# GCN_circulars

GRB_name: GRB130912A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15225
SUBJECT: Konus-Wind observation of GRB 130912A
DATE:    13/09/13 13:20:09 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The short-duration GRB 130812A (Swift-BAT trigger 570465:
D'Elia et al. GCN 15212, Krimm et al. GCN 15216;
Fermi-GBM detection: Zhang et al. GCN 15219)
triggered Konus-Wind at T0=30902.290 s UT (08:35:02.290).

The burst light curve shows two peaks in the time
interval from ~T0-0.1 s to ~T0+0.3 s.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB130912_T30902/

As observed by Konus-Wind, the burst
had a fluence of (1.6  0.2)x10-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.032,
of (2.2  0.6)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The 3-channel time-integrated spectrum
(measured from T0-0.128 to T0+0.256 s)
can be modeled, in the 25 keV - 1.5 MeV range,
by the cutoff power law with the following model parameters:
the photon index alpha = -0.96  0.08,
and the peak energy Ep = 580  65 keV.

The 3-channel spectrum at the maximum count rate
(measured from T0-0.128 to T0+0.256 s)
can be modeled, in the 25 keV - 1.5 MeV range,
by the cutoff power law with the following model parameters:
the photon index alpha = -1.07  0.12,
and the peak energy Ep = 1020  320 keV.

All the quoted results are preliminary.


GRB_name: GRB130912A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15226
SUBJECT: GRB 130912A: RATIR Optical and NIR Upper Limits
DATE:    13/09/13 15:25:38 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:

We observed the field of GRB 130912A (D'Elia et al., GCN 15212) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/09 13.30 to 2013/09 13.49 UTC (22.58 to
27.11 hours after the BAT trigger), obtaining a total of 5.33 hours
exposure in the r and i bands and 2.24 hours exposure in the Z, Y, J, and H
bands.

For a source within the Swift-XRT error circle, in comparison with USNO-B1
and 2MASS, we obtain the following upper limits (3-sigma):

  r     > 23.89
  i     > 23.79
  Z     > 22.86
  Y     > 22.38
  J     > 22.30
  H     > 21.78

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.    Our observations confirm that
the source faded
and is therefore the short GRB afterglow.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB130912A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15227
SUBJECT: GRB 130912A: 5.8 GHz VLA upper limit
DATE:    13/09/13 21:59:59 GMT
FROM:    Wen-fai Fong at CFA  <wfong@cfa.harvard.edu>

W. Fong, B. A. Zauderer and E. Berger (Harvard) report:

"We observed the field of the short-duration GRB 130912A (D'Elia et
al., GCN 15212; Zhang et al., GCN 15219; Golenetskii et al., GCN
15225) with the Karl G. Jansky Very Large Array (VLA) beginning on
2013 Sep 13.26 UT (21.85 hr post-burst) at a mean frequency of 5.8
GHz. In 1 hour of observations, we do not detect any radio source in
coincidence with the optical afterglow (Tanga et al., GCN 15214; Cenko
et al., GCN 15222; Tanvir et al., GCN 15224; Butler et al., GCN 15226)
or within the enhanced XRT position (Beardmore et al., GCN 15217). We
therefore place a 3-sigma limit of 29 microJy on the radio afterglow
of GRB 130912A at 21.85 hr after the burst.

We thank the VLA staff for quickly executing these observations."


GRB_name: GRB130912A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15229
SUBJECT: GRB 130912A: Swift/UVOT Upper Limits 
DATE:    13/09/15 20:52:11 GMT
FROM:    Margaret Chester at PSU  <chester@astro.psu.edu>

M. M. Chester (PSU) and V. D'Elia (ASDC) report on behalf of the 
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 130912A
99 s after the BAT trigger (D'Elia et al., GCN Circ. 15212).
No optical afterglow consistent with the enhanced XRT position 
(Beardmore et al. GCN Circ. 15217) is detected in the initial UVOT 
exposures. Preliminary 3-sigma upper limits using the UVOT photometric 
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposures and subsequent exposures are:

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

white_FC            99          249          147         >20.7
u_FC               311          561          246         >20.2
white               99         6848          785         >21.4
v                  640        23984         1395         >20.3
b                  566        30470         1907         >21.6
u                  311        36236         3907         >21.6
w1                 690        35508         3836         >22.1
m2                1070        34601         2827         >21.8
w2                 616        23070         1376         >21.6

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.28 in the direction 
of the burst (Schlegel et al. 1998).


GRB_name: GRB130606A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15230
SUBJECT: GRB 130606A: Chandra observation
DATE:    13/09/17 13:12:11 GMT
FROM:    Tanmoy Laskar at Harvard U  <tanmoylaskar@gmail.com>

W. Fong, T. Laskar, E. Berger, and R. Margutti (Harvard) report:

"We observed GRB 130606A (Ukwatta et al., GCN 14781) with the Chandra ACIS
instrument, starting on 2013 June 17 03:05:37 UT (10.3 days after the GRB
trigger), for a total exposure of 30 ks. We detect a point source at the
position of the Swift/XRT afterglow. Using the spectral parameters from the
Swift/XRT PC-mode spectrum (http://www.swift.ac.uk/xrt_products/00557589)
and a redshift of z=5.91 (Chornock et al. 2013, ApJ, 774, 26; Castro-Tirado
et al., GCN 14796; Lunnan et al., GCN 14798; Xu et al., GCN 14816), we find
an unabsorbed flux of (2.4 +/- 0.4)e-15 erg/(s cm^2) in the 0.3-10 keV
band. This measurement is consistent with an extrapolation of the Swift/XRT
observations and shows a continuing decline in flux with a power-law decay
slope of -1.8 +/- 0.1 between 0.1 and 10 days after the burst.

We thank Harvey Tananbaum for approving our DDT request and the CXC staff
for rapidly arranging and executing the observations."


GRB_name: GRB130903A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15231
SUBJECT: GRB 130903A: Further Swift XRT observations. 
DATE:    13/09/17 18:40:19 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <dxg35@psu.edu>

Dirk Grupe (Swift MOC/PSU) report on behalf of the Swift XRT team:

We report on two additional Swift XRT observations of the
INTEGRAL-discovered burst GRB 130903A (Mereghetti et al., GCN circ.
15169). As reported in Grupe & Holland (GCN circ. 15173), we found
an X-ray source at a level of 5e-3 counts/s within the INTEGRAL
error circle. Swift obtained a second observation on September 06
for 5.0 ks. The source reported in Grupe & Holland was still
present but at a significantly lower level at (1.1+0.5-0.4)e-3
counts/s suggesting a rather slow decay slope during the 'normal'
X-ray afterglow phase (e.g. see Grupe et al. 2013,
arXiv:1305:3236). However, a decay by a factor of 5 is still
consistent with a background AGN (e.g. Grupe et al. 2010, AJ 187,
64). Therefore we performed a third observation which was executed
on September 16 for a total of 4.6 ks. In this new observation
the source seems to be gone. The 3-sigma upper limit at the 
position of the previously detected X-ray source is at a level of 
1.25e-3 counts/s. We can conclude that the X-ray source reported 
in  Grupe & Holland (GCN circ. 15173) is most-likely the X-ray 
afterglow of GRB 130903A. 

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


GRB_name: GRB130919A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15232
SUBJECT: GRB 130919A: Swift detection of a burst
DATE:    13/09/19 11:18:50 GMT
FROM:    Hans Krimm at NASA-GSFC  <krimm@milkyway.gsfc.nasa.gov>

H. A. Krimm (CRESST/GSFC/USRA), A. A. Breeveld (UCL-MSSL),
D. N. Burrows (PSU), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),
C. B. Markwardt (NASA/GSFC), A. Melandri (INAF-OAB),
K. L. Page (U Leicester), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU) and T. N. Ukwatta (MSU) report on behalf of the
Swift Team:

At 11:07:24 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130919A (trigger=571271).  
The BAT on-board calculated location is 
RA, Dec 207.288, -10.355 which is 
   RA(J2000) = 13h 49m 09s
   Dec(J2000) = -10d 21' 19"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a broad peak of
at least 60 seconds duration.  This was an image trigger, so the 
currently available light curve does not show significant structure. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 23:23 UT on 2013 December 7. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is H. A. Krimm (krimm 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: GRB130913A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15233
SUBJECT: GRB 130913A detected in ground analysis of Swift-BAT data
DATE:    13/09/19 18:34:54 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings (UMBC@NASA GSFC), D. M. Palmer (LANL),
A. Y. Lien (NASA/GSFC/ORAU), and C. B. Markwardt (GSFC)
report on behalf of the Swift science team:

On 2013-09-13 at 00:28:21 Swift-BAT detected a preliminary rate trigger
(Trigger #570531), now designated GRB 130913A. On-board analysis was
terminated prematurely by a preplanned slew maneuver.  No significant
source was found on-board.  In post-processing on the ground, a
significant source was located at RA, Dec 341.960, +1.294, which is

    RA(J2000)  =  22h 47m 50.4s
    Dec(J2000) = +01d 17' 38.0"

with an estimated 90% error radius of 3.3 arcmin.

The lightcurve shows a single FRED peak about 10 seconds long (T100).
Determining a formal T90 is difficult because of the weakness of the burst.

The time-averaged spectrum from T-2 to T+8 sec is fit by a simple
power law model.  This fit gives a photon index of 0.9 +- 0.3 (68% confidence).
The fluence in the 15-150 keV band was (1.3 +- 0.4) x 10^-7 ergs/cm^2 (90%
confidence).

We note the presence of a galaxy cluster at z ~ 0.123 centered within 5
arcmin of the BAT position.  The source went into Moon constraint for Swift
very shortly after discovery, so no TOO was possible, and there will be no
narrow-field instrument data for this GRB.


GRB_name: GRB130919A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15234
SUBJECT: GRB 130919A, Swift-BAT refined analysis
DATE:    13/09/20 02:27:56 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

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

Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 130919A (trigger #571271)
(Krimm, et al., GCN Circ. 15232).  The BAT ground-calculated position is
RA, Dec = 207.281, -10.353 deg which is
    RA(J2000)  =  13h 49m 07.5s
    Dec(J2000) = -10d 21' 11.0"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 77%.

The burst came into the BAT field of view at ~T-60 seconds, following a pre-planned
slew and another slew took it out of the field at around T+215 seconds.
mask-weighted light curve shows a broad peak from T-30 s to T+70 s, with at least
six subpeaks superimposed. T90 (15-350 keV) is 97.3 +- 25.1 sec (estimated error
including systematics).

The time-averaged spectrum from T-20.15 to T+108.07 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.54 +- 0.73,
and Epeak of 71.7 +- 31.8 keV (chi squared 58.75 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T-6.49 sec in the 15-150 keV band is
0.5 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.52 +- 0.14 (chi squared 65.60 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/571271/BA/


GRB_name: GRB130919A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15235
SUBJECT: GRB 130919A: Skynet PROMPT-CTIO optical upper limits
DATE:    13/09/20 04:04:19 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter@physics.unc.edu>

A. Trotter, D. Reichart, J. Haislip, A. LaCluyze, J. Moore, N. Frank, K. 
Ivarsen, M. Nysewander, A. Foster, T. Berger, H. T. Cromartie, R. Egger, 
M. Maples, and J. A. Crain report:

Skynet observed the Swift-BAT localization of GRB 130919A (Krimm et al., 
GCN 15232; Lien et al., GCN 15234, Swift trigger=571271) with three 16" 
telescopes of the PROMPT array at CTIO, Chile (V, R, and I bands).

Starting at 2013-09-19, 23:29 UT and continuing until 2013-09-20, 00:00 
UT (t=12.40-12.93h post-trigger), Skynet took a total of 49 160s 
exposures, at high airmass >3. In stacked images, we do not detect any 
uncatalogued optical source in any band in or near the Swift-BAT error 
circles.  The 3-sigma limiting magnitudes of our images are:

==================================
tmid    scope   expos   fil  limit
==================================
12.67h  Prompt5 12x160s  I  >19.44
12.55h  Prompt4  7x160s  R  >19.24
12.63m  Prompt1 10x160s  V  >19.54
==================================

Magnitudes are in the Vega System, calibrated to 8 APASS-DR7 stars in 
the field.  Magnitudes have not been corrected for line-of-sight Milky 
Way dust extinction, with expected E(B-V)=0.057 (Schlegel et al. 1998).

No further Skynet observations are scheduled.


GRB_name: GRB130831A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15237
SUBJECT: GRB 130831A: Maidanak optical observations, possible emerging Supernova
DATE:    13/09/21 12:04:06 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), A. Volnova (IKI), B. Hafizov (UBAI), O. Burhonov
(UBAI) report on behalf of larger GRB follow-up collaboration:

We continue observation of the afterglow  (Hagen et al., GCN  15139; 
Guidorzi et al., GCN 15140) of the Swift GRB 130831A (Hagen et al., GCN 
  15139)  with AZT-22 telescope equipped with SNUCAM at Maidanak 
observatory. A preliminary photometry of combined images obtained on 
Sep. 16 is following:

T_start              T0+       Filter, Exposure, OT
(UT)                 (mid, d)            (s)

2013-09-16T19:00:13  16.28     R       14x300     22.77 +/- 0.07

The photometry is based on  SDSS stars (see GCN 15190).

This is brighter than we obtained on Sep. 9  (23.11 +/- 0.06) and  on 
Sep. 15 (22.87 +/- 0.08). We suggest the observed re-brightening is an 
emerging Supernova associated with GRB 130831A.

A preliminary lc of the afterglow+SN of GRB 130831A can be found in
http://grb.rssi.ru/GRB130831A/grb130831A_lc_preliminary.PNG


GRB_name: GRB130919A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15238
SUBJECT: Fermi Trigger 401326696: MASTER prompt optical observations
DATE:    13/09/21 12:42:39 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

C. Mallamaci, C. Lopez and F. Podest
Observatorio Astronomico Felix Aguilar (OAFA)

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

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

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

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

V. Krushinski, I. Zalozhnich,  A. Popov, A. Bourdanov, A. Punanova
Ural Federal University


MASTER-ICATE robotic very wide field cameras (FOV=2x384 square degrees,
D=72mm, f/1.2, 1 pix = 22 arcsec, http://observ.pereplet.ru) located in 
Argentina (Observatorio Astronomico Felix Aguilar, 
http://93.180.27.230:8080/) 
synchronously observed 35% part of FERMI GRB130919A (trigger 401326696) 
error box before, during and after the trigger.

Since 40 sec after the trigger cameras pointed to FERMI alert our FOV 
cover 95% part of error box.
We haven't found optical transient  within
FERMI error-box  our first (5 s exposure) set.
The 5-sigma upper limit has been about 12.0 mag.
The 5-sigma upper limit on coadd first 30 images is about 13.0 mag.

The first seconds  movie locate here 
http://master.sai.msu.ru/static/GRB130919A.gif

Our cameras are continuously imaging the sky with 5 sec exposures.

The more accurat error box (by IPN) is requied.
The message may be cited.


GRB_name: GRB130912A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15239
SUBJECT: GRB 130912A:  AAO optical upper limit
DATE:    13/09/21 16:53:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), R. Inasaridze (AAO), O. Kvaratskhelia (AAO), V. 
Ayvazian(AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of Swift GRB 130912A (D'Elia et al., GCN 15212)
with AS-32 (0.7m) telescope of Abastumani Observatory starting  Sep., 13 
(UT) 00:18:46. We obtained several unfiltered frames with exposures of 
120 s. On stacked images within the enhanced XRT circle (Beardmore et 
al., GCN 15217) we did not detect an optical counterpart reported by 
Tanga et al. (GCN 15214).

The details of the photometry are the following:

t_start, UT   filter exptime,s   t-t0, mid, days  OT    uplim

21:39:21      None   31*120       0.68394         n/d    22.3

The photometry is based 3 USNO-B1.0 stars:

USNO-B1.0 id RA             Dec             R2
1040-0030312 03:10:30.46 +14:01:11.1 19.44
1040-0030310 03:10:29.14 +14:01:21.6 17.38
1040-0030302 03:10:25.12 +14:00:31.6 15.90


GRB_name: GRB130907A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15240
SUBJECT: GRB 130907A: Maidanak optical observations
DATE:    13/09/21 17:24:34 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), A. Volnova (IKI), B. Hafizov (UBAI), O. Burhonov 
(UBAI) report on behalf of larger GRB follow-up collaboration:

We observed the field of Swift GRB 130907A (Page et al., GCN 15183) with 
AZT-22 telescope equipped with SNUCAM of Maidanak observatory starting 
Sep., 10  (UT) 11:04:47. We obtained 2 frames with exposures of 300 s in 
R filter. On stacked images we clearly detect the source reported by Lee 
et al., (GCN 15192). The astrometry of the source is following

RA(J2000) 14 23 34.01
Dec(J2000) +45 36 36.6
with uncertainty of 0.18 arcsec in both coordinates.

The details of the photometry are following:

t_start, filter Exposure, t-t0,      OT
(UT)            sec       mid,days
11:04:47 R      2*300     2.56166    21.44 +/- 0.16

The photometry is based on a nearby SDSS-DR9 star J142338.63+453547.2 
with R mag = 18.181 +/- 0.013 (transformation by Lupton 2005)


GRB_name: GRB130903A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15241
SUBJECT: GRB 130903A: optical observations
DATE:    13/09/21 19:07:58 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI),  V. Nevskiy (ISON),  I. Molotov (KIAM), Yu. Krugly(IA 
KhNU), I. Slyusarev (IA KhNU), A. Pozanenko (IKI)  report on behalf of 
larger collaboration:

After the refined analysis of the ISON-Kislovodsk observations (Volnova 
et al., GCN 15171) of GRB 130903A field (Mereghetti et al., GCN 15169) 
in the coordinates of OT reported by Tanga et al. (GCN 15177) we found a 
faint source with a R magnitude 20.40  0.3. Photometry is  based on the 
  stars reported below.

We also observed the field of the field with AZT-8 (0.7m) telescope of 
Institute of Astronomy, Kharkiv National University starting on Sep. 03 
(UT) 01:38:52. We took 11 frames with exposures of 120 seconds in R 
filter. On the stacked image within 1.5 arcmin of error circle 
localization (Mereghetti et al., GCN 15169) we do not detect any
source.

Photometry of combined image is the following

T_start, T0+,    Exp.,  Filter, UL (3 sigma)
(UT) mid (d)     (s)

01:38:52 0.03579 11*120 R       >20.0

and based on SDSS stars, R (gri -> R transformations by Lupton 2005):

# SDSS R Err_R
1 J052835.34-000624.7 15.543 0.013
2 J052817.12-000749.0 14.650 0.012
3 J052841.64-000642.3 14.233 0.013


GRB_name: GRB130831A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15242
SUBJECT: GRB 130831A: RATIR Confirmation of NIR/Optical Afterglow Flattening
DATE:    13/09/22 15:05:22 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

William H. Lee (UNAM), Alan M. Watson (UNAM), Nat Butler (ASU), Alexander
Kutyrev (GSFC), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:

We again observed the field of GRB 130831A (Hagen, et al., GCN 15139) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional
on Sierra San Pedro Mrtir from 2013/09 22.11 to 2013/09 22.31 UTC (21.57
to 21.77 days after the BAT trigger), obtaining a total of 6.40 hours
exposure in the r and i bands and 2.60 hours exposure in the Z, Y, J, and H
bands.

For a source within the Swift-XRT error circle (Evans et al., GCN 15147),
in comparison with SDSS DR9 and 2MASS, we obtain the following detections
and upper limits (3-sigma):

  r     23.02 +/- 0.14
  i     22.78 +/- 0.13
  Z     > 22.87
  Y     > 22.35
  J     21.62 +/- 0.19
  H     > 21.75

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The flux levels are consistent
with our prior upper limits measured 4 days after the GRB (Butler et al.,
GCN 15179) and with the measurements reported by Pozanenko et al. (GCN
15237), confirming a flattening of the afterglow light curve.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB130702A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15243
SUBJECT: GRB 130702A: RTT150 optical observations
DATE:    13/09/23 09:59:57 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

G. Khorunzhev, A. Volnova, A. Pozanenko, 
R. Burenin, M. Pavlinsky, R.  Sunyaev (IKI), 
I. Bikmaev, N. Sakhibullin (KFU/AST), 
I. Khamitov, H.  Kirbiyik (TUG) 

report:

We observed the afterglow of Fermi GRB 130702A (Singer et al., GCN
14967, Cheung et al., GCN 14971; Collazzi et al., GCN 14972), and
their progenitor Supernova SN 2013dx (Schulze et al. GCN 1994; Cenko
et al. GCN 14998) with Russian-Turkish 1.5-m telescope (RTT150,
Bakirlitepe, TUBITAK National Observatory, Turkey) on Aug., 28 starting
at UT 18:21:58. We obtained several images with exposure of 300
seconds in R band. A preliminary photometry of the GRB afterglow + SN
2013dx + host galaxy, based on two SDSS stars suggested by Schulze et
al. (GCN 14978):

T_start              T0+       Filter, Exposure,   OT
(UT)                 (mid, d)            (s)

2013-08-28T18:21:58  57.74046  R       6x300       21.47+/-0.08


GRB_name: GRB130831A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15244
SUBJECT: GRB 130831A: RTT150 optical observations
DATE:    13/09/23 12:08:11 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

G. Khorunzhev, R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
I. Bikmaev, N. Sakhibullin (KFU/AST), 
I. Khamitov, H.  Kirbiyik (TUG) 

report:

The optical afterglow of GRB 130831A (GCN 15139, D. Palmer) was
observed with 1.5-m Russian-Turkish Telescope RTT150 at Bakyrlytepe
(TUBITAK National Observatory, Turkey). The observation started at
2013-09-01 00:42:03 UT, appr. 12 hours after the burst.

Two images each with exposure 300 seconds were obtained in R-band:

1. UT = 00:42:03.678; t-t0 = 11.630h; m_R = 19.57 +- 0.02
2. UT = 00:48:35.373; t-t0 = 11.739h; m_R = 19.62 +- 0.03
 
Images are calibrated using stars proposed by Pozanenko et al. (GCN
15190). The magnitudes are not corrected for the Galactic extinction.


GRB_name: GRB130925A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15246
SUBJECT: GRB 130925A: Swift detection of a burst
DATE:    13/09/25 04:26:41 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL),
J. L. Racusin (NASA/GSFC), M. H. Siegel (PSU) and T. N. Ukwatta (MSU)
report on behalf of the Swift Team:

At 04:11:24 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130925A (trigger=571830).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 41.183, -26.134 which is 
   RA(J2000) = 02h 44m 44s
   Dec(J2000) = -26d 08' 03"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed that the burst
was active during the pre-planned slew before the nominal trigger
with an additional peak extending at least to T+170. The peak count
rate was ~2700 counts/sec (15-350 keV), at ~110 sec after the trigger. 

The XRT began observing the field at 04:13:52.3 UT, 147.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 41.1766, -26.1544 which is equivalent to:
   RA(J2000)  = +02h 44m 42.38s
   Dec(J2000) = -26d 09' 15.8"
with an uncertainty of 5.1 arcseconds (radius, 90% containment). This
location is 76 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 156 seconds after the BAT trigger. No credible 
afterglow candidate has been found in the initial data products. The 
2.7'x2.7' covers 100% of the XRT error circle. The typical 3-sigma
upper limit has been about 19.6 mag. Results from the list  of sources
generated on-board are not available at this time. No correction has
been made for the expected extinction corresponding to E(B-V) of
0.02. 

Burst Advocate for this burst is A. Y. Lien (yarleen 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: GRB130925A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15247
SUBJECT: GRB 130925A: GROND afterglow candidate
DATE:    13/09/25 06:05:22 GMT
FROM:    Vladimir Sudilovsky at MPE  <vsudilov@mpe.mpg.de>

V. Sudilovsky (MPE Garching), D.A. Kann, and J. Greiner
(all MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 130925A (Lien et al., GCN #15246)
simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla
Observatory (Chile).

The first epoch observation started at 04:18:52 UT on 25 Sept 2013,
7 minutes after the GRB trigger. They were performed at an average
seeing of 0.7" and at an average airmass of 1.3. We do not find any
sources within the revised 3".6 Swift XRT error circle. However, we do
find an uncataloged red source 2" east of the error circle at position:

RA  (J2000) = 02:44:42.96 = 41.1790
Dec. (J2000) = -26:09:11.16 = -26.1531

with an uncertainty of 0.3" in each coordinate.

Based on a total exposure of 4.4 minutes in g'r'i'z' and 4 minutes in
JHK, we estimate preliminary magnitudes (all in AB) of

g' > 21.5 mag,
r' > 22 mag,
i' = 21.8  0.1 mag,
z' = 21.3  0.1 mag,
J = 19.6  0.1 mag,
H = 18.6  0.1 mag, and
K = 18.0  0.1 mag.

The source is seen to be brightening in the first images before
fading strongly. We suggest this source to be the afterglow of GRB
130925A.

Given magnitudes are calibrated 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) = 0.02
mag in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB130925A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15248
SUBJECT: GRB 130925A: MAXI/GSC detection
DATE:    13/09/25 08:31:49 GMT
FROM:    Satoshi Nakahira at JAXA/MAXI  <nakahira.satoshi@jaxa.jp>

K. Suzuki, H. Sakakibara, H. Negoro (Nihon U.),
S. Nakahira, H. Tomida, S. Ueno, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA),
T. Mihara, M. Sugizaki, M. Morii, M. Serino, T. Yamamoto, J. Sugimoto,
T. Takagi, M. Matsuoka (RIKEN),
N. Kawai, R. Usui, K. Ishikawa, T. Yoshii (Tokyo Tech),
A. Yoshida, T. Sakamoto, Y. Nakano (AGU),
H. Tsunemi, M. Sasaki (Osaka U.),
M. Nakajima, K. Fukushima, T. Onodera (Nihon U.),
Y. Ueda, M. Shidatsu, T. Kawamuro (Kyoto U.),
Y. Tsuboi, M. Higa (Chuo U.),
M. Yamauchi, K. Yoshidome, Y. Ogawa, H. Yamada (Miyazaki U.),
K. Yamaoka (Nagoya U.)
report on behalf of the MAXI team:

The MAXI/GSC Nova alert system triggered a bright uncatalogued X-ray transient source at
UT 2013-09-25T05:13:41.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(41.38 deg, -25.91 deg) = (02 45 32, -25 54 54)(J2000)
with a 90% C.L. statistical error of 0.2 deg and an additional systematic uncertainty
of 0.1 deg (90% containment radius).
The position is consistent with that of GRB 130925A (Lien et al. GCN #15246),
and apart from GRB 130925A by 0.30 deg.
This detection is, however, about 1 hour after the Swift detection.
The 2-20 keV flux was 290 (-51/+53) mCrab. An absorbed power-law fit to the burst spectrum
gives a photon index 1.62 +/- 0.27.

There was no significant excess flux in the previous transit at 03:41 UT
and in the next transit at 06:47 UT with an upper limit of 20 mCrab for each.

[GCN OPS NOTE(25sep13): Per author's request, the Lien citation of 12526
was changed to 15246.]


GRB_name: GRB130925A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15249
SUBJECT: GRB 130925A: VLT/UVES observations
DATE:    13/09/25 10:45:42 GMT
FROM:    Paul Vreeswijk at Weizmann Inst of Science  <paul.vreeswijk@weizmann.ac.il>

P. M. Vreeswijk (Weizmann), D. Malesani, J. P. U. Fynbo (DARK/NBI),
A. De Cia (Weizmann) and C. Ledoux (ESO) report:

GRB 130925A (Lien et al., GCN 15246; Suzuki et al., GCN 15248) was
observed with UVES at the ESO-VLT, in Rapid Response Mode, starting at
around 5 UT (50 minutes after the Swift trigger). A series of spectra
were taken of the brightest object near the XRT error circle. We
caution that the small field of view of the UVES acquisition camera
and the lack of nearby bright stars does not allow us to identify this
object unambiguously as the optical counterpart discovered by
Sudilovsky et al. (GCN 15247).

Preliminary analysis of the automatically reduced spectra reveals the
presence of a very faint continuum in the red part and a pair of
emission lines at 8845 A and 8873 A. These lines can be identified
with Halpha and [NII] 6585 at a redshift of z=0.347.

We are grateful for the excellent support at Paranal provided by
Jonathan Smoker and Patricia Guajardo, and we thank D. A. Kann and the
GROND team for showing us a finding chart of the afterglow field.


GRB_name: GRB130925A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15250
SUBJECT: GRB 130925A: VLT/X-shooter redshift
DATE:    13/09/25 11:07:01 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>

V. Sudilovsky, D.A. Kann, P. Schady (all MPE Garching), S. Klose (TLS 
Tautenburg), J. Greiner (MPE Garching), and T. Kruehler (ESO) report:

We observed the optical/NIR afterglow (Sudilovsky et al., GCN 15247) of 
GRB 130925A (Swift trigger 571830, Lien et al., GCN 15246) using ESO/VLT 
UT2 equipped with the X-shooter spectrograph.

Observations started at 07:42 UT on 2013-09-25, about 3.5 hr after the 
Swift trigger. A total exposure of 1.6 hr was obtained, covering the 
spectral range from 3000 to 20500 AA.

In the spectrum we detect emission lines, which we interpret as being due 
to [O II](3726,3729), H_beta, [O III](4959), [O III](5007) and H_alpha at 
a common redshift of z = 0.35, in agreement with Vreeswijk et al. (GCN 
15249).


