
spectral lags for the data from ~T-1 sec to ~T+3 sec using unmask-weighted
light curves.  The spectral lags were measured between standard BAT energy
bands: channel 1 (15-25 keV), 2 (25-50 keV), 3 (50-100 keV) and 4 (100-350 keV)
are given below.

Lag Ch4-2    10 +/- 25 ms
Lag Ch3-1    20 +/- 20 ms

We conclude from this analysis that the burst is consistent with being
a short hard burst, but the error bars are too large to be definitive.


GRB_name: GRB100816A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11114
SUBJECT: GRB100816A Swift-XRT refined analysis
DATE:    10/08/16 20:00:21 GMT
FROM:    Owen Littlejohns at U of Leicester  <oml2@star.le.ac.uk>

O. M. Littlejohns (U. Leicester) and S. R. Oates (UCL-MSSL) report on
behalf of the
Swift-XRT team:
 
We have analysed 4.4 ks of XRT data for GRB 100816A (Oates et al. GCN
Circ. 11102), from 89 s to 12.2 ks after the BAT trigger. The data
comprise 144 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Evans et al. (GCN. Circ 11110).
 
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.29 (+0.05, -0.04), with some flaring activity during
the first snapshot.
 
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.16 (+0.22, -0.21). The
best-fitting absorption column is 1.4 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 4.5 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.10 (+0.19, -0.16)
and a best-fitting absorption column of 1.5 (+0.5, -0.4) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.8 x 10^-11 (5.5 x 10^-11) erg cm^-2
count^-1.
 
If the light curve continues to decay with a power-law decay index of
1.29, the count rate at T+24 hours will be 1.6 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.9 x
10^-14 (8.6 x 10^-14) erg cm^-2 s^-1.
 
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00431764.

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


GRB_name: GRB100816A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11115
SUBJECT: GRB 100816A: Swift UVOT Observations
DATE:    10/08/16 21:34:49 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 observing the field of GRB 100816A 91s
after the BAT trigger (Oates et al., GCN Circ. 11102). We detect the
optical afterglow significantly in the white and u filters and
marginally in the v, b and uvw1 filters. The best UVOT position was  
reported
in Oates et al. (GCN Circ. 11102), and is consistent with the
XRT enhanced position (Evans et al., GCN Circ 11110) and with the  
optical
afterglow position reported by TNG (Antonelli et al., GCN Circ 11104).

Preliminary magnitudes and the 3 sigma upper limits are reported below  
for
individual white and u images and summed images for the v, b, uvw1,  
uvm2 and uvw2 filters.

Filter    T_start(s)  T_stop(s)  Exposure    Mag/3SigUL
###########################################################
white (FC) 91         241          147       17.01 +/- 0.05  
white      586        606          19      18.90 +/- 0.19  
v          3991       5626         393       21.56 +/- 0.94
b          4811       6393         341      21.07 +/- 0.35  
u (FC)     305        555          246      18.02 +/- 0.08  
u          4606       4806         197       20.39 +/- 0.35
uvw1       4401       6036         393      20.98 +/- 0.44  
uvm2       4196       34516        1279      > 21.42
uvw2       3787       28671        2475      > 22.19
###########################################################

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.09 mag (Schlegel et al.,
1998, ApJS, 500, 525). The photometry is on the UVOT photometric system
described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB100816A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11116
SUBJECT: GRB 100816A: Gemini-N spectroscopy
DATE:    10/08/16 22:32:01 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir, K. Wiersema (U. Leicester), J. P. U. Fynbo (DARK)
A. J. Levan (U. Warwick) & D. Perley (UC Berkeley) report on
behalf of a larger collaboration:

We obtained medium resolution, long-slit spectroscopy of GRB 100816A
(Oates et al. GCN 11102) with Gemini-N/GMOS following the imaging
reported in Tanvir et al. (GCN 11109).  The afterglow was centred in the
slit, and the nearby candidate host galaxy (see also Im et al. GCN 11108)
was also partially in the slit.  The spectrum covers a wavelength range
from about 4000A to 6700A.

Our analysis of the galaxy trace provides a tentative detection of the OIII
(5007A/4959A) doublet and Hbeta (4863A) at a redshift of z~0.245, although
we caution that all these features are low S/N.  No other lines are clearly seen
even though OII 3727A would be within the spectral range (but we note the
galaxy continuum is not apparent below about 4700A, in part due to declining
detector quantum efficiency in the blue).  Neither have we identified so far
any significant features in the afterglow spectrum.

This is a similar redshift to a number of Swift short-duration burst hosts,
but further observations are encouraged to confirm the result.

We thank the Gemini observers, particularly Alexander
Fritz, for their assistance in obtaining these observations.


GRB_name: GRB100816A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11117
SUBJECT: GRB 100816A : Lulin r'-band observation
DATE:    10/08/17 08:02:50 GMT
FROM:    Yuji Urata at Nat. Central U.  <urata@astro.ncu.edu.tw>

Y. Urata (NCU) and K.Y Huang (ASIAA)
on behalf of EAFON report;

"We started to observe the GRB 100816A (Palmer et al. GCN 11102) using
Lulin One-meter Telescope (LOT) with r'-band filter.  
The observation started at 2010 August 16 18:09 about 17.5 hr after
the burst.  The brightness of afterglow including the possible host
galaxy reported by Im et al. (# 11108) and Tanvir et al (# 11109) is
R=21.6+/-0.1 in Vega. The photometric calibration is performed against
USNO-B1 stars in the field."


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11118
SUBJECT: GRB 100814A : Lulin optical observation
DATE:    10/08/17 08:03:26 GMT
FROM:    Yuji Urata at Nat. Central U.  <urata@astro.ncu.edu.tw>

Y. Urata (NCU) and K.Y Huang (ASIAA)
on behalf of EAFON report;

"We observed the GRB 100814A optical afterglow (Beardmore et al. GCN
11087) using Lulin One-meter Telescope (LOT) with g', r', i' and
z'-band filters. The observation started at 2010 August 16 19:09 about
2.65 days after the trigger.  All of images show the optical afterglow
clearly.  The brightness of the afterglow calibrated against USNO-B1
stars in the field is R~19.2.
The afterglow decays only ~0.5 magnitude from our previous observation
at August 14 (0.7 days after the burst). This interesting feature is
also notified by Pasquale (# 11107).

Further observation is scheduled."


GRB_name: GRB100814A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11119
SUBJECT: Konus-Wind observation of GRB 100814A
DATE:    10/08/17 08:48:16 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 GRB 100814A (Swift-BAT trigger=431605;
Beardmore et al., GCN 11087; Krimm et al., GCN 11094)
triggered Konus-Wind at T0=13811.288s UT (03:50:11.288)

The burst light curve consists of several pulses
with a total duration of ~150 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB100814_T13811/

As observed by Konus-Wind the burst
had a fluence of (1.2 +/- 0.2)x10-5 erg/cm2,
and a 256-ms peak flux measured from T0+1.024s
of (0.75 +/- 0.25)x10-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+155.904 s) is best fit
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model, for which
alpha = -0.4(-0.3, +0.4),
and Ep = 128(-17, +23) keV (chi2 = 59/58 dof).

The spectrum at the maximum count rate
(measured from T0 to T0+8.848 s) is best fit
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model, for which
alpha = 0.55 +/- 0.30,
and Ep = 147(-10, +12) keV (chi2 = 55/58 dof).

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


GRB_name: GRB100816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11120
SUBJECT: GRB 100816A: NOT optical observations
DATE:    10/08/17 09:24:04 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), D. Xu (Weizmann Inst.), J.P.U. Fynbo (DARK/NBI), 
P. Jakobsson (Univ. Iceland), L. Buchhave, T. Hansen (NBI), report on behalf of 
a larger collaboration:

We observed the field of GRB 100816A (Oates et al., GCN 11102) with the 
NOT equipped with ALFOSC. Observations were carried out in the R band. 
The mid point of the observation is August 17.04 UT (24.3 hr after the GRB).

We clearly detect both the optical afterglow (Oates et al., GCN 11102) 
and the putative host galaxy (Im et al., GCN 11108; Tanvir et al., GCN 
11109). We find magnitudes of R = 23.0 +- 0.1 and R = 21.65 +- 0.05 for 
the two objects, respectively, assuming R=17.06 for the nearby USNO star 
1165-0595190. We caution that accurate photometry will have to await for 
late-time templates to isolate the contribution of both objects.

[GCN OPS NOTE(17aug10):  Per author's request, TH was added to the author list.]


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11121
SUBJECT: GRB 100814A: NOT optical observations
DATE:    10/08/17 09:33:24 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani, J.P.U. Fynbo (DARK/NBI), D. Xu (Weizmann Inst.), P. 
Jakobsson (Univ. Iceland), L. Buchhave, T. Hansen (NBI), report on behalf of a 
larger collaboration:

We observed the optical afterglow of GRB 100814A (Schaefer et al., GCN 
11086; Beardmore et al., GCN 11087) with the NOT equipped with ALFOSC. 
Observations were carried out in the R band, with a mean time August 
17.13 UT (2.97 days after the burst).

The optical afterglow is well detected, with R=19.5 compared to several 
USNO stars in the field. The error is about 0.3 mag, completely due to 
the scatter in the calibration stars.

[GCN OPS NOTE(17aug10):  Per author's request, TH was added to the author list.]


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11122
SUBJECT: GRB 100814A : Liverpool Telescope Observations
DATE:    10/08/17 10:52:58 GMT
FROM:    Zach Cano at ARI/John Moores Liverpool  <zec@astro.livjm.ac.uk>

Z. Cano (Liverpool JMU), C. Guidorzi (U.Ferrara) report on behalf of a
larger collaboration:

We observed the optical afterglow of GRB 100814A (Schaefer et al., GCN
11086; Beardmore et al., GCN 11087) with the 2m Liverpool Telescope,
starting at 22:16:09 UT on the 16th of August 2010, in filters r and i.

We clearly detect the afterglow in both filters with the following
magnitudes:

======================================
 Filter   T-To (days)        Mag
--------------------------------------
   R        2.96       19.75 +/- 0.02
   I        2.93       18.32 +/- 0.04
======================================

The photometric calibration is performed against USNO-B1 objects
0720-0016107 (R2=19.58) and 0719-0016667 (I=17.27).  Our detection is
consistent with the values reported by Malesani et al. (GCN 11121).
Observations are ongoing.


GRB_name: GRB100816A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11123
SUBJECT: GRB 100816A: VLT and Gemini-N revised redshift
DATE:    10/08/17 12:56:20 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir (U. Leicester), S. Vergani (GEPI/Obs. Paris and APC/Univ. Paris 7),
J. Hjorth, J. P. U. Fynbo, B. Milvang-Jensen, D. Malesani (DARK),
K. Wiersema (U. Leicester),  P. Vreeswijk (Reykjavik), A. J. Levan (U. Warwick)
P. Goldoni (APC/Univ. Paris 7 and SAp/CEA), S. Covino (INAF/Brera), & L. A. Antonelli (INAF/Roma)
report on behalf of a larger collaboration:

We observed the location of possible short-hard GRB 100816A
(Oates et al. GCN 11102; Markwardt et al. GCN 11111; Norris et al. GCN 11116)
with VLT/X-Shooter on 2010 Aug 17 beginning 04:20 (UT).  We clearly
detect the putative host galaxy of the burst, and identify lines of Halpha,
Hbeta,  OII (3727), NII (6548/6583) and OIII (5007) in emission and CaII H&K
in absorption.  In fact, the system splits (spectrally and spatially) into two
components at redshifts z=0.8034 and z=0.8049 (based on a provisional
wavelength calibration), possibly indicating an interacting system or reflecting
internal velocity components within a single galaxy.  This redshift is inconsistent
with the tentative redshift for this galaxy suggested by Tanvir et al. (GCN 11116).

We have also re-analysed the Gemini-N GMOS afterglow spectroscopy initially
reported in GCN 11116.  The trace shows faint absorption features
consistent with MgII (2797/2803A) doublet and FeII (2600A) at a redshift of
z=0.8035. The agreement of this redshift with that obtained for the galaxy from
the X-shooter data, strongly suggests that it is the host.  We note that none of
the emission lines seen in the X-Shooter spectrum are within the spectral range
of the GMOS data.

We acknowledge the support of the VLT staff, in particular Giovanni Carraro.

[GCN OPS NOTE(19aug10): Per author's request, LAT was added to the author list.]


GRB_name: GRB100816A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11124
SUBJECT: GRB 100816A: Fermi GBM observation
DATE:    10/08/17 19:42:54 GMT
FROM:    Michael Burgess at UAH  <james.burgess@uah.edu>

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

"At 00:37:50.94 UT on 16th August 2010, the Fermi Gamma-Ray Burst  
Monitor
triggered and located GRB 100816A (trigger 303611872 / 100816026),
which was also detected by the SWIFT-BAT (Oates et al. 2010, GCN 11102)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 82 degrees.

The GBM light curve shows a single pulse with a duration (T90) of about
2 s (50-300 keV). The time-averaged spectrum from T0 to
T0+ 2.496 s is best fit by a Band function with Epeak = 136.70 +/-
4.73 keV, alpha = -0.31 +/- 0.05, and beta = -2.77 +/- 0.17
(Castor C-STAT 555.02 for 484 d.o.f.).

The event fluence (10-1000 keV) in this time interval is
(9.10 +/- 0.13) E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+ 0.38 s in the 10-1000 keV band
is 15.59 +/- 0.25 ph/s/cm^2.

A power law function with an exponential high energy cutoff fits
the spectrum equally well (Castor C-STAT 564.38 for 485 d.o.f.)
The cutoff energy, parameterized as Epeak, is 146.30 +/- 3.44 keV
and the power law index is -0.38 +/- 0.04.

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


GRB_name: GRB100816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11125
SUBJECT: GRB 100816A: 10.4-m GTC redshift confirmation
DATE:    10/08/17 21:32:54 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J. Gorosabel (IAA-CSIC, Granada),  A.J. Castro-Tirado (IAA-CSIC), N. Tanvir (U. Leicester), A. de Ugarte Postigo (INAF-OAB), M. Jelinek (IAA-CSIC), P. Kubanek (IAA-CSIC & U. Valencia), R. Cunniffe (IAA-CSIC), M.D. Prez-Ramrez (U. Jaen), J.M. Castro Cern (ESAC), S. Guziy (IAA-CSIC), G. Gmez (GTC, La Palma), and J. Cepa (IAC, Tenerife), report on behalf of a larger collaboration:

"We acquired long-slit spectra of the optical afterglow of the possible short-duration GRB 100816A (Oates et al., GCNC 11102) with the 10.4-m Gran Telescopio Canarias (GTC) at the Observatorio del Roque de los Muchachos on the island of La Palma. Three spectra were taken under non optimal weather conditions with the OSIRIS instrument on Aug 16.1736 - 16.2060 UT (3.5-4.3 hr post-burst) with a total exposure time of 3x900s and covering an approximate spectral range of 4200-8700 A. A comparison of the GTC and the Gemini-N spectra (Tanvir et al., GCNC 11123) shows faint absorption features consistent with the MgII doublet at a preliminary redshift of z = 0.8049. At the present stage of the reduction we can not confirm the existence of emission lines."

We acknowledge the support of the GTC staff.


GRB_name: GRB100816A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11126
SUBJECT: GRB100816A: MITSuME optical upper limits
DATE:    10/08/18 06:09:10 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 100816A (Oates et al., GCN 11102)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2010-08-16 14:00:49 UT (~13.4 h after
the burst). We did not find any new point source within the
enhanced XRT error circle (Evans et al., GCNC 11110) in all
the three bands. We could not detect the previously reported
host galaxy (Im et al., GCN 11108; Tanvir et al., GCN 11109;
Malesani et al., GCN 11120).

Three sigma upper limits of the OT are listed below. We used
GSC 2.3 catalog for flux calibration.


T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.67447    16:49:05  6240.0     >21.0  >20.5  >19.9
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100816A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11127
SUBJECT: Konus-Wind observation of GRB 100816A
DATE:    10/08/18 11:30:01 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 short GRB 100816A (Swift-BAT trigger=431764;
Oates et al., GCN 11102; Markwardt et al., GCN 11111)
triggered Konus-Wind at T0=02273.983s UT (00:37:53.983)

The burst light curve shows a single peak
with a total duration of ~2.8 s. There is also
a hint of a softer (<70 keV) short (~64ms)
weak spike at T0 + 4.7 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB100816_T02273/

As observed by Konus-Wind the burst
had a fluence of (3.3 +/- 0.4)x10-6 erg/cm2,
and a 64-ms peak flux measured from T0 + 0.896 s
of (2.3 +/- 0.4)x10-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+8.448 s) is best fit
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.0(-0.3, +0.4),
and Ep = 148(-26, +41) keV (chi2 = 50.5/61 dof).

Fit of this spectrum by the GRB (Band) model
yields the same values of alpha and Ep, with
beta = -4.6 (<-2.5), chi2 = 50.5/60 dof.

Assuming z=0.8049 (Tanvir et al., GCN 11123;
Gorosabel et al., GCN 11125) and a standard
cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, Omega_Lambda = 0.73,
the isotropic energy release E_iso = (5.8 +/- 0.7)x10^51 erg,
the peak luminosity (L_iso)_max = (7.3 +/- 1.3)x10^51 erg/s.

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


GRB_name: GRB100816A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11128
SUBJECT: GRB 100816A: Fermi GBM observation (correction to GCN 11124)
DATE:    10/08/18 15:45:25 GMT
FROM:    Gerard Fitzpatrick at U.College Dublin/Fermi  <gerard.fitzpatrick@gmail.com>

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

Apologies, the event fluence (10-1000 keV) should be (3.84 +/- 0.13)
E-06 erg/cm^2. This is consistent with the value reported by
Konus-Wind (Golenetskii et al, GCN 11127).

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


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11129
SUBJECT: GRB 100814A: optical observations
DATE:    10/08/18 17:23:27 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 100814A (Beardmore et al. GCN  11087) 
with 0.45-m telescope f ISON-NM observatory  on Aug. 17 (UT) 10:07:17 - 
10:48:07.

The afterglow (Schaefer et al. GCN  11086; Beardmore et al. GCN  11087)  is 
well detected. Preliminary photometry of unfiltered image against USNO-B1.0 
field stars (R)  is following

T-T0,  filter, exposure,  OT
(day)

3.2689    W     300x7    19.79  +/- 0.05

the photometry error is statistical only. 


GRB_name: GRB100814B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11130
SUBJECT: GRB 100814B: Fermi GBM detection
DATE:    10/08/19 16:13:07 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"The Fermi Gamma-ray Burst Monitor (GBM) trigger 303467127 / 100814351 
at 08:25:25.75 UT on 14 August 2010, tentatively classified as a 
solar flare, is in fact due to a GRB. 

The on-ground calculated location of GRB 100814B , using the 
GBM trigger data, is RA = 122.8, DEC = +18.5 (J2000 degrees, 
equivalent to 08h 11m, +18d 30'), with an uncertainty 
of 2.6 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 87 degrees.

The GBM light curve consists of a single pulse 
with a duration (T90) of about 6.4 +/- 1.1 s (50-300 keV). 
The time-averaged spectrum from T0-3.072 s to T0+9.216 s is 
best fit by a Band function with Epeak = 81.0 +6.2/-6.7 keV, 
alpha = -0.62 +0.14/-0.11, and beta = -2.49 +0.15/-0.20 
(Castor C-STAT 521 for 488 d.o.f.).

The event fluence (10-1000 keV) in this time interval is 
(4.7 +/- 0.2)E-06 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0+3.584 s in the 10-1000 keV band 
is 10.4 +/- 0.3 ph/s/cm^2.

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


GRB_name: GRB100814A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11131
SUBJECT: EVLA radio afterglow detection of GRB 100814A
DATE:    10/08/19 23:45:19 GMT
FROM:    Poonam Chandra at Royal Mil. College Canada  <Poonam.Chandra@rmc.ca>

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

"We observed the localization of GRB 100814A (Beardmore et al. GCN
11087) with the Expanded Very Large Array (EVLA) on August 18.38 UT at a
C band wide receiver (receiver frequency range 4-8 GHz). We detect the radio 
afterglow of the GRB at the Swift-XRT position (Beardmore et al. GCN 
11092) at 4.5 and 7.9 GHz frequencies. The flux densities at 
4.5 and 7.9 GHz bands are 198+/-29 uJy and 453+/-23 uJy, respectively.

The EVLA is still undergoing active commissioning and we caution that
these results should be considered preliminary. The National Radio
Astronomy Observatory is a facility of the National Science Foundation
operated under cooperative agreement by Associated Universities, Inc."


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11133
SUBJECT: GRB 100814A: ISON-NM optical observations
DATE:    10/08/22 07:30:05 GMT
FROM:    Leonid Elenin at ISON  <l.elenin@gmail.com>

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

We continue observation of the Swift GRB 100814A (Beardmore et al. GCN
 11087) with 0.45-m telescope of ISON-NM observatory on Aug. 20 (UT)
08:42:06 - 09:33:14 and Aug. 21 (UT) 09:45:22 - 11:04:41.

The afterglow (Schaefer et al. GCN  11086; Beardmore et al. GCN  11087)  is
well detected on stacked images for both epochs. Preliminary photometry of
unfiltered image against USNO-B1.0 star 0720-0016107, assuming R=19.73  is
following:


T-T0,  filter, exposure,  OT
(day)

6.2205    W     300x10    21.66  +/- 0.23
7.2734    W     300x15    22.50  +/- 0.30

The photometry errors are statistical only.


The images of GRB100814A is available at:

http://spaceobs.org/images/GRB1000814A-3epoch.jpg


GRB_name: GRB100814A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11134
SUBJECT: GRB 100814A: Suzaku WAM observation of the prompt emission
DATE:    10/08/23 01:12:09 GMT
FROM:    Yusuke Nishioka at Miyazaki U.  <yusuke613@astro.miyazaki-u.ac.jp>

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


The long GRB 100814A (Swift/BAT trigger #431605 ; Krimm et al., GCN 11094;
Fermi/GBM trigger #303450610 ; von Kienlin et al., GCN 11099) triggered
the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range
of 50 keV - 5 MeV at 03:50:08.51 UT (=T0).

The observed light curve shows a multi-peaked structure starting at
T0-1.5s, ending
at T0+19.5s, followed by a weaker emission seen up to T0+150.5s with a
duration
(T90) of about 110 seconds. The fluence in 100 - 1000 keV was
7.14(+1.03/-1.37) x 10^-6 erg/cm^2. The 1-s peak flux measured from
T0+0.5s was
2.00(-0.48,+0.40) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-1.5s to
T0+150.5s is well fitted by a single power-law with a photon index
of 3.18(+1.03/-0.7) (chi^2/d.o.f = 13.32/15).

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

The light curves for this burst are available at:

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

-- 
------------------------------------
 $B5\:jBg3X(B $B9)3X8&5f2J(B $B1~MQJ*M}3X@l96(B
 $B=$;N2]Dx(B $B#2G/(B
 $B@>2,!!M42p(B
 yusuke613@astro.miyazaki-u.ac.jp
------------------------------------


GRB_name: GRB100823A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11135
SUBJECT: GRB 100823A: Swift detection of a burst
DATE:    10/08/23 17:38:11 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

V. Mangano (INAF-IASFPA), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
M. M. Chester (PSU), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU),
E. A. Hoversten (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC),
P. T. O'Brien (U Leicester), T. Sakamoto (NASA/UMBC),
M. C. Stroh (PSU) and E. Troja (NASA/GSFC/ORAU) report on behalf of
the Swift Team:

At 17:25:35 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100823A (trigger=432420).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 20.703, +5.842, which is 
   RA(J2000)  =  01h 22m 49s
   Dec(J2000) = +05d 50' 31"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single FRED-like peak
with a duration of about 25 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 17:26:44.6 UT, 68.9 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 20.70383, 5.83361
which is equivalent to:
   RA(J2000)  = 01h 22m 48.92s
   Dec(J2000) = +05d 50' 01.0"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 30 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.73e+20
cm^-2, Kalberla et al. 2005), with an excess column of 2.1
(+1.87/-1.66) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 5.93e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 77 seconds after the BAT trigger. No credible
afterglow candidate has  been found in the initial data products. The
2.7'x2.7' sub-image covers 100% of  the XRT error circle. The 3-sigma
upper limit is 19.3 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 V. Mangano (vanessa AT ifc.inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB100823A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11136
SUBJECT: GRB 100823A: Enhanced Swift-XRT position
DATE:    10/08/23 20:20:57 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 251 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100823A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 20.70428, +5.83510 which is equivalent
to:

RA (J2000): 01h 22m 49.03s
Dec (J2000): +05d 50' 06.4"

with an uncertainty of 2.1 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: GRB100823A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11137
SUBJECT: GRB 100823A: Swift-BAT refined analysis
DATE:    10/08/23 22:25:08 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
V. Mangano (INAF-IASFPA), C. B. Markwardt (GSFC/UMD), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100823A (trigger #432420)
(Mangano, et al., GCN Circ. 11135).  The BAT ground-calculated position is
RA, Dec = 20.706, 5.848 deg, which is 
   RA(J2000)  =  01h 22m 49.4s 
   Dec(J2000) = +05d 50' 52.6" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 92%.
 
The mask-weighted light curve shows a single FRED peak starting at ~T-2 sec,
peaking at ~T+1 sec, and ending at T+150 sec.  T90 (15-350 keV) is
16.9 +- 3.5 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.2 to T+18.2 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.19 +- 0.18.  The fluence in the 15-150 keV band is 4.1 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.14 sec in the 15-150 keV band
is 1.0 +- 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/432420/BA/


GRB_name: GRB100823A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11138
SUBJECT: GRB 100823A: WHT observations
DATE:    10/08/24 04:28:24 GMT
FROM:    Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>

A.J. Levan (U. Warwick), N.R. Tanvir (U. Leicester), C. Copperwheat (U. Warwick)
report for a larger collaboration:

We observed the field of GRB 100823A (Mangano et al. GCN 11135) using the
William Herschel Telescope on La Palma with the ACAM instrument. Observations
were conducted in the z-band, and began at 00:37 UT, approximately 7.2 hours
after the burst.

Within the refined X-ray error circle (Goad et al. GCN 11136)  we identify a
source, at

A:
RA(J2000): 01:22:48.97
DEC(J2000) 05:50:08.1

However, we note that a source is also present in the DSS2 images of the field
at this position.

Additionally we note the presence of a brighter source, not present in the DSS
images at

B:
RA(J2000): 01:22:48.79
DEC(J2000) 05:50:10.9

This source may be the afterglow of GRB 100823A (offset approximately ~6 arcseconds
from the XRT position),  or alternatively could either be a red source, not visible in the
DSS2 red image, or a source with high proper motion.

Further observations will be required to assess the nature of any variability.

Images can be found at

http://www.star.le.ac.uk/~anl/100823A


GRB_name: GRB100823A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11139
SUBJECT: GRB 100823A: Swift/UVOT Upper Limits
DATE:    10/08/24 04:37:39 GMT
FROM:    Margaret Chester at PSU  <chester@astro.psu.edu>

M.M. Chester (PSU) and V. Mangano (INAF-IASFPA) report on behalf of
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 100823A
78 s after the BAT trigger (Mangano et al., GCN Circ. 11135).  No
optical afterglow consistent with the enhanced Swift/XRT position
(Goad et al., GCN Circ. 11136) 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
white and u finding chart (FC) and subsequent exposures are:

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

white_FC            78          227          147         >20.1
u_FC               290          539          246         >19.4
white               78        17439         2181         >21.9
v                  619        22361         1331         >20.5
b                  545        16528         1278         >21.3
u                  290         6512          639         >20.4
w1                 669         6307          432         >20.2
m2                 816         6102          413         >20.8
w2                 767        18242         2082         >21.2

The values quoted above 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: GRB100823A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11140
SUBJECT: GRB 100823: 1.5m OSN I-band observations
DATE:    10/08/24 09:48:06 GMT
FROM:    Sergey Guziy at IAA CSIC  <gss@iaa.es>

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

"We have carried out I-band observations of the Swift GRB 100823A
Mangano et al., GCNC 11135) error circle with the 1.5m telescope at
Observatorio de Sierra Nevada, Spain. The data were acquired on Aug
24.1333-24.1890 UT with a total exposure time of 15x300s. The two
objects reported by Levan et al. (GCNC 11138) are clearly detected
with preliminary magnitudes of I = 20.8 for the one within the XRT error
box and 20.4 for the one reported by Levan et al. using as
photometric reference the USNO-B1.0 star located at
RA(J2000) = 01:22:45.502, DEC(J2000) = +05:49:03.02. At the present stage
we can not confirm variability in any of the two sources. Further
observations are planned."


GRB_name: GRB100823A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11141
SUBJECT: GRB 100823A: TNG NIR observations
DATE:    10/08/24 12:02:37 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), A.J. Levan (U. Warwick), D. Malesani (DARK/NBI),
N.R. Tanvir (U. Leicester), E. Palazzi (INAF-IASFBo), A. Fiorenzano
(INAF-TNG), report:

We observed the field of GRB 100823A (Mangano et al. GCN 11135) using the
Italian 3.6m TNG telescope, located in the Canary Islands. A set of J-band
images were acquired on Aug 24.03490 UT (~7.4 hours after the burst; mid
exposure time) for a total exposure time of 16 minutes.

We detect the two objects reported by Levan et al. (GCN 11138) and Guziy
et al. (GCN 11140) with magnitudes J=21.0 for object "A" (the one within
the refined XRT error circle; Goad et al. GCN 11136) and J=19.4 for object
"B", calibrated against the 2MASS catalogue.

Although we have yet to photometrically calibrate the z-band image, from a
comparison of the TNG and WHT images (Levan et al. GCN 11138) we note that
object "B" has a z-J color significantly redder with respect to the
average color of field stars.

As suggested by Levan et al (GCN 11138) object "B" can thus be a red
source not visible in the DSS2 red image. In light of this, its location
outside the XRT refined error circle would make it likely unrelated to the
GRB.


GRB_name: GRB100823A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11142
SUBJECT: GRB 100823A - second epoch WHT observations
DATE:    10/08/24 12:16:50 GMT
FROM:    Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>

A.J. Levan (U. Warwick), N.R. Tanvir (U. Leicester), C. Copperwheat
(U. Warwick) report for a larger collaboration:

We obtained a second epoch of observations of GRB 100823A (Mangano
et al. GCN 11135) with the WHT, beginning at  05:38 UT, approximately
5 hours after our first epoch of observations (Levan et al. GCN
11138), and 12 hours after the GRB.  In our images we detect both
sources A and B, both of which are constant within the photometric
errors.

Additionally, we have inspected archival images of the field obtained
with the UKIRT Wide Field Camera (WFCAM)  in November 2008
in the YJHK bands. Object B is faintly detected in all bands, while
object A is below the detection limit of the shallow observations.

Given the location of object B well outside the refined XRT error
circle (Goad et al. GCN 11136) these results imply that it is not
related to GRB 100823A, confirming the conclusion of D'Avanzo
et al. (GCN 11141). We cannot rule out a faint contribution of
afterglow to object A, but it non-variability in our observations,
coupled with its detection in DSS2 suggest that it is not afterglow
dominated."


GRB_name: GRB100823A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11143
SUBJECT: GRB 100823A: VLT/X-Shooter spectroscopy
DATE:    10/08/24 13:33:09 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

P. D'Avanzo (INAF/Brera), P. Jakobsson (Reykjavik), H. Flores (Paris
Obs.), P. Goldoni (APC/Univ. Paris 7 and SAp/CEA), N. R. Tanvir, K.
Wiersema (U. Leicester), A. J. Levan (U. Warwick), D. Malesani, J. P. U.
Fynbo, and B. Milvang-Jensen (DARK), report on behalf of a larger
collaboration:

We observed the location of GRB 100823A (Mangano et al. GCN 11135) with
the ESO VLT equipped with the X-shooter spectrograph on 2010 Aug 24,
beginning 08:17 UT (15.5 hr after the GRB). The slit was aligned so to
include both objects A and B first mentioned by Levan et al. (GCN 11138;
see also Guziy et al., GCN 11140; D'Avanzo et al., GCN 11141). We detect
both objects in the acquisition image, and confirm that object B is
fainter than the DSS limit.