We thank the Paranal staff for excellent support, in particular Linda 
Schmidtobreick, Jonathan Smoker and Patricia.


GRB_name: GRB130925A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15251
SUBJECT: GRB 130925A: Enhanced Swift-XRT position
DATE:    13/09/25 11:55:00 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 614 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 130925A, 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 = 41.17877, -26.15300 which is equivalent
to:

RA (J2000): 02h 44m 42.91s
Dec (J2000): -26d 09' 10.8"

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: GRB130925A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15252
SUBJECT: GRB 130925A: TAROT La Silla observatory optical observations
DATE:    13/09/25 13:27:30 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A. (IRAP-CNRS-OMP), Gendre B. (IRAP-CNRS-OMP),
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 130925A detected by SWIFT
(trigger 571830) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 88.1s after the GRB trigger
(13.0s after the notice). The elevation of the field increased from
50 degrees above horizon and weather conditions
were good.

We do not detect the afterglow discovered by Sudilovsky
et al. (GCNC 15247, GCNC 15250) and confirmed by Vreeswijk
et al. (GCNC 15249). However, the observations of TAROT
give upper optical limits of the early afterglow.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39):
t0+88.1s to t0+148.1s : Rlim = 17.5

We co-added a series of exposures with diurnal drift:
t0+477s to t0+1081s : Rlim = 19.2

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.


GRB_name: GRB130925A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15253
SUBJECT: GRB 130925A: Initial Similarities to Swift J1644+57
DATE:    13/09/25 14:59:41 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

D. N. Burrows (PSU), D. Malesani (DARK/NBI), A. Y. Lien (NASA/GSFC/ORAU),
S. B. Cenko (NASA/GSFC), and N. Gehrels (NASA/GSFC) report:

At 04:11:24 UT on 25 September 2013, the Swift BAT triggered on an object
denoted as GRB 130925A on the assumption that it is a gamma-ray burst
(Lien et al., GCN 15246).  Here we note that this source presents several
unusual features that are atypical of GRBs.

The initial XRT observations show extremely rapid and dramatic flaring
over the first 10^4 s, far in excess of what we typically see in GRBs.
The high X-ray flux at these relatively late times is likely what resulted
in the detection of this source by MAXI ~ 1 hour after the GRB (Suzuki
et al., GCN 15248).  The Swift/XRT light curve is available at the
following URL:

http://www.swift.ac.uk/xrt_curves/00571830/

We note that this behavior is at first glance similar to the highly
variable soft X-ray light curve observed from Swift J1644+57 (GRB
110328A), which has been interpreted as a newly formed relativistic jet
resulting from the tidal disruption of a star by a super-massive black
hole (Burrows et al. 2011; Levan et al. 2011; Zauderer et al. 2011; Bloom
et al. 2011).  Like Swift J1644+57, GRB 130925A is a BAT image trigger,
is associated with highly absorbed optical/NIR transient emission
(Sudilovsky et al., GCN 15247), and lies at a relatively low redshift
(z = 0.347; Vreeswijk et al., GCN 15249; Sudilovsky et al., GCN 15250).

We encourage observations at all wavelengths to help determine the nature
of this interesting source.


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15254
SUBJECT: GRB 130925A: Swift-XRT refined Analysis
DATE:    13/09/25 15:27:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans, C. Pagani, K.L. Page, A.P. Beardmore, R.L.C. Starling (U.
Leicester) and A. Y. Lien (NASA/GSFC/ORAU) report on behalf of the
Swift-XRT team:

We have analysed 4.7 ks of XRT data for GRB 130925A (Lien et al. GCN
Circ. 15246), from 151 s to 12.0 ks after the BAT trigger. The data
comprise 3.2 ks in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN. Circ 15251).

The light curve behaviour is dominated by sharp, bright flares. The
initial decay follows a power-law with an index of 2.70 (+/- 0.03) and
then breaks at T0+464 (+9,-6) to a virtually flat segment, with a
formal decay index of 0.16 (+0.11, -0.17). At this point the XRT count
rate is 47 ct/sec (approx 2.1e-9 erg cm^-2 s^-1, 0.3-10 keV). Then at
T0+750 a flare begins, which peaks at T0+1000 s at a count rate of ~100
ct/sec. This flare fades steeply to ~8 ct/sec at T0+1240 s at which
point a second, steep and bright flare begins. This peaks at T0+1380 s
at a count rate of ~150 ct/sec. The Swift observations were interrupted
at T0+1503 s as the GRB entered Earth-eclipse; the count-rate by this
time had fallen to ~50 ct/sec.

The MAXI detection (Suzuki et al., GCN Circ. 15248) took place while
the GRB was thus unobservable by Swift and corresponds to an XRT count
rate of ~80 ct/sec.

Swift began observing the GRB again at T0+4.75 ks; the count rate was
~8 ct/sec, but rapidly rising due to another flare which peaked 200 s
later at ~130 ct/sec, and then faded to ~3 ct/sec by T0+6.1 ks. Another
flare began shortly after, at T0+6.6 ks and peaked at T0+7.1 ks at 150
ct/sec. Observations were interrupted soon after this as the GRB again
went into eclipse. The next observation began at T0+10.5 ks at which
time the count rate was ~5 ct/sec but again rising in a flare which
peaked at T0+11.2 ks, at a count rate of ~20 ct/sec. This decayed to ~5
ct/sec by T0+11.6ks and then began to rise again, but the Swift
observations stopped just after this. Further observations are planned.


The time-averaged WT mode spectrum can be modelled with an absorbed
power-law with a photon index of 1.73 (+/-0.02) and an absorption
column of 6.8e21 cm^-2 at z=0.347 (Vreeswijk et al., GCN Circ. 15249)
in addition to the Galactic value of 0.17e21 cm^-2 (Kalberla et al,
2005). However as is typical during flaring episodes, there is strong
spectral evolution during the XRT observations. We therefore extracted
a further 4 spectra, one before the flares and one during each of them.
These spectra were fitted above 0.5 keV to avoid possible instrumental
effects at low energies caused by the accumulation of charge traps due
to radiation damage since the release of the current CALDB WT gain file
(version 13).

In the spectra for the first 2 flares there is evidence for additional
soft emission above the simple power-law. There are known calibration
issues which can cause bumps such as these to appear artificially (see
http://www.swift.ac.uk/analysis/xrt/digest_cal.php#abs) so we extracted
the spectra using only single-pixel events, however the soft component
is still present. It can be well modelled by adding in a thermal
component (reducing the cstat of the fits by ~120). In the first flare
this has a temperature of 33 (+/-3) eV, and in the second flare 45 (+/-
6) eV. 

Details of the power-law fits are given below (for the first two flare
spectra these are the fits which include the soft component); note that
it is likely that some spectral evolution occurred during the flares,
thus these are still aggregated values. As for the time-averaged fit,
the Galactic column was fixed to 0.17e21 cm^-2 (Kalberla et al 2005)
and the free absorber was set to have a redshift of z=0.347 (GCN Circ.
15249) 

Pre-flare (T0+ 150-500 s):
NH = 1.66 (+/- 0.05) e22 cm^-2
Gamma = 1.70 (+/- 0.04)

Flare 1 (T0+ 1240-1500 s)
NH = 2.2 (+/- 0.1) e22 cm^-2
Gamma = 2.28 (+/- 0.06)

Flare 2 (T0+ 4650-6100 s)
NH = 1.59 (+/- 0.07) e22 cm^-2
Gamma = 2.03 (+/- 0.04)

Flare 3 (T0+ 6700-7300 s)
NH = 1.66 (+/- 0.06) e22 cm^-2
Gamma = 1.79 (+/- 0.03)

Flare 4 (T0+11.5-12.9 ks)
NH = 1.3 (+/- 0.2) e22 cm^-2
Gamma = 2.39 (+/- 0.2)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00571830.

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


GRB_name: GRB130925A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15255
SUBJECT: Fermi GBM detection of GRB 130925A and a possible precursor
DATE:    13/09/25 16:13:06 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick@ucdconnect.ie>

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

At 04:09:26.73 UT on 25 September 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB130925A (trigger 401774969/130925173),
which was also detected approximately 2 minutes later by Swift (Lien et
al., GCN 15246). The on-ground
calculated location is consistent with the Swift location. The GBM data
show that the event
was still in progress at the time of the Swift trigger. The burst was
sufficiently
bright that a Fermi Automatic Repointing Request (ARR) was triggered. This
event may
not actually be a GRB, as indicated by Burrows et al. (GCN 15253). Downlink
of the full data set for
this event was delayed due to the ARR; more details will be provided when
the data are available.

At 03:56:23.29 UT, 15 minutes prior to the GBM detection of GRB130925A,
GBM triggered and located
GBM trigger 401774186/130925164.  The on-ground calculated location, using
the GBM trigger
data, is RA = 48.3 , DEC = -21.8  (J2000 degrees,
equivalent to 03h 13m, -21d 42.0'), with an uncertainty
of 12.8  degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).
This is also consistent with the Swift location of GRB130925A
(Lien et al., GCN 15246). The temporal and positional coincidence indicate
that this may be
a precursor pulse to GRB130925A.

The GBM light curve for this possible precursor consists of a single peak
with a duration (T90) of about 6.6 s (50-300 keV).
The time-averaged spectrum from T0-4 s to T0+2.5 s is
adequately fit by a simple power law function with index -2.25 +/- 0.07

The event fluence (10-1000 keV) in this time interval is
(6.9 +/- 0.6)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-3 s in the 10-1000 keV band is 3.0 +/- 0.2 ph/s/cm^2.


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15256
SUBJECT: GRB 130925A: Historical non-detection from Rosat-HRI
DATE:    13/09/25 17:03:21 GMT
FROM:    Jonathan Gelbord at PSU/Swift  <jgelbord@gmail.com>

J. M. Gelbord (Eureka Scientific) reports:

Historical X-ray data covering the position of GRB 130925A (Evans et al., GCN Circ 15246) is available from the ROSAT archive at HEASARC.  The deepest data set is a 5.5 ks observation with the ROSAT HRI taken 1997-07-01, in which the position of GRB 130925A is 9' off axis.  There is no trace of an X-ray source at this position.

Using a source extraction region of 24" and a concentric annular background region from 80" to 240", formally I find 0.2 +/- 3.6 counts in the HRI band.  The three sigma upper limit is 14.8 counts (using the Bayesian approach of Kraft, Burrows & Nousek 1991, ApJ 374, 344).  Given the nominal exposure time of 5.5 ks, this translates to 2.7E-03 HRI counts per sec.

We use WebPIMMS ( http://heasarc.gsfc.nasa.gov/Tools/w3pimms.html ) to convert the 3-sigma HRI count rate limit to a limit in the Swift-XRT band.  Assuming the auto-generated spectral model for GRB 130925A (available from http://www.swift.ac.uk/xrt_products/00571830 ) fitted to the XRT PC-mode data for GRB 130925A (through T0+29.8 ks; NH (intrinsic) = 9.4E+21, Gamma = 2.61), together with NH (Galactic) = 1.66E+20 and z=0.347 (Vreeswijk et al., GCN Circ 15249 and Sudilovsky et al., GCN Circ 15250), the 3-sigma HRI count rate limit translates to an XRT count rate of 5.7E-3 counts per second.  If we instead adopt the harder spectral model resulting from the fit to the WT-mode data (NH (Intrinsic) = 6.8E+21 and Gamma = 1.73), the equivalent XRT count rate would be 7.8E-3 counts per second.

Thus, the Rosat HRI upper limit reveals that GRB 130925A at T0+200s was at least 10^6 times brighter and at T0+30ks was still at least 100 times brighter than any X-ray source at this position in July 1997.


GRB_name: GRB130925A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15257
SUBJECT: GRB 130925A Swift-BAT refined analysis
DATE:    13/09/26 00:03:46 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

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

Using the data set from T-239 to T+7152 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 130925A (trigger #571830)
(Lien, et al., GCN Circ. 15246).  The BAT ground-calculated position is
RA, Dec = 41.186, -26.146 deg which is
    RA(J2000)  =  02h 44m 44.5s
    Dec(J2000) = -26d 08' 47.4"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 9%.

The mask-weighted light curve covers only a small part of this exceptionally
long GRB (if indeed it is a GRB at all).  As reported by the Fermi-GBM team
(Fitzpatrick, GCN Circ. # 15255) the event may have begun 17 minutes prior to
the BAT trigger, and the source was still detected in BAT at T+2 hours.  Thus
we cannot estimate a T90 at this time.  There were multiple peaks and several
late-time flares.

In the current analysis, the burst was first detected by BAT at T-59 sec, when
the target entered the BAT field of view already emitting, and last detected by
BAT in a survey interval ending at T+7152 sec.

BAT also detected a flux increase during the first flare detected by XRT (Evans
et al. GCN Circ. # 15254) that peaked at about T+1000 seconds.  BAT did not see
a significant increase at the time of the next flare (brightest in XRT), peaking
at about T+1380 seconds, though the source was still detected.  BAT did strongly
detect increases during the XRT-observed flares that peaked at approximately
T+4950 and T+7100 seconds.  BAT did not detect emission during another, smaller,
flare observed by XRT that peaked at about T+11000 seconds.

BAT has not detected significant flux from this location in the 15-50 keV band
prior to the current event.

The time-averaged spectrum from T-59 to T+903 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.85 +- 0.14,
and Epeak of 33.4 +- 20.0 keV (chi squared 38.18 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 4.1 +- 0.1 x 10^-05 erg/cm2
and the 1-sec peak flux measured from T-35.64 sec in the 15-150 keV band is
7.3 +- 0.6 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.09 +- 0.04 (chi squared 45.62 for 57 d.o.f.).  The flares at T+4950 and
T+7100 seconds have photon indices in simple power-law fits of 2.19 +- 0.36
and 2.34 +- 0.28 respectively.  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/571830/BA/


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15258
SUBJECT: GRB 130925A: RATIR Optical and NIR Observations
DATE:    13/09/26 01:55:31 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:

We observed the field of GRB 130925A (Lien, et al., GCN 15246) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/09 25.27 to 2013/09 25.50 UTC (2.30 to
7.81 hours after the BAT trigger), obtaining a total of 3.67 hours exposure
in the r and i bands and 1.43 hours exposure in the Z, Y, J, and H bands.

We find an uncatalogued source in the enhanced Swift-XRT error circle
(Evans et al., GCN 15251).  In comparison with USNO-B1 and 2MASS, we obtain
the following detections and upper limits (3-sigma):

  r     22.26 +/- 0.11
  i     21.75 +/- 0.10
  Z     20.25 +/- 0.06
  Y     20.77 +/- 0.14
  J     19.98 +/- 0.07
  H     19.85 +/- 0.12

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The source is spatially coincident
and about as bright as the source reported by Sudilovsky et al. (GCN
15247), which was observed minutes rather than hours after the GRB.
 Further observations are planned.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB130925A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15260
SUBJECT: Konus-Wind observation of GRB 130925A
DATE:    13/09/26 15:36:02 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The very long GRB 130925A
(Swift-BAT trigger #571830: Lien et al., GCN 15246;
Markwardt et al., GCN 15257;
MAXI/GSC detection: Suzuki et al., GCN 15248;
Fermi/GBM detection: Fitzpatrick, GCN 15255;
INTEGRAL/SPI-ACS observation: Savchenko et al., GCN 15259)
was detected by Konus-Wind in the waiting mode.

The light curve shows several multi-peaked pulses separated
by long periods of a low-level emission with a total duration of ~4500 s.
At least three major emission episodes can be distingushed:
the first one, which triggered BAT, started at ~T0(BAT)-130 s
and lasted until ~T0(BAT)+170 s; the second, more fluent episode,
from ~T0(BAT)+1750 s to ~T0(BAT)+2950 s;
and the third, the weakest one, which onset corresponds
to the MAXI detection, from ~T0(BAT)+3730 s to ~T0(BAT)+4360 s.

The possible precursor detected by GBM is clearly seen
at ~T0(BAT)-900 s in the softest KW energy band.

As observed by Konus-Wind, the burst had a fluence of
(5.0  0.1)x10^-4 erg/cm2 and a 2.944-s peak energy flux,
measured from T0(BAT)+2548.858, of (1.0  0.03)x10^-6 erg/cm2
(both in the 20 - 10000 keV energy range).

The emission shows no signs of strong spectral variability.
Modeling the KW 3-channel time-integrated spectrum
(from T0(BAT)-120 s to T0(BAT)+4340 s) by a power law
with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.42  0.04, and Ep = 181  10 keV.

Assuming z = 0.347 (Vreeswijk et al., GCN 15249) and a
standard cosmology model with H_0 = 71 km/s/Mpc, Omega_M = 0.27,
Omega_Lambda = 0.73,
the isotropic energy release E_iso = (1.50  0.03)x10^53 erg,
the peak isotropic luminosity L_iso = (4.0  0.1)x10^50 erg,
and Ep_rest is 244   13 keV.

Thus, the prompt gamma-ray emission properties of this GRB: fluence, Ep,
and E_iso are similar to those observed in other long energetic GRBs;
the only outstanding feature of the burst is its huge duration.
In that, it resembles other ultra-long bursts: GRB 111209A at z=0.677
(with total duration of ~10000 s: Golenetskii et al., GCN 12663)
and GRB 121027A at z=1.77 (with a total duration of >4000 s: Starling et al.,
in preparation).
Therefore, we suggest that the extremely rapid and dramatic X-ray flaring
observed over the first 10^4 s after the BAT trigger (Evans et al., GCN 15254)
at least partially corresponds to the burst prompt emission.

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

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB130925A/


GRB_name: GRB130925A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15261
SUBJECT: GRB 130925A: Fermi GBM Detection
DATE:    13/09/26 15:42:20 GMT
FROM:    Peter Jenke at MSFC  <peter.a.jenke@nasa.gov>

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

"At 04:09:26.73 UT on September 25 2013, the Fermi Gamma-Ray
Burst Monitor triggered and located 
GRB 130925A (trigger 401774969/130925173), 
which was also detected by Swift (Lien et al. GCN 15246)
and MAXI (Suzuki et al., GCN 15248).

The trigger resulted in an Autonomous Repoint Request (ARR) 
that was accepted and the LAT slewed to the GBM in-flight 
location which was consistent with the Swift/XRT position 
(Evans et al. GCN 15251).  The angle from the Fermi LAT boresight
is 22 deg from Swift/XRT position.

The GBM light curve consists of multiple peaks with a 
duration (T90) of about 212 s (50-300 keV).
The time-averaged spectrum from T0-6 s to T0+288 s is 
best fit with a power law function with an exponential high-energy 
cutoff parameterized as Epeak = 107 +/- 3 keV and 
an Index = -1.50 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(2.83 +/- 0.06)E-07 erg/cm^2. The 1.0-sec peak photon flux 
measured starting from T0+83 s in the 10-1000 keV band
is 11.5 +/- 0.3 ph/s/cm^2.

This event, although initially classified as a GRB, has been 
shown to exhibit behavior consistent with a Tidal Disruption 
Event (Burrows et al. GCN 15253). Its location suggests that 
it is the same source as 
GBM trigger 401774186/130925164 (G. Fitzpatrick GCN 15255). 

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


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15262
SUBJECT: GRB 130925A: Continued RATIR Optical and NIR Observations
DATE:    13/09/26 17:50:25 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:

We observed the field of GRB 130925A (Lien, et al., GCN 15246) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/09 26.28 to 2013/09 26.51 UTC (26.43 to
31.98 hours after the BAT trigger), obtaining a total of 3.66 hours
exposure in the r and i bands and 1.12 hours exposure in the Z, Y, J, and H
bands.

For the uncatalogued source in the enhanced Swift-XRT error circle (Evans
et al., GCN 15251) reported previously (Butler et al., GCN 15258), in
comparison with 2MASS, we obtain the following detections and upper limit
(3-sigma):

 r      22.29 +/- 0.16
 i      21.36 +/- 0.13
 Z      > 21.5
 Y      21.28 +/- 0.29
 J      19.69 +/- 0.06
 H      20.02 +/- 0.17

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  Compared to our observations the
night before (GCN 15258), the source has apparently remained approximately
constant in flux in all bands.   We cannot determine, as did Sudilovsky et
al. (GCN 15247), that the source is fading.


We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB130925A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15263
SUBJECT: GRB 130925A: optical upper limit
DATE:    13/09/27 10:43:49 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), N. Minikulov (Institute of Astrophysics), S. Abdulaev 
(Institute of Astrophysics), I. Molotov (KIAM), A. Pozanenko (IKI) 
report on behalf of  larger GRB follow-up collaboration:

We observed the  field of GRB 130925A (Lien, et al., GCN 15246) with 
AZT-8 (0.7m) telescope of Gissar observatory in R filter starting on 
Sep. 25 (UT) 22:15. We do not detect optical afterglow (Sudilovsky et 
al., GCN 15247). A preliminary photometry of combined image is following

T_start              T0+       Filter, Exposure, OT,  UL(3 sigma)
(UT)                 (mid, d)            (s)

2013-09-25T22:16:55  0.7766    R       60x60     n/d  19.9


The photometry is based on the reference star USNO-B1.0 0638-0038928
RA 02:45:02.36 Dec -26:10:50.2 (J2000), assuming R = 17.07


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15264
SUBJECT: GRB 130925A: sub-mm non-detection with SMA
DATE:    13/09/27 10:47:02 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

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

"We observed the position of GRB 130925A (Lien et al., GCN 15246) beginning
2013 Sep 26.31 UT
(dt = 1.1 d) with the SMA at a mean frequency of 230 GHz.  We find no
significant radio emission
at the position of the enhanced Swift-XRT position (Evans et al., GCN
15250) to a 3-sigma limit of 1.89 mJy.
Observations are ongoing.

We thank the SMA staff for prompt execution of these observations."


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15265
SUBJECT: GRB 130925A: sub-mm non-detection with SMA
DATE:    13/09/27 10:50:00 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

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

"We observed the position of GRB 130925A (Lien et al., GCN 15246) beginning
2013 Sep 26.31 UT
(dt = 1.1 d) with the SMA at a mean frequency of 230 GHz.  We find no
significant radio emission
at the position of the enhanced Swift-XRT position (Evans et al., GCN
15250) to a 3-sigma limit of 1.89 mJy.
Observations are ongoing.

We thank the SMA staff for prompt execution of these observations."


GRB_name: GRB130925A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15266
SUBJECT: GRB 130925A: Swift/UVOT Upper Limits
DATE:    13/09/27 11:37:03 GMT
FROM:    Stephen Holland at STScI  <sholland@stsci.edu>

S. T. Holland (STScI) and
A. Y. Lien (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:

    The Swift/UVOT began settled observations of the field of GRB
130925A 157 s after the BAT trigger (Lien et al. 2013, GCNC 15246).
We do not detect any new source consistent with the GROND afterglow
position (Sudilovsky et al. 2013, GCNC 15247) in any of the UVOT
exposures.  Preliminary 3-sigma upper limits, using the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373),
for the finding chart and summed exposures are presented below.

---------------------------------------------------
Filter        TSTART     TSTOP   Exposure       Mag
---------------------------------------------------
white (FC)      157        306        147     >21.4
    u (FC)      315        564        246     >20.6
---------------------------------------------------
    v           645       7269        381     >20.0
    b           571       6121        170     >20.6
    u           719       5983        274     >20.4
 uvw1          5579     11,956        701     >21.1
 uvm2          5374     11,436       1082     >21.2
 uvw2          4964       7136        393     >20.7
white           595       6929        618     >22.0
---------------------------------------------------

    The quoted upper limits have not been corrected for the expected
extinction due to the Galactic reddening along the line of sight to
this burst of E(B-V) = 0.02 mag (Schlafly et al. 2011, ApJS, 737,
103).


GRB_name: GRB130925A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15267
SUBJECT: GRB 130925A: Swift/UVOT Detection of the Host Galaxy 
DATE:    13/09/27 18:22:43 GMT
FROM:    Stephen Holland at STScI  <sholland@stsci.edu>

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

     Deep Swift/UVOT imaging taken between 157 s and 184.8 ks after
the BAT trigger (Lien et al, 2013, GCNC 15246) shows a faint source at
the location of the GROND detection (Sudilovsky et al. 2013, GCNC
15247).  This source has a preliminary magnitude, on the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373),
of white = 22.9 +/- 0.3 mag and is detected with a significance of 4.7
sigma.  This magnitude has not been corrected for the expected
extinction due to the Galactic reddening along the line of sight to
this burst of E(B-V) = 0.02 mag (Schlafly et al. 2011, ApJS, 737,
103).  The total white exposure time is 18 ks.  There is no evidence
for variability.

     The probability of finding a galaxy of this apparent luminosity
within the UVOT-enhanced XRT error circle (Evans et al. 2013, GCNC
15251) is 0.01 using the method of Bloom et al. (2002, AJ, 423, 1111).
The positional coincidence and lack of variability suggest that this
is the host galaxy of GRB 130925A.  There is no evidence in the UVOT
data that this source has any extended structure.


GRB_name: GRB130925A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15268
SUBJECT: Fermi LAT Upper Limits on GRB 130925A
DATE:    13/09/28 00:03:12 GMT
FROM:    Daniel Kocevski at SLAC  <dankocevski@gmail.com>

D. Kocevski, J. Racusin (NASA/GSFC), G. Vianello (Stanford), M. Axelsson
(Stockholm University), Nicola Omodei (Stanford) report on behalf of the
Fermi-LAT team:

A preliminary examination of the Fermi LAT data of the field containing GRB
130925A (Lien, et al., GCN 15246) has revealed no significant emission
above 40 MeV. The GRB was located ~22 degrees away from the LAT boresight
at the time of the first GBM detected emission associated with this burst
at 03:56:23.29 UT on 25 September 2013 (GCN 15255), hereafter T0(GBM), and
the subsequent autonomous repoint ensured that the source remained in the
field-of-view for the next ~2000s until it was occulted by the Earth.

Using an unbinned likelihood analysis, we estimate the following LAT upper
limits at 95% confidence for three separate time intervals, one covering
the entire 2000s that the source stayed in the LAT field-of-view, and two
of which correspond to the first and third emission episodes detected by
INTEGRAL/SPI-ACS (GCN 15259) and Konus-Wind (GCN 15260). We note that the
source was not in the LAT field-of-view during the second interval reported
in GCNs 15259 & 15260.

Interval 1: T0(GBM) to T0(GBM)+2000 = 7.3e-07 photons cm-2 s-1 (4.8e-10
ergs cm-2 s-1)
Interval 2: T0(GBM)+900s to T0(GBM)+1100s = 5.5e-06 photons cm-2 s-1
(3.6e-09 ergs cm-2 s-1)
Interval 3: T0(GBM)+4900 to T0(GBM)+5400 = 2.5e-06 photons cm-2 s-1
(1.6e-09 ergs cm-2 s-1)

This analysis covers an energy range of 0.1 to 10 GeV with a 12 deg
extraction region centered on the best known source position (GCN 15246).
 The upper limits are computed using the P7SOURCE_V6 instrument response
functions, where we assume a power-law source spectrum fixed to a photon
index of -2.1, reflecting a typical value for high-energy emission in GRBs.
For reference, T0(GBM) = T0(BAT)-900s.

The Fermi LAT point of contact for this burst is Magnus Axelsson (
magnusa@astro.su.se).

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


GRB_name: GRB130929A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15269
SUBJECT: GRB 130929A: Swift detection of a burst
DATE:    13/09/29 10:07:59 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

F. E. Marshall (NASA/GSFC), J. R. Cummings (NASA/UMBC),
J. A. Kennea (PSU), C. Pagani (U Leicester), K. L. Page (U Leicester),
M. H. Siegel (PSU) and T. N. Ukwatta (MSU) report on behalf of the
Swift Team:

At 09:36:33 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130929A (trigger=572308).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 135.069, -47.565 which is 
   RA(J2000) = 09h 00m 17s
   Dec(J2000) = -47d 33' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
structure with a duration of about 10 sec.  The peak count rate
was ~3407 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 09:38:14.6 UT, 101.5 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 135.0241, -47.5605
which is equivalent to:
   RA(J2000)  = 09h 00m 05.78s
   Dec(J2000) = -47d 33' 37.9"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 110 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

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

UVOT took a finding chart exposure of 150 seconds with the White 
filter  starting 280 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 0% of the  XRT error circle. The 8'x8'
region for the  list of sources  generated on-board covers 100% of the
XRT error  circle. The list of sources is  typically complete to about
18 mag. No  correction has been made for the large,  but uncertain
extinction  expected. 

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: GRB130929A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15270
SUBJECT: GRB 130929A: TAROT La Silla observatory optical observations
DATE:    13/09/29 11:59:55 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A. (IRAP-CNRS-OMP), Gendre B. (IRAP-CNRS-OMP),
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 130929A detected by SWIFT
(trigger 572308) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 38.0s after the GRB trigger
(15.1s after the notice). The elevation of the field increased from
45 degrees above horizon and weather conditions
were partially cloudy.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+38.0s to t0+98.0s : Rlim = 13.6

The second image is 30.0s exposure in tracking mode:
t0+112s to t0+142s : Rlim = 14.4

We co-added a series of exposures:
t0+112s to t0+303s : Rlim = 15.1

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon=268.1127 lat= -0.9424
and the galactic extinction in R band is about 8 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.