In the spectra, we detect continuum from source A, and identify its
spectrum as being that of an M-dwarf based on evident TiO bands. Given
that object B is also likely unrelated to the GRB (D'Avanzo et al., GCN
11141; Levan et al., GCN 11142), we conclude that either the GRB event
is itself associated with a flare from this star, or that the GRB
afterglow is a fainter source not reported so far.

We acknowledge the support of the VLT staff, in particular Claudia Cid,
Stephane Brillant, Jonathan Smoker, and Christophe Martayan.


GRB_name: GRB100823A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11144
SUBJECT: GRB 100823A: Swift XRT refined analysis
DATE:    10/08/24 13:59:54 GMT
FROM:    Vanessa Mangano at INAF-IASFPA  <vanessa@ifc.inaf.it>

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

We have analyzed 8.7 ks of XRT data for GRB 100823A (Mangano  et al. GCN
Circ. 11135), from 59 s to 22 ks after the  BAT trigger. The data
comprise 68 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 light curve can be modeled with a broken power-law decay with an
initial decay index of alpha1=2.9 (+/-0.2) , a break at T+163 (+/-11) s
and a final decay index of alpha2=1.19 (+/-0.03).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index    of 3.6 (+0.8, -0.6). The
best-fitting absorption column is  2.8 (+1.2, -0.9) x 10^21 cm^-2,
in excess of the Galactic value of 3.7 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum (extracted from T+137.5 s to T+22.3 ks, 8.65 ks
exposure) has a photon index of 2.2 (+0.3, -0.2) and a best-fitting 
absorption
column of 2.1 (+0.6, -0.5) 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 (6.6 x 10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
0.87, the count rate at T+48 hours will be 9.0 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of
3.6 x 10-14 (5.9 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00432420.

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


GRB_name: GRB100823A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11145
SUBJECT: GRB 100823A: Candidate IR afterglow
DATE:    10/08/24 17:13:52 GMT
FROM:    Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>

A.J. Levan (U. Warwick), K. Wiersema, N. Tanvir (U. Leicester),
C. Copperwheat (U. Warwick) report on behalf of a larger collaboration:

We obtained infrared imaging of the location of GRB 100823A ( using
LIRIS on the 4.2m WHT, beginning at 01:34 UT, ~8 hours after the
burst. Observations were obtained in the JH and K bands, with a
total exposure time of 540 s in each band.

We detect sources A and B of Levan et al. (GCN), but also find a
new source within the XRT error circle of Goad et al. GCN 11135,
but see also,
http://www.swift.ac.uk/xrt_positions/00432420/image.php
with a position of,

C: 
RA(J2000) 01:22:48.94 
DEC(J2000) 05:50:05.9

The object has K=19.6 calibrated against 2MASS, and is faintly
visible in the H-band, but not in the J or z, suggestive of a red colour.
At the current time we cannot make statements as to the variability of
the source, but its red colour, akin to extinguished GRB afterglows,
coupled with a location within the XRT error circle leads us to
suggest that it is the afterglow of GRB 100823A.


GRB_name: GRB100823A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11146
SUBJECT: GRB100823A : MOA optical observation
DATE:    10/08/25 12:41:45 GMT
FROM:    Suzuki Daisuke at MOA-II  <dsuke@stelab.nagoya-u.ac.jp>

D. Suzuki, K. Omori, N. Miyake,  S. Kobara, H. Naito and T. Sako (STE Lab, Nagoya Univ.),
T. Saito (Tokyo Metropolitan College of Industrial Technology)
and K. Wada (Konan Univ.) on behalf of the MOA Collaboration  report:

We searched for an optical afterglow of GRB 100823A (GCN 11135, Mangano et al.)
starting from 17:30:34 UT on 2010 Aug 23 (5 minutes after the burst)
with the MOA-II 1.8m telescope at Mt.John observatory in New Zealand.
In a single image of a 60sec exposure with a wideband Red filter (center
wavelength ~ 750nm and FWHM ~ 250nm), we found an object not found in the USNO-B1.0 catalog
within the error circle of the Swift XRT source position (GCN 11136 Goad et al.).
The position coincides with the source C (GCN 11145, Levan et al.) and 
the magnitude is estimated to be I=17.1mag.

Additionally, we obtained a second epoch of observation of GRB 100823A 
starting from 14:59:16 UT on 2010 Aug 24 (approximately 21.5 hours after the burst).
In a single image of a 300sec exposure with a wideband Red filter,
we detected source A (GCN 11138, Levan et al.) with magnitude I=21.3mag
,but we did not detect the source C in this epoch.

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


GRB_name: GRB100807A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11147
SUBJECT: GRB100807A: R band observations
DATE:    10/08/25 15:22:51 GMT
FROM:    Janos Kelemen at Konkoly Obs/Hungary  <kelemen@konkoly.hu>

J. Kelemen on behalf of the GRB OT observing program at the Konkoly Observatory.

On 08 august 2010 21:29:00 UT (130547 s after the burst) we observed the field 
of GRB 100807A detected by Swift (trigger=431128; Grupe et al., GCN 11067) 
with a 60/90 cm  Schmidt telescope located at the Mountain Station of the 
Konkoly Observatory using R filter. The total exposure of the coadded CCD 
images were 1800 s. We examined the position reported Cenko et al., GCN 11073. 
No fading object brighter than 21.6 +/- 0.2 was detected. 

Time      Mag     Error.      Flag.
[s]       [R]    [1-sigma]  
-------------------------------------
130547   21.6      0.2      Upper Limit
-------------------------------------

The above magnitudes have not been corrected for the Galactic extinction. 


GRB_name: GRB100823A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11148
SUBJECT: GRB 100823A:  Swift/UVOT Evidence for Fading Afterglow Emission
DATE:    10/08/26 19:03:19 GMT
FROM:    Margaret Chester at PSU  <chester@astro.psu.edu>

M. M. Chester (PSU), T.S. Koch (PSU), E. A. Hoversten (PSU), and
V. Mangano (INAF-IASFPA) report on behalf of the Swift/UVOT team:

Further examination of Swift/UVOT observations of GRB 100823A show
that a source detected in the white finding chart exposure, initially
thought to correspond to the DSS2 source mentioned in Levan et
al., GCN Circ. 11138, faded in subsequent exposures to an apparently
steady level.  The source was marginally detected in the u finding
chart exposure.  The position of the source in both the finding chart
and later images is consistent with the enhanced XRT position (Goad et
al., GCN Circ. 11136).  We propose this result as further evidence that
Source C in Levan et al., GCN Circ. 11145, and referenced in Suzuki et
al., GCN Circ. 11146, is the afterglow of GRB 100823A.

Magnitudes for the white and u finding charts and white optimally co-
added exposures are given in the following table.  All photometry was
performed using the UVOT photometric system (Poole et al. 2008, MNRAS,
383, 627).  The values quoted 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).

Filter    T_start(s)     T_stop(s)     Exp(s)     Mag    Error     S/N
white_FC     78            227           147      20.7   +/-0.3    2.9
u_FC        290            539           246      20.4   +/-0.4    2.1
white       576          57266          3157      23.4   +/-0.8    2.3
white     61907          63386          1453      22.9   +/-0.7    2.4
white     67668          73670          2674      23.3   +/-0.8    2.1
white     73673          75876          2168      23.0   +/-0.7    2.5

The UVOT position determined from co-adding all of the later images
(after T=56215s) is:

     RA (J2000)  01:22:49.03  =  20.70429 (deg)
    Dec (J2000) +05:50:06.4   =  +5.83511 (deg)

with an estimated uncertainty of 0.9 arcsec (radius, 90% confidence,
statistical + systematic).


GRB_name: GRB100725B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11149
SUBJECT: GRB 100725B: Maidanak optical upper limit
DATE:    10/08/27 14:11:00 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss@gmail.com>

A. Volnova (SAI MSU), A. Pozanenko (IKI), B. Satovski (Astrotel), M.
Ibrahimov (MAO) report on behalf of  larger GRB  follow-up
collaboration:

We observed the field of the Swift GRB 100725B (Baumgartner et al.,
GCN 10983) with AZT-22 telescope of  Maidanak observatory in R-band on
Jul.25 between (UT) 16:36:55 - 17:51:54 under good waether conditions
(seeing 0.7"). We took 9 images with exposure 300 seconds. We do not
detect any sources in enhanced XRT error circle (Goad et al. GCN
10986). The upper limit (3 sigma) of stacked image is based on
SDSS-DR7 is the following:

t-t0,d filter exp.,  uplim
0.24295 R 9x300 22.7


GRB_name: GRB100725B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11150
SUBJECT: GRB 100725B: Mondy optical upper limit
DATE:    10/08/27 14:11:49 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss@gmail.com>

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

We observed the field of the Swift GRB 100725B (Baumgartner et al.,
GCN 10983) with AZT-33IK telescope of Sayan observatory (Mondy) on
Jul.25 between (UT) 16:36 - 20:18 under variable weather conditions
and mean seeing ~2.0". In the stacked image of the best of 36 images
we do not detect any sources in enhanced XRT error circle (Goad et al.
GCN 10986). The upper limit (3 sigma) of the stacked image based on
SDSS-DR7 field stars is the following:

t-t0,d filter exp.,s uplim
0.31128 R 36*90 21.3


GRB_name: GRB100823A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11151
SUBJECT: GRB 100823A: MAXI/GSC detection
DATE:    10/08/27 16:06:32 GMT
FROM:    Motoko Suzuki at RIKEN  <motoko@crab.riken.jp>

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

The Gas Slit Camera (GSC) of MAXI detected a bright X-ray source at the
position consistent with GRB 100823A (Mangano et al, GCN 11135).
Assuming the XRT position (Goad et al., GCN 11136), the transit
of GSC over the source started at 17:25:25 UT on 23 August 2010,
10 seconds before the Swift/BAT trigger time.
A significant (8 sigma in 2-20 keV) rise of the count rate above the background
was observed at 17:25:33, and the burst was detected significantly for 25 seconds.
The peak X-ray flux (4-10 keV) was about 2.5 Crab, which was corrected for the collimator transmission efficiency assuming the source position by Swift XRT.
There are significant time structure within the transit light curve, 
which would be simply triangular for a steady source.
From the preliminary spectral analysis, the time-averaged spectrum 
from T+0 to T+25 sec is best fit by a power-law model with a photon index 
of 2.0 +/- 0.2. The fluence in the 2-20 keV band is 5.1 +0.5 -0.9 x 10^-7 erg/cm2.

The sky image and the transit light curve is shown at the MAXI web site
http://maxi.riken.jp/ in the "News" section.


GRB_name: GRB100823A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11152
SUBJECT: GRB 100823A: optical observations
DATE:    10/08/27 20:23:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), A. Volnova (SAI MSU),  B. Satovski (Astrotel),  M. 
Ibrahimov (MAO) report on behalf of  larger GRB  follow-up collaboration:

We observed the field of the Swift GRB 100823A (Mangano et al. GCN 11135) 
with AZT-22 telescope of Maidanak observatory. Several images in I-filter 
were obtained starting on Aug. 23 (UT) 20:47:02.

We do not detect the object C (Levan et al. GCN 11145;  Suzuki et al. GCN 
11146) up to I=22.2m. We clearly detect both objects A and B (Levan et al. 
GCN  11138). The photometry of stacked image is based on  USNO-B1.0 star 
0958-0013520 located at RA(J2000) = 01:22:45.50, DEC(J2000) = +05:49:03.0 
and used as reference star in GCN 11140 (Guziy et al).

Object,   t-T0,       Filter,   Exposure,    OT,                  Upper 
limit (3 sigma)
              (mid, d)               (s)
A           0.16605   I        19*180        21.06+/-0.09           22.2
B           0.16605   I        19*180        20.60+/-0.06           22.2

The photometry of  the object A is compatible with photometry reported in 
GCN 11146 (Suzuki et al).
Using photometry of the object C starting 5 minutes after burst (Suzuki et 
al. GCN 11146) and upper limit I=22.2m at 0.16605 days one can estimate 
power law decay index alpha > 1.25.

We thank Otabek Burhonov for performing the observations and for his 
support. 


GRB_name: GRB100814A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11153
SUBJECT: GRB 100814A: Maidanak optical observations
DATE:    10/08/27 20:30:05 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova  (SAI MSU), A. Pozanenko (IKI),  O. Vozyakova (SAI MSU), B. 
Satovski (Astrotel),  M. Im (Seoul National Univ), M. Ibrahimov (MAO) report 
on behalf of  larger GRB  follow-up collaboration:

We observed the field of the Swift GRB 100814A (Beardmore et al. GCN  11087) 
with AZT-22 telescope of Maidanak observatory. Several images in R  were 
obtained starting on Aug. 14 (UT) 22:56:44. We clearly the afterglow 
(Schaefer et al. GCN  11086; Beardmore et al. GCN  11087). The photometry of 
stacked image against USNO-B1.0 field stars  is following

 t-T0,       Filter,   Exposure,    OT,       Upper limit (3 sigma)
(mid, d)               (s)
0.81185   R         30*60         18.75+/-0.01          23.4

the photometry error is statistical only. 


GRB_name: GRB100823A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11154
SUBJECT: GRB 100823A: optical upper limit
DATE:    10/08/27 20:45:22 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 100823A (Mangano et al. GCN 11135) 
with AZT-11 telescope of CrAO observatory. Several images in R-filter were 
obtained on Aug. 23 between (UT) 22:05 - 22:53.

In enhanced XRT position (Goad et al. GCN 11136) we do not detect any source 
up to R=20.7. The photometry of stacked image is based on  USNO-B1.0 star 
0958-0013520 located at RA(J2000) = 01:22:45.50, DEC(J2000) = +05:49:03.0 
(assuming R=16.75):

 t-T0,       Filter,   Exposure,    OT,       Upper limit (3 sigma)
(mid, d)               (s)
 0.2111   R         15*180         n/d           20.7


GRB_name: GRB100826A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11155
SUBJECT: GRB100826A: Fermi-LAT Observations
DATE:    10/08/30 20:52:22 GMT
FROM:    Julie McEnery at NASA/GSFC  <julie.e.mcenery@nasa.gov>

Julie McEnery (NASA/GSFC) and Nicola Omodei (Stanford) report
on behalf of the Fermi-LAT collaboration.

The Fermi Large Area Telescope (LAT) detected emission from
GRB 100826A also detected by GBM (trigger 304556304) at
22:58:22.89 on August 26, 2010.

The GBM location was at a very large angle of (~70 degrees) to
the LAT  boresight, and no significant excess is seen using
standard analysis procedures.

Using a non-standard data selection, over 350 counts above
background were detected within a 50 s interval coinciding with
the first GBM broad peak. The LAT light curve has a very similar
structure to this GBM peak, with the maximum count rate occurring
at ~22 s post-trigger. A preliminary study of the instrument
performance  at such a large inclination suggests that these events
are likely to be low energy gamma-rays, with energies less than 200
MeV. This data selection has insufficient spatial resolution to provide
a reliable LAT localization.

Further analysis is ongoing.

The Fermi LAT point of contact for this burst is Julie McEnery
(julie.mcenery@nasa.gov).


GRB_name: GRB100826A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11156
SUBJECT: IPN triangulation of GRB 100826A
DATE:    10/08/30 22:30:23 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley, on behalf of the IPN 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,

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

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

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

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, report:

The long, bright GRB 100826A, observed by the Fermi/LAT and Fermi/GBM at 
22:58:22.89 UT (McEnery & Omodei, GCN 11155), was also detected by 
Konus-Wind, Mars Odyssey (HEND), MESSENGER (GRNS), and Suzaku (WAM).

We have triangulated it to a preliminary 3 sigma error box whose
coordinates are:
-----------------------------------------------
     RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
  279.593 (18h 38m 22s)   -22.128 (-22d 07' 42")
Corners:
  279.356 (18h 37m 25s)   -20.511 (-20d 30' 38")
  279.424 (18h 37m 42s)   -18.324 (-18d 19' 27")
  279.708 (18h 38m 50s)   -25.604 (-25d 36' 13")
  280.041 (18h 40m 10s)   -26.935 (-26d 56' 07") 
-----------------------------------------------

The error box area is ~1.5 sq. deg
This error box may be improved.


GRB_name: GRB100826A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11158
SUBJECT: Konus-Wind observation of GRB 100826A
DATE:    10/08/31 08:45:39 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 100826A (observed by the Fermi/LAT
and Fermi/GBM: McEnery & Omodei, GCN 11155;
localized by IPN: Hurley et.al, GCN 11156)
triggered Konus-Wind at T0=82709.729s UT (22:58:29.729)

The burst light curve shows a complex structure with
a total duration of ~150 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/GRB100826_T82709/

As observed by Konus-Wind the burst
had a fluence of (3.0 +/- 0.25)x10-4 erg/cm2,
and a 256-ms peak flux, measured from T0+17.664s,
of (1.9 +/- 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+130.560 s) is best fit
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.31 (-0.05, +0.06),
the high energy photon index beta = -2.1 (-0.2, +0.1),
the peak energy Ep = 606(-109, +134)keV (chi2 = 85.2/87 dof).

The spectrum at the maximum count rate
(measured from T0+14.336 to T0+18.432 s) is best fit
in the 20 keV - 10 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.84 (-0.11, +0.13),
the high energy photon index beta = -2.00 (-0.15, +0.10),
the peak energy Ep = 536(-97, +134)keV (chi2 = 82.5/79 dof).

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


GRB_name: GRB100901A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11159
SUBJECT: GRB 100901A: Swift detection of a burst with an optical afterglow
DATE:    10/09/01 14:00:55 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

S. Immler (CRESST/GSFC/UMD), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
S. Campana (INAF-OAB), V. D'Elia (ASDC), P. A. Evans (U Leicester),
J. M. Gelbord (PSU), O. Godet (U Leicester), C. Gronwall (PSU),
C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),
E. A. Hoversten (PSU), O. M. Littlejohns (U Leicester),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), C. Pagani (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL), T. A. Pritchard (PSU),
A. Rowlinson (U Leicester), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC) and
R. L. C. Starling (U Leicester) report on behalf of the Swift Team:

At 13:34:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100901A (trigger=433065).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 27.245, +22.744, which is 
   RA(J2000)  =  01h 48m 59s
   Dec(J2000) = +22d 44' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single symmetric
peak structure with a duration of about 10 sec.  The peak count rate
was ~800 counts/sec (15-350 keV), at ~1 sec after T_zero. 

The XRT began observing the field at 13:36:51.0 UT, 160.6 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 27.2642, 22.7584 which
is equivalent to:
   RA(J2000)  = 01h 49m 3.41s
   Dec(J2000) = +22d 45' 30.1"
with an uncertainty of 3.0 arcseconds (radius, 90% containment). This
location is 82 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
7.08e+20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 147 seconds after the BAT trigger. There is a
candidate afterglow in  the rapidly available 2.7'x2.7' sub-image at 
  RA(J2000)  = 01:49:03.42 =  27.26424 
  DEC(J2000) = +22:45:30.8  =  22.75856  with a 90%-confidence error
radius of about 0.81 arc sec. This position is 0.6  arc sec. from the
center of the XRT-Enhanced error circle. The estimated magnitude is
19.67 with a 1-sigma error of about  0.18. No correction has been made
for the expected extinction corresponding to E(B-V) of 0.10. 

Burst Advocate for this burst is S. Immler (immler 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: GRB100901A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11160
SUBJECT: GRB 100901A: Faulkes Telescope North afterglow candidate
DATE:    10/09/01 14:04:33 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), Z. Cano, A. Melandri (LJMU),
D. Kopac (U. Ljubljana) report on behalf of a large collaboration:

The Faulkes Telescope North automatically began observing Swift
GRB 100901A (Immler et al. GCN Circ. 11159) on September 01,
13:36:29 UT, 2.32 minutes from the GRB trigger time.
We clearly identify an uncatalogued object at the following position:

RA(J2000):  01:49:03.41
Dec(J2000): +22:45:30.8

This is consistent with the UVOT candidate (GCN 11159).
Observations are going on.


GRB_name: GRB100901A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11161
SUBJECT: GRB 100901A: MASTER Optical Early Limits
DATE:    10/09/01 14:55:56 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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


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

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


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


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



Two MASTER   robotic telescopes (MASTER-Net: http://observ.pereplet.ru)
located  near Baykal Lake (Tunka)  and Blagoveschensk was pointed to the
Swift GRB 100901A (Immler et al., GCN Circ 11159) 47  sec  after Notice 
time  (103 s after trigger time) and 45 s after Notice time (101s after trigger 
time).

  We have a number polarization, unfiltered and R images  with exposition 
20, 30, 40, 60... s.  but near horizont.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd? Filter
--------------------------------------------------------------------------
13:35:51       13:35:51     20       16.1       101.0          N    Unfiltr
13:35:51       13:37:32     80       16.6       101.0          Y    Unfiltr
13:35:53       13:36:13     20       16.5       103.0          N    Polariz
13:35:53       13:38:02     90       17.4       103.0          Y    Polariz


The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100901A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11162
SUBJECT: GRB 100901A: confirmation of the afterglow
DATE:    10/09/01 14:58:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the  Swift GRB 100901A (Immler  et al., GCN 11159)   with 
AZT-33IK telescope of Sayan observatory (Mondy) starting Sep. 01 (UT)
13:44:30.  We confirm the afterglow candidate  (Immler  et al., GCN 11159; 
Guidorzi et al., GCN 11160) at the following preliminary position
(J2000) RA=01 49 03.29 Dec +22 45 30.0. We clearly detect the afterglow in 
single images of 60 s exposure obtained in R-filter.

Observations are continuing.


GRB_name: GRB100901A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11163
SUBJECT: GRB 100901A: MASTER: the OT brightenning 
DATE:    10/09/01 15:41:39 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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


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

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


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


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


We clearly see (MASTER-Net: http://observ.pereplet.ru)
located  near Baykal Lake (Tunka)  and Blagoveschensk) brightenning  OT at 
the  Swift position (Immler et al., GCN Circ 11159).
R mag = 17 (38 min after GRB time)

The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11164
SUBJECT: GRB 100901A: Gemini-N Redshift
DATE:    10/09/01 17:02:09 GMT
FROM:    Ryan Chornock at Harvard  <rchornock@cfa.harvard.edu>

R. Chornock, E. Berger (Harvard), D. Fox (Penn State), A. J. Levan (U. Warwick),
N. R. Tanvir, and K. Wiersema (U. Leicester) report on behalf of a larger
collaboration:

We obtained spectroscopy of the optical afterglow (Immler et al., GCN 11159;
Guidorzi et al., GCN 11160; Ivanov et al., GCN 11161; Klunko et al., GCN 11162)
of GRB 100901A (Immler et al., GCN 11159) using GMOS on the Gemini-North 8-m
telescope starting on 2010 September 1.61 UT.  A set of four 400s observations
were obtained covering the wavelength range 3825-6675 Angstroms.  Numerous
absorption lines are present.  The highest redshift system is at z=1.408, with
many absorptions from Fe II, Al II, and Si II.  The presence of several Fe II*
absorptions establishes this as the redshift of the host galaxy of GRB 100901A.
 Two intervening systems at z=1.315 and 1.318 also have absorptions from Mg II
and Fe II.

We thank A. Stephens and the Gemini staff for their help in obtaining these
observations.


GRB_name: GRB100901A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11165
SUBJECT: GRB 100901A: MASTER power low decay
DATE:    10/09/01 17:46:51 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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


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

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


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

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


We clearly see (MASTER-Net: http://observ.pereplet.ru, Tunka) 
OT after 386 s (T-T_trigger) at the 
Swift position (Immler et al., GCN Circ 11159) and strongly brighter than 
UVOT estimation (Immler et al., GCN Circ 11159).
After this time we see power low decay F ~ t_(-alpha), with alpha ~ 
0.5+-0.2.

This is preliminary result.  Observations are continued at Tunka, Ural 
and Kislovodsk in different filters.

The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11166
SUBJECT: GRB 100901A: optical observation at Mt.Terskol
DATE:    10/09/01 18:50:15 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We started observation of the Swift GRB 100901A (Immler  et al., GCN 11159) 
with the Z-600 telescope of Mt.Terskol observatory in R-filter  on   Sep.01 
(UT) 17:50. In a combined image we clearly detect  the afterglow (Immler et 
al., GCN 11159; Guidorzi et al., GCN 11160; Ivanov et al., GCN 11161; Klunko 
et al., GCN 11162).

Preliminary photometry is based on the reference star USNO-B1.0 
#1127-0027231 RA(J2000) = 01 49 06.78 Dec(J2000) = +22 47 03.3 assuming 
R=15.37:

T0+     Filter, Exposure, OT
(d)                 (s)

0.1821 R     5x60          17.28 +/-0.03

The finding chart can be found at
http://grb.rssi.ru/GRB100901A/GRB100901A_R_100901_Terskol.jpg 


GRB_name: GRB100901A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11167
SUBJECT: GRB 100901A: Enhanced Swift-XRT position
DATE:    10/09/01 21:59:30 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 52 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 100901A, 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 = 27.26485, +22.75850 which is equivalent
to:

RA (J2000): 01h 49m 3.56s
Dec (J2000): +22d 45' 30.6"

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: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11168
SUBJECT: GRB 100901A: optical observation at Mt.Terskol
DATE:    10/09/01 23:22:35 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We are continuing observations of the Swift GRB 100901A (Immler  et al., GCN 
11159) with the Z-600 telescope of Mt.Terskol observatory in R-filter 
(Andreev  et al., GCN 11166). In a combined image at mid time Sep. 01 (UT) 
20:09 we still detect  bright afterglow (Immler et al., GCN 11159; Guidorzi 
et al., GCN 11160; Ivanov et al., GCN 11161; Klunko et al., GCN 11162).

Preliminary photometry is based on the reference star USNO-B1.0 
#1127-0027231 RA(J2000) = 01 49 06.78 Dec(J2000) = +22 47 03.3 assuming 
R=15.37:

T0+     Filter, Exposure, OT
(d)                 (s)

0.2742 R     5x60          17.05 +/-0.02


GRB_name: GRB100901A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11169
SUBJECT: GRB 100901A: Swift-BAT refined analysis
DATE:    10/09/02 01:02:07 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
S. Immler (CRESST/GSFC/UMD), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+663 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100901A (trigger #433065)
(Immler, et al., GCN Circ. 11159).  The BAT ground-calculated position is
RA, Dec = 27.252, 22.751 deg, which is 
   RA(J2000)  =  01h 49m 00.5s 
   Dec(J2000) = +22d 45' 02.9" 
with an uncertainty of 3.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 40%.
 
The mask-weighted light curve shows two main peaks.  The first starts at
~T-5 sec, peaks at ~T+5 sec, and ends at ~T+10 sec.  The second starts
at ~T+300 sec, peaks at ~T+390, and ends at ~T+490 sec.  We note that the
burst location went out of the BAT FoV at T+650 sec during a slew
due to an observing constraint.  T90 (15-350 keV) is 439 +- 33 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-2.4 to T+471.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.52 +- 0.21.  The fluence in the 15-150 keV band is 2.1 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-1.81 sec in the 15-150 keV band
is 0.8 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/433065/BA/


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11170
SUBJECT: GRB 100901A - NOT optical observation
DATE:    10/09/02 03:09:25 GMT
FROM:    Annalisa De Cia at U of Reykjavik,Science Inst.  <annalisa@raunvis.hi.is>

A. De Cia, P.M. Vreeswijk and P. Jakobsson (University of
Iceland) report:

We observed the field of GRB 100901A (Immler et al., GCN 11159)
with the NOT equipped with ALFOSC in good weather conditions.
Observations were carried out in the R filter for 15 minutes,
with mean time 12.13 hours after the GRB trigger.

We measure R=17.3 for the afterglow, not corrected for Galactic
extinction, calibrated against the USNO-B1.0 1127-0027231
reference star (R=15.37) used by Andreev et al., GCN 11166 and
GCN 11168.

 time after trigger       exposure (s)         R mag

     12.13 hours            3 x 300             17.3

We acknowledge the careful assistence of the NOT staff, in
particular Tapio Pursimo.


GRB_name: GRB100901A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11171
SUBJECT: GRB 100901A: Swift-XRT Team refined analysis
DATE:    10/09/02 06:00:48 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) and S. Immler (CRESST/GSFC/UMD) report on behalf 
of the Swift-XRT team:

We have analysed 13 ks of XRT data for GRB 100901A (Immler et al., GCN 
Circ. 11159), from 128 s to 33.2 ks after the BAT trigger. The data 
comprise 448 s in Windowed Timing (WT) mode (the first 9 s were taken 
while Swift was slewing) with the remainder in Photon Counting (PC) mode. 
The enhanced XRT position for this burst was given by Osborne et al. (GCN. 
Circ 11167).

The first snapshot (data collected until ~620 s after the trigger) 
consists of a number of superimposed flares, with the main peak around 410 
s; this peak was also seen in the BAT data (Sakamoto et al., GCN Circ. 
11169). The light curve then shows a decaying trend with alpha = 0.74 +/- 
0.12, until around 12 ks, after which there is a small rebrightening, to a 
plateau level of around 0.3 count s^-1.

A spectrum formed from the WT mode data can be fitted with an absorbed 
power-law with a photon spectral index of 1.68 (+/-0.04). The best-fitting 
absorption column is 3.6 (+0.7, -0.6) x 10^21 cm^-2, at a redshift of 
1.408 (Chornock et al., GCN Circ 11164), in addition to the Galactic value 
of 7.1 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a 
photon index of 2.19 (+/-0.07) and a best-fitting absorption column of 3.9 
(+/-0.9) x 10^21 cm^-2 (in addition to the Galactic vale). The counts to 
observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this 
spectrum is 3.5 x 10^-11 (5.1 x 10^-11) erg cm^-2 count^-1.

Because of the rebrightening/plateau shape of the light curve at this time, we 
cannot sensibly predict the count rate at 24 hours.

The results of the XRT-team automatic analysis are available at 
http://www.swift.ac.uk/xrt_products/00433065.

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


GRB_name: GRB100901A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11172
SUBJECT: GRB100901A: MITSuME  Okayama Optical Observation
DATE:    10/09/02 06:13:46 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 100901A (Immler et al., GCN 11159)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2010-09-1 13:36:08 UT (~2.0 min after
the burst).  We detected the previously reported afterglow
(Immler et al., GCN 11159; Guidorzi et al., GCN 11160;
Klunko et al., GCN 11162; Ivanov et al., GCN 11165;
Andreev et al., GCN 11166, GCN 11168; De Cia et al., GCN 11170)
in all the three bands. Our results show that the brightness of
the afterglow began to increase at ~0.14 days after the burst.


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'  g'_err   Rc  Rc_err   Ic  Ic_err
----------------------------------------------------------------------
0.01195    13:51:23  1560.0      18.6  0.5    17.4  0.1    16.8  0.2
0.03343    14:22:18  1560.0      18.1  0.1    17.9  0.1    17.4  0.1
0.05475    14:53:00  1560.0      18.7  0.1    18.5  0.1    17.6  0.1
0.07594    15:23:32  1440.0      18.7  0.1    18.4  0.1    18.0  0.2
0.09685    15:53:38  1500.0      18.9  0.1    18.5  0.1    18.0  0.2
0.11790    16:23:57  1560.0      19.1  0.2    18.7  0.2    17.9  0.2
0.13912    16:54:30  1560.0      18.8  0.1    18.4  0.1    17.8  0.1
0.16013    17:24:46  1500.0      18.7  0.1    18.0  0.1    17.2  0.1
0.18107    17:54:55  1560.0      18.2  0.1    17.6  0.1    17.1  0.1
0.20223    18:25:23  1500.0      18.0  0.1    17.7  0.1    17.0  0.1
0.22363    18:56:12  1500.0      18.2  0.1    17.6  0.1    17.0  0.1
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11173
SUBJECT: GRB 100901A: THO optical observations
DATE:    10/09/02 08:55:23 GMT
FROM:    Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen@kassiopeia.net>

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

Taurus Hill Observatory (A95, Varkaus, Finland) C-14 telescope and SBIG
ST-8XME CCD camera were used to detect GRB 100901A optical afterglow.
The observations were started at 2010-09-01 21:08:30 (UT) and stopped at
2010-09-02 01:11:13 (UT). A number of unfiltered and BVR observations with
varying exposure times were made. The afterglow was detected at following
position RA 1 49 03.45 and DEC +22 45 30.5 consistent those given by Immler
s. et al. (GCN 11159) and Guidorzi C. et al. (GCN 11160) to within positional 
errors. 