GRB_name: GRB130929A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15271
SUBJECT: GRB 130929A: Enhanced Swift-XRT position
DATE:    13/09/29 14:59:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 2970 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 130929A, 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 = 135.02362, -47.56076 which is equivalent
to:

RA (J2000): 09h 00m 5.67s
Dec (J2000): -47d 33' 38.7"

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: GRB130929A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15272
SUBJECT: GRB 130929A, Swift-BAT refined analysis
DATE:    13/09/29 17:14:26 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
F. E. Marshall (NASA/GSFC), T. Sakamoto (AGU), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
  
Using the data set from T-70 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 130929A (trigger #572308)
(Marshall, et al., GCN Circ. 15269).  The BAT ground-calculated position is
RA, Dec = 135.028, -47.554 deg which is
    RA(J2000)  =  09h 00m 06.7s
    Dec(J2000) = -47d 33' 14.6"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 44%.
  
The mask-weighted light curve shows a single FRED peak.  T90 (15-350 keV) is
11.10 +- 2.98 sec (estimated error including systematics).
  
The time-averaged spectrum from T-1.93 to T+11.50 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.00 +- 0.18.  The fluence in the 15-150 keV band is 6.9 +- 0.8 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+1.32 sec in the 15-150 keV band
is 1.7 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.
  
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/572308/BA/


GRB_name: GRB130929A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15273
SUBJECT: GRB 130929A: Swift-XRT refined Analysis
DATE:    13/09/30 05:08:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U.
Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), P.
D'Avanzo (INAF-OAB), V. Mangano (PSU), M.C. Stroh (PSU), D.N. Burrows
(PSU) and F.E. Marshall report on behalf of the Swift-XRT team:

We have analysed 13 ks of XRT data for GRB 130929A (Marshall  et al.
GCN Circ. 15269),  from 237 s to 45.5 ks after the  BAT trigger. The
data are entirely in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Goad et al. (GCN. Circ 15271).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.23 (+0.13, -0.10).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+0.7, -0.6). The
best-fitting absorption column is  3.3 (+1.3, -1.0) x 10^22 cm^-2, in
excess of the Galactic value of 7.1 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 7.8 x 10^-11 (2.8 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.3 (+1.3, -1.0) x 10^22 cm^-2
Galactic foreground: 7.1 x 10^21 cm^-2
Excess significance: 4.1 sigma
Photon index:      2.2 (+0.7, -0.6)

If the light curve continues to decay with a power-law decay index of
1.23, the count rate at T+24 hours will be 4.6 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.6 x
10^-14 (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/00572308.

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


GRB_name: GRB130831A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15274
SUBJECT: GRB 130831A: Continued RATIR Optical and NIR Observations
DATE:    13/09/30 16:17:13 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

William H. Lee (UNAM), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), Nat
Butler (ASU), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC),
Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:

We observed the field of GRB 130831A (Hagen, et al., GCN 15139) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/09 30.12 to 2013/09 30.49 UTC (29.58 to
29.94 days after the BAT trigger), obtaining a total of 6.27 hours exposure
in the r and i bands and 2.65 hours exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle (Evans et al., GCN 15147),
in comparison with 2MASS, we obtain the following detections and upper
limits (3-sigma):

  r     23.84 +/- 0.18
  i     23.23 +/- 0.15
  Z     > 23.04
  Y     > 22.53
  J     > 22.37
  H     > 21.72

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.  The source has faded relative to
our last measurement (t~21.5 days; Lee et al., GCN 15242) by about 0.8
magnitudes in r and J and 0.5 magnitudes in i.  Our measurements (see,
also, Watson et al., GCN 15179; Butler et al., GCN 15165) are consistent
with a bump or re-brightening in the lightcurve at t~10 days (see,
Pozanenko et al., GCN 15237), followed by continued fading.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB130929A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15275
SUBJECT: GRB 130929A: Swift/UVOT Upper Limits
DATE:    13/09/30 18:07:07 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 130929A
280 s after the BAT trigger (Marshall et al., GCN Circ. 15269).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 15271) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC           280          430          147         >21.0
white              280         1008          334         >21.4
v                  586         4628          236         >19.7
b                  512          705           39         >19.0
u                  487        10592          709         >20.6
w1                 462         6710          255         >19.6
m2                 437         6505          308         >19.7
w2                 562         4423          236         >19.7

The magnitudes in the table are not corrected for the 
large Galactic extinction in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB130930A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15276
SUBJECT: GRB 130930A: Swift detection of a burst
DATE:    13/09/30 19:32:49 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

T. N. Ukwatta (MSU), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),
D. Kocevski (NASA/GSFC/ORAU), H. A. Krimm (CRESST/GSFC/USRA),
K. L. Page (U Leicester) and T. Sakamoto (AGU) report on behalf of the
Swift Team:

At 19:09:32 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130930A (trigger=572489).  
The BAT on-board calculated location is 
RA, Dec 190.661, -35.502 which is 
   RA(J2000) = 12h 42m 39s
   Dec(J2000) = -35d 30' 08"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual with image triggers, the BAT 
light curve showed no significant structure. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 03:51 UT on 2013 November 26. There will thus be no XRT
or UVOT data for this trigger before this time. 

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


GRB_name: GRB130925A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15278
SUBJECT: IPN Observations of GRB 130925A
DATE:    13/09/30 22:05:33 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley, on behalf of the IPN team, 

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

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

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

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

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

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

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

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

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

Eight IPN spacecraft observed GRB 130925A (Lien et al. GCN 15246,
Markwardt et al. 15247).  When the responses of all the spacecraft are
considered, the IPN had an uninterrupted view of this event from
roughly 900 s before the Swift BAT trigger, to ~7100 s after it.
Constraints on the arrival directions of the four main emission
episodes strengthen the case for their common origin, as suggested by
Savchenko et al. (GCN 15259).  The following table details the
observations.  The times are relative to the BAT trigger at 15084 s UT
(04:11:24).  N/O means the episode was not observable.

 ----------------------------------------------------------------------------
 Instrument/ |    Precursor |   1st         |   2nd          |    3rd
 spacecraft  |      -900 s  | episode       | episode        |  episode*
             |              | -130 -> +170 s|+1750 -> +2950 s|+3730 -> +4360 s
 ----------------------------------------------------------------------------
 Swift BAT          No           Trig            N/O              No
 Fermi GBM          Trig         Trig            N/O              No
 INTEGRAL SPI-ACS   No           Yes             Yes              Yes
 Konus Wind         Yes          Yes             Yes              Yes
 MESSENGER          No           Yes             Yes              No
 Mars Odyssey       No           N/O             Yes              No
 Suzaku WAM         No           No              Yes              No
 RHESSI             Yes          Yes             N/O              No
------------------------------------------------------------------------------
*also observed and localized by MAXI (Suzuki et al. GCN 15248)

We conclude from these observations that the total duration of this
event in >25 keV gamma-rays above the IPN flux/fluence threshold was 
at least 5260 s, and ~7150 s long when the later episodes, observed only
by BAT (GCN 15257), are included.


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15280
SUBJECT: GRB 130925A: continuing Swift/XRT monitoring
DATE:    13/10/01 17:52:33 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI), S. B. Cenko (NASA/GSFC), D. N. Burrows (PSU), A. 
Y. Lien (NASA/GSFC/ORAU), P. A. Evans (U. Leicester), and N. Gehrels 
(NASA/GSFC) report:

Swift has been continuously monitoring the X-ray counterpart of GRB 
130925A (Lien et al., GCN 15246), with data currently extending up to 
512 ks after the trigger. The intense X-ray flaring activity reported by 
Burrows et al. (GCN 15253) and Evans et al. (GCN 15254) ceased between 
12 and 28 ks after the trigger. The X-ray light curve from 27.9 to 512.4 
ks can be modelled with an initial power-law decay with an index of 
alpha = 0.84 +/- 0.03, followed by a possible break at 310 (+60, -50) ks 
to an alpha of 1.38 (+0.47, -0.23). The updated X-ray light curve is 
available at the following URL:

http://www.swift.ac.uk/xrt_curves/00571830/

While the duration of the prompt emission and the flaring activity are 
extraordinary among GRBs (Suzuki et al., GCN 15248; Fitzpatrick, GCN 
15255; Markwardt et al., GCN 15257; Savchenko et al., GCN 15259; 
Golenetskii et al., GCN 15260; Jenke, GCN 15261; Hurley et al., GCN 
15278), the late-time behaviour is typical of long-duration GRB 
afterglows, and quite different from that of the TDE Swift J1644+57, 
which showed continuous flares and dips, with no regular power-law decay 
(e.g. Burrows et al. 2011, Nat, 476, 421). There is also no prior 
detection of the source in BAT before the trigger (Markwardt et al., GCN 
15257).

The extremely long-lived high-energy emission coupled with the 
relatively steady power-law X-ray decay at t > 20 ks is reminiscent of 
the so-called "ultra-long" GRBs (Levan et al. 2013, arXiv:1302.2352), 
including GRB 101225A (Thoene et al. 2011, Nat, 480, 72; Campana et al. 
2011, Nat, 480, 69), GRB 111209A (Gendre et al. 2013, ApJ, 766, 30), and 
GRB 121027A. The origin of these events and their relation to 
traditional long-duration GRBs (i.e., the core-collapse of a massive 
star) remain controversial, so we encourage continued multi-wavelength 
follow-up of this object.


GRB_name: GRB131001A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15281
SUBJECT: GRB 131001A detected in ground analysis of Swift-BAT data
DATE:    13/10/02 03:40:26 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings (UMBC/GSFC) reports on behalf of the Swift-BAT team:

At 2013-10-01T05:37:24, while Swift was slewing, GRB 131001A occurred.  The
BAT lightcurve shows a single 5-second long FRED peak.  In a mosaic of images
created from BAT slew data, a significant source was found at
RA, Dec 8.302, +25.557, which is

RA  (J2000)   00h 33m 12.4s
Dec (J2000)   25d 33' 27"

with an estimated 90% uncertainty radius of 1.8 arcmin.

A Swift TOO has been requested to locate the X-ray afterglow, and approved with
the source ID number20297.  Observations are in progress.


GRB_name: GRB131002A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15282
SUBJECT: GRB 131002A: Faulkes Telescope North optical afterglow
DATE:    13/10/02 07:17:47 GMT
FROM:    Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>

C. Guidorzi (U. Ferrara) on behalf of a large collaboration reports:

The 2-m Faulkes Telescope North automatically began observing GRB
131002A on October 02 2013 at 06:57:26 UT (~3.1 min after the burst 
trigger).

Within the XRT error circle  we find a fading uncatalogued object at
coordinates

RA(2000.0)=   16:52:52.86
Dec(2000.0)=  +82:03:16.4  (error 0.5")

with R=15.2 +- 0.2 mag, calibrated against nearby USNOB-1 stars.


GRB_name: GRB131002A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15283
SUBJECT: GRB 131002A: Swift detection of a burst
DATE:    13/10/02 07:49:31 GMT
FROM:    Caryl Gronwall at PSU/Swift-UVOT  <caryl@astro.psu.edu>

B. N. Barlow (High Point University), V. D'Elia (ASDC), P. A. Evans (U  
Leicester), C. Gronwall (PSU), A. Y. Lien (NASA/GSFC/ORAU), D.  
Malesani (DARK/NBI), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U  
Leicester), T. Sakamoto (AGU), M. H. Siegel (PSU) and M. C. Stroh  
(PSU) report on behalf of the Swift Team:
At 06:54:21 UT, the Swift Burst Alert Telescope (BAT) triggered and  
located GRB 131002A (trigger=572721). Swift slewed immediately to the  
burst. The BAT on-board calculated location is
RA, Dec 253.275, +82.057 which is
RA(J2000) = 16h 53m 06s
Dec(J2000) = +82d 03' 26"
with an uncertainty of 3 arcmin (radius, 90% containment, including  
systematic uncertainty). The BAT light curve showed two pulses with  
total duration of ~50 seconds. The first pulse happened at T0 lasting  
around 2 seconds, with peak count rate of ~3000 counts/sec (15-350  
keV). The second pulse happened at ~T+45 with a duration of around 15  
seconds and peak count rate ~2000 counts/sec (15-350 keV).
The XRT began observing the field at 06:55:27.9 UT, 66.7 seconds after  
the BAT trigger. Using promptly downlinked data we find a bright,  
fading, uncatalogued X-ray source with an enhanced position:
RA, Dec 253.2159, 82.0536 which is equivalent to:
RA(J2000) = 16h 52m 51.83s
Dec(J2000) = +82d 03' 13.0"
with an uncertainty of 2.0 arcseconds (radius, 90% containment). This  
location is 31 arcseconds from the BAT onboard position, within the  
BAT error circle. This position may be improved as more data are  
received; the latest position is available at http://www.swift.ac.uk/sper 
.
A power-law fit to a spectrum formed from promptly downlinked event  
data gives a column density in excess of the Galactic value (5.56 x  
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.6  
(+1.37/-1.25) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 9.38e-10 erg cm^-2 s^-1  
(0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White  
filter starting 869 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 0.08.
Burst Advocate for this burst is B. N. Barlow (bbarlow AT  
highpoint.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: GRB131002B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15284
SUBJECT: GRB 131002B: Swift detection of a burst
DATE:    13/10/02 11:21:59 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

M. C. Stroh (PSU), D. N. Burrows (PSU), V. D'Elia (ASDC),
P. A. Evans (U Leicester), C. Gronwall (PSU), J. A. Kennea (PSU),
P. T. O'Brien (U Leicester), T. Sakamoto (AGU) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 10:54:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131002B (trigger=572742).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 75.061, -75.727 which is 
   RA(J2000) = 05h 00m 15s
   Dec(J2000) = -75d 43' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak 
with a duration of about 40 sec.  The peak count rate
was ~1800 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 10:55:21.3 UT, 52.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 75.1213, -75.7017 which is equivalent to:
   RA(J2000)  = +05h 00m 29.11s
   Dec(J2000) = -75d 42' 06.1"
with an uncertainty of 5.9 arcseconds (radius, 90% containment). This
location is 105 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 7.25e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 62 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 M. C. Stroh (stroh AT astroh.org). 
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: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15286
SUBJECT: NuSTAR observations of GRB 130925A
DATE:    13/10/02 15:16:42 GMT
FROM:    Eric Bellm at Caltech  <ebellm@caltech.edu>

E. C. Bellm, F. A. Harrison, K. Forster, K. K. Madsen, V. Rana
(Caltech), S. E. Boggs, J. Tomsick (U.C. Berkeley), J. M. Miller
(Michigan), and S. B. Cenko (NASA/GSFC) report on behalf of the NuSTAR
collaboration:

NuSTAR observed the unusual ultra-long GRB/TDE candidate GRB 130925A
(GCN 15246) beginning 44.3 hours after the Swift trigger for a total
of 39.2 ksec exposure time.

NuSTAR detects the source to >20 keV; the average 3-20 keV flux over
the interval was 1.3E-12 erg/cm^-2/s^-1.  The data may be fit with an
absorbed power law with spectral index Gamma ~ 3.

NuSTAR observes a broad absorption feature centered near 6 keV.
Simultaneous Swift-XRT spectra support the existence of this feature
at lower SNR.  An F-test of a Gaussian absorption feature fit to the
combined data sets yields a detection significance of 5.5 sigma.
Preliminary searches for features in the early-time XRT data have not
identified any clear signatures; additional tests are ongoing.

Further observations are in progress; we encourage continued
monitoring of this interesting event at all wavelengths.

We thank the NuSTAR Mission Operations Team for the rapid turnaround
that enabled this observation.


GRB_name: GRB131002A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15287
SUBJECT: GRB 131002A: Enhanced Swift-XRT position
DATE:    13/10/02 15:52:22 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 1599 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 131002A, 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 = 253.22092, +82.05433 which is equivalent
to:

RA (J2000): 16h 52m 53.02s
Dec (J2000): +82d 03' 15.6"

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

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

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


GRB_name: GRB131001A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15288
SUBJECT: GRB 131001A: Swift UVOT and XRT Upper Limits 
DATE:    13/10/02 17:32:47 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <dxg35@psu.edu>

A. A. Breeveld (UCL-MSSL), D. Grupe (PSU) and J. R. Cummings
(UMBC/GSFC) report on behalf of the Swift team:

The Swift/UVOT began settled observations of the field of GRB 131001A
79990 s after the BAT trigger (Cummings et al., GCN Circ. 15281).
No optical afterglow consistent with the BAT position (Cummings et al.,
GCN Circ. 15281) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial
exposures are:

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

u                79990        86246          972         >20.94

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

The Swift XRT observed the field of GRB 131001A for a total of 972s. 
No source was found in the BAT error circle. The 3 sigma upper limit
at the position of GRB 131001A applying the method described in Kraft
et al. (1991, ApJ, 374, 344) is 0.01 counts/s.

This circular is an official product of the Swift team.


GRB_name: GRB130930A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15289
SUBJECT: Swift J1242.9-3530, Swift-BAT refined analysis
DATE:    13/10/02 18:43:17 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

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

Using the data set from T0 to T+1699 sec from the recent telemetry downlink,
we report further analysis of Swift J1242.9-3530 (formerly cited as GRB 130930A,
BAT trigger #572489) (Ukwatta, et al., GCN Circ. 15276).  The BAT ground-
calculated position is RA, Dec = 190.725, -35.511, which is
RA (J2000)      12h 42m 53.9s
Dec (J2000)     -35d 30' 40"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.

The mask-weighted light curve varies slowly over the duration of the observation.
The emission appears to extend before and after the observation so we cannot
determine a T90 interval.

The time-averaged spectrum from T0 to T0+1699 sec is best fit by a simple power-
law model.  The power-law index of the time-averaged spectrum is 1.90 +- 0.18.
The fluence in the 15-150 keV band is (3.9 +/- 0.4) x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.00 sec in the 15-150 keV band
is 0.036 +- 0.004 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The source is also detected at a similar intensity in ground analysis of an
earlier observation, from T0-46108 to T0-44561 seconds, but is not detected
in an observation with a similar pointing from T0-51899 to T0-50201 seconds.
The 90% confidence upper limit is 0.2 times the intensity observed later.
We note that the location of the source is 27 degrees from the Galactic plane
and not in the direction of the Galactic center.

The narrow-field instruments of Swift cannot observe this location until late
November at the earliest due to the proximity of the Sun.

The data included in the automated analysis covers only T-239 to T+963 seconds.
The results of the batgrbproduct automated analysis will be available if the US
government ever returns to normal operations at
http://gcn.gsfc.nasa.gov/notices_s/572489/BA/


GRB_name: GRB131002A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15290
SUBJECT: GRB 131002A: ISON-NM optical observations
DATE:    13/10/02 19:06:52 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed optical transient(Guidorzi et al., GCN 15282)  of  the Swift 
GRB 131002A (Barlow et al., GCN 15283)  with 0.4-m SANTEL-400AN 
telescope of ISON-NM observatory starting on Oct., 2 (UT) 06:55:23 (i.e. 
58 s after burst trigger) in robotic mode. Series of 30 s  exposures 
were obtained in clear filter.  After PSF subtraction of a nearby bright 
star we clearly detect the optical transient in each single  frames of 
initial series. Coordinates of the optical transient are (J2000) 16 52 
53.29 +82 03 15.6 with uncertainty of 0.25" in both coordinates. 
Preliminary photometry  is based  on USNO-B1.0 (R2)  stars. The maximum 
brightness of the OT (15.2  +/-  0.05) was detected in the second frame 
at 0.00141 days after trigger.

Light curve of the initial stage of the OT can be found at
http://grb.rssi.ru/GRB131002A/GRB131002A_ISON-NM_lc.png


GRB_name: GRB131002B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15291
SUBJECT: GRB 131002B: Enhanced Swift-XRT position
DATE:    13/10/02 19:20:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 923 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 131002B, 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 = 75.12235, -75.70299 which is equivalent
to:

RA (J2000): 05h 00m 29.37s
Dec (J2000): -75d 42' 10.8"

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: GRB131002A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15292
SUBJECT: GRB 131002A: Swift-XRT refined Analysis
DATE:    13/10/02 19:30:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

K.L. Page (U. Leicester), C. Pagani (U. Leicester), B. Sbarufatti
(INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), M.C. Stroh
(PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), A.P. Beardmore (U.
Leicester) and report on behalf of the Swift-XRT team: report on
behalf of the Swift-XRT team:

We have analysed 6.5 ks of XRT data for GRB 131002A,  from 56 s to 29.9
ks after the  BAT trigger. The data comprise 44 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 late-time light curve (from T0+5.1 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.05 (+0.26, -0.24).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.03 (+0.19, -0.18). The
best-fitting absorption column is  1.0 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 5.6 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.6 x 10^-11 (4.6 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.0 (+0.5, -0.4) x 10^21 cm^-2
Galactic foreground: 5.6 x 10^20 cm^-2
Excess significance: 1.9 sigma
Photon index:      2.03 (+0.19, -0.18)

If the light curve continues to decay with a power-law decay index of
1.05, the count rate at T+24 hours will be 7.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x
10^-13 (3.6 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00572721.

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


GRB_name: GRB131001A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15293
SUBJECT: GRB 131001A, Swift-BAT refined analysis
DATE:    13/10/02 23:18:50 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
  
We report further analysis of BAT GRB 131001A (Cummings, GCN Circ. 15281).
The BAT ground-calculated position is RA, Dec = 8.304, 25.557 deg which is
    RA(J2000)  =  00h 33m 13.0s
    Dec(J2000) = +25d 33' 26"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.
  
The mask-weighted light curve shows a single FRED peak.  T90 (15-350 keV) is
4.9 +- 0.3 sec (estimated error including systematics).
  
The time-averaged spectrum from T0 to T+5 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.8 +- 0.6,
and Epeak of 55 +- 14 keV (chi squared 55.6 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 4.9 +- 0.6 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+5.49 sec in the 15-150 keV band is
2.57 +- 0.25 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.81 +- 0.12 (chi squared 66.2 for 57 d.o.f.).  All the quoted errors are
at the 90% confidence level.
  
Since this burst was ground-detected the usual automated results of the
batgrbproduct analysis are not available.


GRB_name: GRB131002A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15294
SUBJECT: GRB 131002A: Swift/UVOT Detection
DATE:    13/10/03 11:42:38 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and B. N. Barlow (High Point University) 
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131002A 77 
s after the BAT trigger (Barlow et al., GCN Circ. 15283). A fading 
source consistent with the optical position (Guidorzi GCN Circ. 15282) 
is detected in the initial UVOT exposures.

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

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

white               77          227          147         17.94  0.06
white              870         1020          147         19.40  0.11
v                  620         1071           59         18.89  0.36
b                  546          739           39         19.41  0.31
u                  290         7169          736        >21.1
w1                 669         6964          510        >20.7
m2                 645        13293          939        >21.1
w2                 770        11860         1199        >21.5

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


GRB_name: GRB131002B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15295
SUBJECT: GRB 131002B: Swift/UVOT Upper Limits
DATE:    13/10/03 13:03:10 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and M. C. Stroh (PSU) report on behalf of the 
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131002B
62 s after the BAT trigger (Stroh et al., GCN Circ. 15284).
No optical afterglow consistent with the XRT position (Beardmore et al. 
GCN Circ. 15291) is detected in the initial UVOT exposures. There is a 
DSS source lying just on the edge of the XRT region at 05:00:29.386 
-75:42:07.58.
Preliminary 3-sigma upper limits using the UVOT photometric system 
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding 
chart (FC) exposure and subsequent exposures are:

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

white_FC            62          212          147         >21.8
white             5216         5416          197         >22.1
v                 5627         5826          197         >20.3
b                 5011         6512          260         >21.4
u                  275         6442          274         >21.0
w1                6037         6237          197         >20.4
m2                5832         6031          197         >20.1
w2                5422         5622          197         >20.5

The magnitudes in the table 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: GRB131002B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15296
SUBJECT: GRB 131002B: Swift-XRT Refined Analysis
DATE:    13/10/03 16:59:09 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M.C. Stroh and B. Sbarufatti report on behalf of the Swift-XRT team:

We have analysed 1.8 ks of XRT data for GRB 131002B,  from 58 s to 6.5
ks after the  BAT trigger. The data comprise 282 s in Windowed Timing
(WT) mode with the remainder in Photon Counting (PC) mode. 

The light curve consists of a relatively flat region of WT data from
T+58 to T+333 s with a count rate ranging between 10 and 50 cts/s. The
WT observation ended when Swift entered the SAA. PC data exists from
T+5.0 to T+6.5 ks with a count rates between 0.1 and 0.04 cts/s. Since
there is only 1.8ks of data on this source, it is difficult to be
confident that a fit to these data points truly models the overall
behavior in this GRB.

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.46 (+0.04, -0.03). The
best-fitting absorption column is  consistent with the Galactic value
of 9.1 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 4.7 x 10^-11 (5.2 x 10^-11) erg cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Galactic foreground: 9.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.46 (+0.04, -0.03)

If the light curve continues to decay with a power-law decay index of
2.05, the count rate at T+24 hours will be 2.0 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.2 x
10^-15 (1.0 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/00572742.

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


GRB_name: GRB131002B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15297
SUBJECT: GRB 131002B: GROND upper limits
DATE:    13/10/03 17:21:12 GMT
FROM:    Sebastian Schmidl at TLS Tautenburg  <schmidl@tls-tautenburg.de>

V. Sudilovsky (MPE Garching), S. Schmidl (TLS Tautenburg) and J.Greiner
(MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 131002B (Swift trigger 572742, Stroh et al.,
GCN 15284) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla
Observatory (Chile).

Observations started on October 03, 2013, at 03:15:17 UT, 16.35 hrs after
the GRB trigger. They were performed at an average seeing of 1".8 and at
an average airmass of 2.0 .

We do not detect any fading source inside the 2".2 XRT error circle
(Beardmore et al., GCN 15291).
Based on a total exposure time of 1500 s in g'r'i'z' and 1200 s in JHK, at
a midtime of 16.59 hrs after the burst, we estimate the following
preliminary 3-sigma upper limits (all in AB system) of

g' > 24.7 mag,

r' > 24.4 mag,

i' > 23.7 mag,

z' > 23.5 mag,

J > 21.6 mag,

H > 21.0 mag and

K > 20.4 mag.

Given magnitudes are calibrated 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)=0.12 mag
in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB131002B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15298
SUBJECT: GRB 131002B, Swift-BAT refined analysis
DATE:    13/10/03 18:29:14 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

G. Sato (ISAS), 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), A. Y. Lien (NASA/GSFC/ORAU),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), M. C. Stroh (PSU), J. Tueller (GSFC),
T. N. Ukwatta (MSU), (i.e. the Swift-BAT team):

Using the data set from T-240 to T+418 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 131002B (trigger #572742)
(Stroh, et al., GCN Circ. 15284).  The BAT ground-calculated position is
RA, Dec = 75.135, -75.701 deg which is
  RA(J2000)  =  05h 00m 32.4s
  Dec(J2000) = -75d 42' 05.2"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a single wide peak that has a main pulse
starts at ~T-6 and ends at ~T+20, and the remaining emission lasts until ~T+42.
T90 (15-350 keV) is 39.10 +- 8.08 sec (estimated error including systematics).

The time-averaged spectrum from T-5.95 to T+41.60 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.36 +- 0.84,
and Epeak of 34.0 +- 4.3 keV (chi squared 62.16 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 6.2 +- 0.6 x 10^-07 erg/cm2
and the 1-sec peak flux measured from T+5.48 sec in the 15-150 keV band is
0.6 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.15 +- 0.14 (chi squared 81.27 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/572742/BA/


GRB_name: GRB131002A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15300
SUBJECT: GRB 131002A: Fermi GBM observation
DATE:    13/10/04 15:44:29 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 06:55:06.99 UT on 2 October 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131002A (trigger 402389709 / 131002288) which
was also detected by the Swift/BAT (Barlow et al. 2008, GCN 15283). GBM 
triggered ~46 sec later than Swift/BAT on the second pulse of the GRB.
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 128.2 degrees.

The GBM light curve shows a single pulse with a duration (T90) of 
about 12 s (50-300 keV). The time-averaged spectrum from T0-4.096 s to
T0+4.096 s is
well fit by a simple power law function with index -1.6 +/- 0.1 keV. 

The event fluence (10-1000 keV) in this time interval is
(1.4 +/- 0.3)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0 -2.1 s in the 10-1000 keV band
is 2.1 +/- 0.4 ph/s/cm^2.

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


GRB_name: GRB130925A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15301
SUBJECT: GRB 130925A: 3mm observations with CARMA
DATE:    13/10/04 16:39:51 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

B. A. Zauderer, E. Berger, T. Laskar (Harvard) report on behalf of a larger
collaboration
as part of the CARMA Key Project "A Millimeter View of the Transient
Universe":

"We observed the position of GRB 130925A (Lien et al., GCN 15246) with the
Combined Array for Research in Millimeter Astronomy (CARMA) beginning
2013 Sep 26.36 (dt = 1.19 d) at a mean frequency of 93 GHz.  Observations
were
conducted in the compact E configuration, with significant flagging for
shadowed
antennas required.  We do not detect any significant radio emission to a
3-sigma
limit of 0.6 mJy at the position of the Swift-XRT position (Evans et al.,
GCN 15251).

We thank the CARMA observers and staff for prompt execution of these
observations."