The following magnitudes were obtained from the observations using USNO-B1.0
1127-0027231 (R = 15.37 and B = 16.38)) as the comparison:

+T0 (hour)     Filter         Exp (sec)     Mag     Mag err     Limit
7.606             unfiltered       2x120     17.1           0.1         18.4
7.678             unfiltered       2x120     17.2           0.2         18.5
10.607           unfiltered       3x300     17.3           0.1         19.6
11.141           Rc                3x300     17.4            0.1         20.0
11.228            B                 3x300     18.1            0.2         19.1
   

A jpg color image of the 4x300sec observations is available at the
following URL:

http://cutenews.kassiopeia.net/data/upimages/GRB100901A_LRGB_web_nuoli.jpg


GRB_name: GRB100901A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11174
SUBJECT: GRB 100901A: SARA-N observations
DATE:    10/09/02 12:28:03 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike@clemson.edu>

Adria C. Updike, Dieter H. Hartmann (Clemson University) and William Keel,
Erin Darnell (U Alabama) report:

We observed the field of GRB 100901A (Immler et al., GCN 11159) with the
0.9m SARA-North telescope located at KPNO beginning 18 hours and 45
minutes after the trigger under good conditions.  In 240s exposures, we
clearly detect the afterglow in all images.

Filter    Mag     Mag error    UT Start
---------------------------------------
B         18.7    0.1          08:20
V         18.2    0.1          08:24
R         18.0    0.1          08:28
I         17.9    0.1          08:32

Magnitudes are reported relative to the USNO B1.0 and NOMAD catalogs field
stars. Observations in all bands continued for 4 hours.  Further
observations are planned.


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11175
SUBJECT: GRB 100901A : HCT optical observations
DATE:    10/09/02 13:34:34 GMT
FROM:    D.K. Sahu at Indian Inst of Astrophysics,Bangalore  <dks@iiap.res.in>

D.K. Sahu, B.C. Bhatt, Sonam Arora and Pepsi Anto (IIA, Bangalore) report.

Optical afterglow of GRB 100901A (Immler et al. GCN 11159)
was obsrved   with the 2m. Himalayan Chandra Telescope of the
Indian Astronomical Observatory, Hanle, India. A series of
exposures were taken in Bessell V, R and I  bands, between
17:35 UT and 22:15 UT on 01/09/2010. The optical afterglow was
detected in all our frames. The preliminary R and I magnitudes
of the optical afterglow calibrated using  USNO B1.0 1127-0027231
reference star (R=15.37, I=15.13) is as under:
Mid UT      Exposure     Filter      Mag
17:42       300sec        R        17.34 +/- 0.05
19:44       300sec        R        17.03 +/- 0.05
22:05       300sec        R        17.08 +/- 0.04
17:51       300sec        I        17.05 +/- 0.05
19:51       300sec        I        16.76 +/- 0.04

This message may be cited.


GRB_name: GRB100901A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11176
SUBJECT: Swift/UVOT Observations of GRB100901A
DATE:    10/09/02 13:40:17 GMT
FROM:    Tyler Pritchard at PSU  <tapritchard@astro.psu.edu>

T. A. Pritchard (PSU) and Immler (CRESST/GSFC/UMD)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 100901A
147 s after the BAT trigger (Immler et al., GCN Circ. 11159).
We detect an object not present in the DSS in all filters within 0.1
arcsec of the Enhanced Swift-XRT position (Osborne et al., GCN Circ. 11169)

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)        147           297           147     19.55  0.19
u (FC)            305           555           246     17.52  0.10
white             585           605           20      18.58  0.32
white             4849          5051          198     18.66  0.07
b                 561           581           19      17.85  0.30
b                 4644          4844          197     18.69  0.11
u                 305           555           246     17.52  0.10
u                 4439          4639          197     18.08  0.10
v                 129           139           10 >17.21
v                 3824          4024          197     18.50  0.21
w1                4234          4434          197     18.53  0.16
m2                4029          4229          197     19.22  0.32
w2                611           626           15 >17.6
w2                5055          5255          197 >20.04
w2                9620          10520         885     20.73  0.32


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


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11177
SUBJECT: GRB 100901A: Vega telescope optical afterglow observation
DATE:    10/09/02 14:40:47 GMT
FROM:    Drejc Kopac at Math Phys U,Slovenia  <drejc.kopac@fmf.uni-lj.si>

D. Kopac, B. Dintinjana and A. Gomboc (U. Ljubljana) report:

We observed the field of GRB 100901A (Immler et al., GCN 11159) with the
0.7m Vega telescope located in Ljubljana, starting at 20:31:31 UT on 2010
September 01, approx. 7 hours after the trigger. We took 10 images in R
band with exposure time 180s and we clearly detect the optical afterglow
(Guidorzi et al., GCN 11160). Our preliminary photometry yields

Mid time from    Filter   Magnitude
trigger (days)
-------------------------------------
0.302            R        17.2 +- 0.1
-------------------------------------

Magnitude is calibrated against the USNO-B1.0 1127-0027192 reference star
(R2=17.58) and is not corrected for Galactic extinction.


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11178
SUBJECT: GRB 100901A: MASTER optical flare at 420s discovery
DATE:    10/09/02 18:20:57 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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


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

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


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

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


We  (MASTER-Net: http://observ.pereplet.ru, Tunka, Ivanov et al., 
GCN Circ 11161) clearly detected optical flare   (maxmag~17.0,unfiltered) at 426+-40 s   after 
trigger time (Immler et al., GCN Circ 11159)  synchronously  with 
Xray flare  (Page et al.,  GCN Circ 11171).

We have ~ 11 hours Unfiltered, R,I, Polarization continuously 
observations on same telescope systems. The redaction is continued.

The first 10 000 s relative optical flux light curve  is 
available at http://observ.pereplet.ru/images/GRB100901A/opt_flux_lc.png


The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11179
SUBJECT: GRB 100901A: ROTSE-III Detection
DATE:    10/09/02 19:20:08 GMT
FROM:    Shashi Bhushan Pandey at ROTSE  <shaship@umich.edu>

S. B. Pandey and W. Zheng (U Mich), report on behalf of the ROTSE
collaboration:

Due to bad weather conditions, the ROTSE-3a telescope at Siding Springs
Observatory, Australia did not respond to GRB 100901A (Swift trigger
433065, 
Immler S. et al., GCN 11159). Automated re-pointing of ROTSE-3c at the
H.E.S.S. site at Mt. Gamsberg, Namibia and ROTSE-3b at the McDonald
Observatory, Texas observed the optical afterglow starting ~ 8.6 to 22.0
hours after the burst. 
The optical afterglow was detected in all the stacked frames. The optical 
afterglow candidate appears to decay with a power-law index of ~1.2 at
later epochs. Further imaging is ongoing.


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11180
SUBJECT: GRB 100901A: 1.5m OSN BVRI-band observations.
DATE:    10/09/02 19:34:45 GMT
FROM:    Juan Carlos Tello at IAA-CSIC  <jtello@iaa.es>

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

"We have taken several series of BVRI-band images of the  Swift GRB 100901A
(Immler et  al. GCNC  11159) optical afterglow  (Guidorzi et  al. GCNC
11160) with the  1.5m  telescope at  Observatorio  de Sierra  Nevada, Spain.
  The  afterglow is  well  detected  in  the four  bands,  with preliminary
 average magnitudes (calibrated against  USNO  B1.0  and GSC  3.2 stars) of
 B~18.0 (Sep  2.021 UT), V~17.4  (Sep 2.035 UT),  R~17.3 (Sep 2.003 UT) and
I~17.3 (Sep 2.049 UT)."


GRB_name: GRB100902A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11181
SUBJECT: GRB 100902A: Swift detection of a burst
DATE:    10/09/02 19:51:36 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

T. Sakamoto (NASA/UMBC), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
W.B Landsman (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL),
A. Rowlinson (U Leicester), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC),
R. L. C. Starling (U Leicester) and M. C. Stroh (PSU) report on behalf
of the Swift Team:

At 19:31:54 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100902A (trigger=433160).  BAT slewed to the location
after a brief delay due to observing constraints. 
The BAT on-board calculated location is 
RA, Dec 48.646, +30.973 which is 
   RA(J2000) = 03h 14m 35s
   Dec(J2000) = +30d 58' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a small spike 
around the trigger time.  There are brighter spikes around T+150 sec 
and T+200 sec with a duration of 50 sec.  The peak count rate
was ~1200 counts/sec (15-350 keV), at ~210 sec after the trigger. 

The XRT began observing the field at 19:37:10.1 UT, 316.2 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
48.6294, 30.9791 which is equivalent to:
   RA(J2000)  = 03h 14m 31.05s
   Dec(J2000) = +30d 58' 44.8"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 56 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.13e+21
cm^-2, Kalberla et al. 2005), with an excess column of 4.1
(+2.41/-2.03) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 0.1 s image was 2.20e-07 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of nominal 150 seconds with the
White filter  starting 325 seconds after the BAT trigger. No credible
afterglow candidate has  been found in the initial data products. Data
from the 2.7'x2.7' sub-image are  not available at this time. The
8'x8' region for the list of sources  generated on-board covers 100%
of the XRT error circle. The list of  sources is typically complete to
about 18 mag. No correction  has been made for the expected extinction
corresponding to E(B-V) of 0.31. 

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: GRB100902A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11182
SUBJECT: GRB 100902A: MASTER Optical Early Limit
DATE:    10/09/02 20:22:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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


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


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


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



MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located at Ural (Kourovka)  was pointed to the
Swift GRB 100902A (Sakamoto et al., GCN Circ 11181) 27  sec  after 
Notice time (104 s after trigger time) in two polarizations.

Thre is no optical transient at XRT position (Sakamoto et al., GCN Circ 
1118) brighter 17 mag (exposition 20 s).

The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100902A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11183
SUBJECT: GRB 100902A: Faulkes Telescope South observations
DATE:    10/09/02 20:28:11 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), A. Melandri (INAF-OAB),
N. Tanvir (U. Leicester) on behalf of a large collaboration report:

The 2-m Faulkes Telescope South automatically began observing
GRB 100902A (Sakamoto et al. GCN Circ. 11181) on September 02,
19:34:38 UT, 164 seconds from the GRB trigger time and during
the major gamma-ray spikes (GCN 11181).
Within the XRT error circle we do not find any source
down to the following limiting magnitudes:

Mid time from      Exposure    Filter   Limiting Magnitude
trigger (s)           (s)
------------------------------------------------------------
169                   10          R > 15.6
203                 3x10          R > 16.0
------------------------------------------------------------

Calibration is against some nearby USNOB-1 stars.
The relatively poor limits are due to the vicinity to the Moon.


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11184
SUBJECT: GRB 100901A: ISON-NM optical observations
DATE:    10/09/02 20:41:25 GMT
FROM:    Leonid Elenin at ISON  <l.elenin@gmail.com>

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

We observed the field of the Swift GRB 100901A (Immler et al. GCN Circ.
11159)
with 0.45-m telescope of ISON-NM observatory on Sep. 02 (UT) 09:55:53 -
10:22:06.

The afterglow (Immler et al., GCN 11159; Guidorzi et al., GCN 11160; Ivanov
et al., GCN 11161;
Klunko et al., GCN 11162)  is well detected. For the preliminary photometry
of unfiltered image
we used USNO-B1.01127-0027229 field stars, assuming R=16.16:

T-T0      filter   exposure   mag.  mag. error
--------------------------------------------------------------

0.8561    W      20x60     17.82    +/- 0.03

--------------------------------------------------------------


GRB_name: GRB100902A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11185
SUBJECT: GRB 100902A: MASTER Prompt Optical Observations
DATE:    10/09/02 21:02:48 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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

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


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


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



MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located at Ural (Kourovka)  was pointed to the
Swift GRB 100902A (Sakamoto et al., GCN Circ 11181) 27  sec  after Notice time 
(104 s after trigger time) in two polarizations.

Thre is no optical transient at XRT position (Sakamoto et al., GCN Circ 1118) 
with next limits:

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd? Filter
--------------------------------------------------------------------------
19:33:38       19:33:58     20        17.0      104.0          N  Polariz
19:34:12       19:34:42     30        17.3      132.0          N  Polariz
19:34:57       19:35:57     40        17.3      177.0          N  Polariz
19:35:51       19:36:41     50        17.4      231.0          N  Polariz
19:33:38       19:36:41    140        18.0      104.0          Y  Polariz
--------------------------------------------------------------------------

The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100901A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11187
SUBJECT: GRB 100901A: TLS Observations: Break?
DATE:    10/09/03 01:34:04 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann, S. Klose, U. Laux, and B. Stecklum (TLS Tautenburg) report:

We observed the afterglow of the double-peaked Swift GRB 100901A (Immler
et al., GCN 11159) with the TLS 1.34m Schmidt telescope through several
holes in the persistent cloud cover. Otherwise, conditions were excellent.
We clearly detect the afterglow in all single 300 sec frames at high
signal-to-noise (statistical error 0.03 - 0.04 mag). In comparison to five
USNOB1.0 (R2 magnitude) stars, we find:

time  Rc dRc
1.382892 18.93 0.13
1.386920 19.00 0.15
1.422927 19.04 0.13
1.426955 19.13 0.14

We compile all available GCN data (Klunko et al., GCN 11162; Gorbovsky et
al., GCN 11163; Andreev et al., GCN 11166; Andreev et al., GCN 11168; De
Cia et al., GCN 11170; Kuroda et al., GCN 11172; Hentunen et al., GCN
11173; Updike et al., GCN 11174; Sahu et al., GCN 11175; Pritchard &
Immler, GCN 11176; Kopac et al., GCN 11177; Ivanov et al., GCN 11178;
Snchez-Ramrez et al., GCN 11180; Elenin et al., GCN 11184) and can make
the following statements on the light curve evolution of this
extraordinary burst:

The light curve shows three peaks. The first is the prompt flare reported
by Ivanov et al., GCN 11178 (it should also be seen strongly in the UVOT u
band event mode finding chart). The second peak is at ~ 0.026 days,
reported by Gorbovsky et al., GCN 11163. Then another rebrightening sets
in (Kuroda et al., GCN 11172), which peaks at about 0.35 days (e.g.,Sahu
et al., GCN 11175, also seen strongly in the X-rays, Page & Immler, GCN
11171) . The afterglow begins to decay after that, and we find that the
decay seems to have become steeper between the latest reported data
(Updike et al., GCN 11174; Elenin et al., GCN 11184) and our detections at
~1.4 days. This may possibly be a jet break. Note that the R1 magnitudes
are systematically ~ 0.2 mag brighter and thus the significance of the
break is reduced if this calibration is used instead.

Observationally, the late rebrightening makes this one of the brightest
afterglows ever detected beyond 0.35 days, on par with that of GRB 060729
and several others.