GRB_name: GRB131002A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15302
SUBJECT: GRB 131002A, Swift-BAT refined analysis
DATE:    13/10/04 20:40:57 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), B. N. Barlow (High Point University),
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL),
N. Gehrels (GSFC), J. Norris (BSU), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), G. Sato (ISAS), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 131002A (trigger #572721)
(Barlow, et al., GCN Circ. 15283).  The BAT ground-calculated position is
RA, Dec = 253.103, 82.036 deg which is
  RA(J2000)  =  16h 52m 24.8s
  Dec(J2000) = +82d 02' 08.3"
with an uncertainty of 3.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 71%.

The mask-weighted light curve shows two peaks separated by ~45 seconds.
The first short peak starts at ~T0 and lasts for ~1 sec,  the second long peak
starts at ~T+40 and ends at ~T+60. T90 (15-350 keV) is 55.59 +- 3.98 sec
(estimated error including systematics).

The spectral lag for the first short pulse is 0.114 s +- 0.04 s (for the 50-100 keV and
15-25 keV bands), and the spectrum is slightly softer than the second long pulse.
Therefore, the spectral and timing properties match better to those of regular long bursts
than those normally seen in short bursts with extended emission.

The time-averaged spectrum from T-0.20 to T+59.67 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.63 +- 0.19.  The fluence in the 15-150 keV band is 6.4 +- 0.8 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+43.17 sec in the 15-150 keV band
is 1.3 +- 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/572721/BA/


GRB_name: GRB131004A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15303
SUBJECT: GRB 131004A: Swift detection of a burst (may be short)
DATE:    13/10/04 21:53:57 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

L. M. Z. Hagen (PSU), D. N. Burrows (PSU), V. D'Elia (ASDC),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), V. Mangano (PSU),
F. E. Marshall (NASA/GSFC) and B. Sbarufatti (INAF-OAB/PSU) report on
behalf of the Swift Team:

At 21:41:03 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131004A (trigger=573190).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 296.151, -2.960 which is 
   RA(J2000) = 19h 44m 36s
   Dec(J2000) = -02d 57' 35"
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 2 sec.  The peak count rate
was ~8500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 21:42:13.4 UT, 70.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 296.11549, -2.95806 which is equivalent
to:
   RA(J2000)  = 19h 44m 27.72s
   Dec(J2000) = -02d 57' 29.0"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 127 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (6.97 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 4.5
(+2.61/-2.22) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 75 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the BAT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.28. 

Burst Advocate for this burst is L. M. Z. Hagen (lea.zernow.hagen 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: GRB131004A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15304
SUBJECT: GRB 131004A: optical afterglow from the NOT
DATE:    13/10/04 22:44:30 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>

D. Xu, D. Malesani, J. Hjorth (DARK/NBI), P. Jakobsson (Univ. Iceland), 
T. Kruehler (ESO Santiago), Nicolaas Groeneboom, and Anders Hafreager 
(Univ. Oslo), report:

We observed the field of GRB 131004A (Hagen et al., GCN 15303) using the 
NOT equipped with AlFOSC. Consistent with the XRT position, we detect a 
new source at coordinates:

RA = 19:44:27.08
Dec = -02:57:30.2

The source is not visible in the DSS, and brighter than its limiting 
magnitude, hence it is very likely the afterglow of GRB 131004A. At a 
time of 0.43 hr after the GRB, we measure R = 20.2 +- 0.1 mag compared 
to nearby USNO-B1 R2 magnitudes, where the error is mostly due to 
calibration.


GRB_name: GRB131004A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15305
SUBJECT: GRB 131004A: TNG optical afterglow confirmation
DATE:    13/10/04 23:38:34 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

D. Malesani (DARK/NBI), P. D'Avanzo (INAF-OAB), L. di Fabrizio, G.
Tessicini (INAF-TNG) report on behalf of the CIBO collaboration:

We observed the field of the possible short GRB 131004A (Hagen et al. GCN
15303) with the Italian 3.6m TNG telescope located in Canary Islands,
equipped with the DOLoRes imager.

The optical candidate reported by Xu et al (GCN 15304) is clearly seen in
a 60 s R-band image taken at a mid t-t0=1.1 hours. From a preliminary
photometry we estimate for this source a magnitude of
R = 20.8 +/- 0.1 (calibrated against the USNOB1 catalogue).

Given the evidence of fading with respect to the report of Xu et al. (GCN
15304) we confirm this source as the optical afterglow of GRB 131004A. The
inferred power-law decay index is
alpha=0.59 +/- 0.15.


We acknowledge the TNG visitor astronomer X. Dumesque for support.


GRB_name: GRB131004A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15306
SUBJECT: GRB 131004A: Liverpool Telescope optical afterglow observations
DATE:    13/10/05 00:06:15 GMT
FROM:    Drejc Kopac at Math Phys U,Slovenia  <drejc.kopac@fmf.uni-lj.si>

D. Kopac (U. Ljubljana), R. J. Smith (LJMU), C. G. Mundell (LJMU), N. R.
Tanvir (U. Leicester) and A. Gomboc (U. Ljubljana), on behalf of a large
collaboration report:

The 2-m Liverpool Telescope automatically began observing the field of GRB
131004A (Hagen et al., GCN 15303). We detect the optical afterglow in the
position consistent with the NOT (Xu et al., GCN 15304) and TNG (Malesani
et al., GCN 15305). Our preliminary photometry yields:

Mid time from   Exp    Filter   Magnitude
trigger (min)   (sec)
-------------------------------------------
85.1            300    i'       20.2 +- 0.1
111.3           300    i'       20.6 +- 0.1
-------------------------------------------

The magnitudes are calibrated agains I magnitudes of nearby USNO-B1.0
stars and are not corrected for the Galactic extinction.


GRB_name: GRB131004A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15307
SUBJECT: GRB131004A: Magellan Redshift
DATE:    13/10/05 00:56:31 GMT
FROM:    Ryan Chornock at Harvard  <rchornock@cfa.harvard.edu>

R. Chornock, R. Lunnan, and E. Berger (Harvard) report:

We observed the optical afterglow (Xu et al., GCN 15304; Malesani et al., GCN 
15305; Kopac et al., GCN 15306) of the possible short GRB 131004A (Hagen et al., 
GCN 15303) using LDSS-3 on the 6.5-m Magellan Clay Telescope.  A sequence of 
3x1200s spectroscopic exposures of the afterglow began at 23:44 on 4 October UT. 
  A preliminary reduction reveals a flat continuum with superposed weak emission 
lines from [O II], H-beta, and [O III] at a common redshift of 0.717.  Possible 
weak features consistent with Ca II H+K absorption at this same redshift are 
also present.


GRB_name: GRB131004A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15308
SUBJECT: GRB 131004A: Enhanced Swift-XRT position
DATE:    13/10/05 03:15:17 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 465 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 131004A, 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 = 296.11332, -2.95861 which is equivalent
to:

RA (J2000): 19h 44m 27.20s
Dec (J2000): -02d 57' 31.0"

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

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

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


GRB_name: GRB131004A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15309
SUBJECT: GRB 131004A: GROND observations of the afterglow
DATE:    13/10/05 08:38:02 GMT
FROM:    Sebastian Schmidl at TLS Tautenburg  <schmidl@tls-tautenburg.de>

S. Schmidl, A. Nicuesa Guelbenzu, S. Klose (all TLS Tautenburg), and J.
Greiner (MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 131004A (Swift trigger 573190; Hagen et al.,
GCN 15303) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started on October 4, 2013, at 23:41 UT, 2 hrs after the GRB
trigger. They were performed at an average seeing of 0".9 and at an
average airmass of 1.1.

The optical afterglow, discovered by Xu et al. (GCN 15304), is clearly
detected.

Based on a total exposure time of 460 s in g'r'i'z' and 480 s in JHK, at a
midtime of 2.75 hrs after the burst, we measure the following preliminary
AB magnitudes:

g' = 22.9 +/- 0.1,
r' = 22.1 +/- 0.1,
i' = 21.6 +/- 0.1,
z' = 21.4 +/- 0.1,
J = 20.2 +/- 0.2,
H = 20.2 +/- 0.2, and
K > 19.8 .

Given magnitudes are calibrated 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)=0.29 mag
in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB131004A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15310
SUBJECT: GRB131004A: TNG Redshift confirmation
DATE:    13/10/05 09:32:49 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

V. D'Elia (INAF-OAR/ASDC), P. D'Avanzo (INAF-OAB), D. Malesani (DARK/NBI),
L. di Fabrizio, G. Tessicini (INAF-TNG) report on behalf of the CIBO
collaboration:


We observed the optical afterglow (Xu et al., GCN 15304; Malesani et  
al., GCN 15305; Kopac et al., GCN 15306) of the possible short GRB  
131004A (Hagen et al., GCN 15303) using DOLORES/LR-B (wavelength  
range: 3000-8000 AA) on the 4-m TNG Telescope at Canary islands. We  
obtain a 1800 s spectrum starting at 2013-10-04 23:00:38 UT, i.e.,  
1.33 hr from the burst.

A preliminary reduction reveals weak emission lines from [O II],  
H-gamma and H-delta at a common redshift of 0.71.

We thus confirm the redshift reported by Chornock et al. (GCN 15307).

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.


GRB_name: GRB131004A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15311
SUBJECT: GRB 131004A: Swift-XRT refined Analysis
DATE:    13/10/05 11:54:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

C. Pagani (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A.
Maselli  (INAF-IASFPA), D.N. Burrows (PSU), J.A. Kennea (PSU), V.
Mangano (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester)
and  report on behalf of the Swift-XRT team: report on behalf of the
Swift-XRT team:

We have analysed 9.1 ks of XRT data for GRB 131004A,  from 79 s to 34.7
ks after the  BAT trigger. The data are entirely in Photon Counting
(PC) mode.  the light curve is consistent with a constant source of
mean count rate 7.4e-02 ct/sec. A power-law fit gives an index of 0.1
(+2.0, -1.6).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.16 (+0.27, -0.26). The
best-fitting absorption column is  3.1 (+1.0, -0.9) x 10^21 cm^-2, in
excess of the Galactic value of 7.0 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 3.9 x 10^-11 (6.8 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.1 (+1.0, -0.9) x 10^21 cm^-2
Galactic foreground: 7.0 x 10^20 cm^-2
Excess significance: 4.7 sigma
Photon index:      2.16 (+0.27, -0.26)

If the light curve continues to decay with a power-law decay index of
0.1, the count rate at T+24 hours will be 0.029 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-12 (1.9 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/00573190.

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


GRB_name: GRB131004A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15312
SUBJECT: GRB 131004A: RATIR Optical and NIR Upper Limits
DATE:    13/10/05 15:33:25 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos A. de
Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley
(GSFC) report:

We observed the field of GRB 131004A (Hagen, et al., GCN 15303) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/10 5.12 to 2013/10 5.30 UTC (5.12
to 9.44 hours after the BAT trigger), obtaining a total of 2.17 hours
exposure in the r and i bands and 0.94 hours exposure in the Z,
Y, J, and H bands.

For a source within the Swift-XRT error circle, in comparison with 2MASS, we
obtain the following upper limits (3-sigma):

  r     > 23.91
  i     > 23.33
  Z     > 22.56
  Y     > 21.86
  J     > 21.81
  H     > 21.26

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. We did not detect the source
reported in Xu et al. (GCN 15304). In comparison with earlier GROND
observations (Schmidl, et al., GCN 15309) the source has faded by a minimum
of 1.7 magnitudes in the r band. This implies a power-law decay steeper
than t^-1.7.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131004A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15313
SUBJECT: GRB 131004A: Swift/UVOT Detection
DATE:    13/10/05 16:42:18 GMT
FROM:    MSSL Swift/UVOT team at MSSL/Swift  <msslba@googlemail.com>

M. De Pasquale (UCL-MSSL) and L. M. Z. Hagen (PSU) report on behalf of the
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131004A
75 s after the BAT trigger (Hagen et al., GCN Circ. 15303).
A source consistent with the XRT position (Evans et al. GCN Circ. 15308)
and the position of the source given in Xu et al. (GCN Circ. 15304)
is detected in the initial and summed UVOT exposures.

The preliminary coordinates of this source are:

    RA  (J2000) =  19:44:27.09 = 296.11287 (deg.)
    Dec (J2000) = -02:57:30.4  =  -2.95844 (deg.)

with an estimated uncertainty of 0.55 arc sec. (radius, 90% confidence).

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

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

white_FC            75          225          147         19.23 Â± 0.11
white               75         5688          520         20.18 Â± 0.12

u_FC               288          537          246         19.96 Â± 0.34
u                  288         6715          659         20.72 Â± 0.40

v                  617         6100          432         >20.24
b                  543         6770          285         >21.0

w1                 666         6510          432         >20.9
m2                 814         6305          413         >20.8
w2                 593         5895          432         >21.0


The magnitudes in the table are not corrected for substantial Galactic
extinction
due to the reddening of E(B-V) = 0.28 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB131004A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15314
SUBJECT: GRB 131004A: CARMA 93 GHz upper limit
DATE:    13/10/05 19:11:45 GMT
FROM:    Ashley Zauderer at CfA  <bevinashley@gmail.com>

B. A. Zauderer, E. Berger, W. Fong (Harvard) report on behalf of a larger
collaboration and the CARMA Key Project "A Millimeter View of the Transient
Universe":

"We observed the position of GRB 131004A (Hagen et al., GCN 15303) with
CARMA at a mean frequency of 93 GHz beginning 2013 October 5.04 (dt=3.4
hours).  We do not find significant radio emission at the position of the
enhanced Swift-XRT and UVOT localizations (Evans et al., GCN 15308; De
Pasquale et al., GCN 15313), or the optical afterglow detection (Xu et al.,
GCN 15304), to a 3-sigma upper limit of ~0.3 mJy.  No further radio
observations are planned.

We thank the CARMA staff for prompt execution of these observations."


GRB_name: GRB131004A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15315
SUBJECT: GRB 131004A: Fermi GBM observation
DATE:    13/10/06 02:20:22 GMT
FROM:    Shaolin Xiong at UAH  <sx0002@uah.edu>

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

"At 21:41:03.68 UT on 04 October 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131004A (trigger 402615666 / 131004904),
which was also detected by the Swift/BAT (Hagen et al. 2013, GCN 15303).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 93 degrees.

The GBM light curve consists of multiple pulses
with a duration (T90) of about 1.4 s (50-300 keV).
The time-averaged spectrum from T0-0.19 s to T0+0.58 s is
well fit by a simple power law function with index -1.75 +/- 0.06.

The event fluence (10-1000 keV) in this time interval is
(6.2 +/- 0.6)E-7 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+0.192 s in the 10-1000 keV band
is 10.4 +/- 1.6 ph/s/cm^2.

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


GRB_name: GRB131004A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15316
SUBJECT: GRB 131004A, Swift-BAT refined analysis
DATE:    13/10/06 04:09:43 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

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

Using the data set from T30 to T+62 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 131004A (trigger #573190)
(Hagen, et al., GCN Circ. 15303).  The BAT ground-calculated position is
RA, Dec = 296.108, -2.952 deg which is
  RA(J2000)  =  19h 44m 26.0s
  Dec(J2000) = -02d 57' 05.6"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 73%.

The mask-weighted light curve shows a single short spike starts at ~T-0.18,
peaks at ~T0, and ends at ~T+1.35. T90 (15-350 keV) is 1.54 +- 0.33 sec
(estimated error including systematics).

The time-averaged spectrum from T-0.25 to T+1.80 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.81 +- 0.11.  The fluence in the 15-150 keV band is 2.8 +- 0.2 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T-0.27 sec in the 15-150 keV band
is 3.4 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The burst spectrum appears at the softer end of short bursts, which have
an average spectral index of 1.2 when fitting with a simple power-law model
(Sakamoto et al. 2011). The spectral lag for this burst is 0.130 s +- 0.020 s
(for the 50-100 keV and 15-25 keV bands), which is significantly longer
than those of regular short bursts.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/573190/BA/


GRB_name: GRB131004A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15317
SUBJECT: GRB 131004A: Skynet PROMPT/DSO-14 upper limits
DATE:    13/10/07 04:17:33 GMT
FROM:    Nathan Frank at U.North Carolina  <nrfrank@live.unc.edu>

N. Frank, A. Trotter, D. Reichart, J. Haislip, A. LaCluyze, A. Smith, D. Caton, L. Hawkins, T. Berger, H. T. Cromartie, R. Egger, A. Foster, K. Ivarsen, M. Maples, J. Moore, M. Nysewander, E. Speckhard, and J. A. Crain report:

Skynet observed the Swift/XRT localization of the field of GRB 131004A (Hagen et al., GCN 15303, Swift trigger # 573190) with four 16" telescopes of the PROMPT array at CTIO, Chile and with the 14" telescope at the Appalachian State University Dark Sky Observatory (DSO), North Carolina, starting at 2013-10-04, 23:39:35 UT and continuing until 2013-10-05, 02:21:12 UT (t=1.9-4.7h post-trigger).

Skynet took a total of 220 160s exposures simultaneously in each of the BVRI bands. In stacked images, we do not detect any uncatalogued optical source in any band at or near the reported position. The 3-sigma limiting magnitudes of our images are:

==============================================
t(mean)   telescope        band      exposures           3-sig lim mag
-------------------------------------------------------------------------
2.5h          Prompt3             B          25x160s                18.98
2.7h           Prompt1             V          32x160s                21.56
3.4h           Prompt4             R          55x160s                21.85
3.5h           Prompt5             I            50x160s                21.12
2.9h           DSO-14                I            7x160s                  18.46
==============================================

Magnitudes are in the Vega system, calibrated to five APASS stars in the field. Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.28 (Schlegel et al. 1998).

No further Skynet observations are scheduled.


GRB_name: GRB131004A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15318
SUBJECT: GRB 131004A: Correction to XRT refined analysis
DATE:    13/10/07 07:09:57 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

There was a mistake in the "Swift-XRT refined analysis" circular (GCN 
Circ. 15311) in which it was erroneously stated that the light curve was 
consistent with a constant source. In fact, the light curve is decaying 
as a power-law with an index of 1.01 (+/- 0.07). We apologise for any 
confusion caused. As ever, the full light curve and related GRB products 
are online at http://www.swift.ac.uk/xrt_products/00573190

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


GRB_name: GRB131004A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15319
SUBJECT: GRB 131004A: MOSFIRE NIR imaging
DATE:    13/10/08 09:31:30 GMT
FROM:    Daniel Perley at Caltech  <dperley@astro.caltech.edu>

D. A. Perley (Caltech) reports:

I imaged the location of GRB 131004A (GCN 15303) in Ks-band with MOSFIRE 
on the Keck I telescope on the night of 2013-10-07 for a total 
integration time of 291 seconds under good seeing conditions but some 
cloud cover.  The midpoint of the integration was 07:21 UT, 2.40 days 
after the GRB.

At the location of the optical transient reported by Xu et al. (GCN 
15304), no source is detected to a limiting magnitude of Ks > 20.6.  The 
nearest detected object to this location is a faint (Ks = 19.7), compact 
source approximately 1.4 arcsec to the west, at RA=19:44:26.99, 
dec=-02:57:30.15.

Given the moderate redshift of z=0.717 (Chornock et al., GCN 15307), 
these results suggest either that the host of this event is a relatively 
low-mass galaxy or that the GRB exploded outside the bulk of the stellar 
light of its host.  The >1.5 sec duration and significant lag reported 
in the BAT refined analysis (Lien et al., GCN 15316) may suggest the 
former interpretation is more likely.

I thank D. Malesani for providing the NOT image to verity the location 
of the optical transient.


GRB_name: GRB130831A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15320
SUBJECT: GRB 130831A: VLT/FORS2 spectroscopic detection of a supernova
DATE:    13/10/09 09:54:39 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>

S. Klose, A. Nicuesa Guelbenzu (both TLS Tautenburg), T. Kruehler (ESO), 
J. Greiner, D. A. Kann, A. Rau, V. Sudilovsky (all MPE Garching), F. Olivares E. (UNAB, 
MCSS, Chile), and S. Schulze (PUC, MCSS, Chile), on behalf of a larger 
collaboration report:


We observed the optical transient following GRB 130831A (e.g., Hagen et 
al. 2013, GCN 15139; Guidorzi et al. 2013, GCN 15140; Xu et al. 2013, GCN 
15142; Yoshii et al. 2013, GCN 15143) with VLT/FORS2 equipped with the 
300V grism on Sep 29 and Sep 30, 2013, between 28.5 and 29.5 days after 
the burst under excellent sky conditions with mean seeing around 0.6". The 
total exposure time of the spectrum was 1.53 hr and covers the spectral 
range between approximately 440 and 920 nm.

In the combined spectrum, we detect the optical emission over the full 
spectral range. The spectrum peaks at about 800 nm and shows broad 
absorption features, very much reminiscent of the spectrum of, e.g., GRB 
031203 / SN 2003lw (z=0.1055; Malesani et al. 2004, ApJ 609, L5), and the 
recent GRB 120714B / SN 2012eb (z=0.40; Klose et al. 2012, GCN 13613), GRB 
130215A / SN 2013ez (z=0.597; de Ugarte Postigo et al., GCN 14303), GRB 
130427A / SN 2013cq (z=0.34; Xu et al. 2013, ApJ 776, 98), and GRB 130702 
/ SN 2013dx (z=0.145; Schulze et al. 2013, GCN 14994), all obtained around 
SN maximum light.

We conclude that we have spectroscopically discovered the appearence of a 
broad-line SN following GRB 130831A at z=0.4791 (Cucchiara et al. 2013, 
GCN 15144), confirming the conclusion of Pozanenko et al. (GCN 15237) 
based on the optical light curve.

[GCN OPS NOTE(12oct13): Per author's request, VS was added to the author list.]


GRB_name: GRB130831A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15321
SUBJECT: GRB 130831A: Continued RATIR Optical and NIR Observations 
DATE:    13/10/09 21:22:00 GMT
FROM:    Alan M. Watson at Instituto de Astronomia UNAM  <alan@astro.unam.mx>

William H. Lee (UNAM), Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC), Michael G. Richer (UNAM), Chris Klein (UCB),
Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino
Cucchiara (UCSC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM),
Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC),
and Harvey Moseley (GSFC) report:

We observed the field of GRB 130831A (Hagen, et al., GCN 15139) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/10 9.10 to 2013/10 9.47 UTC (925.41
to 934.19 hours after the BAT trigger), obtaining a total of 6.08 hours
exposure in the r and i bands and 2.61 hours exposure in the Z,
Y, J, and H bands.

For a source within the Swift-XRT error circle, in comparison with 2MASS, we
obtain the following upper limits (3-sigma):

  r > 24.14
  i > 23.63
  Z > 22.94
  Y > 22.45
  J > 22.23
  H > 21.74

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

As compared with our previous RATIR observations (Lee et al., GCN 15274) we 
confirm the fading in r and i by at least 0.3 and 0.4 and magnitudes, respectively. 
The upper limits in Z, Y, J, and H are also consistent with fading. 

Overall our measurements (Butler et al. GCN 15165, Watson et al. GCN 15179, 
Lee et al., GCN 15242, 15274) are consistent with the re-brightening due to 
a SN, as reported by Pozanenko et al. (GCN 15237) and spectroscopically by 
Klose et al. (GCN 15320), and fading.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro 
Mrtir.


GRB_name: GRB130925A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15322
SUBJECT: GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
DATE:    13/10/10 14:57:27 GMT
FROM:    Remo Rufinni at ICRA  <ruffini@icra.it>

R. Ruffini, C.L. Bianco, M. Enderli, M. Muccino, A.V. Penacchioni, G.B.
Pisani, J.A. Rueda, N. Sahakyan, Y. Wang, L.Izzo report:

The observed X-ray emission in the afterglow of GRB 130925A (Lien et al., GCN 15247; Fitzpatrick et al., GCN 15255) presents an unprecedented sequence of flares departing from the canonical single power law decay (L \propto t^{-1.5}) observed in energetic GRBs-SNe (the "golden sample", Pisani et al. 2013, A&A 552, L5, arXiv:1304.1764). Correspondingly the X-ray Luminosity after 2*10^4 s in the rest-frame of the burst is almost constant (L \propto t^{-0.3}) and the energy emitted is a factor 30 larger than in the golden sample.

In the Induced Gravitational Collapse (IGC) paradigm, after the "input" due to a supernova explosion and the Black Hole formation (Ruffini 2013, IJMPD, 22, 1360009, arXiv:1310.1836), the "output" of a newly born Neutron Star from the Supernova and the Black Hole may remain bound in an elliptical orbit. This can explain the repeated flaring activity and the source of the larger observed energy.

In the canonical IGC scenario at z = 0.35 (Sudilovsky et al., GCN 15250, Vreeswijk et al., GCN 15249), assuming a 1998bw-like SN, a supernova should be expected to peak around the 10 - 16 October. It is crucial to perform optical observations in order to find out if the presence of the above mentioned binary nature in the "output" can modify the canonical scenario. Periodicities on time scales down to few minutes should be explored.


GRB_name: GRB131011A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15328
SUBJECT: GRB 131011A: GROND afterglow observations
DATE:    13/10/13 07:41:49 GMT
FROM:    Vladimir Sudilovsky at MPE  <vsudilov@mpe.mpg.de>

V. Sudilovsky, M. Tanga,
and J. Greiner (all MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 131011A (Kasliwal et al., GCN #15324)
simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120,
405) mounted at the 2.2 m MPG telescope at La Silla Observatory
(Chile).

Observations started at 03:30 UT on 13 October 2013.
They were performed at an average seeing of 1.3" and at and
average airmass of 1.2. We find the afterglow candidate reported by Kasliwal et al.

Based on the first 1500 sec g'r'i'z' and 1200 sec JHK exposure,
we estimate preliminary magnitudes (all in AB) of

g' = 21.9  0.1 mag
r' = 21.7  0.1 mag,
i' = 21.5  0.1 mag,
z' = 21.3  0.1 mag,
J = 21.1  0.1 mag,
H = 20.5  0.2 mag,
K = 20.2  0.4 mag,

Magnitudes are calibrated against nearby SDSS (griz) and 2MASS (JHK) stars, and
are not corrected for the Galactic foreground extinction corresponding to
a reddening of E_(B-V)= 0.02 mag in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB131011A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15330
SUBJECT: iPTF 13dsw/Fermi403206457: X-Shooter redshift
DATE:    13/10/13 10:27:04 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

A. Rau (MPE Garching), T. Kruehler (ESO), J. Greiner (MPE Garching)
report for the GROND team:

We observed the optical afterglow candidate iPTF13dsw of the Fermi-GBM 
trigger 403206457 (Kasliwal et al. 2013, GCN 15324; Xu et al. 2013, 
GCN 15325; Perley et al. 2013, GCN 15327; Sudilovsky et al. 2013, GCN 15328)
using ESO/VLT UT3 equipped with the X-shooter spectrograph. The observations
started on 2013-10-13 at 03:59 UT. A total exposure of 5x900 s was obtained, 
covering the spectral range from ~3000 AA to ~24000 AA.

In the spectrum, we identify several very weak absorption features
which we interpret as absorption from FeII, MgII and MgI at a common
redshift of z = 1.874. This redshift is consistent with flux being
detected down to ~3200 AA, and a broad absorption feature around
3400 AA corresponding to Lyman\alpha. The combined evidence of fading, 
powerlaw slope SED and redshift suggests iPTF13dsw to be the optical 
afterglow of GRB 131011A.

We thank the Paranal staff for expert support, in particular Andrea
Mehner,  Christophe Martayan, Julio Navarrete, Felipe Gaete, L.
Schmidtobreick, and A. Smette.


GRB_name: GRB131011A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15331
SUBJECT: GRB 131011A: Fermi GBM detection
DATE:    13/10/14 00:09:15 GMT
FROM:    Peter Jenke at MSFC  <peter.a.jenke@nasa.gov>

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

At 17:47:34.99 UT on October 11 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131011A (trigger 403206457/131011741).
A candidate optical afterglow was found by iPTF (Kasliwal et al. 2013, GCN
15324) using the GBM on-ground location.
Additional follow-ups confirmed that the optical source has faded (Xu et
al. 2013, GCN 15325) and has a redshift of 
z = 1.874 (Rau et al. 2013, GCN 15330).  A weak X-ray
source consistent with the optical afterglow was detected by the 
Swift XRT (Page et al. 2013, GCN 15329).

The angle of the burst direction to the Fermi LAT boresight is 74 degrees.

The GBM light curve consists of one main peak and a small 
post burst with a combined duration (T90) of about 77 s (50-300 keV).
The time-averaged spectrum from T0-3 s to T0+25s is
well fit by a Band function with Epeak of 220 +/- 30 keV.
Alpha = -0.79 +/- 0.08 and Beta = -2.0 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(6.60 +/- 0.03)E-05 erg/cm^2. The 1.0-sec peak photon flux measured
starting from T0+4.3 s in the 10-1000 keV band
is 4.3 +/- 0.4 ph/s/cm^2.

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


GRB_name: GRB131014A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15332
SUBJECT: GRB 131014A: Fermi GBM detection
DATE:    13/10/14 13:13:57 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick@ucdconnect.ie>

G. Fitzpatrick (UCD) and S. Xiong (UAH) report on behalf of the Fermi GBM
Team:

At 05:09:00.20 UT on 14 October 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131014A (trigger 403420143/131014215).
High peak flux from the GRB caused GBM to issue a repoint request
that reoriented the satellite to place the GRB near the LAT boresight
for 2.5 hours, subject to Earth limb contraints.

The on-ground calculated location, using the GBM trigger
data, is RA = 101.9 , DEC = -20.0  (J2000 degrees,
equivalent to 06h 47m, -20d 0.0'), with an uncertainty
of 1.00  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 71.9  degrees.

The GBM light curve consists of a single peak
with a duration (T90) of about 3.2 s (50-300 keV).
The event fluence (10-1000 keV) in this time interval is
1.9E-4 +/- 2E-7 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.3 s in the 10-1000 keV band is 311.5 +/- 1.3 ph/s/cm^2.

The time-averaged spectrum from T0-1.0 s to T0+4.2 s is
adequately fit by a Band function with Epeak = 318 +/- 3 keV,
alpha = -0.34 +/- 0.01, and beta = -2.58 +/- 0.02

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


GRB_name: GRB131014A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15333
SUBJECT: GRB 131014A: Fermi-LAT detection
DATE:    13/10/14 17:23:36 GMT
FROM:    Elisabetta Bissaldi at U.Innsbruk/IAPP  <Elisabetta.Bissaldi@uibk.ac.at>

R. Desiante (University of Udine and INFN Trieste), D. Kocevski(NASA/Goddard),
G. Vianello (Stanford), F.Longo, E.Bissaldi (University and INFN Trieste)
and E.Troja (NASA/GSFC/CRESST) report on behalf of the Fermi-LAT team:


At 05:09:00.20 on 2013-10-14 Fermi LAT detected high energy emission
from GRB 131014A, which was also detected by Fermi-GBM (G. Fitzpatrick
and S. Xiong, GCN 15332).

The best LAT on-ground location is found to be RA, DEC 100.5, -19.1 (J2000)
with an error radius of 0.45 deg (68% containment, statistical error only).
This was at the edge of the field of view of the LAT at the time of the
trigger (~70 deg away from the instrument axis). The burst triggered an
autonomous repoint of the spacecraft, which moved it well within the LAT
field-of-view for an additional 500s, before the source was occulted
by the Earth.

Due to the large angle at which the burst was observed during most of the
exposure, we expect a systematic error on the position of up to 0.5 deg.
This is due to the fact that the reconstruction of the direction of incoming
photons is biased toward the axis of the instrument for sources at very
large off-axis angles.

More than 7 photons above 100 MeV and 3 photons above 1 GeV are observed
within 100 seconds. The highest energy photon is a 1.8 GeV event which is
observed ~15 seconds after the GBM trigger.
A single peaked emission lasting roughly 5 seconds can be seen using the
non-standard LAT Low Energy (LLE) with a significance of ~23 sigma.

A Swift ToO request for this burst has been submitted and approved.

The Fermi LAT point of contact for this burst is
Rachele Desiante (rachele.desiante@ts.infn.it).

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


GRB_name: GRB131014A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15334
SUBJECT: GRB 131014A Tiled Swift observations
DATE:    13/10/14 17:26:27 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a series of observations, tiled on the sky, of the
Fermi/LAT GRB 131014A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00019

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

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

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


GRB_name: GRB131014A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15335
SUBJECT: GRB 131014A: Swift detection of a possible X-ray afterglow
DATE:    13/10/14 22:10:16 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@swift.psu.edu>

J. A. Kennea (PSU) and Alex Amaral-Rogers (U Leicester) report on behalf 
of the Swift/XRT team

On October 14, 2013 at 17:24 UT, Swift began a series of target of 
opportunity observations to cover the region around GRB131014A 
(Fitzpatrick et al., GCN #15332, Evans, GCN #15334), approximately 12.3 
hours after the burst was detected by Fermi. In Swift/XRT Photon Counting 
mode data we detect an uncatalogued point source at the following 
location: RA/Dec(J2000) = 100.30064, -19.09711, which is equivalent to:

RA(J2000) = 06h 41m 12.2s
Dec(J2000) = -19d 05m 49.6s

with an estimated uncertainty of 4.4 arc-seconds radius (90% containment). 
This position is 11.3' from the LAT position reported by Desiante et al. 
(GCN #15333). The source brightness is 0.07 +/- 0.01 XRT count/s. We 
cannot yet confirm whether this source is fading.


GRB_name: GRB131014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15336
SUBJECT: GRB 131014A: Nanshan optical observations
DATE:    13/10/14 23:52:12 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu (DARK/NBI), X. Zhang, G.-J. Feng, A. Esamdin, L. Ma (XAO) report:

We observed the XRT field (Kennea et al., GCN 15335), which contains
an uncatalogued point source as the possible X-ray afterglow of GRB
131014A (Fitzpatrick et al., GCN 15332; Desiante et al., GCN 15333),
using the 1m telescope located Mt. Nanshan, Xinjiang, China. We
obtained 2x600s R-band images at a high airmass of ~2.4 and at the
mean time of 2013-10-14 22:52:52 UT (i.e., 17.73 hr after the Fermi
trigger).

A faint source is marginally detected at the North-West border of the
XRT error circle in Kennea et al. (GCN 15335) in the stacked image,
and its position is consistent with that of the object already present
in the DSS finding chart at coordinates

R.A. (J2000) = 06:41:11.950
Dec. (J2000) = -19:05:46.94

However, the seemingly extended structure of the object within the XRT
error in the DSS chart is not present in our image, which sets a
constraint of R > ~20.5 mag for any source within the XRT error
circle, calibrated with nearby USNO B1 field.


GRB_name: GRB131014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15337
SUBJECT: GRB 131014A: NOT afterglow candidate
DATE:    13/10/15 07:21:29 GMT
FROM:    Steve Schulze at U of Iceland  <sts30@hi.is>

S. Schulze (PUC, MCSS), D. Xu , D. Malesani, J. P. U. Fynbo (DARK/NBI), T. Kangas (NOT), H. Ghasemi, A. Takalo, C. Xavier, Y. Litus, J. Saario, T. Tuominen, J. Harmanen, and M. Khansari (Tuorla Observatory) report on behalf of a large collaboration:

We observed the field of GRB 131014A (Fitzpatrick & Xiong, GCN15332; Desiante et al., GCN 15333) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 6 x 300 s R-band images. The mean time of the NOT observation is October 15.221 UT, 1.01 days after the Fermi trigger.

We detect an uncatalogued source within the error circle of the possible X-ray afterglow (Kennea et al., GCN 15335) at:

R.A.(J2000) = 06:41:12.240
Dec. (J2000) = -19:05:51.49

with an uncertainty of 0.4''.

This source may be the optical afterglow of GRB 131014A, but we cannot presently assess its variability and thus confirm its nature. We measure a R1 magnitude of 23.11 +/- 0.12 mag calibrated against four USNO B1 stars (0709-0091487, 0708-0089714, 0709-0091459, 0709-0091432).

We also note the presence of a brighter source (R.A. = 06:41:12.1, Dec. = -19:05:47.6) just to the North of the XRT error circle, which is however detected in the SDSS r-band frames.


GRB_name: GRB131014A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15338
SUBJECT: Konus-Wind observation of GRB 131014A
DATE:    13/10/15 07:56:52 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration very bright GRB 131014A
(Fermi GBM detection: Fitzpatrick & Xiong, GCN 15332;
Fermi LAT detection: Desiante et al., GCN 15333)
triggered Konus-Wind at T0=18541.405 s UT (05:09:01.405).

The light curve shows multiple bright, overlapped
pulses from ~T0 s to ~T0+6~s.
The emission at this phase of the event is seen up to ~12 MeV.
The burst was followed by a ~150s-long decaying tail of
a weak, soft, extended emission.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131014_T18541/

As observed by Konus-Wind, the burst
had a fluence of (2.05  0.03)x10-4 erg/cm2,
and a 64-ms peak flux, measured from T0+1.664 s,
of (2.10  0.04)x10-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+12.288 s)
is best fit in the 50 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.79  0.04,
the high energy photon index beta = -2.89  0.08,
the peak energy Ep = 346  9 keV,
chi2 = 118/94 dof.

The spectrum near the maximum count rate
(measured from T0+1.536 s to T0+1.792 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.42  0.07,
the high energy photon index beta = -2.87  0.13,
the peak energy Ep = 607  25 keV,
chi2 = 77.5/77 dof.

All the quoted results are preliminary.


GRB_name: GRB131014A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15339
SUBJECT: GRB 131014A: Enhanced XRT position
DATE:    13/10/15 13:18:11 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester) and A. Amral-Rogers (U. Leicester) report on
behalf of the Swift-XRT team:

Using 1.7 ks of XRT Photon Counting mode data and 5 UVOT images for GRB
131014A, 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 = 100.30220, -19.09781 which is equivalent to:
   RA (J2000) = 06h 41m 12.53s
   Dec (J2000) = -19d 05' 52.1"
with an uncertainty of 2.3 arcsec (radius, 90% confidence).

This position is 5.9 arcsec from the initial XRT position reported by 
Kennea & Rogers (GCN 15335) and 11.2 arcmin from the LAT position 
(Desiante et al. (GCN 15333), but 4.1 arcsec from the NOT optical 
position of Schulze et al (GCN 15337).

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


GRB_name: GRB131014A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15340
SUBJECT: GRB 131014A: RATIR Optical and NIR Observations
DATE:    13/10/15 17:19:59 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

E. Troja (GSFC), Alan M. Watson (UNAM), Nat Butler (ASU),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael
G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC),
Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de
Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:

We observed the field of GRB 131014A (Fitzpatrick et al., GCN 15332,
Desiante, et al., GCN 15333) with the Reionization and Transients Infrared
Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at
the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from
2013/10 15.36 to 2013/10 15.52 UTC (27.45 to 31.41 hours after the GBM
trigger), obtaining a total of 2.84 hours exposure in the r and i bands,
1.19 hours exposure in the Z and Y bands, and 1.09 hours exposure in the
J and H bands.

For a source within the Swift-XRT error circle (Kennea et al. GCN 15335),
in comparison with 2MASS, we obtain the following measurements:

   r    23.42  0.21
   i    22.76  0.17
   Z   23.1  0.4 (2.7 sigma)
   Y   21.20  0.27
   J    21.9  0.6 (1.8 sigma)
   H   21.8  0.7 (1.6 sigma)

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. The object is located 0.4 arcsec 
from
the NOT afterglow candidate (Schulze et al., GCN 15337) and consistent 
with it.
We cannot determine whether the source is fading. No other uncatalogued
source is detected within the XRT error circle.

Despite the large errors, our preliminary analysis indicates a blue 
continuum in YJH,
suggestive of a possible z-band dropout, and implying a high-redshift (z 
~ 6) for
GRB 131014A.

Further observations are planned.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131011A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15341
SUBJECT: Fermi 403206457 / GRB 131011A: AAO optical observations
DATE:    13/10/15 18:50:42 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), R. Inasaridze (AAO), G. Inasaridze (AAO), V. 
Zhuzhunadze (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the optical afterglow (Kasliwal et al. 2013, GCN 15324; Xu 
et al. 2013, GCN 15325; Perley et al. 2013, GCN 15327; Sudilovsky et al. 
2013, GCN 15328) of Fermi trigger 403206457 / GRB 131011A (Jenke, GCN 
15331) with AS-32 (0.7m) telescope of Abastumani Observatory  on Oct. 12 
starting (UT) 22.32. We obtained several unfiltered images of 120 s 
exposure. The optical afterglow is clearly visible in a stacked image in 
coordinates (J2000) RA= 02 10 06.32 Dec= -04 24 40.5
(uncertainty of 0.33 arcseconds on both axes) which is coincide with 
position reported  by Kasliwal et al. (GCN 15324).

The photometry of combined image against nearby SDSS stars reported by
Xu et al. (GCN 15325), R magnitude, transformed by Lupton gri -> R
transformation is following:

Date        T_start     t-t0,      exp,    OT
             (UT)        mid, d     s
2013-10-12  22:32:33    1.2218     26x120  21.33 +/- 0.09

A finding chart can be found at 
http://grb.rssi.ru/GRB131011A/GRB131011A_AS32.png


GRB_name: GRB131014A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15342
SUBJECT: GRB 131014A: Swift/UVOT Upper Limits
DATE:    13/10/15 20:59:52 GMT
FROM:    Craig Swenson at PSU/Swift  <cswenson@astro.psu.edu>

C. A. Swenson (PSU) and Alex Amaral-Rogers (U Leicester) report
on behalf of the Swift/UVOT team:

The Swift/UVOT began observations of the field of GRB 131014A
starting approximately 45.7 ks after the Fermi LAT detection (Desiante et
al. 2013, GCN 15333).  We do not detect any new source consistent
with the NOT afterglow candidate (Schulze et al. 2013, GCN 15337).

Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the summed
exposures are presented below.

----------------------------------------------------
Filter       TSTART      TSTOP    Exposure       Mag
----------------------------------------------------
     u        45,688     74,324        1239     >20.9
----------------------------------------------------

The quoted upper limits have not been corrected for the expected
extinction due to the Galactic reddening along the line of sight to
this burst of E(B-V) = 0.22 mag (Schlegel et al. 1998).


GRB_name: GRB131011A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15343
SUBJECT: GRB 131011A: Swift/UVOT Upper Limits
DATE:    13/10/15 21:11:12 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

L. M. Z. Hagen (PSU) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began observations of the field of GRB 131011A
starting 83.9 ks after the Fermi trigger 403206457 (Kasliwal et al., GCN 15324).
No optical afterglow consistent with the PTF position is detected in the initial UVOT
exposures.

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

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

w2           83920    97601         4896         >22.10

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


GRB_name: GRB131014A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15344
SUBJECT: GRB 131014A: Swift-XRT refined Analysis
DATE:    13/10/16 11:06:55 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

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

We have analysed 11 ks of XRT data for the Fermi/LAT-detected burst:
GRB 131014A,  from 44.1 ks to 173.4 ks after the  Fermi/LAT trigger. The
data are entirely in Photon Counting (PC) mode.  An X-ray source is
detected within the Fermi/LAT error circle.

The enhanced XRT position was given in GCN Circ. 15339 (Evans &
Amaral-Rogers).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.53 (+/-0.28).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+0.7, -0.6). The
best-fitting absorption column is  6.8 (+4.0, -3.0) x 10^21 cm^-2, in
excess of the Galactic value of 2.2 x 10^21 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.9 x 10^-11 (8.5 x 10^-11) erg
cm^-2 count^-1.

A summary of the PC-mode spectrum is thus:
Total column:      6.8 (+4.0, -3.0) x 10^21 cm^-2
Galactic foreground: 2.2 x 10^21 cm^-2
Excess significance: 2.5 sigma
Photon index:      2.2 (+0.7, -0.6)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020300.

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


GRB_name: GRB131014A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15346
SUBJECT: GRB 131014A: RATIR Optical/NIR Afterglow Confirmation
DATE:    13/10/16 22:34:10 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska
(UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen
Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego
(UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos
Romn-Ziga (UNAM), Neil Gehrels (GSFC), and
Harvey Moseley (GSFC) report:

We reobserved the field of GRB 131014A (Fitzpatrick, et al., GCN 15332;
Desiante, et al., GCN 15333) with the Reionization and Transients Infrared
Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at
the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from
2013/10 16.36 to 2013/10 16.52 UTC (51.38 to 55.33 hours after the
GBM trigger), obtaining a total of 2.11 hours exposure in the r and i bands
and 0.88 hours exposure in the Z, Y, J, and H bands.

We do not detect the source reported in Troja et al. (GCN 15340).
In comparison with SDSS DR9 and 2MASS, we obtain the following upper
limits (3-sigma):

   r   >23.8
   i   >23.4
   Z   >22.4
   Y   >21.7
   J   >21.4
   H   >20.9

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We note that the source reported in Troja et al. (GCN 15340) lies within 
the
XRT localization reported in Kennea et al. (GCN 15335), but is ~4 arcsec
offset from the XRT enhanced position (Evans et al., 15339).
However, the source shows evidence of fading in our latest exposures
(>3 sigma level, i band; 2-sigma level, r and Y band), suggesting that
it is associated with GRB131014A.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131014A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15347
SUBJECT: GRB 131014A: GROND observations
DATE:    13/10/17 07:11:16 GMT
FROM:    Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>

D. A. Kann (MPE Garching), T. Kruehler (ESO), K. Varela and J. Greiner
(both MPE Garching) report on behalf of the GROND team:

We observed the field of the Fermi GBM/LAT GRB 131014A (Fitzpatrick &
Xiong, GCN #15332) simultaneously in g'r'i'z'JHKs with GROND (Greiner et
al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla
Observatory (Chile).

Observations started at 07:07 UT on 16 October 2013, 2.08 days after the
GRB. They were performed at an average seeing of 1".0 and at an average
airmass of 1.1. Observations were slightly affected by passing clouds. We
obtained a total exposure of 4500 sec in g'r'i'z' and 3600 sec in JHK.

We detect several sources in and near the refined XRT error circle by
Evans & Amral-Rogers (GCN #15339). Source 1 is the one reported by Schulze
et al. (GCN #15337), also detected by Troja et al. (GCN #15340) and
claimed to be fading by Troja et al. (GCN #15346).

We estimate preliminary magnitudes and upper limits (all in the AB system)
in an aperture of 1".8:

g' = 24.1  0.2 mag
r' = 22.8  0.1 mag,
i' = 22.5  0.1 mag,
z' = 22.2  0.1 mag,
J > 21.5 mag,
H > 21.0 mag,
K > 19.4 mag

This source lies significantly outside the refined XRT error circle
(Evans & Amral-Rogers, GCN #15339), is extended in our images and we find
no evidence of fading as compared to the earlier (t = 1 day) measurement
of Schulze et al. (GCN #15337), also using image subtraction versus the
NOT image. We thus do not consider it the afterglow of GRB 131014A. The
colors and the apparent extent of the source are consistent with a
low-redshift galaxy.

Source 2 is consistent with being point-like in our images and found at:

RA (J2000) = 06:41:12.41
Dec. (J2000) = -19:05:53.5

We estimate preliminary magnitudes and upper limits (all in AB) for a
point source of:

g' > 25.0 mag
r' = 24.8  0.3 mag,
i' = 23.8  0.2 mag,
z' = 22.8  0.1 mag,
J = 21.7  0.2 mag,
H = 21.6  0.4 mag,
K > 19.8 mag

This source is extremely red and lies on the edge of the refined XRT error
circle.

Source 3 also lies on the edge of the error circle at

RA (J2000) = 06:41:12.56
Dec. (J2000) = -19:05:50.1

We estimate preliminary magnitudes and upper limits (all in AB) for a
point source of:

g' = 25.1  0.4 mag
r' = 24.5  0.2 mag,
i' = 24.1  0.2 mag,
z' = 23.8  0.3 mag,
J > 22.0 mag,
H > 21.5 mag,
K > 19.8 mag,

At present, no statement about variability for either source 2 or 3 can be
made.

Magnitudes are calibrated against SDSS (griz) and 2MASS (JHK) stars, and
are not corrected for the Galactic foreground extinction corresponding to
a reddening of E_(B-V)= 0.26 mag in the direction of the burst (Schlegel
et al. 1998).


GRB_name: GRB131014A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15348
SUBJECT: GRB 131014A: Suzaku WAM observation of the prompt emission
DATE:    13/10/17 10:20:56 GMT
FROM:    Takafumi Kawano at Hiroshima U/Suzaku-HXD-WAM  <tkawano@hep01.hepl.hiroshima-u.ac.jp>

T. Kawano, M. Ohno, K. Takaki, R. Nakamura, S. Furui, Y. Fukazawa(Hiroshima
U.), T. Yasuda, M. Tashiro, Y. Terada, Y. Ishida, H. Ueno, S. Sugimoto
(Saitama U.), M. Yamauchi, N. Ohmori, M. Akiyama (Univ. of Miyazaki), K.
Yamaoka (Nagoya U.), S. Sugita (Ehime U.), Y. E. Nakagawa, M. Kokubun, T.
Takahashi (ISAS/JAXA), W. Iwakiri(RIKEN), Y. Hanabata (ICRR), Y. Urata
(NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku
WAM team, report:



The bright, long GRB 131014A (Fermi GBM detection: Fitzpatrick & Xiong, GCN
15332; Fermi LAT detection: Desiante et al., GCN 15333) triggered the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50
keV - 5 MeV at UT 05:09:0.269(=T0).

The observed light curve shows a bright peak followed by a weaker emission
seen up to T0+5 s with a duration (T90) of about 3 seconds.

The fluence in 100 - 1000 keV was 2.02 (-0.11, +0.39) x10^-4 erg/cm^2.

The 1-s peak flux measured from T0+1.6 s was 270 (-28, +34)  photons/cm^2/s
in the same energy range.


Preliminary result shows that the time-averaged spectrum from T0 s to T0+5
s is well fitted by a GRB Band model as follows.

the low-energy photon index alpha: -0.81 (-0.85, +1.16),

the high-energy photon index beta: -2.95 (-0.40, +0.18),

and the peak energy Epeak: 285 (-88, +33) keV, (chi^2/d.o.f = 24.3/23).


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


The light curves for this burst will be available at:

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


GRB_name: GRB131018A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15349
SUBJECT: GRB 131018A: Swift detection of a burst
DATE:    13/10/18 13:01:28 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
P. D\'Avanzo (INAF-OAB), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), S. T. Holland (STScI), J. A. Kennea (PSU),
A. Y. Lien (NASA/GSFC/ORAU), F. E. Marshall (NASA/GSFC),
A. Maselli (INAF-IASFPA), C. Pagani (U Leicester),
K. L. Page (U Leicester), P. Romano (INAF-IASFPA), M. H. Siegel (PSU)
and R. L. C. Starling (U Leicester) report on behalf of the Swift
Team:

At 12:47:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131018A (trigger=574935).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 98.462, -19.882 which is 
   RA(J2000) = 06h 33m 51s
   Dec(J2000) = -19d 52' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a broad single peak
structure with a duration of about 100 sec.  The peak count rate
was ~500 counts/sec (15-350 keV), at ~56 sec after the trigger. 

The XRT began observing the field at 12:49:41.4 UT, 112.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
98.4716, -19.8961 which is equivalent to:
   RA(J2000)  = 06h 33m 53.19s
   Dec(J2000) = -19d 53' 45.9"
with an uncertainty of 2.3 arcseconds (radius, 90% containment). This
location is 60 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 2.03
x 10^21 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 4.45e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 120 seconds after the BAT trigger. 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
0.26. 

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


GRB_name: GRB131018A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15350
SUBJECT: GRB131018A, optical observations
DATE:    13/10/18 13:22:50 GMT
FROM:    Arne A. Henden at AAVSO  <arne@aavso.org>

Arne Henden (AAVSO), as part of a larger collaboration, reports:

We observed the field of GRB131018A using the Mt. John University Observatory 
Optical Craftsman 61cm telescope (part of AAVSOnet), with observations starting 
at 12:55:24 UT (7.6 minutes after the Swift trigger) under poor seeing 
conditions and bright moonlight.  We do not see any optical afterglow at the XRT 
position to a limiting magnitude of R=17 (using APASS calibrations).

[GCN OPS NOTE(18oct13): The "A' suffix was added to the GRB name.]


GRB_name: GRB131014A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15351
SUBJECT: GRB 131014A: XRT position information
DATE:    13/10/18 13:30:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

The Swift-XRT localisation of GRB 131014A has unusually significant
uncertainty, which is not included in the positions previously 
circulated (GCNs 15335, 15339), or on the website. The afterglow was 
detected towards the edge of two of the initial tiled pointings, and 
near the centre of a dedicated follow-up pointing. Positions derived 
from these individual pointings vary by up to 4" when the Swift star 
tracker attitude is used. If we instead create enhanced positions (using 
the UVOT to derive the astrometry) we find astrometric corrections of 
~5-8", although we find significant variation between these corrections. 
This suggests that there is some degeneracy in the aspect solution.

Given this variation we suggest that the XRT position should be assumed
to have an uncertainty of 6", rather than the values previously
announced or posted online. Thus the best available XRT position is
RA, Dec=100.3033, -19.0971, which is equivalent to:
RA:   06h 41m 12.80s
Dec: -19Â° 05â€² 49.6â€²â€²
with an uncertainty of approx 6". This is the enhanced position derived
from the follow-up observation, which was centred on the afterglow.

Some low-level scatter in the aspect solutions is seen in all enhanced 
positions, and is calibrated into our enhanced position errors. GRB 
131014A shows an exceptionally large scatter in the aspect solutions 
which is not currently understood. Futhermore, as this is a late-time 
tiled follow up, where the source is faint and individual exposures are 
short, the normal mechanisms which remove outlying aspect solutions 
cannot be applied.


GRB_name: GRB131018A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15352
SUBJECT: GRB 131018A: Enhanced Swift-XRT position
DATE:    13/10/18 17:51:15 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 1872 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 131018A, 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 = 98.47133, -19.89620 which is equivalent
to:

RA (J2000): 06h 33m 53.12s
Dec (J2000): -19d 53' 46.3"

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

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

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


GRB_name: GRB131018A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15353
SUBJECT: GRB 131018A: P60 Observations
DATE:    13/10/18 21:05:59 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a
larger collaboration:

We have observed the location of the Swift GRB131018A (Melandri et al.,
GCN 15349) with the robotic Palomar 60 inch telescope.  Two 60 s frames
were obtained before the telescope closed due to the imminent sunrise.  We
find no new sources within the enhanced XRT error circle (Goad et al., GCN
15352).  Using nearby point sources from SDSS for photometric calibration,
we the following upper limits:

r' > 20.1 mag at 12:56 UT (dt = 8.6 min)
i' > 19.5 mag at 12:58 (dt = 10.0 min)


GRB_name: GRB131018A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15354
SUBJECT: GRB 131018A, Swift-BAT refined analysis
DATE:    13/10/18 23:08:41 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

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

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 131018A (trigger #574935)
(Melandri, et al., GCN Circ. 15349).  The BAT ground-calculated position is
RA, Dec = 98.473, -19.897 deg which is
  RA(J2000)  =  06h 33m 53.4s
  Dec(J2000) = -19d 53' 48.5"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a single long peak starts at ~T+21 sec
and ends at ~T+118 sec. T90 (15-350 keV) is 73.22 +- 18.97 sec
(estimated error including systematics).

The time-averaged spectrum from T+21.10 to T+117.74 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.24 +- 0.14.  The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+59.41 sec in the 15-150 keV band
is 0.5 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/574935/BA/


GRB_name: GRB131018A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15355
SUBJECT: GRB 131018A: KAIT Optical Upper Limit
DATE:    13/10/18 23:16:37 GMT
FROM:    Weikang Zheng at UC Berkeley  <zwk@astro.berkeley.edu>

WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and
S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the
KAIT GRB team:

The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to GRB 131018A (Melandri et al., GCN 15349)
starting at 12:50:47 UT, 179 s after the burst. Observations were
performed with an automatic sequence in the V, I, and clear(roughly R)
filters, and the exposure time was 20 s per image. Comparing to the SDSS
image, we do not detect new sources in our single images or in coadds of
5 images within the enhanced XRT error circle (Goad et al., GCN 15352).
There is a faint stellar object (r = 22.2 mag) in the SDSS image 1.8"
from the enhanced XRT position, but it is beyond our limiting magnitudes
of R ~ 18.7 for single images and R ~ 19.6 for 5 coadded images.


GRB_name: GRB131018A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15356
SUBJECT: GRB 131018A: Swift-XRT refined Analysis
DATE:    13/10/19 01:01:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

V. D'Elia (ASDC), A. Maselli  (INAF-IASFPA), J.A. Kennea (PSU), V.
Mangano (PSU), M.C. Stroh (PSU), A.P. Beardmore (U. Leicester), P.A.
Evans (U. Leicester), B.P. Gompertz (U. Leicester) and A. Melandri
report on behalf of the Swift-XRT team:

We have analysed 11 ks of XRT data for GRB 131018A (Melandri  et al.
GCN Circ. 15349),  from 119 s to 25.2 ks after the  BAT trigger. The
data comprise 171 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN. Circ 15352).

The light curve can be modelled with an initial power-law decay with an
index of alpha=4.24 (+0.17, -0.15), followed by a break at T+549 s to
an alpha of 0.30 (+/-0.06).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.06 (+0.13, -0.12). The
best-fitting absorption column is  4.3 (+/-0.3) x 10^21 cm^-2, in
excess of the Galactic value of 2.0 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.16 (+0.18, -0.17)
and a best-fitting absorption column of 3.1 (+/-0.6) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.8 x 10^-11 (6.7 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.1 (+/-0.6) x 10^21 cm^-2
Galactic foreground: 2.0 x 10^21 cm^-2
Excess significance: 2.9 sigma
Photon index:      2.16 (+0.18, -0.17)

If the light curve continues to decay with a power-law decay index of
0.30, the count rate at T+24 hours will be 0.040 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.5 x
10^-12 (2.7 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/00574935.

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


GRB_name: GRB131018B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15357
SUBJECT: GRB 131018B: Fermi-LAT detection of a burst
DATE:    13/10/19 10:02:36 GMT
FROM:    Giacomo Vianello at SLAC  <giacomov@slac.stanford.edu>

G. Vianello (Stanford), R. Desiante (University of Udine and INFN Trieste)
and F.Longo (University of Trieste and INFN Trieste) report on behalf of
the Fermi-LAT team:

At 16:08:39 on 2013-10-18 Fermi LAT detected high energy emission from GRB
131018B, which was also detected by Fermi-GBM ( trigger bn131018673).