Comparing the extraordinary light curve evolution with our afterglow data
base (Kann et al. 2010, ApJ, 720, 1513), we find that the evolution is
remarkably similar to that of two other afterglows, namely GRB 060906
(Cenko et al. 2009, ApJ, 693, 1484) and GRB 970508 (e.g., Garcia et al.
1998, ApJ, 500, L105). In the extinction-corrected z = 1 system (we assume
beta = 0.6, A_V = 0.1 - typical values - for GRB 100901A, and use z =
1.408, Chornock et al., GCN 11164), we find that the large-amplitude
optical flares of these three afterglows can be brought to a reasonable
match if we shift the GRB 060906 light curve by (Delta t = x 4.8; Delta
mag = +0.4) (it is faster and brighter) and that of GRB 970508 by (Delta
t = / 8.2; Delta mag = - 3.7) (it is slower and fainter). In log-log
space, all three rebrightenings look remarkably similar. GRB 100901A and
GRB 060906 match strongly except that the rebrightening of GRB 060906 has
a lower total amplitude - the pre- and post-rebrightening decay slopes are
strongly similar. For GRB 970508, the optical flare evolves faster, also,
the pre-flare evolution is a flat plateau. The post-flare decay is again
very similar. Pandey & Zheng (GCN 11179) report a post-flare decay of
alpha ~ 1.2 for GRB 100901A, and Zeh et al. 2006, ApJ, 637, 889 indeed
find alpha = 1.24 +/- 0.01 for GRB 970508!

Finally, we point out that the strong, late optical flare may be an energy
injection, and the shells which have produced this refreshed shock may be
the same ones that created the second BAT flare at 390 seconds (Sakamoto
et al., GCN 11169) which also was seen in the optical (Gorbovsky et al.,
GCN 11163). Such reverberation effects have been discussed by Vestrand et
al. 2006, Nature, 442, 172 (GRB 050820A) as well as Guidorzi et al. 2007,
A&A, 474, 793 (GRB 070311).

Further optical and especially NIR follow-up is strongly encouraged.
Monitoring in Tautenburg will continue in the next days if weather
permits.

This message may be cited.


GRB_name: GRB100902A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11188
SUBJECT: GRB 100902A: Enhanced Swift-XRT position
DATE:    10/09/03 01:53:07 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 4941 s of XRT Photon Counting mode data and 6 UVOT
images for GRB 100902A, 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 = 48.62930, +30.97904 which is equivalent
to:

RA (J2000): 03h 14m 31.03s
Dec (J2000): +30d 58' 44.5"

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

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

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


GRB_name: GRB100901A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11189
SUBJECT: GRB100901A: MITSuME  Okayama Optical Observation at 1 day after the burst
DATE:    10/09/03 05:48:08 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 100901A (Immler et al., GCN 11159)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2010-09-2 16:51:50 UT (~1.14 day after
the burst).  We detected the previously reported afterglow
(Immler et al., GCN 11159; Guidorzi et al., GCN 11160; Klunko et al.,
GCN 11162; Ivanov et al., GCN 11165; Andreev et al., GCN 11166,
GCN 11168; De Cia et al., GCN 11170; Kuroda et al., GCN 11172) in
all the three bands.

Photometric results of the OT are listed below.
The magnitudes are obtained from the sum of exposures. No significant
variation was detected during these exposures, though the S/N was not
so good. We used SDSS catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'  g'_err   Rc  Rc_err   Ic  Ic_err
----------------------------------------------------------------------
1.17902    17:51:57  6060.0      19.4  0.1    19.0  0.1    18.5  0.1
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11190
SUBJECT: GRB 100901A: Kanata Telescope observation of the optical afterglow
DATE:    10/09/03 06:03:58 GMT
FROM:    Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida@oao.nao.ac.jp>

M. Yoshida, M. Sasada, T. Komatsu and K. S. Kawabata (HASC, Hiroshima
University)

We performed R band imaging observation of the optical afterglow of
GRB 100901A (Immler et al., GCN 11159) with the 1.5m Kanata telescope
of Hiroshima University.

The observation was made from 2010-09-02 15:07:24 UT (~1.06 day after
the burst) to 15:50:33 UT.  The previously reported afterglow (e.g
Immler et al. GCN 11159; Kuroda et al. GCN 11172; or Kann et al.
GCN 11187) was clearly detected. The afterglow showed a marginal
increasing trend in brightness within this observation.

Photometric results of the afterglow are listed below. We used USNO-
B1.0 1127-0027231 (R = 15.37) for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]     Rc    err
-----------------------------------------------
1.070266   15:15:21   900.0       18.62   0.10
1.081620   15:31:42   900.0       18.60   0.07
1.096759   15:53:30   900.0       18.54   0.04
-----------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11191
SUBJECT: GRB 100901A: optical observation at Mt.Terskol
DATE:    10/09/03 06:56:22 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We are continuing observations of the Swift GRB 100901A (Immler  et al., GCN 
11159) with the Z-600 telescope of Mt.Terskol observatory in R-filter 
(Andreev  et al., GCN 11166). In a combined image at mid time Sep. 03 (UT) 
00:36 we detect  afterglow (Immler et al., GCN 11159; Guidorzi et al., GCN 
11160; Ivanov et al., GCN 11161; Klunko et al., GCN 11162).

In comparison with our previous photometry (Andreev  et al., GCNs 11166, 
11168) below we used several  reference stars of SDSS DR7 and Lupton 
transformation ugriz -> BVRI:

T0+     Filter, Exposure,  OT
(d)                 (s)

1.4599 R     10x120        19.22 +/- 0.05

The photometry above is consistent with steady decay based on early 
photometry (Kann et al, GRB 11187). We note however the systematic faintness 
of about ~0.25m in SDSS DR7 in comparison with USNO-B1.0 R2 which can 
explain possible contradiction of MITSUME observation calibrated against 
SDSS (Kuroda et al, GCN  11189) and photometry reported in Yoshida et al 
(GCN 11190). Detailed calibration of the field stars is necessary.


GRB_name: GRB100902A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11192
SUBJECT: GRB 100902A: optical observation at Mt.Terskol
DATE:    10/09/03 11:20:36 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed  the field of the Swift GRB 100902A (Sakamoto  et al, GCN 11181) 
with the Z-600 telescope of Mt.Terskol observatory in R-filter between (UT) 
00:52:20 - 01:26:40. In enhanced XRT error circle (Beardmore et al, GCN 
11188) we do not detect  any object. The object at distance of 4" from the 
center of the enhanced  XRT error circle (Beardmore et al, GCN 11188) in 
coordinates (J2000) RA =03 14 31.35 Dec= +30 58 44.8 with uncertainty of 1" 
is detected at magnitude R ~ 20 and upper limit of stacked image of R=21 (3 
sigma). At present time we cannot confirm variability of the object.

The finding chart can be found at
http://grb.rssi.ru/GRB100902A/GRB100902A_R_Z600.jpg


GRB_name: GRB100902A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11193
SUBJECT: GRB 100902A: Swift/UVOT Upper Limits
DATE:    10/09/03 11:58:54 GMT
FROM:    Wayne Landsman at GSFC/SSAI  <wayne.b.landsman@nasa.gov>

W. Landsman (GSFC/Adnet) and T. Sakamoto (NASA/UMBC) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 100902A 326 s after the BAT trigger (Sakamoto et al., GCN Circ. 11181).   No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ.  11188)  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           326          475          147>20.4
white              326         1008          295>20.8
w1                 532        18249          823>20.7
m2                1063        14541         1136>20.8
w2                 632        12947         1528>21.2

The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.31 in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB100902A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11194
SUBJECT: GRB 100902A: Swift XRT refined analysis 
DATE:    10/09/03 13:12:51 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>

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

We have analysed 7.9 ks of XRT data for GRB 100902A (Sakamoto et al. GCN Circ. 
11181), from 306 s to 18.2 ks after the BAT trigger. The data comprise 306 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 11188).

The light curve can be modelled with an initial power-law decay with an index 
of alpha=2.4 (+/-0.1), followed by a break at T+1730 (+/-210) s to an alpha of 
0.8 (+/-0.1). Overlaid on this broken power law decay are two large flares, 
which peak at 400 and 420 s with count rates of 1390 (+/-140) and 1440 (+/-150) 
count s^-1 respectively.

A spectrum formed from all the PC mode data to date can be fitted with an 
absorbed power-law with a photon spectral index of 2.5 (+/-0.2). The 
best-fitting absorption column is 3.39 (+/-0.6) x 10^21 cm^-2, in excess 
of the Galactic value of 1.1 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 3.8 x 10^-11 (9.7 x 10^-11) erg cm^-2 count^-1.
We do not report a WT time averaged spectral fit here as this would be 
affected by the spectral evolution during the flaring activity, evident
in the hardness ratio.

If the light curve continues to decay with a power-law decay index of 0.8, the 
count rate at T+24 hours will be 0.013 count s^-1, corresponding to an 
observed (unabsorbed) 0.3-10 keV flux of 5.7 x 10^-13 (1.4 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at 
http://www.swift.ac.uk/xrt_products/00433160.

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


GRB_name: GRB100902A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11195
SUBJECT: Tentative redshift of GRB100902A from Swift-XRT data
DATE:    10/09/03 13:40:08 GMT
FROM:    Sergio Campana at INAF-OAB  <sergio.campana@brera.inaf.it>

S. Campana (INAF-OAB), R. L. C. Starling (U Leicester), P. A. Evans  (U 
Leicester), and T. Sakamoto (NASA/UMBC) report on behalf of the Swift Team:

Swift BAT triggered on the early activity of GRB 100902A (Sakamoto et 
al. 2010, GCN 11181). Swift XRT started observing 316 s after the 
trigger observing the main event. By using the Swift/XRT spectrum 
repository at http://www.swift.ac.uk/xrt_spectra/ (see Evans et al. 
2009, MNRAS, 397, 1177) we selected two time intervals with an almost 
constant hardness ratio. These are at the end of the main event between 
500-550 s (in Window Timing, WT, mode) and the entire first orbit in 
Photon Counting (PC) mode (between 600-3000 s). We then fit the two 
spectra with XSPEC using the model tbabs*ztbabs (cutoff), keeping the 
same absorption pattern and leaving free the cutoff power-law model for 
the two spectra (the cutoff power-law model provides much better results 
in terms of column density evaluation with respect to a simple power-law 
model when small spectral variations are present).
We assume a Galactic column density of 1.1x1021 cm-2 (Kalberla et al. 
2005, A&A 440 775) and we allow for a 30% uncertainty in the fit.  We 
fit the spectrum using C-statistics. In the intrinsic column density vs. 
redshift plane there is just one deep minimum hinting for a redshift 
z=4.5^+0.3_-0.2 (90% confidence level) and an intrinsic column density 
N_H(z)=(2.3^+0.5_-0.3)x1023 cm-2. The X-ray spectrum is very soft with 
Gamma~3.9 at the end of the prompt phase (with a cut-off energy >17 keV) 
and with Gamma~1.9 and E_cut~5 keV in the PC spectrum. The two spectra 
indicate the same redshift even separately.
The high redshift and the large absorbing column density are in line 
with the non-detection with UVOT and other ground based optical facilities.

The contour plot is available at
http://www.brera.inaf.it/utenti/campana/100902.gif


GRB_name: GRB100902A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11196
SUBJECT: GRB 100902A: 1.5m OSN I-band Upper Limits
DATE:    10/09/03 18:31:15 GMT
FROM:    RubÃ©n SÃ¡nchez-RamÃ­rez at IAA-CSIC  <ruben@iaa.es>

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

"We have carried out I-band observations of the  Swift GRB 100902A
(Sakamoto et al. GCNC  11181) on Sep 3.1076 - 3.1492 UT (~7.05 hr after
the onset of the burst, mean observing time) with the  1.5m  telescope at
Observatorio  de Sierra  Nevada, Spain. We do not detect any optical
source within the SWIFT/XRT error circle (Beardmore et al. GCNC 11188).
The 3 sigma limiting magnitude of the co-added I-band image (Texp=16x200s)
is I ~ 21.8, calibrated against the USNO B1.0 catalogue."


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11197
SUBJECT: GRB 100901A: HCT optical observations
DATE:    10/09/03 19:52:42 GMT
FROM:    D.K. Sahu at Indian Inst of Astrophysics,Bangalore  <dks@iiap.res.in>

D.K. Sahu,  Sonam Arora,  N. Shantikumar Singh and Sreeja S. Kartha
(IIA, Bangalore) report.
We observed the optical afterglow of GRB 100901A (Immler et al., GCN 11159)
in Bessell V, R, and I bands with the 2m. Himalayan Chandra Telescope of
the Indian Astronomical  Observatory, Hanle, India. Observations were made
between 18:43 UT and 19:50 UT on 02/09/2010. The optical afterglow was
detected in our individual frames of 300sec each in R and I bands.
The preliminary R and I magnitudes of the optical afterglow
calibrated using  USNO B1.0 1127-0027231 reference
star (R=15.37, I=15.13) is as under:

Mid UT      Exposure     Filter      Mag
18:50       3X300sec        R        18.71 +/- 0.10
19:12       3X300sec        I        17.51 +/- 0.15


GRB_name: GRB100901A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11198
SUBJECT: GRB 100901A: Lightbuckets Optical Observations
DATE:    10/09/03 20:02:34 GMT
FROM:    Tilan Ukwatta at GSFC/GWU  <tilan.ukwatta@gmail.com>

T. N. Ukwatta (GWU/GSFC), T. Sakamoto (GSFC/UMBC), N. Gehrels (GSFC),
and K. S. Dhuga (GWU)

We observed the Swift GRB 100901A (Immler et al., GCN 11159)
with the Lightbuckets 0.61m rental telescope LB-0001 in Rodeo, NM,
USA. Under good weather conditions, observations were carried out in
the R filter starting Sep. 02 (UT) 07:05 (~ 17.5 hours after
the GRB trigger) and a followup observation was performed on
Sep. 03 (UT) 07:01 under acceptable weather conditions.

The burst afterglow is clearly detected with a R magnitude of ~18.05
in the first observation. The afterglow, not corrected for Galactic
extinction, is calibrated against the USNO-B1.0 R1 mag catalog.

Time after trigger      Exposure (s)        R Magnitude

17.5 hours (0.7 days)      3 x 60            ~ 18.05
41 hours   (1.7 days)     10 x 60            > 19.1


We acknowledge the helpful assistance of the Lightbuckets staff, in
particular LightBuckets CEO Stephen G. Cullen.


GRB_name: GRB100829A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11199
SUBJECT: IPN Triangulation of the very bright GRB 100829A
DATE:    10/09/03 20:42:29 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

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

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

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

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

and

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


Fermi (GBM), Konus-Wind, Swift (BAT),  MESSENGER (GRNS), and RHESSI
observed the very bright GRB 100829A at about 75729 s UT (21:02:09) (the 
Fermi/GBM trigger 304808530). The burst was outside the coded field of 
view of the BAT.

We have triangulated this burst to the following 3 sigma error box:
-----------------------------------------------
      RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
   90.409 (06h 01m 38s)   +30.314 (+30d 18' 49")
Corners:
   90.335 (06h 01m 20s)   +29.523 (+29d 31' 22")
   90.353 (06h 01m 25s)   +30.317 (+30d 19' 02")
   90.490 (06h 01m 58s)   +31.121 (+31d 07' 16")
   90.464 (06h 01m 51s)   +30.310 (+30d 18' 37")
-----------------------------------------------

The error box area is 278 sq. arcmin.
The maximum distance between the box corners is 1.6 deg.
This error box may be improved.


GRB_name: GRB100901A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11200
SUBJECT: GRB 100901A: multicolor photometry at Mt.Terskol
DATE:    10/09/03 21:36:18 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev, A. Sergeev (Terskol Branch of Institute of Astronomy), 
A.Pozanenko (IKI), N. Parakhin, S. Velichko, N. Borachok (IC AMER)
V. Petkov (Baksan Neutrino Observatory INR RAS) on behalf of larger GRB 
follow up collaboration report:

We performed multicolor observations of the afterglow (Immler et al., GCN 
11159; Guidorzi et al., GCN 11160; Ivanov et al., GCN 11161; Klunko
et al., GCN 11162) of the Swift GRB 100901A (Immler  et al., GCN 11159) with 
the Zeiss-2000 and  Meade-35 telescopes of Mt.Terskol of the first day after 
burst onset. The afterglow photometry is based on several  reference stars 
of SDSS DR7 and Lupton transformation ugri -> BV:

T0+      Filter,            OT
(d)

Telescope: Meade-35
0.3527  V               17.80+/-0.05

Telescope: Zeiss-2000
0.3704  B              18.11+/- 0.02
0.4490  B              18.45+/- 0.02
0.4579  V              18.06+/- 0.02
0.4634  r(Gunn)      17.85+/- 0.02
0.4714  g(Gunn)     18.37+/- 0.02

The photometry is still preliminary and can be updated later. 