The best LAT on-ground location is found to be (RA, DEC) = 304.41, 23.11
(J2000) with an error radius of 0.13 deg (68% containment, statistical
error only), which was 25 deg from the LAT boresight at the time of the
trigger. This position is 12 deg away from the best available GBM
localization. This can be explained by the large statistical error on the
GBM position (4 deg) and its typical systematic error, which is of the
order of few degrees.

The data from the Fermi LAT show an increase in the event rate within 10
degrees of the reported position starting few seconds after the GBM trigger
(a delay common to many Fermi-LAT GRBs), which behaves spatially and
temporally like a new transient point source. This excess has a high
significance (~6 sigma).

More than 10 photons above 100 MeV are observed within 2000 seconds after
the trigger. The highest energy photon is a 13 GeV event which is observed
250 seconds after the GBM trigger.

A Swift ToO request for this burst has been submitted.

The Fermi LAT point of contact for this burst is Rachele Desiante (
rachele.desiante@ts.infn.it).

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


GRB_name: GRB131018A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15358
SUBJECT: GRB 131018A: Swift/UVOT Upper Limits
DATE:    13/10/19 17:28:41 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <m.depasquale@ucl.ac.uk>

M. De Pasquale (UCL-MSSL) and A. Melandri (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131018A
99 s after the BAT trigger (Melandri et al., GCN Circ. 15349).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 15352) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC           120          270          147         >21.3
u_FC               279          528          246         >20.5
white              120        13702         1588         >22.4
v                   99         7600          581         >20.3
b                  534        19468         2174         >22.0
u                  279        18703         2368         >21.9
w1                 657        17790         1382         >21.3
m2                 632         7805          568         >20.5
w2                 584         7395          568         >20.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.26 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB131018A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15359
SUBJECT: GRB 131018A: RATIR Optical and NIR Observations
DATE:    13/10/19 18:51:08 GMT
FROM:    Nat Butler at Az State U  <natbutler@asu.edu>

Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess
Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and
Harvey Moseley (GSFC) report:

We observed the field of GRB 131018A (Melandri, et al., GCN 15349) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/10 19.34 to 2013/10 19.53 UTC (19.36 to
23.83 hours after the BAT trigger), obtaining a total of 2.58 hours
exposure in the r and i bands and 1.09 hours exposure in the Z, Y, J, and H
bands.

We detect no new sources within the enhanced Swift-XRT error circle (Goad,
et al., GCN 15352).  In comparison with the SDSS DR9 and 2MASS, we obtain
the following upper limits (3-sigma):

  r > 23.30
  i > 23.18
  Z > 22.43
  Y > 22.05
  J > 21.70
  H > 21.27

The SDSS source present in the XRT error circle (see also, Zheng, et al.,
GCN 15355) is well-detected, apparently non-extended, and is measured to
have the following magnitudes:

  r     22.06 +/- 0.11
  i     20.73 +/- 0.05
  Z     20.10 +/- 0.05
  Y     19.63 +/- 0.05
  J     19.64 +/- 0.06
  H     19.18 +/- 0.06

The above magnitude are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131018B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15360
SUBJECT: GRB 131018B: Fermi GBM observation
DATE:    13/10/19 20:28:54 GMT
FROM:    Binbin Zhang at UAH  <binbin.zhang@uah.edu>

Bin-Bin Zhang(UAH) reports on behalf of the Fermi GBM Team:

"At 16:08:39.181 UT on October 18 2013, the Fermi Gamma-Ray Burst Monitor 
triggered and located GRB 131018B (trigger 403805322/131018673), which is also 
detected by Fermi/LAT (Vianello et al. GCN 15357). The GBM on-ground location
is consistent with the LAT position (Vianello et al., GCN 15357). The angle from 
the Fermi LAT boresight is 23 degrees.

The GBM light curve consists of one FRED-shape pulse with a duration (T90) of 
about 38 s (50-300 keV). The time-averaged spectrum from T0+0 s to T0+30 s 
is well best fit with a power law function with an exponential high-energy cutoff 
parameterized as Epeak = 77 +/- 7 keV and an Index = -0.25 +/- 0.30. The event 
fluence (10-1000 keV) in this time interval is (2.14 +/- 0.16)E-06 erg/cm^2. The 
1.0-sec peak photon flux measured starting from T0+1 s in the 10-1000 keV band 
is 2.2 +/- 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: GRB131018B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15361
SUBJECT: GRB 131018B: Swift-XRT observations
DATE:    13/10/20 19:35:14 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, A. Melandri, M. G. Bernardini (INAF-OAB), P. A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:

We have analysed 2.8 ks of XRT data for the Fermi/LAT-detected burst:
GRB 131018B (Vianello et al., GCN 15357; Zhang, GCN 15360),  from 83.1
ks to 95.2 ks after the  Fermi/LAT trigger. The data are entirely in
Photon Counting (PC) mode.  An uncatalogued X-ray source is detected
within the Fermi/LAT error circle. The refined XRT position is RA, Dec
= 304.53693, +23.18759 which is equivalent to:

RA (J2000): 20 18 08.86
Dec(J2000): +23 11 15.3

with an uncertainty of 4.9 arcsec (radius, 90% confidence). This
position is 514 arcsec from the Fermi/LAT position.  We cannot
determine at the present time whether the source is fading.


We note the presence of two further sources within the LAT error box.

Source #2 has the following position RA, Dec = 304.41156, +23.16636
which is equivalent to:

RA (J2000): 20 17 38.77
Dec(J2000): +23 09 58.9

with an uncertainty of 5.4 arcsec (radius, 90% confidence). 

Source #3 has the following position RA, Dec = 304.52361 +23.06517
which is equivalent to:

RA (J2000): 20 18 05.67
Dec(J2000): +23 03 54.6

with an uncertainty of 6.0 arcsec (radius, 90% confidence). 

Both sources are present in the Swift-XRT point source catalogue
(D'Elia et al. 2013; A&A 551, A142) and are likely not related with GRB
131018B. 


The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020308.

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

[GCN OPS NOTE(22oct13): Per author's reuqest, the affiliations of the authors
was corrected.]


GRB_name: GRB131018B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15362
SUBJECT: GRB 131018B: Swift/UVOT Upper Limits
DATE:    13/10/20 21:17:55 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (MSSL-UCL) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131018B
83 ks after the LAT trigger (Vianello et al., GCN Circ. 15357).
No new optical candidate is detected within the LAT 
error circle (Vianello et al., GCN Circ. 15357) in the initial UVOT exposures.
We note an optical source within the error circle of the 
candidate XRT position (D'Avanzo et al., GCN Circ. 15361), 
which is found in the USNO-B1 catalogue.

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

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

white          90363     91160          785         >21.7
v              91168     91427          255         >19.4
u              88969     95244         1300         >20.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.58 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB131014A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15363
SUBJECT: IPN Triangulation of GRB 131014A
DATE:    13/10/21 16:02:54 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

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

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

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

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

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

The long-duration, intense GRB 131014A (GCN 15332, 15338, 15348) was 
observed by Fermi (GBM: trigger 403420143), Konus-Wind, INTEGRAL 
(SPI-ACS), Swift (BAT), Suzaku (WAM), and MESSENGER (GRNS), at about 
18540 s UT (05:09:00). The burst was outside the coded field of view of 
the BAT.

The burst was localized by the Fermi-LAT to a 2290 sq. arcmin. error 
circle (1 sigma, GCN 15333), and the X-ray afterglow was found by the 
Swift-XRT (GCN 15335).

We have triangulated it to a 3 sigma error box whose
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   100.286 (06h 41m 09s) -19.130 (-19d 07' 49")
  Corners:
   100.122 (06h 40m 29s) -19.544 (-19d 32' 39")
   100.356 (06h 41m 25s) -19.177 (-19d 10' 38")
   100.448 (06h 41m 48s) -18.714 (-18d 42' 52")
   100.215 (06h 40m 52s) -19.083 (-19d 05' 00")
  ---------------------------------------------
The error box area is 251 sq. arcmin, and its maximum dimension is
53 arcmin (the minimum one is 10 arcmin).

The box area is about 10 times smaller than that of the LAT error circle 
(2290 sq. arcmin.).

The reported Swift-XRT source (GCN 15339) is inside the box.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB131014_T18541/IPN/

Some improvement in this triangulation is possible.


GRB_name: GRB131014A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15364
SUBJECT: GRB 131014A: RATIR Optical/NIR Afterglow Retraction
DATE:    13/10/21 23:39:18 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska
(UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen
Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM),
Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga
(UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:

We reobserved the field of GRB 131014A (Fitzpatrick, et al., GCN 15332;
Desiante, et al., GCN 15333) with the Reionization and Transients Infrared
Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at
the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from
from 2013/10 17.36 to 2013/10 17.53 UTC (75.50 to 79.48 hours after the
GBM trigger), and again the next night from 2013/10 18.35 to 2013/10
18.53 UTC (99.18 to 103.48 hours after the GBM trigger), obtaining a
total of 2.3 hours exposure in the r and i bands and 1.0 hours exposure
in the Z, Y, J, and H bands each night.

These observations reach similar depths to prior RATIR observations of the
field (Troja, et al., GCNs 15340, 15346) in which we report a candidate
optical/NIR afterglow, albeit with marginal statistical significance.
Although the optical/NIR candidate afterglow appears fainter in the 2nd
and 3rd nights relative to our 1st night, it is similarly bright in the
4th night as on the 1st night. The co-addition of data from nights 2
through 4 yields flux levels (in all bands) statistically consistent 
with those
measured on night 1. An image subtraction analysis confirms this result.

We conclude that our source is not the optical/NIR afterglow of GRB 
131014A.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131024A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15365
SUBJECT: GRB 131024A: Swift detection of a burst
DATE:    13/10/24 12:37:23 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. L. Racusin (NASA/GSFC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), H. A. Krimm (CRESST/GSFC/USRA),
A. Maselli (INAF-IASFPA), K. L. Page (U Leicester),
D. M. Palmer (LANL), P. Romano (INAF-IASFPA), M. H. Siegel (PSU),
E. Troja (NASA/GSFC/UMCP) and T. N. Ukwatta (MSU) report on behalf of
the Swift Team:

At 12:26:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131024A (trigger=575707).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 290.464, -64.603 which is 
   RA(J2000) = 19h 21m 51s
   Dec(J2000) = -64d 36' 08"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  As is usual with an image trigger, the available
BAT light curve shows no significant structure. 

The XRT began observing the field at 12:28:34.2 UT, 133.5 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 290.48228, -64.60181 which
is equivalent to:
   RA(J2000)  = 19h 21m 55.75s
   Dec(J2000) = -64d 36' 06.5"
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This
location is 28 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 4.45
x 10^20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 136 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.05. 

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


GRB_name: GRB131011B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15366
SUBJECT: IPN triangulation of GRB 131011B (Swift Trigger 574266)
DATE:    13/10/24 16:05:11 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

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

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

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

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

Swift trigger 574266 (Beardmore et al., GCN 15323), was also observed by
MESSENGER GRNS, Konus-Wind, and INTEGRAL SPI-ACS.  We have triangulated it
to a preliminary, 3 sigma error box whose area is ~40000 sq. arcmin., and
whose coordinates are:

CENTER:
   RA(2000)                        DEC(2000)  
113.600 deg. = 7 h 34 m 24 s     80.277 deg. = 80 o 16 ' 38"
CORNERS:
119.660 deg. = 7 h 58 m 38 s     72.631 deg. = 72 o 37 '  51 "
 56.573 deg. = 3 h 46 m 17 s     87.670 deg. = 87 o 40 '  13 "
118.606 deg. = 7 h 54 m 25 s     70.117 deg. = 70 o  7 '  01 "
 81.813 deg. = 5 h 27 m 15 s     86.290 deg. = 86 o 17 '  23 "

This error box is also consistent with the Konus ecliptic latitude
determination.  It lies approximately 80 degrees from the Swift BAT
localization (GCN 15323), confirming that Swift trigger 574266 was
indeed a GRB ~68 degrees from the center of the BAT field of view, and
unrelated to VY Ari.  Improvements in the IPN localization are possible.


GRB_name: GRB131024A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15367
SUBJECT: GRB 131024A: Enhanced Swift-XRT position
DATE:    13/10/24 17:00:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 1446 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 131024A, 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 = 290.48247, -64.60275 which is equivalent
to:

RA (J2000): 19h 21m 55.79s
Dec (J2000): -64d 36' 09.9"

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: GRB131011B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15368
SUBJECT: Konus-Wind observation of GRB 131011B
DATE:    13/10/24 17:52:37 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration GRB 131011B
(Swift-BAT trigger 574266: Beardmore, et al., GCN 15323;
IPN triangulation: Hurley at al., GCN 15366)
triggered Konus-Wind at T0=80208.914 s UT (22:16:48.914).

The burst light curve shows a broad multi-peaked pulse from ~T0-35 s
till ~T0+40 s.
The emission is seen up to ~12 MeV.

The K-W ecliptic latitude response indicates the source located
at medium-to-high Northern ecliptic latitude,
which is at odds with the BAT position reported in GCN 15323,
however, consistent with the recent IPN box (GCN 15366).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131014_T80208/

As observed by Konus-Wind, the burst
had a fluence of (7.7  0.3)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.212 s,
of (6.0  0.6)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+31.744 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.68  0.06,
the high energy photon index beta = -2.21  0.09,
the peak energy Ep = 270  18 keV,
chi2 = 110/97 dof.

The spectrum near the maximum count rate
(measured from T0 to T0+7.936 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.63  0.04,
the high energy photon index beta = -2.22  0.14,
the peak energy Ep = 331  33 keV,
chi2 = 131/97 dof.

All the quoted values are preliminary.


GRB_name: GRB131024A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15369
SUBJECT: GRB 131024A: Skynet R-COP optical observations
DATE:    13/10/24 19:12:32 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter@physics.unc.edu>

A. Trotter, J. Haislip, D. Reichart, A. Verveer, T. Spuck, A. LaCluyze, 
N. Frank, J. Moore, T. Berger, H. T. Cromartie, R. Egger, A. Foster, K. 
Ivarsen, M. Maples, M. Nysewander, E. Speckhard, and J. A. Crain report:

Skynet observed the Swift/XRT localization of the field of GRB 131024A 
(Racusin et al., GCN 15365, Swift trigger # 575707) with the 14-inch 
R-COP telescope at Perth Observatory, Australia, starting at 2013-10-24, 
12:28:14 UT and continuing until 14:25 UT (t=1.9-118m post trigger). 
R-COP took a total of 44x20-80s exposures simultaneously in the BRI bands.

In a stack of 2 early R-band images at a mean time t=6.9m we marginally 
detect (S/N~3.5 sigma) an uncataloged source in the R band within the 
XRT error circle, with R~18.9 mag. In later stacks at mean times 
~70-80m, we obtain only 3-sigma upper limits in all three bands:

band    t(mean) exp     mag
B       69m      9x80s  >19.2
R       80m     12x80s  >19.8
I       83m     16x80s  >18.9

Magnitudes are in the Vega system, calibrated to four APASS-DR7 stars in 
the field, and have not been corrected for line-of-sight Milky Way dust 
extinction, with expected E(B-V)=0.05 (Schlegel et al. 1998).

No further Skynet observations are scheduled.


GRB_name: GRB131024A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15370
SUBJECT: GRB 131024A, Swift-BAT refined analysis
DATE:    13/10/24 20:47:07 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), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
J. L. Racusin (NASA/GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+303 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 131024A (trigger #575707)
(Racusin, et al., GCN Circ. 15365).  The BAT ground-calculated position is
RA, Dec = 290.544, -64.599 deg which is
    RA(J2000)  =  19h 22m 10.5s
    Dec(J2000) = -64d 35' 54.8"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 78%. The burst started during a pre-planned slew. 
Low-level emission begins around T-150 sec. Then there is a first peak from T-70 
to T-50 sec, a second peak from T-15 to T-4 sec and a third peak from T-2 to 
T+20 sec.  We note that there is a gap in the currently available data from 
~T-140 to T-120 sec. T90 (15-350 keV) is 112.00 +- 36 sec (estimated error 
including systematics).

The time-averaged spectrum from T-111.00 to T+17.00 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.85 +- 0.18.  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-55.50 sec in the 15-150 keV band
is 0.3 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/575707/BA/


GRB_name: GRB131024B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15371
SUBJECT: GRB 131024B: Swift detection of a burst
DATE:    13/10/24 21:56:41 GMT
FROM:    Hans Krimm at NASA-GSFC  <krimm@milkyway.gsfc.nasa.gov>

H. A. Krimm (CRESST/GSFC/USRA), M. M. Chester (PSU),
S. T. Holland (STScI), J. A. Kennea (PSU), V. Mangano (PSU),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
A. Maselli (INAF-IASFPA), J. L. Racusin (NASA/GSFC),
B. Sbarufatti (INAF-OAB/PSU), C. A. Swenson (PSU),
E. Troja (NASA/GSFC/UMCP) and B.-B. Zhang (UAH) report on behalf of
the Swift Team:

At 21:35:31 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131024B (trigger=575754).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 144.403, +44.240 which is 
   RA(J2000) = 09h 37m 37s
   Dec(J2000) = +44d 14' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multiple-peak
structure with a duration of about 30 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 21:37:21.8 UT, 110.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
144.5032, 44.2715 which is equivalent to:
   RA(J2000)  = 09h 38m 00.76s
   Dec(J2000) = +44d 16' 17.6"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 282 arcseconds from the BAT onboard position. 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 (1.27 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.6
(+1.51/-1.36) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 5.91e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
278 seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the
XRT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The
8'x8' region for the list of sources generated on-board covers 100% of the XRT
error circle. The list of sources is typically complete to about 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.02. 

Burst Advocate for this burst is H. A. Krimm (krimm 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.)

[GCN OPS NOTE(24oct13):  The Admin changed the burst name from an "A" to a "B"
in the first sentence.]


GRB_name: GRB131024A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15372
SUBJECT: GRB 131024A: Swift-XRT refined Analysis
DATE:    13/10/25 00:37:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Maselli  (INAF-IASFPA), A. Melandri (INAF-OAB), V. Mangano (PSU),
M.C. Stroh (PSU), D.N. Burrows (PSU), P.A. Evans (U. Leicester), B.P.
Gompertz (U. Leicester), J.P. Osborne (U. Leicester), B. Sbarufatti
(INAF-OAB/PSU) and J.L. Racusin report on behalf of the Swift-XRT team:

We have analysed 6.5 ks of XRT data for GRB 131024A (Racusin  et al.
GCN Circ. 15365),  from 151 s to 24.0 ks after the  BAT trigger. The
data comprise 20 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN. Circ 15367).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=0.46 (+/-0.05).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.08 (+0.18, -0.17). The
best-fitting absorption column is  7.7 (+3.7, -3.2) x 10^20 cm^-2,
consistent with the Galactic value of 4.4 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 3.4 x 10^-11 (4.3 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7.7 (+3.7, -3.2) x 10^20 cm^-2
Galactic foreground: 4.4 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.08 (+0.18, -0.17)

If the light curve continues to decay with a power-law decay index of
0.46, the count rate at T+24 hours will be 0.036 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-12 (1.6 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/00575707.

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


GRB_name: GRB131024A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15373
SUBJECT: GRB 131024A: GROND upper limits
DATE:    13/10/25 02:06:46 GMT
FROM:    Vladimir Sudilovsky at MPE  <vsudilov@mpe.mpg.de>

V. Sudilovsky, K. Varela, D. A. Kann and J. Greiner
(all MPE Garching) report on behalf of the GROND team:

We observed the field of the GRB 131024A (Racusin et al., GCN #15365)
simultaneously in g'r'i'z'JHKs with GROND (Greiner et
al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla
Observatory (Chile).

Observations started at 00:20 UT on 25 October 2013, 12 hours after the
GRB. They were performed at an average seeing of 1.6" and at an average
airmass of 1.4.

Based on two co-added observations with individual exposure times of 1500s
in g'r'i'z' and 1200s in JHK, we do not detect any source with the
enhanced XRT circle (Osborne et al., GCN #15367) down to preliminary
limiting magnitudes (all in the AB system):

g' > 25.1 mag,
r' > 24.7 mag,
i' > 23.9 mag,
z' > 23.8 mag,
J > 21.6 mag,
H > 21.0 mag,
K > 20.0 mag.

We do note there is a marginally detected source in r' at roughly 1.6"
north-east of the center of the error circle.

Magnitudes are calibrated against GROND zeropoints (griz) and 2MASS stars
(JHK), and
are not corrected for the Galactic foreground extinction corresponding to
a reddening of E_(B-V)=0.04 mag in the direction of the burst (Schlegel
et al. 1998).


GRB_name: GRB131024B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15374
SUBJECT: GRB 131024B: Enhanced Swift-XRT position
DATE:    13/10/25 03:20:30 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 1402 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 131024B, 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 = 144.50331, +44.27151 which is equivalent
to:

RA (J2000): 09h 38m 0.79s
Dec (J2000): +44d 16' 17.4"

with an uncertainty of 2.8 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: GRB131024A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15375
SUBJECT: GRB 131024A: Swift/UVOT Upper Limits
DATE:    13/10/25 03:21:43 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>

M. H. Siegel (PSU) and J. L. Racusin (NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131024A
137 s after the BAT trigger (Racusin et al., GCN Circ. 15365).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al., GCN Circ. 15367) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

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

white (fc)         136          286          147         >20.63
white              136         1542          392         >21.69
v                  624         1592          116         >18.91
b                  550         1517           97         >19.75
u (fc)             294          544          245         >19.99
u                  294         1492          569         >20.49
uvw1               673         1468           97         >19.15
uvm2               648         1606          106         >18.99
uvw2               600         1567          116         >19.48

The magnitudes in the table 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: GRB131024B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15376
SUBJECT: GRB 131024B: Nanshan optical upper limit
DATE:    13/10/25 03:26:23 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu (DARK/NBI), X. Zhang, C-H. Bai, A. Esamdin, L. Ma (XAO) report:

We observed the field of GRB 131024B (Krimm et al., GCN 15371) using the 1m
telescope located on Mt. Nanshan, Xinjiang, China. We obtained 4x300s
R-band frames at a mean time of  2013-10-24 23:21:53 UT, i.e., 1.773 hr
after the BAT trigger.

No optical source is detected within the XRT error circle in the stacked
image down to a limiting magnitude of R=21.0, calibrated with nearby SDSS
field.


GRB_name: GRB131024B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15378
SUBJECT: GRB 131024B: Swift-XRT refined Analysis
DATE:    13/10/25 13:31:33 GMT
FROM:    Alessandro Maselli at INAF/IASF Palermo  <maselli@ifc.inaf.it>

H. A. Krimm (CRESST/GSFC/USRA), A. Maselli (INAF-IASFPA) and P. A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

We have analysed 5.5 ks of XRT data for GRB 131024B (Krimm  et al. GCN
Circ. 15371),  from 100 s to 29.1 ks after the BAT trigger. The data
comprise 185 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 15374).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.30 (+0.22, -0.47). At T+232 s  the decay
steepens to an alpha of 3.4 (+2.8, -1.0) before breaking again at T+328
s to a final decay with index alpha=1.72 (+0.13, -0.11).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.60 (+/-0.14). The
best-fitting absorption column is  1.9 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 1.3 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.79 (+0.25, -0.23)
and a best-fitting absorption column of 1.0 (+/-0.6) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.1 x 10^-11 (5.0 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.0 (+/-0.6) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^20 cm^-2
Excess significance: 2.6 sigma
Photon index:      1.79 (+0.25, -0.23)

If the light curve continues to decay with a power-law decay index of
1.72, the count rate at T+24 hours will be 1.2 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.0 x
10^-15 (6.0 x 10^-15) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00575754.

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


GRB_name: GRB131024B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15379
SUBJECT: GRB 131024B : Xinglong TNT upper limit
DATE:    13/10/25 13:48:56 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

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

We began to observe GRB 131024B  (Krimm et al., GCN 15371) 
with Xinglong 0.8-m TNT telescope at 21:38:56  (UT), 
about 3.4 min after the burst.  3*300 sec  R-band images were obtained. 

No any optical counterpart within the XRT error circle  was detected 
down to a limit of 18.4 mag in R band, calibrated by USNO B1.0 R2mag 
at the mean time of 11.25 min after the burst.

This message may be cited.


GRB_name: GRB131024B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15380
SUBJECT: GRB 131024B: Swift/UVOT Upper Limits
DATE:    13/10/25 14:20:06 GMT
FROM:    Margaret Chester at PSU  <chester@astro.psu.edu>

M. M. Chester (PSU) and H. A. Krimm (CRESST/GSFC/USRA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131024B
121 s after the BAT trigger (Krimm et al., GCN Circ. 15371).
No optical afterglow consistent with the XRT position (Beardmore et 
al. GCN Circ. 15374) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the second 
finding chart (FC) exposure and subsequent exposures are given in 
the following table.  (The first finding chart in White was 
incomplete and is not included in the analysis.)

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

u_FC               278          528          246         >19.7
white              559         5579          413         >21.8
v                  609         5990          413         >20.6
b                  535         5374          228         >20.5
u                  278         6484          539         >20.3
w1                 658         6401          413         >20.4
m2                4558         6195          393         >20.9
w2                 585         5785          413         >21.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).
************************************************************************
Dr. Margaret Chester    
Swift Deputy Mission Director              U.S. Mail: 
The Pennsylvania State University          Swift Explorer Program
Department of Astronomy & Astrophysics     2582 Gateway Drive
Office:  (814) 865-7746                    State College, PA  16801
Cell:  (814) 359-9026                      FAX:  (814) 865-9100


GRB_name: GRB131024B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15381
SUBJECT: GRB 131024B: RATIR Optical and NIR Observations
DATE:    13/10/25 15:45:15 GMT
FROM:    Antonino Cucchiara at UCSC/UCO Lick  <acucchia@ucolick.org>

Antonino Cucchiara (ORAU/GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), 
Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), 
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), 
Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), 
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:

We observed the field of GRB 131024B (Krimm, et al., GCN 15371) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/10 25.41 to 2013/10 25.52 UTC (12.28
to 14.87 hours after the BAT trigger), obtaining a total of 1.78 hours
exposure in the r and i bands and 0.74 hours exposure in the Z,
Y, J, and H bands.

For a source within the Swift-XRT error circle, in comparison with the SDSS DR9 
and 2MASS, we obtain the following upper limits (3-sigma):

  r > 23.68
  i > 23.35
  Z > 22.44
  Y > 22.01
  J > 21.75
  H > 21.49

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro 
Mrtir.


GRB_name: GRB131024B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15382
SUBJECT: GRB 131024B: Fermi GBM observation
DATE:    13/10/25 16:48:55 GMT
FROM:    Binbin Zhang at UAH  <binbin.zhang@uah.edu>

Bin-Bin Zhang (UAH) reports on behalf of the Fermi GBM Team:

"At 21:35:28.85 UT on October 24 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131024B (trigger 404343331/131024900), which was also
detected by Swift (Krimm et al., GCN 15371). The GBM on-ground location
 is consistent with the Swift/XRT position (Beardmore et al., GCN 15374). The angle from
the Fermi LAT boresight is 83 degrees.

The GBM light curve consists of a multiple-peak structure with a duration
of about 52 s (50-300 keV). The time-averaged spectrum from T0+0 s to T0+41 s
is well best fit with a power law function with an exponential high-energy cutoff
parameterized as Epeak = 1047 +/- 627 keV and an Index = -1.01 +/- 0.12. The event
fluence (10-1000 keV) in this time interval is (6.35 +/- 0.61)E-06 erg/cm^2. The
1.0-sec peak photon flux measured starting from T0+1 s in the 10-1000 keV band
is 1.48 +/- 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: GRB131024B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15383
SUBJECT: GRB 131024B, Swift-BAT refined analysis
DATE:    13/10/25 19:01:28 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.krimm@nasa.gov>

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

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 131024B (trigger #575754)
(Krimm, et al., GCN Circ. 15371).  The BAT ground-calculated position is
RA, Dec = 144.464, 44.284 deg which is
    RA(J2000)  =  09h 37m 51.3s
    Dec(J2000) = +44d 17' 02.1"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 40%.

The mask-weighted light curve shows activity starting around T-10 sec and
continuing to ~T+100 sec.  There are several weak peak superimposed.
T90 (15-350 keV) is 64.00 +- 22 sec (estimated error including systematics).

The time-averaged spectrum from T-12.59 to T+51.41 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.85 +- 0.23.  The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10^-6 erg/cm2. 
  The 1-sec peak photon flux measured from T+10.91 sec in the 15-150 keV band is 
0.1 +- 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/575754/BA/


GRB_name: GRB131026A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15385
SUBJECT: GRB 131026A: TAROT La Silla observatory optical observations
DATE:    13/10/26 07:20:49 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D. (IRAP-CNRS-OMP), Gendre B.,
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 131026A detected by SWIFT
(trigger 575905) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 86.9s after the GRB trigger
(13.7s after the notice). The elevation of the field decreased from
12 degrees above horizon and weather conditions
were good.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+86.9s to t0+146.9s : Rlim = 16.8

The second image is 30.0s exposure in tracking mode:
t0+160.5s to t0+190.5s : Rlim = 17.4

We co-added a series of exposures:
t0+160.5s to t0+451.9s : Rlim = 18.9

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon=125.5580 lat=-30.3300
and the galactic extinction in R band is about 0.2 magnitude
estimated from D. Schlegel et al. 1998ApJ...500..525S.