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11201
SUBJECT: GRB 100901A: optical observation at Mt.Terskol
DATE:    10/09/04 01:15:38 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We are continuing observations of the Swift GRB 100901A (Immler  et al., GCN
11159) with the Z-600 telescope of Mt.Terskol observatory in R-filter. In
combined images we still detect  afterglow (Immler et al., GCN 11159). The
photometry is based  on several  reference stars of SDSS DR7 and Lupton
transformation griz -> R used in our previous reports (GCNs 11191, 11200):

T0+     Filter, Exposure,   OT
(d)                 (s)

2.4073  R     15x120        20.13  +/-0.12
2.4282  R     15x120        20.28  +/-0.16


GRB_name: GRB100902A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11202
SUBJECT: GRB 100902A: Swift-BAT refined analysis
DATE:    10/09/04 01:15:41 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from telemetry downlinks,
we report further analysis of BAT GRB 100902A (trigger #433160)
(Sakamoto, et al., GCN Circ. 11181).  The BAT ground-calculated position is
RA, Dec = 48.626, 30.970 deg, which is 
   RA(J2000)  =  03h 14m 30.3s 
   Dec(J2000) = +30d 58' 13.2" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 72%.
 
The mask-weighted light curve shows several strong peaks.  The first starts
around T-60 sec and returns to background around T+70 sec.  We note that
this burst location came into the BAT FoV around T-80 sec, so there could have been
prior activity for this burst.  Then come two stronger peaks at ~T+130 and 
~T+205 sec; then a smaller peak at ~T+400 sec.  T90 (15-350 keV) is
428.8 +- 43.0 sec (estimated error including systematics).
 
The time-averaged spectrum from T-49.5 to T+409.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.98 +- 0.13.  The fluence in the 15-150 keV band is 3.2 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+207.89 sec in the 15-150 keV band
is 1.0 +- 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/433160/BA/


GRB_name: GRB100904A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11203
SUBJECT: GRB 100904A: Swift detection of a burst
DATE:    10/09/04 01:42:08 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

T. N. Ukwatta (GSFC/GWU), W. H. Baumgartner (GSFC/UMBC),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), J. M. Gelbord (PSU),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. Rowlinson (U Leicester), M. H. Siegel (PSU)
and C. A. Swenson (PSU) report on behalf of the Swift Team:

At 01:33:43 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100904A (trigger=433273).  Due to the Sun constraint,
Swift could not slew to the burst. 
The BAT on-board calculated location is 
RA, Dec 172.919, -16.209 which is 
   RA(J2000) = 11h 31m 41s
   Dec(J2000) = -16d 12' 31"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 30 sec.  The peak count rate
was ~1300 counts/sec (15-350 keV), during the second peak at 
~2 sec after the trigger. 

Due to the proximity of the burst to the Sun, Swift cannot slew to the BAT
position. The burst does not become observable by Swift until November 7th;
there will thus be no XRT or UVOT data for this trigger. 

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


GRB_name: GRB100829A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11204
SUBJECT: Konus-Wind observation of GRB 100829A
DATE:    10/09/04 11:13:35 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 100829A, (localized by IPN:
Golenetskii et.al, GCN 11199)
triggered Konus-Wind at T0=75727.937s UT (21:02:07.937)

The burst light curve started with a bright complex
~2.5s-long structure, followed by a weaker emission
episode at T0 + 6 s. The total duration of the burst is ~10 s.
The emission is seen up to 1.5 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB100829_T75727/

As observed by Konus-Wind the burst
had a fluence of (1.40  0.15)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0+1.472s,
of (2.4  0.6)x10-5 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+10.240 s) is best fit
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.44(-0.12, +0.14),
and Ep = 278(-47, +73) keV (chi2 = 36.2/61 dof).

Fitting this spectrum by the GRB (Band) model
yields to the same values of alpha and Ep, with
beta = -9.4 (<-2.3), chi2 = 36.2/60 dof.

The spectrum at the maximum count rate
(measured from T0+0.256 to T0+2.048 s) is best fit
in the 20 keV - 2 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.90 (-0.17, +0.35),
the high energy photon index beta = -2.7 (<-2.2),
the peak energy Ep = 263(-71, +56) keV (chi2 = 48.5/51 dof).

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


GRB_name: GRB100901A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11205
SUBJECT: GRB10901A: Optical observations at IAO
DATE:    10/09/04 13:33:16 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), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 100901A (Immler et al., GCN 11159)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.
Our observations started on 2010-09-02 13:22:45 UT (~1.0 day after the
burst) and 2010-09-03 15:24:41 UT (~2.1 day after the burs). We detected
the previously reported afterglow (Immler et al., GCN 11159;
Guidorzi et al., GCN 11160; Kuroda et al., GCN 11172; Kuroda et al.,
GCN 11189; Ukawatta et al., GCN 11198) in all the three bands.

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

#T0+[day]  MID-UT    T-EXP[sec]   g'  g'_err   Rc  Rc_err   Ic  Ic_err
----------------------------------------------------------------------
1.04604    14:40:28  1560.0     19.49  0.04  18.86  0.04  18.25  0.05
1.08548    15:37:16  1560.0     19.59  0.04  18.93  0.04  18.41  0.06
1.14442    17:02:08  1500.0     19.64  0.05  19.11  0.04  18.50  0.07
2.13035    16:41:52  4020.0     20.71  0.08  19.96  0.06  20.04  0.17
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100902A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11206
SUBJECT: GRB100902A: Optical upper limits at IAO
DATE:    10/09/04 13:34:25 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), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 100902A (Sakamoto et al. GCNC 11181)
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 2010-09-03 18:04:55 UT (~0.94 day after the
burst). We did not find any new point source within the Enhanced
XRT error circle (Beardmore et al. GCNC 11188) 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
------------------------------------------------------
0.94445    18:11:55   720.0      >21.8  >21.4  >20.2
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100904A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11207
SUBJECT: GRB 100904A: Swift-BAT refined analysis
DATE:    10/09/04 13:50:20 GMT
FROM:    Tilan Ukwatta at GSFC/GWU  <tilan.ukwatta@gmail.com>

T. N. Ukwatta (GWU), 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/UMD),
D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC),
(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 100904A (trigger #433273)
(Ukwatta, et al., GCN Circ. 11203).  The BAT ground-calculated position is
RA, Dec = 172.907, -16.185 deg which is
   RA(J2000)  =  11h 31m 37.6s
   Dec(J2000) = -16d 11' 05.5"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.

The mask-weighted light curve shows two overlapping peaks.  The first starts
around T-18 sec and peaks around T-13 sec. The second peaks around T+3 sec.
T90 (15-350 keV) is 31.3 +/- 7.9 sec (estimated error including
systematics).

The time-averaged spectrum from T-14.5 to T+23.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.67 +/- 0.16.  The fluence in the 15-150 keV band is 1.3 +/- 0.1 x 10^-06
erg/cm2.
The 1-sec peak photon flux measured from T+2.29 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/433273/BA/


GRB_name: GRB100901A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11208
SUBJECT: GRB 100901A: UKIRT zYJHK Observation
DATE:    10/09/04 14:41:16 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

  Myungshin Im, Changsu Choi, Hyunsung Jun, Eugene Kang (CEOU/Seoul
  National University), Y. Urata (NCU), P. Choi (Pomona College),
  T. Sakamoto (NASA/GSFC), N. R. Tanvir (U. Leicester), and A. Levan
  (U. Warwick) on behalf of a larger collaboration

   We observed GRB 100901A (Immler et al. GCN 11159) in z, Y, J, H,
  and K filters using UKIRT. The observation started at Sept. 04,
  10:49:31 UT or roughly 2.88 days after the BAT alert.
   We detect the afterglow in images in all the filters,
  with a preliminary magnitude of K=17.82 +- 0.2 mag (Vega)
  calibrated against a 2MASS star at RA=01h49m05.59s and Dec=22d44m51.86s.
   The K-band magnitude is consistent with an expected brightness
  in NIR assuming fading of the brightness with alpha=1.2 a spectral
  slope of beta=0.6 since the report of Kann et al. (GCN 11187).
   Further observation of the object is ongoing.


GRB_name: GRB100902A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11209
SUBJECT: GRB 100902A: GROND observations; afterglow candidate
DATE:    10/09/04 15:31:29 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>

A. Updike (Clemson Univ.), A. Nicuesa Guelbenzu, S. Klose (both TLS 
Tautenburg), and J. Greiner (MPE Garching), report on behalf of the GROND 
team:

GROND (Greiner et al. 2008, PASP 120, 405), the 7-channel imager mounted 
at the 2.2m ESO/MPI telescope on La Silla, started follow-up observations 
of GRB 100902A (Sakamoto et al. 2010, GCN 11181) on September 4 at 7:40 UT 
(about 1.5 days after the trigger). Airmass was around 2. Due to bad 
weather on La Silla no earlier observations were possible.

Within the enhanced 1.5 arcsec XRT error circle (Beardmore et al. 2010, 
GCN 11188) we find a faint source at coordinates RA, DEC (J2000) = 
03:14:30.96, +30:58:44.8 (+/-0.5 arcsec).

Preliminary measured AB mags are:

r' = 24.1 +/- 0.3
i' = 24.0 +/- 0.4

using GROND zeropoints.

At present it is not clear if this is the afterglow or the underling host. 
No statements about variability or fading can be made at the moment.


GRB_name: GRB100902A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11210
SUBJECT: GRB 100902A: UKIRT JK Observation
DATE:    10/09/05 07:10:32 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

  Myungshin Im, Changsu Choi, Hyunsung Jun, Eugene Kang (CEOU/Seoul
  National University), Y. Urata (NCU), P. Choi (Pomona College),
  and  T. Sakamoto (NASA/GSFC), on behalf of a larger collaboration

   We observed GRB 100902A (Sakamoto et al. GCN 11181) in J and K filters
  using UKIRT. The observation started at Sept. 04, 14:24:39 UT or roughly
  1.79 days after the BAT alert.
   The reduced images with non-optimal calibration frames do not show a clear
  sign of the afterglow candidate reported in Updike et al.
  (GCN 11209), although both the J and K images show a faint smudge at
  the reported location which may corresponds to the afterglow.
   The significance of the detection is only ~3 sigma (J ~ 20.8 mag,
  K ~ 19 mag in Vega), therefore it is difficult to draw a firm conclusion
  on detection or non-detection of the afterglow in our data. Further
  analysis of the UKIRT data is ongoing.


GRB_name: GRB100901A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11211
SUBJECT: GRB 100901A: Submm observations from SMA
DATE:    10/09/05 07:20:30 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (DARK/NBI),  S. Martin Ruiz (ESO),
G. Petitpas (SMA), and A. J. Castro-Tirado (IAA-CSIC)
report on behalf of a larger collaboration:

"We have observed the field of GRB 100901A (Immler et al.
GCNC 11159) from SMA in the 345 GHz band starting on
September 3rd at 9 UT (43.5 h after the burst). The
observing conditions were very good, with a water vapour
of PWV~1 mm. However, preliminary analysis does not show
any new source at the position of the afterglow down to
a 3-sigma limit of 2.25 mJy."


GRB_name: GRB100901A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11212
SUBJECT: GRB10901A: Murikabushi telescope observation at 3 days after the burst
DATE:    10/09/05 13:46:08 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), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 100901A (Immler et al., GCN 11159)
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 2010-09-04 17:11:19 UT (~3.15 day after the
burst). We detected the previously reported afterglow (Immler et al.,
GCN 11159; Guidorzi et al., GCN 11160; Kuroda et al., GCN 11205)
in g' and Rc bands.

Photometric results and three sigma upper limit of the OT are listed
below. We used SDSS catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'  g'_err   Rc  Rc_err   Ic
----------------------------------------------------------------------
3.15442    17:16:32   540.0      21.1  0.2    20.6  0.2    >20.1
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11213
SUBJECT: Optical observations of GRB 100901A
DATE:    10/09/05 13:54:39 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Stefano Sposetti (Gnosca, Switzerland) reports to the AAVSO International 
High Energy Network the following optical observations of GRB 100901A (GCN 
#11159, Immler et al.):

Stefano Sposetti reports a clear detection of the optical afterglow of GRB 
100901A (GCN #11159, Immler et al., and many subsequent reports), and 
obvious fading over the four hour span of observations.  The afterglow was 
observed unfiltered (R-band zero point) beginning at 23:25UT on 2010 
September 01 (approximately 10 hours post-burst), and continuing to 03:50 
UT on 2010 September 02.  Observations were made using an SBIG ST8XE CCD 
attached to a 0.4-m Newtonian sited in Gnosca, Switzerland.  A total of 
sixty 30-second integrations and 215 60-second integrations were obtained. 
An ensemble of stars from the USNO-A2.0 catalog were used for the 
magnitude comparison. The frames were co-added into sixteen frames of 
15-minutes duration each, to enable time-series photometry. 
Signal-to-noise in all of the images was between 24 and 52.

The following time-series data were derived:

     date       mag(CR)
Sept 1.98105  17.43
Sept 1.99242  17.50
Sept 2.00391  17.49
Sept 2.01520  17.53
Sept 2.02619  17.66
Sept 2.03711  17.67
Sept 2.04803  17.57
Sept 2.05896  17.63
Sept 2.07011  17.66
Sept 2.08135  17.72
Sept 2.09257  17.83
Sept 2.10413  17.79
Sept 2.11637  17.80
Sept 2.12767  17.79
Sept 2.13897  17.85
Sept 2.15026  17.91

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


GRB_name: GRB100905A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11214
SUBJECT: GRB 100905A: Swift detection of a burst
DATE:    10/09/05 15:24:02 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), P. T. O'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
A. Rowlinson (U Leicester), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), E. Troja (NASA/GSFC/ORAU) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 15:08:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100905A (trigger=433442).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 31.530, +14.932 which is 
   RA(J2000) = 02h 06m 07s
   Dec(J2000) = +14d 55' 54"
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 6 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 15:09:29.9 UT, 75.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 31.5505, 14.9300 which
is equivalent to:
   RA(J2000)  = 02h 06m 12.12s
   Dec(J2000) = +14d 55' 47.9"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 71 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 5.35
x 10^20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White 
filter starting 77 seconds after the BAT trigger. No credible 
afterglow candidate has been found in the initial data products. The 
2.7'x2.7' sub-image covers 100% of the XRT error circle. The 3-sigma 
upper limit is typically 19.3 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 F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB100905A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11215
SUBJECT: GRB 100905A: Faulkes Telescope North observations
DATE:    10/09/05 15:57:12 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara), I. A. Steele, C. G. Mundell (LJMU),
A. Gomboc (U. Ljubljana) report on behalf of a large collaboration:

The Faulkes Telescope North automatically began observing Swift
GRB 100905A (Marshall et al. GCN Circ. 11214) on September 05,
15:10:32 UT, 138 s from the GRB trigger time.

Within the XRT error circle we do not find any source down to
the following limiting magnitudes:

Mid Time from       Exposure      Filter      Lim. Mag.
GRB (s)               (s)
-------------------------------------------------------
179                  3x10          R > 19.8
604                   120          R > 20.0
839                   100          i' > 19.0
-------------------------------------------------------

Magnitudes are calibrated against nearby USNOB-1 stars
R2 and I values.
Observations stopped soon due to twilight.


GRB_name: GRB100905A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11216
SUBJECT: GRB 100905A: MASTER Prompt Optical Observations
DATE:    10/09/05 17:43:04 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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

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

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


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



MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located at Tunka   was pointed to the Swift GRB 100905A (Marshall et al. 
GCN Circ. 11214) 33  sec  after Notice time (55 s after GRB trigger time) 
in two polarizations bands.