GRB_name: GRB131026A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15388
SUBJECT: Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
DATE:    13/10/26 17:18:25 GMT
FROM:    Valerio D'Elia at ASDC  <delia@asdc.asi.it>

L. Izzo (URoma/ICRA), V. D'Elia (ASDC), P. D'Avanzo, A. Melandri  
(INAF-OAB), A. Maselli (INAF-IASFPA) report:


We have analysed 8.93 ks of XRT data for Swift Trigger 575905 (Cenko  
et al. GCN Circ. 15384). Two sources were detected at SNR>4, inside a  
region of 3 arcmin from the BAT position at the following coordinates:

Source 1 - (1RXS J010222.4+323020)
RA,Dec = 01h 02m 22.8s, +32 30' 02.7"

Source 2
RA,Dec = 01h 02m 02.6s, +32 30' 00.9",

with an uncertainty of 4.1" and 4.6", respectively.

Source 1 matches a catalogued X-ray source (1RXS J010222.4+323020 of  
the ROSAT/RASSFSC table is 18" away), while source 2 is an  
uncatalogued source, but below the RASS limit.

We can not say at the present time whether source 2 is fading. The  
count rate at the position of Source 2 is (4.3 +/- 1.0) x 10^-3 cts/s.  
This corresponds to an observed 0.3-10 keV flux of 1.54 x 10^-13  
erg/cm2/s (assuming a typical GRB spectrum with photon spectral index  
of 2). If we consider the Galactic absorption in this direction (5.1 x  
10^20 cm^-2; Kalberla et al. 2005) this corresponds to an unabsorbed  
flux of 1.78 x 10^-13 erg/cm2/s.

The results of the XRT-team automatic analysis are available at:
http://www.swift.ac.uk/possible_GRBs/00575905

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

----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.


GRB_name: GRB131026A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15389
SUBJECT: Swift Trigger 575905/ GRB 131026A: MITSuME Okayama and Ishigakijima Optical upper limits
DATE:    13/10/27 11:07:44 GMT
FROM:    Daisuke Kuroda at OAO/NAOJ  <dikuroda@oao.nao.ac.jp>

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

We observed the field of GRB 1301026A (Swift Trigger 575905) (Cenko et al., GCNC
15384) with the optical three color (g', Rc and Ic) CCD camera attached to the
MITSuME 50cm telescope of Okayama Astrophysical Observatory and the Murikabushi
1m telescope of Ishigakijima Astronomical Observatory.

We did not find any new point source within the BAT error circle (Cenko et al.,
GCNC 15384) in all the three bands.

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

Okayama Astrophysical Observatory:
The observation started on 2013-10-26 10:01:09 UT (~3.4 h after the burst).
T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.24326    12:29:49    6300.0    >19.7  >19.6  >18.6
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


Ishigakijima Astronomical Observatory:
The observation started on 2013-10-26 13:13:44 UT (~6.6 h after the burst).
T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.30110    13:53:07    3360.0    >21.6  >21.0  >20.4
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]


GRB_name: GRB131024B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15390
SUBJECT: GRB 131024B: MASTER prompt optical observation
DATE:    13/10/27 11:38:44 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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

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

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

V. Krushinski, I. Zalozhnich,  A. Popov, A. Bourdanov
Ural Federal University

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

C. Mallamaci, C. Lopez and F. Podest
Observatorio Astronomico Felix Aguilar (OAFA)

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Kislovodsk was pointed to the  GRB131024B 27 sec s after notice 
time and 36 sec after GRB time at 2013-10-24T21-36-07.864 UT. On our first 
(10s exposure) set we haven't found optical transient  within SWIFT 
error-box (Krimm et. al GCN15371).
The 5-sigma upper limit has been about 17.2 mag.
This is the prompt observations becaus GRB duration time T_90 = 64+-22 sec 
(Baumgartner et al., GCN Baumgartner).
Such long circular delay was due to with daily power cut on observatory.
The message may be cited.


GRB_name: GRB131024B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15391
SUBJECT: GRB 131024B: Mondy optical upper limits
DATE:    13/10/28 15:45:00 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 131024B (Krimm et al., GCN 15371) 
with AZT-33IK telescope of Sayan observatory (Mondy) starting Oct., 24 
(UT) 21:49:49, i.e. in ~14 minutes after the burst trigger. We obtained 
several images in R-filter with exposure of 30 and 60 seconds. Within 
the enhanced XRT circle (Beardmore et al., GCN 15374) we did not detect 
any optical counterpart.

The details of the photometry are the following:

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

21:49:49    0.02074       R       1860   n/d   21.8
21:49:49    0.03325       R       4020   n/d   22.5

The photometry is based 3 SDSS stars, R (gri -> R transformations by 
Lupton 2005):

SDSS id             R
J093757.56+441843.7 15.803
J093748.35+441919.6 17.774
J093744.86+441756.7 15.530


GRB_name: GRB131024B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15392
SUBJECT: GRB 131024B: AAO optical upper limit
DATE:    13/10/28 15:55:03 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), R. Inasaridze (AAO), G. Inasaridze (AAO), V. 
Zhuzhunadze (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of Swift GRB 131024B (Krimm et al., GCN 15371) 
with AS-32 telescope of Abastumani Observatory starting Oct., 25 (UT) 
00:26:12. We obtained several unfiltered images with exposures of 120 s. 
On stacked images within the enhanced XRT circle (Beardmore et al., GCN 
15374) we did not detect any optical counterpart.

The details of the photometry are the following:

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

00:26:12   0.16094     None   46x120   n/d     22.6

The photometry is based 3 SDSS stars, R (gri -> R transformations by
Lupton 2005):

SDSS id             R
J093757.56+441843.7 15.803
J093748.35+441919.6 17.774
J093744.86+441756.7 15.530


GRB_name: GRB131026A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15394
SUBJECT: Swift 575905/GRB 131026A: optical observations
DATE:    13/10/28 17:52:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), R. Inasaridze (AAO), G. Inasaridze (AAO), V.
Zhuzhunadze (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko 
(IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of Swift Trigger 575905/GRB 131026A (Cenko et al., 
GCN 15384)  with AS-32 telescope of Abastumani Observatory starting 
Oct., 26 (UT) 21:06:35. We obtained several unfiltered images with 
exposures of 180 s. We investigated stacked image and found that both 
XRT sources (Izzo et al., GCN 15388) coincide with known optical 
sources, i.e.

source 1 (XRT) = SDSS J010222.74+323005.0 (01:02:22.75 +32:30:05.0)
source 2 (XRT) = TYC 2281-1221-1 (01 02 02.468 +32 30 01.53)

Within BAT error circle (Cenko et al., GCN 15384) we found a point-like 
source which is not presented in SDSS catalog. Coordinates of the source 
are (J2000) RA=   01 02 14.64, Dec = +32 30 35.7  with uncertainties of 
0.2 arcsec in both coordinates. The details of the photometry of the 
source  are the following:

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

21:06:35   0.64270     None   32x180   21.67 +/- 0.08  22.6

The photometry is based SDSS stars, R (gri -> R transformations by
Lupton 2005):

SDSS id                   R(Lupton)
J010212.32+323137.9       18.988
J010208.62+323107.7       17.448
J010155.76+322851.8       17.317

We subdivide total number of images in two combined images and compare 
astrometry and photometry of the two combined images. One can conclude 
that the upper limit of a proper motion of the source is 3 arcsec per 50 
minutes, and one can marginally suggest that brightness of the source is 
increased at ~0.3m between the two combined images.

Finding chart can be found in 
http://grb.rssi.ru/GRB131026A_Swift_575905/GRB131026A_chart2.png

Additional observations in optic and X-ray are encouraged.


GRB_name: GRB131011A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15395
SUBJECT: GRB 131011A: ATCA 34GHz upper limit
DATE:    13/10/29 02:23:40 GMT
FROM:    Paul Hancock at U of Sydney  <hancock@physics.usyd.edu.au>

P. Hancock (Curtin University/CAASTRO), T. Murphy, B. Gaensler, M. Bell, D.
Burlon (University of
Sydney/CAASTRO), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI)

We observed GRB131011A (GCN 15324) with the Australia Telescope
Compact Array at 34GHz for 55 minutes centered on 11:20UT  Oct-17-2013 in
poor weather.

We detect no radio source at the optical location of the GRB and place a
3sigma upper limit of 120uJy on the flux of an
afterglow.

These observations were obtained as part of ATCA project C2689. We
thank the observatory staff for their support and scheduling the
observations. The Australia Telescope is funded by the Commonwealth of
Australia for operation as a National Facility managed by CSIRO.


GRB_name: GRB131028A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15396
SUBJECT: GRB 131028A: Fermi GBM detection
DATE:    13/10/29 13:35:30 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

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

"At 01:49:02.35 UT on 28 October 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131028A (trigger 404617745 / 131028076).

The on-ground calculated location, using the GBM trigger
data, is RA = 57.0, DEC = +72.2 (J2000 degrees,
equivalent to 03 h 48 m, 72 d 12 '), with an uncertainty
of 1.2 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 123 degrees.

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

The GBM light curve consists of a single pulse
with a duration (T90) of about 17 s (50-300 keV).
The time-averaged spectrum from T0-1.28 s to T0+22.27 s is
best fit by a Band function with Epeak = 888 +/-18 keV,
alpha = -0.71 +/- 0.01, and beta = -3.4 +/-0.2. 

The event fluence (10-1000 keV) in this time interval is
(1.62 +/- 0.02)E-04 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+8.13 s in the 10-1000 keV band is 62 +/- 1 ph/s/cm^2.

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


GRB_name: GRB131028A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15397
SUBJECT: IPN Triangulation of GRB 131028A (long/bright)
DATE:    13/10/29 15:42:55 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

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

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

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

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

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

The long, bright GRB 131028A was observed by Konus-Wind, Fermi (GCN 
15396), INTEGRAL (SPI-ACS), Swift (BAT), AGILE (MCAL), and MESSENGER 
(GRNS) at about 6542 s UT (01:49:02). The burst was outside the coded 
field of view of the BAT.

We have triangulated it to a 3 sigma error box whose
coordinates are:
---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    61.225 (04h 04m 54s) +71.595 (+71d 35' 41")
  Corners:
    69.087 (04h 36m 21s) +70.098 (+70d 05' 51")
    66.215 (04h 24m 52s) +70.982 (+70d 58' 56")
    52.752 (03h 31m 00s) +72.570 (+72d 34' 14")
    56.127 (03h 44m 30s) +72.015 (+72d 00' 52")
  ---------------------------------------------
The error box area is 1.3 sq. deg, and its maximum dimension is
5.8 deg (the minimum one is 1.2 deg).

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB131028_T06546/IPN/

Some improvement in this triangulation is possible.


GRB_name: GRB131028A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15398
SUBJECT: Konus-Wind observation of GRB 131028A
DATE:    13/10/29 15:50:06 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The bright, long-duration, hard-spectrum GRB 131028A
(Fermi GBM detection: von Kienlin, GCN 15396;
IPN triangulation: Hurley at al., GCN 15397)
triggered Konus-Wind at T0=6546.966 s UT (01:49:06.966).

The burst light curve shows a bright, hard pulse from ~T0 to ~T0+20 s,
followed by a tail of softer emission in next ~50 s.
The emission in the main pulse is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131028_T06546/

As observed by Konus-Wind, the burst
had a fluence of (2.41  0.05)x10-4 erg/cm2,
and a 64-ms peak flux, measured from T0+5.760 s,
of (6.6  0.3)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+20.736 s)
is best fit in the 50 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.82  0.02,
the high energy photon index beta = -3.07  0.17,
the peak energy Ep = 901  25 keV,
chi2 = 97.2/93 dof.

The spectrum near the maximum count rate
(measured from T0+5.376 s to T0+6.400 s)
is best fit in the 50 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.56  0.06,
the high energy photon index beta = -3.18  0.42,
the peak energy Ep = 1277  91 keV,
chi2 = 119/86 dof.

All the quoted values are preliminary.


GRB_name: GRB131029A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15399
SUBJECT: GRB 131029A: Fermi-LAT detection of a burst
DATE:    13/10/30 10:15:12 GMT
FROM:    Judith Racusin at GSFC  <judith.racusin@nasa.gov>

J. L. Racusin (NASA/GSFC), G. Vianello (Stanford), Elisabetta Bissaldi (University & INFN Trieste), Rachele Desiante 
(University of Udine and INFN Trieste), Francesco Longo (University and INFN Trieste), report on behalf of 
the Fermi-LAT team:

Starting around 23:20:48.58 on October 29, 2013 Fermi LAT detected high energy emission from GRB 131029A, 
which was also detected by Fermi-GBM (trigger 404781651/131029973).

The best LAT on-ground location is found to be RA, DEC 200.785, 48.298 (J2000) with an error radius of 0.26 deg 
(68% containment, statistical error only), this was 60 deg from the LAT boresight at the time of the trigger (i.e., close 
to the limit of the LAT field of view). This position is ~6 deg away from the best available GBM position, well within 
the error radius if we include a typical systematic error of 3 deg.  The burst position was observed by the LAT from 
the trigger until ~T0+800 s.

The data from the Fermi LAT show a significant increase in the event rate within 10 degree of the GBM location after 
the GBM trigger that is spatially and temporally correlated with the GBM emission with high significance. More than 
19 photons above 100 MeV and more than 3 photons above 1 GeV are observed within 800 seconds. The highest 
energy photon is a 1.3 GeV event which is observed 70 seconds after the GBM trigger.

A Swift ToO has been requested for this burst.

The Fermi LAT point of contact for this burst is Judith Racusin (judith.racusin@nasa.gov).

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


GRB_name: GRB131029A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15400
SUBJECT: GRB 131029A Tiled Swift observations
DATE:    13/10/30 10:23:41 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a series of observations, tiled on the sky, of the
Fermi/LAT GRB 131029A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00020

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

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

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


GRB_name: GRB131029A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15401
SUBJECT: GRB 131029A: Fermi GBM observation
DATE:    13/10/30 13:40:38 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE) and P. Jenke  (UAH)
report on behalf of the Fermi GBM Team:

"At 23:20:48.58 UT on 29 October 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131029A (trigger 404781651 / 131029973), 
which was also detected by Fermi/LAT (Racusin et al. 2013, GCN 15399). 
The GBM on-ground location is consistent with the LAT position. 
At the time of triggering the angle from the Fermi LAT boresight was
59 degrees. 

The GBM light curve consists of a double peaked pulse 
with a duration (T90) of about 105 s (50-300 keV).
The time-averaged spectrum from T0-3.072 s to T0+100.353 s is
best fit by a Band function with Epeak = 230 +/- 20 keV,
alpha = -1.02 +/- 0.04, and beta = -2.1 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(3.0 +/- 0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+4.2 s in the 10-1000 keV band
is 4.6 +/- 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: GRB131030A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15402
SUBJECT: GRB 131030A: Swift detection of a burst with an optical counterpart
DATE:    13/10/30 21:08:51 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

E. Troja (NASA/GSFC/UMCP), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
J. R. Cummings (NASA/UMBC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), V. Mangano (PSU),
C. B. Markwardt (NASA/GSFC), A. Maselli (INAF-IASFPA),
K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU),
B. Sbarufatti (INAF-OAB/PSU), C. A. Swenson (PSU) and
T. N. Ukwatta (MSU) report on behalf of the Swift Team:

At 20:56:18 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131030A (trigger=576238).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 345.080, -5.389 which is 
   RA(J2000) = 23h 00m 19s
   Dec(J2000) = -05d 23' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed multiple peaks
structure with a duration of about 45 sec.  The peak count rate
was ~31500 counts/sec (15-350 keV), at ~6 sec after the trigger. 

The XRT began observing the field at 20:57:37.1 UT, 78.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 345.0657, -5.3659 which is equivalent to:
   RA(J2000)  = +23h 00m 15.77s
   Dec(J2000) = -05d 21' 57.2"
with an uncertainty of 5.1 arcseconds (radius, 90% containment). This
location is 97 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 5.43e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 89 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 23:00:16.13 = 345.06720
  DEC(J2000) = -05:22:05.1  =  -5.36808
with a 90%-confidence error radius of about 0.74 arc sec. This position is 9.5
arc sec. from the center of the XRT error circle. The estimated magnitude is
14.97 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.06. 

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: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15403
SUBJECT: GRB 131030A: Watcher OT detection
DATE:    13/10/30 21:54:06 GMT
FROM:    Petr Kubanek at AIO  <pkubanek@gmail.com>

Petr KubÃ¡nek (Porsche Engineering Services s.r.o. & Institute of
Physics, Czech Republic), Martin Topinka, Lorraine Hanhol, Seamus Meehan
(UCD, Ireland) reports on behalf of wider collaboration:

Watcher telescope at Boyden Observatory, South Africa, running RTS2
observatory control system, started automatic observation of GRB 131030A
(GCN 15402, E.Troja et.al.) at 20:57:24.070 UT. On image acquired on
20:58:49.830 UT, e.g. 171s post GRB, we clearly identify optical
counterpart mentioned at the above GCN.

Futher observations, as well as analysis, are ongoing.


GRB_name: GRB131029A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15404
SUBJECT: GRB 131029A: Swift-XRT follow up
DATE:    13/10/30 21:59:13 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), J.L. Racusin
(NASA/GSFC) report on behalf of the Swift-XRT team

The Swift-XRT has observed the vicinity of GRB 131029A (Racusin et al.,
GCN 15399); gathering 600-900 s on each of 7 tiled pointings (see Evans,
GCN Circ. 15400), covering the entire LAT 90% error circle.

No credible X-ray afterglow has been found: we find three sub-threshold
(i.e. low significance) detections, 2 of which are near to catalogued
X-ray sources and the other is near to an object in SIMBAD.

The 3-sigma XRT upper limit for the field is approximately 0.01 ct/sec.

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


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15405
SUBJECT: GRB 131030A: MASTER  optical observation
DATE:    13/10/30 22:07:29 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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

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

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

V. Krushinski, I. Zalozhnich,  A. Popov, A. Bourdanov
Ural Federal University

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

C. Mallamaci, C. Lopez and F. Podest
Observatorio Astronomico Felix Aguilar (OAFA)

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Kislovodsk was pointed to the  GRB131030A 50 min (3000s) after 
GRB time at 2013-10-30 21-46-10.273 UT.
On our first  (180 sec) images  we  found optical transient  within SWIFT 
error-box (E. Troja et. al GCN15402).
The unfiltred magnitude is 16.5;
The 5-sigma upper limit has been about 19.0 mag.
So long pointing time was due to with daily power cut on the observatory.
The message may be cited.


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15406
SUBJECT: GRB 131030A - Liverpool Telescope Optical Afterglow Confirmation 
DATE:    13/10/30 22:17:57 GMT
FROM:    Carole Mundell at ARI, JMU,Liverpool  <cgm@astro.livjm.ac.uk>

F.J. Virgili, C.G. Mundell (LJMU), J. Japelj, A. Gomboc (U.
Ljubljana), R.J. Smith (LJMU), A. Melandri (INAF-OAB) report:

The 2-m Liverpool Telescope robotically followed up GRB 131030A (Swift
Trigger 576238; Troja et al. GCN 15402) immediately after the GRB
trigger time.  The automated procedure detected an uncatalogued source
at the location of the UVOT source. We confirm the fading nature of the
object with

R = 16.9  0.2 mag (vs. USNOB1) 34.8 min after the burst.

thereby confirming this as the GRB afterglow.

Observations and analysis are ongoing.


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15407
SUBJECT: GRB 131030A: NOT redshift
DATE:    13/10/30 22:48:32 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu, J. P. U. Fynbo (DARK/NBI), P. Jakobsson, Z. Cano (U. Iceland),
B. Milvang-Jensen, D. Malesani (DARK/NBI), A. de Ugarte Postigo
(IAA-CSIC, DARK/NBI) & M. Hayes (Stockholm University) report on
behalf of a larger collaboration:

We observed the optical afterglow of GRB 131030A (Troja et al., GCN
15402) with the NOT equipped with the AlFOSC instrument. The transient
is clearly detected in our acquisition image with a magnitude R ~ 17
at a mean time of 0.569 hr after the GRB.

A single spectrum of 1200 s covering the range from 3800 to 8000 AA
was obtained with a mean epoch of 0.894 hr after the burst. The
spectrum displays a strong continuum with features of Fe II, Mg II and
Al II at a common redshift of z = 1.293 (wavelength calibration based
on archival data), which we identify as the redshift of the GRB. We
also detect an intervening system at z = 1.16 displaying Fe II and Mg
II.


GRB_name: GRB131030A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15408
SUBJECT: GRB 131030A: Spectroscopy from 10.4m GTC
DATE:    13/10/30 22:51:59 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
R. Sanchez-Ramirez (IAA-CSIC), J. Gorosabel (IAA-CSIC), 
J.P.U. Fynbo (DARK/NBI), N.R. Tanvir (U. Leicester) and 
C.A. Alvarez Iglesias (ULL/IAC) report on behalf of a larger collaboration:

We have observed the afterglow of GRB131030A (Troja et al. GCN 15402) 
with the 10.4m GTC telescope at Roque de los Muchachos Observatory (Spain)
starting at 21:50 UT (54 min after the burst). We used the R2000B grism that covers
the range from 3950 to 5700 A at a resolution of ~2200.  

A single 600s exposure reduced with archive calibrations shows a strong trace 
with absorption features of AlIII, ZnII, CrII, NiII, FeII, NiII* and FeII* at a common redshift 
of z=1.295, which we identify as the redshift of the GRB. An additional intervening 
system is seen at z=1.164, with lines of AlIII, FeII and MnII.


GRB_name: GRB131029A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15409
SUBJECT: GRB 131029A: Nanshan optical observations
DATE:    13/10/30 23:41:36 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu (DARK/NBI), G.-J. Feng, H.-B. Niu, A. Esamdin, L. Ma (XAO) report:

We observed the field of the LAT error circle of GRB 131029A (Racusin
et al., GCN 15399) using the 1m telescope located at Mt. Nanshan,
Xinjiang, China, equipped with a 1.2x1.2 deg^2 CCD camera. Three
R-band frames with exposures of 180s, 240s, and 300s were obtained at
a mean time of 13.656 hr after the Fermi/LAT trigger.

At the reported three sub-threshold XRT positions (Evans, GCN 15400),
no optical transient is detected down to a limiting magnitude of
R=19.5 mag, calibrated with nearby SDSS field.


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15410
SUBJECT: GRB 131030A: D50+BART detection and light curve optical decay
DATE:    13/10/31 01:31:14 GMT
FROM:    Jan Strobl at AI AS CR,Ondrejov  <jan@strobl.cz>

Jan Strobl (1,3), Martin Jelinek (2), Cyril Polasek (1), Michal Jakubec 
(1), Petr Skala (1,3) and Rene Hudec (1,3)
(1. AI ASCR Ondrejov, 2. IAA CSIC Granada, 3. FEE CTU Prague)

We observed the field of the Swift GRB 131030A (Troja et al., GCNC 15402) 
with the 0.5m telescope D50 and 0.25m telescope BART in Ondrejov (Czech 
Republic), starting at 20:57:16 UT, i.e. 56s after the trigger.

The optical afterglow (Virgili et al, GCNC 15406) is clearly detected in 
our images. After an initial peak of about 13.8m (unfiltered, calibrated 
using USNO-B R-band) the lightcurve decays with \alpha~0.9.

This message can be cited.


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15411
SUBJECT: GRB 131030A: 1.23m CAHA BVRI-band observations
DATE:    13/10/31 02:14:28 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

V. Terron (IAA/CSIC), M. Fernandez (IAA/CSIC), J. Gorosabel (IAA/CSIC-UPV/EHU), report on behalf of a larger collaboration:

We imaged the GRB131030A (GCNC 15402) optical afterglow (GCNC 15403, 15405, 14506, 15410) with the 1.23m CAHA telescope. Two BVRI-band series were taken starting 2.01 hr post burst. The optical afterglow is well detected in the four bands at a level of R~18.0 (Vega), calibrated against the USNO B1.0 catalog.


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15412
SUBJECT: GRB 131030A: SAO RAS optical observations
DATE:    13/10/31 10:36:52 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin,
reports on behalf of SAO RAS GRB follow-up team:

We observed the field of GRB 131030A (Troja et al., GCN#15402)
with the 1-meter telescope Zeiss-1000 of Special Astrophysical
Observatory of RAS in four bands: B, V, Rc, Ic. Observations
were started since 23 minutes after the Swift trigger.
The weather conditions were excellent, but the air masses of
the object was about 3-6.

Optical counterpart was clearly detected at all images.
Preliminary results of Rc band photometry are as following:

T_mid, UT   T - T0, h   exposure, s   R mag   +/- error
21:18:45    0.374        60           16.55 +/- 0.02
21:34:05    0.630        60           17.09 +/- 0.03
21:44:14    0.799       120           17.26 +/- 0.02
21:56:27    1.003       120           17.39 +/- 0.03
22:07:26    1.186       120           17.53 +/- 0.03
22:21:30    1.420       360           17.63 +/- 0.02
22:30:08    1.564       480           17.69 +/- 0.03

The magnitudes were calibrated against the set of USNO B1 stars
(R2) and not corrected for the Galaxy extinction.
Rc band light curve and the first image is shown at
ftp://ftp.sao.ru/pub/grb/GRB131030A/GRB131030A_image_LC.jpg


GRB_name: GRB131030A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15413
SUBJECT: Konus-Wind observation of GRB 131030A
DATE:    13/10/31 10:40:11 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration GRB 131030A
(Swift-BAT trigger 576238: Troja, et al., GCN 15402)
triggered Konus-Wind at T0=75377.811 s UT (20:56:17.811).

The burst light curve shows a multi-peaked pulse from
~T0-3 s till ~T0+25 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/GRB131030_T75377/

As observed by Konus-Wind, the burst
had a fluence of (6.6  0.4)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+11.648 s,
of (1.0  0.1)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+27.904 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.71  0.12,
the high energy photon index beta = -2.95  0.28,
the peak energy Ep = 177  10 keV,
chi2 = 76/96 dof.

Assuming the redshift z=1.293 (Xu, et al., GCN 15407;
de Ugarte Postigo, et al., GCN 15408),
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is (3.0  0.2)x10^53 erg,
the peak luminosity L_iso is (1.0  0.1)x10^53 erg/s,
and the rest-frame peak energy Ep,i = (406  22) keV

All the quoted values are preliminary.


GRB_name: GRB131030A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15414
SUBJECT: GRB 131030A: Swift/UVOT Detection
DATE:    13/10/31 11:46:48 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131030A 90 
s after the BAT trigger (Troja et al., GCN Circ. 15402). A fading source 
consistent with the XRT position (Troja et al. GCN Circ. 15402) is 
clearly detected in the initial UVOT exposures.

The preliminary UVOT position is:
     RA  (J2000) =  23:00:16.14 = 345.06723 (deg.)
     Dec (J2000) = -05:22:05.2  =  -5.36811 (deg.)
with an estimated uncertainty of 0.50 arc sec. (radius, 90% confidence).

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

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

white_FC            90          239          148         14.87  0.02
white              582          601           20         16.13  0.05
u_FC               302          552          246         15.30  0.03
b                  557          577           20         16.30  0.08
v                  631          651           19         15.98  0.13
uvw1               681          701           19         16.42  0.17
uvm2               656          676           20         16.63  0.24
uvw2               606          626           20         17.97  0.36

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.06 in the direction of the 
burst (Schlegel et al. 1998).


GRB_name: GRB131024C
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15415
SUBJECT: GRB 131024C: ICSP discovery of a burst in X-rays by balloon borne  study
DATE:    13/10/31 11:52:50 GMT
FROM:    Sandip K. Chakrabarti at S.N. Bose Nat. Centre for Basic Sci.  <chakraba@bose.res.in>

GRB 131024C: ICSP discovery of a burst in X-rays by balloon borne study

Sandip K. Chakrabarti (SNBNCBS, ICSP & ICRANET), D. Bhowmick (ICSP), S.
Chakraborty (ICSP), R. Sarkar (ICSP)

Indian Centre for Space Physics (ICSP)  balloon borne Dignity-45 mission
with a 2 inch diameter (~ 20 sq cm)
Bicron (NaI) X-ray detector was surveying a slice of the sky with a 40
degree FOV circular  collimator
(transparent >100keV), tilted at 40 degree with the zenith. At 07:48:54
UT, it detected a GRB with a location
within a 20 degree radius circle centered at around

   RA(J2000) = 13h 27m 59s
   Dec(J2000) = +52d 44m 43.7s

The peak count (at 07:48:54s UT) rate was ~ 740/sec (20-100keV) after a
possible precursor 4s earlier. The total duration,
with weaker peaks is about 10 seconds. The light curve, 2s average
spectrum at the peak, the dynamical spectrum, and
the approximate location of the GRB are given in the webpage:
http://www.csp.res.in/ICSP-WEB/Balloon/Near%20space%20Exploration.html

Our time resolution was one second, so finer time stamp was not possible.
The balloon altitude at the time of observation was 34km.
Hence there was a severe absorption at the lower energy of the spectrum.
The flux at the peak is 1.53x10^-6 ergs/cm^2/s  (20-100keV).

We verified with FERMI and SWIFT teams that the satellites were on the
other side of the sky and thus both have missed it.