There is no optical transient at XRT position (Marshall et al.
GCN Circ. 11214).
Following data has been received:

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd? Band
--------------------------------------------------------------------------
15:09:10       15:09:20     10        16.5       55.0          N  Polariz
15:09:39       19:09:59     20        17.1       84.0          N  Polariz
15:10:45       15:11:15     30        17.3      150.0          N  Polariz
15:11:35       15:12:15     40        17.5      200.0          N  Polariz
--------------------------------------------------------------------------

The observations and data reductions is continued.

The message may be cited.


GRB_name: GRB100904A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11217
SUBJECT: GRB100904A: BOOTES-3 Upper Limit
DATE:    10/09/05 20:06:20 GMT
FROM:    Juan Carlos Tello at IAA-CSIC  <jtello@iaa.es>

J.C. Tello, J. Gorosabel, A.J. Castro-Tirado (IAA-CSIC, Granada) P.
Kubanek (IAA-CSIC and IPL-UV) W. Allen (Vintage Lane Obs.), Ph. Yock
and Kuan-Yu Lin (Auckland Univ.), report on behalf of a larger collaboration:

"We have carried out  observations of the  Swift GRB 100904A
(Ukwatta et al. GCNC  11203) on Sep 4.2982 - 4.3145 UT (~5.98 hr after
the onset of the burst, mean observing time) with the 0.6m Yock-Allen
robotic telescope (BOOTES-3) located in Blenheim, New Zealand.
Observations were carried out at high airmass (~ 7).

We do not detect any optical source within the Swift-BAT refined analysis
error circle (Ukwatta et al. GCNC 11207).
The 3 sigma limiting magnitude of the co-added unfiltered image (Texp=16x60s)
is R ~ 18.0, using USNO-B1.0 as photometric reference."

[GCN OPS NOTE(06sep10): Per author's request, K-YL was added to the author list.]


GRB_name: GRB100905A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11218
SUBJECT: GRB 100905A: Swift-BAT refined analysis
DATE:    10/09/05 21:39:43 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/UMD),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 100905A (trigger #433442)
(Marshall, et al., GCN Circ. 11214).  The BAT ground-calculated position is
RA, Dec = 31.542, 14.919 deg, which is 
   RA(J2000)  =  02h 06m 10.0s 
   Dec(J2000) = +14d 55' 08.2" 
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-1.7 sec,
peaking at ~T+0.5 sec, and ending at ~T+3 sec.  T90 (15-350 keV) is
3.4 +- 0.5 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.6 to T+2.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.09 +- 0.19.  The fluence in the 15-150 keV band is 1.7 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.03 sec in the 15-150 keV band
is 0.6 +- 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/433442/BA/


GRB_name: GRB100905A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11219
SUBJECT: GRB 100905A: Enhanced Swift-XRT position
DATE:    10/09/05 21:51:09 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 1956 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 100905A, 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 = 31.55023, +14.92941 which is equivalent
to:

RA (J2000): 02h 06m 12.06s
Dec (J2000): +14d 55' 45.9"

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: GRB100905A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11220
SUBJECT: GRB100905A: 1.5m OSN upper limit
DATE:    10/09/06 01:16:38 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

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

"We have observed the field of GRB100905A (Marshall et al.
GCNC 11214) using the 1.5m telescope of the Observatorio
de Sierra Nevada, in Granada (Spain). In a 7x300s combined
I-band frame, with mean epoch September 5.9792 UT (8.36 hours
after the burst onset), we do not detect any new source within
the enhanced XRT position (Evans et al. GCNC 11219) down to a
3-sigma limiting magnitude of 22.8. USNO-B1.0 has been used as
reference catalogue."


GRB_name: GRB100901A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11221
SUBJECT: GRB 100901A: Possible WSRT Radio Detection
DATE:    10/09/06 04:36:07 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <Alexander.J.VanDerHorst@nasa.gov>

A.J. van der Horst (NASA/MSFC/ORAU), K. Wiersema (U of Leicester),
A.P. Kamble, R.A.M.J. Wijers, E. Rol (U of Amsterdam) and
C. Kouveliotou (NASA/MSFC) report on behalf of a large collaboration:

"We observed the position of the GRB 100901A afterglow at 4.9 GHz
with the Westerbork Synthesis Radio Telescope at September 3 20.35 UT
to September 4 08.50 UT, i.e. 2.29 - 2.79 days after the burst (GCN 11159).
We detect a radio source at the position of the X-ray and UV/optical
counterpart (GCN 11195) at the 4-sigma level, with a flux density of
134 +/- 33 microJy.

We would like to thank the WSRT staff for scheduling and obtaining
these observations."


GRB_name: GRB100905A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11222
SUBJECT: GRB 100905A: UKIRT zJHK Observation
DATE:    10/09/06 04:55:03 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

  Myungshin Im, Changsu Choi, Hyunsung Jun, Eugene Kang (CEOU/Seoul
  National University), Y. Urata (NCU), P. Choi (Pomona College),
  T. Sakamoto (NASA/GSFC), and N. Gehrels (NASA/GSFC) on behalf
  of a larger collaboration

   We observed GRB 100905A (Marshall et al. GCN 11214) in z, J, H,
  and K filters using UKIRT. The observation started at Sept. 05,
  15:22 UT or roughly 17 minutes after the BAT alert, until the
  sunrise.
   The reduced images with non-optimal calibration frames show
  a "possible" very faint source within the XRT error circle
  (Evans et al. GCN 11219) whose significance is only 2-3 sigma
  in each image (2-sigma limit, J=19.8, H=19.0,
  and K=18.7 mag). The faint smudge show up in all zJHK filter
  images, suggesting this could be an afterglow, but we do not
  exclude the possibility that this is just a spurious detection.
   Further analysis of the UKIRT data is ongoing.


GRB_name: GRB100905A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11223
SUBJECT: GRB 100905A: Swift-XRT refined analysis.
DATE:    10/09/06 08:08:17 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester) and F. E. Marshall (NASA/GSFC) report on
behalf of the Swift-XRT team:

We have analysed 7.1 ks of XRT data for GRB 100905A (Marshall et al. GCN
Circ. 11214), from 78 s to 13.6 ks after the BAT trigger. The data
comprise 71 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. The enhanced XRT position for this burst was given
by Evans et al. (GCN. Circ 11219).

The light curve shows some initial flaring activity, with the flares
peaking  at around 290, 320 and 400 s after the trigger. The flares peak
an order of magnitude brighter than the underlying emission, which
can be modelled with a single power-law, with a decay index of
alpha=0.86 (+/-0.06).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.0 (+/-0.3). The best-fitting
absorption column is 1.9 (+0.6, -0.5) x 10^21 cm^-2, in excess of the
Galactic value of 5.4 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode
spectrum has a photon index of 1.97 (+0.12, -0.18) and a best-fitting
absorption column of 8.4 (+4.1, -2.8) x 10^20 cm^-2. The counts to
observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from
this spectrum is 3.9 x 10^-11 (4.8 x 10^-11) erg cm^-2 count^-1.

If the light curve continues to decay with a power-law decay index of
0.86, the count rate at T+24 hours will be 2.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-13 (1.3 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00433442.

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


GRB_name: GRB100905A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11224
SUBJECT: GRB100905A: MITSuME Okayama optical upper limits
DATE:    10/09/06 08:57:02 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 100905A (Marshall et al., GCN 11214)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2010-09-05 15:31:18 UT (~23 min after
the burst). We did not find any new point source within the
enhanced XRT error circle (Evans et al., GCNC 11219) 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
------------------------------------------------------
0.09641    17:27:05 10380.0     >20.9  >20.6  >19.7
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100905A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11225
SUBJECT: GRB100905A: Optical upper limits at IAO
DATE:    10/09/06 08:58:15 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), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration:

We observed the field of GRB 100905A (Marshall et al., GCN 11214)
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 2010-09-05 18:56:36 UT (~0.16 day after the
burst).  We did not find any new point source within the enhanced XRT
error circle (Evans et al., GCNC 11219) 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
------------------------------------------------------
0.16300    19:02:58  1440.0      >21.1  >21.4  >19.5
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB100829A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11226
SUBJECT: GRB 100829A: MASTER optical observations
DATE:    10/09/06 13:55:22 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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


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


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

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

As we  wroute (Gorbovskoy et. al., GCN CIRCULAR N11157) MASTER   robotic 
telescopes 
(MASTER-Net: http://observ.pereplet.ru, 6 Very Wide Field cameras and 2 
Wide Field Telescopes ) located  near Kislovodsk  was pointed to the FERMI 
GRB 100829A (FERMI Trigger N 304808530 ) 
30  sec  after Notice time and 44 s after trigger time.

Unfortunately error box from IPN Triangulation of the very bright GRB 
100829A (Golenetskii et al., GCN Circ N11199) very near horizont (see 
image http://observ.pereplet.ru/images/GRB100829A/WFC_FOW.jpg ).

mailto: lipunov@sai.msu.ru


GRB_name: GRB100906A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11227
SUBJECT: GRB 100906A: Swift detection of a burst with an optical afterglow
DATE:    10/09/06 14:07:13 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

C. B. Markwardt (NASA/GSFC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU), V. D'Elia (ASDC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
J. M. Gelbord (PSU), O. Godet (U Leicester), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), W.B Landsman (GSFC),
O. M. Littlejohns (U Leicester), F. E. Marshall (NASA/GSFC),
D. C. Morris (GWU/GSFC), P. T. O'Brien (U Leicester),
K. L. Page (U Leicester), B. Sbarufatti (INAF-OAB/IASFPA),
M. H. Siegel (PSU), R. L. C. Starling (U Leicester) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 13:49:27 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 100906A (trigger=433509).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 28.709, +55.614, which is 
   RA(J2000)  =  01h 54m 50s
   Dec(J2000) = +55d 36' 50"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multiple bright peaks
with a duration of about 130 sec.  The peak count rate
was ~11000 counts/sec (15-350 keV), at ~10 sec after the trigger. 

The XRT began observing the field at 13:50:47.6 UT, 80.2 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 28.68305, 55.62985
which is equivalent to:
   RA(J2000)  = 01h 54m 43.93s
   Dec(J2000) = +55d 37' 47.5"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 78 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 (2.21 x
10^21 cm^-2, Kalberla et al. 2005), with an excess column of 2.6
(+2.21/-1.90) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 0.1 s image was 2.34e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
146 seconds after the BAT trigger. There is a candidate afterglow in the
rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 01:54:44.11 =  28.68380
  DEC(J2000) = +55:37:49.6  =  55.63045
with a 90%-confidence error radius of about 0.61 arc sec. This position is 1.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
14.90 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.36. 

A bright XRT flare at ~120 s corresponds to the last peak in the prompt emission. 
The UVOT bright source is probably also associated in time with the flare.  More
information to follow. 

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: GRB100906A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11228
SUBJECT: GRB 100906A: MASTER early OT observations
DATE:    10/09/06 14:12:54 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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


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

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


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


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



Two MASTER   robotic telescopes (MASTER-Net: http://observ.pereplet.ru)
located  near Baykal Lake (Tunka)  and Blagoveschensk was pointed to the
Swift GRB 100906A (Markwardt et al., GCN CIRCULAR
11227) 23  sec  after Notice 
time (38 s after trigger time) and 43 s after Notice time (58s after 
trigger time).

  We have a number polarization, unfiltered images  with exposition 
10, 20, 30, 40, 60... s.

We see bright OT at Swift Uvot position (Markwardt et al., GCN CIRCULAR
11227).


The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100906A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11229
SUBJECT: GRB 100906A : Faulkes Telescope North optical observations
DATE:    10/09/06 14:30:42 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm@astro.livjm.ac.uk>

A. Melandri (INAF-OAB), D. Kopac (U. Ljubljana) and Z. Cano (LJMU)
report on behalf of a large collaboration:

The Faulkes Telescope North automatically began observing Swift
GRB 100906A (trigger = 433509, Markwardt et al., GCN 11227) on
September 06,13:53:03 UT, about 3.5 minutes from the GRB trigger time.
We clearly identify an uncatalogued object at the following position:

RA(J2000):  01:54:44.09
Dec(J2000): +55:37:49.5

The position is consistent with UVOT candidate and the object is  
clearly fading.
Preliminary photometry gives a magnitude of R=15.5 +/- 0.1 @800 s  
after the
burst event.

Observations are going on.


GRB_name: GRB100906A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11230
SUBJECT: GRB 100906A: Gemini-N/GMOS redshift
DATE:    10/09/06 15:15:39 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir, K. Wiersema (U. Leicester) and A. J. Levan (U. Warwick)
report on behalf of a larger collaboration:

We observed the location of GRB 100906A (Markwardt et al. GCN 11227;
Ivanov et al. GCN 11228; Melandri et al. GCN 11229) with
the Gemini-North Telescope on Mauna Kea using the GMOS spectrograph.
Observations began at 14:30 UT, approximately 40 minutes post burst.

We detect strong continuum from the afterglow, and identify numerous
absorption lines, including CIV (1458, 1551A), FeII (2344, 2374, 2383A)
at a common redshift of z=1.727.

Further analysis is ongoing.

We acknowledge the support of Chad Trujillo in obtaining these observations.


GRB_name: GRB100906A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11231
SUBJECT: GRB 100906A: MASTER preliminary polarization prompt light curve
DATE:    10/09/06 15:23:17 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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

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

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


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



Two MASTER   robotic telescopes (MASTER-Net: http://observ.pereplet.ru)
located  near Baykal Lake (Tunka)  and Blagoveschensk was pointed to the
Swift GRB 100906A (Markwardt et al., GCN CIRCULAR
11227) 23  sec  after Notice time (38 s after trigger time) and 43 s after 
Notice time (58s after trigger time) (Ivanov et al., GCN CIRCULAR 11228).

We see brightening and decay of the prompt optical emission in both 
polarizations.

The preliminary light curve is available at
http://observ.pereplet.ru/images/GRB100906A/pre_lc.gif

This automatical phtometry calbrated by   USNOB1  stars.


The message may be cited.

mailto: lipunov@sai.msu.ru


GRB_name: GRB100906A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11232
SUBJECT: GRB 100906A: UKIRT zYJHK Observation
DATE:    10/09/06 15:27:40 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

  Myungshin Im, Changsu Choi, Hyunsung Jun, Eugene Kang (CEOU/Seoul
  National University), Y. Urata (NCU), P. Choi (Pomona College),
  T. Sakamoto (NASA/GSFC), and N. Gehrels (NASA/GSFC) on behalf
  of a larger collaboration

    Using UKIRT, we obtained multiple sets of zYJHK images of GRB 100906A
  (Markwardt et al. GCN 11227) with a series of  z, Y, J, H, and K filters
  using UKIRT. The observation started at Sept. 06, 14:23 UT or roughly 34
  minutes after the BAT alert.
   We clearly identify an uncatalogued source in images in all the filters.
   The preliminary magnitude of the afterglow is J= 14.93 +- 0.02 and
  K=13.54 +- 0.02 (Vega), calibrated against 2MASS stars in the vicinity.


GRB_name: GRB100906A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  11233
SUBJECT: GRB 100906A: Swift-BAT refined analysis
DATE:    10/09/06 16:31:20 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/UMD),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 100906A (trigger #433509)
(Markwardt, et al., GCN Circ. 11227).  The BAT ground-calculated position is
RA, Dec = 28.697, 55.634 deg, which is 
   RA(J2000)  =  01h 54m 47.4s 
   Dec(J2000) = +55d 38' 03.7" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 46%.
 
The mask-weighted light curve shows several bright peaks.  The first pair
of overlapping peaks starts at ~T-0.2 sec, peaks at ~T+2 and ~T+10 sec,
and almost returns to background at ~T+35 sec.  There is a small peak
at ~T+50 sec. Then there are four overlapping peaks from ~T+100 to ~T+118 sec.
T90 (15-350 keV) is 114.4 +- 1.6 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.2 to T+130.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.78 +- 0.03.  The fluence in the 15-150 keV band is 1.2 +- 0.0 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+10.48 sec in the 15-150 keV band
is 10.1 +- 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/433509/BA/