GRB_name: GRB131030A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15416
SUBJECT: GRB 131030A: Enhanced Swift-XRT position
DATE:    13/10/31 12:00:09 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 2695 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 131030A, 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 = 345.06732, -5.36845 which is equivalent
to:

RA (J2000): 23h 00m 16.16s
Dec (J2000): -05d 22' 06.4"

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

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

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


GRB_name: GRB131030A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15417
SUBJECT: GRB 131030A: Swift-XRT refined Analysis
DATE:    13/10/31 14:09:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Melandri (INAF-OAB), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A.
Kennea (PSU), B.P. Gompertz (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), P.
D'Avanzo (INAF-OAB) and E. Troja report on behalf of the Swift-XRT
team:

We have analysed 6.9 ks of XRT data for GRB 131030A (Troja  et al. GCN
Circ. 15402),  from 68 s to 41.4 ks after the  BAT trigger. The data
comprise 1.0 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 Evans et
al. (GCN. Circ 15416).

The late-time light curve (from T0+4.3 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.18 (+0.06, -0.07).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.11 (+/-0.03). The
best-fitting absorption column is  1.17 (+/-0.07) x 10^21 cm^-2, in
excess of the Galactic value of 4.7 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.09 (+0.13, -0.12)
and a best-fitting absorption column of 1.16 (+0.30, -0.28) x 10^21
cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.5 x 10^-11 (4.7 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.16 (+0.30, -0.28) x 10^21 cm^-2
Galactic foreground: 4.7 x 10^20 cm^-2
Excess significance: 4.0 sigma
Photon index:      2.09 (+0.13, -0.12)

If the light curve continues to decay with a power-law decay index of
1.18, the count rate at T+24 hours will be 0.055 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x
10^-12 (2.6 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/00576238.

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


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15418
SUBJECT: GRB 131030A: T21 optical observations
DATE:    13/10/31 15:45:15 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:

We have detected GRB 131030A optical afterglow at iTelescope observatory
T21 (Mayhill, New Mexico). We used 0.43-m/6.8 astrograph and FLI-PL6303E
CCD. Three unfiltered images and three photometric R filter images with 600 sec 
exposure time were made.

The afterglow was detected at the following position RA 23:00:16.17 and 
DEC -05:22:05.0.

The following magnitudes were obtained from the observations using 
NOMAD1 0846-0702870 (R=17.120) as a comparison star:

Tmid(h)+T0       Filter             Exp. time (sec)       Mag            Mag err. 
8.53                  unfiltered       3x600                   18.57CR     0.12
9.26                  R                  3x600                   19.43R        0.24


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15419
SUBJECT: GRB 131030A: TAROT La Silla observatory optical observations
DATE:    13/10/31 16:05:28 GMT
FROM:    Bruce Gendre at ASDC  <bruce.gendre@gmail.com>

Klotz A. (IRAP-CNRS-OMP), Gendre B. (ARTEMIS),
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 131030A detected by SWIFT (trigger 576238, 
Troja et al. GCN 15402) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory, La Silla observatory, Chile.

The observations started 2.85h after the GRB trigger. The elevation of 
the field increased from 59 degrees above horizon and weather conditions
were good.

We clearly detected the fading counterpart mentioned by previous teams 
(Virgili et al., GCN 15406, Strob et al. GCN 15410) from T0+2.85h to 
T0+9.13h

This message may be cited.


GRB_name: GRB131030A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15420
SUBJECT: GRB 131030A: RATIR Optical and NIR Observations
DATE:    13/10/31 17:08:16 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC),
Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos A. de
Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:

We observed the field of GRB 131030A (Troja, et al., GCN 15402) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/10 31.08 to 2013/10 31.37 UTC (4.91
to 11.97 hours after the BAT trigger), obtaining a total of 4.26 hours
exposure in the r and i bands and 1.69 hours exposure in the Z,
Y, J, and H bands.

We detect the uncatalogued source reported by UVOT (Troja et al., GCN
Circ. 15414). In comparison with the SDSS DR9 and 2MASS, we obtain the
following detections:

  r     19.14 +/- 0.01
  i     18.92 +/- 0.01
  Z     18.76 +/- 0.02
  Y     18.61 +/- 0.02
  J     18.62 +/- 0.02
  H     18.40 +/- 0.02

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. We can confirm that this source
fades during our observations with power-law decay indices of approximately
t^-0.9 in the r, i, Z and Y bands and a shallower decay of t^-0.5 and
t^-0.4 in the J and H bands, respectively.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131031A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15421
SUBJECT: GRB 131031A found in ground analysis of BAT data
DATE:    13/10/31 21:10:02 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings reports on behalf of the Swift science team:

At 11:33:31 UT, Swift-BAT rate-triggered on GRB 131031A (trigger 576277).  No
significant source was found onboard.  In ground analysis, a significant source
was found at the very edge of the BAT field of view (3% coded).  The location is
RA, Dec 29.618, -1.603, which is:

RA (J2000)    01h 58m 28.3s
Dec (J2000)  -01d 36' 11"

with an estimated error radius of 4 arcmin (90% containment).  This GRB also
triggered Fermi GBM.

The burst was about 8 seconds long, with a multipeaked structure.

A Swift TOO request has been submitted to locate the afterglow with XRT and UVOT.


GRB_name: GRB131031A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15422
SUBJECT: GRB 131031A: 1.23m CAHA I-band and 1.5m OSN R-band observations of Swift/BAT error circle
DATE:    13/10/31 23:28:53 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

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

We imaged the field of the GRB131031A (Cummings GCN 15421) with the 1.23m CAHA telescope. The observations were carried out at 21:24--22:04 UT (mean epoch 10.2 hours post burst) in the I-band with a total exposure time of 7x300s. Visual comparison with the SDSS did not reveal new objects brighter than I~20.5 (Vega) within the BAT error circle.  A contemporaneous 900s R-band image taken with the 1.5m OSN telescope did not reveal any new object either brighter than R>19.5 (Vega).


GRB_name: GRB131030A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15423
SUBJECT: GRB 131030A: P60 observations
DATE:    13/11/01 00:48:58 GMT
FROM:    Daniel Perley at Caltech  <dperley@astro.caltech.edu>

D. A. Perley (Caltech) and S. B. Cenko (NASA/GSFC) report on behalf of a
larger collaboration:

We observed the afterglow of GRB 131030A (GCN 15402, Troja et al.) with 
the robotic Palomar 60-inch telescope in the g, r, i, and z filters. 
Three exposures of 180 seconds each were acquired in each filter at four 
separate epochs starting at 5.09, 6.63, 8.12, and 9.65 hours after the 
Swift trigger, respectively.  The light curve in these bands shows a 
steady power-law decline with decay index alpha~0.95, similar to that 
reported by RATIR over the same timescale (GCN 15420, Littlejohns et al.)

Photometry from the first epoch (calibrated relative to SDSS) yields:

t_mid(d) exp(s) filter   magnitude
0.21434  3x180    g  = 19.14 +/- 0.02
0.21912  3x180    r  = 18.81 +/- 0.02
0.22391  3x180    i  = 18.61 +/- 0.03


GRB_name: GRB131031A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15424
SUBJECT: GRB 131031A: Swift-XRT observations
DATE:    13/11/01 06:36:03 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

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

We have analysed 3.7 ks of XRT data for the Swift/BAT-detected burst:
GRB 131031A,  from 39.7 ks to 52.0 ks after the  Swift/BAT trigger. The
data are entirely in Photon Counting (PC) mode.  An X-ray source is
detected within the Swift/BAT error circle. Using 1649 s of PC mode
data and 1 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 = 29.61022, -1.57882 which is equivalent to:

RA (J2000): 01h 58m 26.45s
Dec(J2000): -01d 34' 43.7"

with an uncertainty of 4.7 arcsec (radius, 90% confidence). This
position is 91 arcsec from the Swift/BAT position.  The source has a
mean count rate of 8.8e-03 ct/sec; we cannot determine at the present
time whether it is fading.


The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020317.

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


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15425
SUBJECT: GRB131030A : xinglong TNT optical observation
DATE:    13/11/01 07:29:08 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

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

We began to observe GRB 131030A  (Troja et al. GCN 15402) 
with Xinglong 0.8-m TNT telescope at 13:59:04 (UT) , Oct. 31th,
about 17 hours after the burst.  10*300 sec  R-band images were obtained. 

The optical counterpart (Troja et al. GCN 15402)   was clearly detected 
with a magnitude of 19.4+/-0.1 mag in R band, calibrated by USNO B1.0 R2mag 
at the mean time of 17.397h after the burst.

This message may be cited.


GRB_name: GRB131031A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15426
SUBJECT: GRB 131031A: 1.23m CAHA afterglow candidate
DATE:    13/11/01 08:48:12 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

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

Further analysis of the observations of the field of GRB 131031A (Cummings 
GCN 15421) obtained with the 1.23m CAHA in I-band, 10.2 hr after the burst 
(Terron et al. GCN 15422), reveals a source consistent with the XRT afterglow 
candidate at the following coordinates (J2000+/-0.5"):

R.A.: 01:58:26.46
Dec: -01:34:48.1

This source is not present in the archival SDSS images and has a magnitude of 
i(AB)=21.63+/-0.25 as compared with SDSS field stars. Thus, we propose it as 
the optical afterglow of GRB 131031A. Further observations will be needed to 
check for variability.


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15427
SUBJECT: GRB 131030A: Bassano Bresciano Observatory optical observations
DATE:    13/11/01 09:20:06 GMT
FROM:    Ulisse Quadri at Bassano Bresciano Obs  <oabb@ulisse.bs.it>

U.Quadri, L.Strabla and R.Girelli report:

We imaged the field of GRB 131030A detected by SWIFT 
(trigger 576238,Troja et al. GCN 15402) with the robotic 
telescope of (IAU station 565) Bassano Bresciano 
Observatory, Italy.

The observations started 20h 11m. after the 
GRB trigger,with our schmidt telescope 
D=320 mm F/D=3.1.

Weather conditions were good.

We co-added a series of 30 unfiltered CCD exposures of 120sec.


We detect a (fading) afterglow in the error box given by SWIFT.
at the following position (+/- 3 arcsec):

RA (J2000) =  23h 00m 16.12s
DEC(J2000) = -05d 22p 06.9s


The results of our photometry are:

    Date        UT        Vmag   +/- err  
               Middle    

2013-10-31   17:40:39     19.17    0.21
2013-10-31   18:22:02     19.62    0.28
2013-10-31   19:04:46     20.45    0.22


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

The message may be cited.


GRB_name: GRB131031A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15428
SUBJECT: Konus-Wind observation of GRB 131031A
DATE:    13/11/01 09:21:25 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration GRB 131031A (Cummings, GCN 15421)
triggered Konus-Wind at T0=41619.496 s UT (11:33:39.496).

The burst light curve shows a multi-peaked structure from
~T0-0.5 s till ~T0+6 s.
The emission is seen up to ~7 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131031_T41619/

As observed by Konus-Wind, the burst
had a fluence of (4.8  1.2)x10-6 erg/cm2,
and a 64-ms peak flux, measured from T0+0.064 s,
of (3.8  0.5)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by a simple power law with the photon index 2.09  0.15,
chi2 = 82.5/99 dof.

The spectrum at the maximum count rate (measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 15 MeV range
by a simple power law with the photon index 1.96  0.18,
chi2 = 51.3/72 dof.


All the quoted values are preliminary.


GRB_name: GRB131031A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15429
SUBJECT: GRB 131031A: MASTER  optical observation
DATE:    13/11/01 10:36:33 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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

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

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

V.Krushinski, I.Zalozhnih,  A. Popov
Ural Federal University, Kourovka

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

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB131031A 11 s after notice 
time  and 51 s after GRB time at 2013-10-31 11:34:23UT by FERMI trigger 
N404912015.
Using very wide field cameras (FOV=2x384 square degrees, D=72mm, f/1.2, 1 
pix = 22 arcsec), we cover Swirt  error box (Cummings et al. GCN15421).
The 5-sigma upper limit has been about 11 mag on single 5 sec image and 
12.5 on coaad of 12 continuously images with total exposure 60 sec.
On  40-cm  MASTER-II telescope with FOV 4 sq. degree look at a center 
of FERMI GBM error box  (ra=01 47 16 dec=+00 33 34 r=2.3) and not cover 
Swirt error box .

The message may be cited.


GRB_name: GRB131030A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15430
SUBJECT: GRB 131030A - RoboPol optical afterglow polarimetry
DATE:    13/11/01 13:16:41 GMT
FROM:    Dmitry Blinov at U of Crete/FORTH  <blinov@physics.uoc.gr>

M. Balokovic, T. Hovatta, O. King, T. Pearson, A. Readhead
Caltech, USA

D. Blinov, N. Kylafis, G. Panopoulou, I. Papadakis, I. Papamastorakis,
V. Pavlidou, P. Reig, K. Tassis
University of Crete/FORTH, Greece

P. Khodade, C. Rajarshi, A. Ramaprakash, R. Rouneq
Inter-University Centre for Astronomy and Astrophysics, India

E. Angelakis, I. Myserlis, L. Fuhrmann, J. A. Zensus
Max Planck Institute for Radio Astronomy, Germany

R. Feiler, A. Kus, B. Pazderska, E. Pazderski
Nicolaus Copernicus University, Poland

We observed GRB 131030A (Swift Trigger 576238; Troja et al. GCN 15402)
using the RoboPol (http://robopol.org) polarimeter on the 1.3m Skinakas
observatory  telescope (Greece). We confirm the presence of an uncatalogued
source  at the location (RA=23h00m16s, Dec=-05d22m05s). Preliminary analysis
showed that emission of the source is linearly polarized at high significance.

Further analysis will be presented elsewhere.

[GCN OPS NOTE(01nov13):  This was delayed in distribution by 17 hours because
a new entry in the list had to be added.]


GRB_name: GRB131018B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15431
SUBJECT: GRB 131018B: Further Swift-XRT observations.
DATE:    13/11/01 13:32:42 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), P. A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

We have analysed 6.7 ks of XRT data for the Fermi/LAT-detected burst GRB 131018B (Vianello et al., GCN 15357; Zhang, GCN 15360), from 1081.2 ks to 1100.0 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode. The uncatalogued X-ray source reported in D'Avanzo et al. (GCN 15361) is not longer detected. The source count rate changed from 5.7e-3 +/- 1.8e-3 cts/s in the first epoch (D'Avanzo et al., GCN 15361) to a 3-sigma upper limit of 1.1e-3 cts/s. 
We can conclude that this source is likely the X-ray afterglow of GRB 131018B.

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


GRB_name: GRB131030A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15432
SUBJECT: LOAO B,R Observation of GRB131030A
DATE:    13/11/01 13:34:48 GMT
FROM:    Changsu Choi at Seoul Nat U  <changsu@astro.snu.ac.kr>

Myungshin Im and Changsu Choi (CEOU/Seoul National Univ.), on behalf of a
larger collaboration: 

We observed GRB 131030A (Troja et al., GCN 15402) in B,R band using a 1-m
telescope at Mt. Lemmon Optical Observatory (LOAO) in Arizona, US. 

The observation started at 2013-10-31 01:42:46 UT, or about 4.78 hours after
the BAT alert. 

In all of the BR images, we identify the afterglow, with approximate
magnitudes B ~ 19.29 +/-0.07, R ~ 18.88 +/- 0.09 mag (first epoch),
calibrated against stars in vicinity based on USNO-B1 photometry. 

We also confirm fading of the object from serial set of data we took about 4
and 6 hours later. 

Further observations are planned.

We thank the LOAO operator, Jae-Hyuk Yoon and In-Kyung Baek for performing 
the observation.

[GCN OPS NOTE(01nov13): This was delayed in distribution by 8 hours
because a new entry had to be added to the list.]


GRB_name: GRB131031A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15433
SUBJECT: GRB 131031A: Swift/UVOT Upper Limits
DATE:    13/11/01 13:47:39 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

Paul Kuin (UCL/MSSL) and Eleonora Troja (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began observations of the field of GRB 131031A
39.7ks after the ground-detected BAT trigger (Cummings, GCN
Circ. 15421). An otical afterglow candidate was reported
by Gorosabel et al. (GCN Circ. 15426) but no optical afterglow
consistent with the XRT position (Gompertz et al., GCN Circ. 15423)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the
initial exposures are:

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

white            40274        52042         1559         >21.1
v                40825        47155          762         >20.1
u                39724        51207         1559         >21.1

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


GRB_name: GRB131031A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15434
SUBJECT: GRB 131031A: Fermi GBM detection
DATE:    13/11/01 16:11:16 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

G. Fitzpatrick (UCD) and P. N. Bhat (UAH) report on behalf of the Fermi GBM Team:

At 11:33:32.82 UT on 31 October 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131031A (trigger 404912015/131031482). This
GRB was also detected by Swift in ground analysis (Cummings, GCN 15421)
and by Konus-Wind (Golenetskii et al., GCN 15428). The angle from
the Fermi LAT boresight is 46 degrees.

The on-ground calculated location is consistent with the Swift location.
The GBM light curve is multi-peaked with a duration (T90) of about 7.4 s
(50-300 keV). The time-averaged spectrum from T0+0.003 s to T0+7.424 s is
adequately fit by a Band function with Epeak = 92.1 +/- 7.0 keV,
alpha = -0.8 +/- 0.1  , and beta = -2.3 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(4.3 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.6 s in the 10-1000 keV band is 10.2 +/- 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: GRB131030A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15435
SUBJECT: GRB 131030A: the 2nd epoch of SAO RAS observations
DATE:    13/11/01 18:40:36 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov@sao.ru>

A. S. Moskvitin and T. N. Sokolova
report on behalf of SAO RAS GRB follow-up team:

We observed the GRB 131030A field (Troja et al., GCN#15402)
on October, 31, with the 1-m telescope Zeiss-1000 of SAO RAS.
The weather conditions were good. The observations were
carried out in three bands: B, V, Rc.

We clearly detected the OT at the level R = 20.4 +/- 0.1.
T_start = 18:16:11 UT,
T_end = 21:59:15 UT,
T_mid - T0 = 24.059 hours.
The total Rc-band exposure was 3000 seconds.

The OT magnitude was calibrated against the same set of USNO B1 stars
(R2) as in GCN #15412 and not corrected for the Galaxy extinction.


GRB_name: GRB131030A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15436
SUBJECT: GRB 131030A: Continued RATIR Optical and NIR Observations
DATE:    13/11/01 19:26:33 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC),
Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos A. de
Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:

We again observed the field of GRB 131030A (Troja, et al., GCN 15402) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on
the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional
on Sierra San Pedro Mrtir from 2013/11 1.08 to 2013/11 1.20 UTC (29.01 to
31.91 hours after the BAT trigger), obtaining a total of 2.13 hours exposure
in the r and i bands and 0.88 hours exposure in the Z, Y, J, and H bands.

We continue to detect the uncatalogued source reported by UVOT (Troja et
al., GCN Circ. 15414), at fainter magnitudes than the first epoch of RATIR
observations (Littlejohns et al., GCN Circ. 15420). In comparison with the
SDSS DR9 and 2MASS, we obtain the following detections:

  r     20.73 +/- 0.03
  i     20.45 +/- 0.03
  Z     20.19 +/- 0.05
  Y     20.06 +/- 0.07
  J     20.07 +/- 0.08
  H     19.57 +/- 0.11

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison with the first epoch
of
RATIR observations these magnitudes can be modelled with power-law
decays, with indices of approximately t^-1.1 for the r and i bands, t^-1.0
for
the Z, Y and J bands and t^-0.8 for the H band.


We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131018B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15437
SUBJECT: GRB 131018B: RATIR Optical/NIR Observations
DATE:    13/11/01 22:57:14 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska
(UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen
Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM),
Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga
(UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:


We observed the field of GRB 131018B (Vianello, et al., GCN 15357; 
Zhang, et
al., GCN 15360) with the Reionization and Transients Infrared Camera 
(RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio
Astronmico Nacional on Sierra San Pedro Mrtir from 2013/10 20.09 to
2013/10 20.27 UTC (33.94 to 38.36 hours after the GBM trigger),  and again
the next night from 2013/10 21.09 to 2013/10 21.27 UTC (57.93 to 62.34
hours after the GBM trigger). We obtained a total of 2.8 hours exposure 
in the
r and i bands and 1.3 hours exposure in the Z, Y, J, and H bands each 
night.

During the 1st night of observations, the position of the X-ray afterglow
reported by D'Avanzo et al. (GCN 15361, 15431) falls at the edge of our 
field
of view in the Z and J bands. For a source within the Swift-XRT error 
circle, in
comparison with 2MASS, we obtain the following upper limits (3-sigma):

   Z   > 22.6
   J    > 21.6

During the 2nd night of observations, the XRT position was observed in all
filters. For a source within the Swift-XRT error circle, in comparison 
with 2MASS
and SDSS DR9, we obtain the following upper limits (3-sigma):

   r   > 23.8
   i   > 23.5
   Z  > 22.8
   Y  > 22.2
   J   > 21.9
   H  > 21.4

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131031A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15438
SUBJECT: GRB131031A: RATIR Optical and NIR Observations
DATE:    13/11/02 00:56:18 GMT
FROM:    Antonino Cucchiara at UCSC/UCO Lick  <acucchia@ucolick.org>

A. Cucchiara (ORAU/GSFC), Nat Butler (ASU), Alan M. Watson (UNAM), 
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), 
Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), 
Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), 
Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), 
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), 
and Harvey Moseley (GSFC) report:

We observed the field of GRB 131031A (Cummings et al., GCN 15421) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on
Sierra San Pedro Mrtir from 2013/11 1.21 to 2013/11 1.48 UTC (17.44
to 23.99 hours after the BAT trigger), obtaining a total of 4.47 hours
exposure in the r and i bands and 1.81 hours exposure in the Z,
Y, J, and H bands.

The source within the XRT error circle (Gompertz et al., GCN 15424) and 
confirmed by Gorosabel et al. (GCN 15426) is clearly detected. 
In comparison with the SDSS DR9 and 2MASS, we
obtain the following detections and upper limits (3-sigma):

 r 22.38 +/- 0.07
 i 22.34 +/- 0.09
 Z 21.89 +/- 0.14
 Y > 21.81
 J > 21.36 
 H > 20.69 

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro 
Mrtir.


GRB_name: GRB131031A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15439
SUBJECT: GRB 131031A: RATIR Optical and NIR Observations and Upper Limits
DATE:    13/11/02 22:01:34 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC),
Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja
(GSFC), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid
Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM),
Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:

We again observed the field of GRB 131031A (Cummings et al., GCN 15421)
with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico
Nacional on Sierra San Pedro Mrtir from 2013/11 2.09 to 2013/11 2.49 UTC
(38.53 to 48.15 hours after the BAT trigger), obtaining a total of 6.23
hours exposure in the r and i bands and 2.50 hours exposure in the Z, Y,
J, and H bands.

The source detected in the first epoch of RATIR observations (Cucchiara et
al., GCN 15438) within the Swift-XRT error circle (Gompertz et al., GCN
15424) and confirmed by Gorosabel et al. (GCN 15426) has faded. In
comparison with 2MASS, we obtain the following detections and upper limits
(3-sigma):

  r     22.98 +/- 0.11
  i     > 22.36
  Z     > 21.85
  Y     > 21.78
  J     > 21.62
  H     > 21.19

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison to the first epoch
of RATIR observations (Cucchiara et al., GCN 15438), the source has faded
by 0.6 magnitudes in the r band. This is consistent with a power-law decay
of
approximately t^-0.75.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131103A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15440
SUBJECT: GRB 131103A: Swift detection of a burst
DATE:    13/11/03 22:19:31 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. R. Cummings (NASA/UMBC), S. D. Barthelmy (GSFC),
D. N. Burrows (PSU), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC),
J. A. Kennea (PSU), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester),
K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of
the Swift Team:

At 22:07:25 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131103A (trigger=576562).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 348.954, -44.670 which is 
   RA(J2000) = 23h 15m 49s
   Dec(J2000) = -44d 40' 11"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of at least 20 sec with possible
emission on a longer timescale.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 22:08:42.0 UT, 76.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 348.92161, -44.63816 which
is equivalent to:
   RA(J2000)  = 23h 15m 41.19s
   Dec(J2000) = -44d 38' 17.4"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 141 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 (1.11 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 4
(+2.09/-1.83) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 1.31e-09 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
0.01. 

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


GRB_name: GRB131103A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15441
SUBJECT: GRB 131103A: Swift-XRT refined Analysis
DATE:    13/11/04 12:20:15 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

D.N. Burrows (PSU), J.A. Kennea (PSU), V. Mangano (PSU), J.P. Osborne
(U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), B.
Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC) and
J.R. Cummings report on behalf of the Swift-XRT team:

We have analysed 9.1 ks of XRT data for GRB 131103A (Cummings  et al.
GCN Circ. 15440),  from 82 s to 25.5 ks after the  BAT trigger. The
data comprise 793 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The refined XRT position is RA, Dec =
348.9213, -44.6377 which is equivalent to:

RA (J2000): 23 15 41.11
Dec(J2000): -44 38 15.7

with an uncertainty of 3.5 arcsec (radius, 90% confidence).

The late-time light curve (from T0+5.9 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.16 (+/-0.26).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.76 (+0.27, -0.25). The
best-fitting absorption column is  4.0 (+0.8, -0.7) x 10^21 cm^-2, in
excess of the Galactic value of 1.1 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.15 (+0.18, -0.17)
and a best-fitting absorption column of 3.5 (+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 4.0 x 10^-11 (7.2 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.5 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^20 cm^-2
Excess significance: 8.9 sigma
Photon index:      2.15 (+0.18, -0.17)

If the light curve continues to decay with a power-law decay index of
1.16, the count rate at T+24 hours will be 6.4 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.6 x
10^-13 (4.6 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00576562.

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


GRB_name: GRB131103A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15442
SUBJECT: GRB 131103A: Enhanced Swift-XRT position
DATE:    13/11/04 14:25:13 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 7277 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 131103A, 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 = 348.91855, -44.64060 which is equivalent
to:

RA (J2000): 23h 15m 40.45s
Dec (J2000): -44d 38' 26.1"

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: GRB131103A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15443
SUBJECT: GRB 131103A: Swift/UVOT Detection
DATE:    13/11/04 15:51:58 GMT
FROM:    Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>

N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), and J. R. Cummings (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131103A
87 s after the BAT trigger (Cummings et al., GCN Circ. 15440).
A decaying source consistent with the XRT position  (Goad et al. GCN Circ. 15442)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  23:15:40.55 = 348.91894 (deg.)
    Dec (J2000) = -44:38:25.4  = -44.64040 (deg.)
with an estimated uncertainty of 0.60 arc sec. (radius, 90% confidence).

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

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

white               87          237          147         19.41 +/- 0.13
white            19290        19893          599         21.45 +/- 0.17
v                  629        12543         1173        >20.0
b                  554        25509         1664         21.64 +/- 0.23
u                  299          549          246         18.93 +/- 0.13
w1                 678        24073         1116        >20.6
w2                6741         6941          197        >19.8

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


GRB_name: GRB131030A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15444
SUBJECT: GRB 131030A: Continued RATIR Optical and NIR Observations
DATE:    13/11/04 20:01:34 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC),
Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego
(UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos
Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC)
report:

We again observed the field of GRB 131030A (Troja, et al., GCN Circ. 15402)
with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico
Nacional
on Sierra San Pedro Mrtir from 2013/11 4.10 to 2013/11 4.17 UTC (101.35
to 103.16 hours after the BAT trigger), obtaining a total of 1.04 hours
exposure in the r and i bands and 0.29 hours exposure in the Z, Y, J, and
H bands.

We continue to detect the uncatalogued source reported by UVOT (Troja et
al., GCN Circ. 15414) in the r, i and Z bands, at fainter magnitudes than
the previous epochs of RATIR observations (Littlejohns et al., GCN Circ.
15436; Littlejohns et al., GCN Circ. 15420). For a source within the
Swift-XRT error circle, in comparison with the SDSS DR9 and 2MASS, we
obtain the following detections and upper limits (3-sigma):

  r     22.48 +/- 0.13
  i     22.71 +/- 0.30
  Z     21.70 +/- 0.34
  Y     > 21.28
  J     > 21.05
  H     > 20.49

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison with the second epoch
of RATIR observations the source has faded by an average of 1.8 magnitudes
in the r, i and Z bands. The upper limits all indicate that the source has
faded by a minimum of approximately 1 magnitude in the Y, J and H bands.
Our observations in the Z, Y, J and H bands are consistent with the
previously reported power-law decay indices (Littlejohns et al., GCN Circ.
15436), however, there is indication of a steeper decay in both the r and
i bands. Between this and the second epoch of RATIR observations we find
power-laws of t^-1.33 for the r band and t^-1.72 for the i band.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131103A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15445
SUBJECT: GRB 131103A: NOT and VLT observations
DATE:    13/11/04 20:14:45 GMT
FROM:    Steve Schulze at U of Iceland  <sts30@hi.is>

Z. Cano (U Iceland), S. Schulze (PUC, MCSS), D. Malesani (DARK/NBI), P. Jakobsson (U Iceland), D. J. Watson (DARK/NBI), N. R. Tanvir (U Leicester), D. Xu, J. P. U. Fynbo (DARK/NBI) and M. Hayes (Stockholm University) report on behalf of a larger collaboration:

We observed the field of GRB 131103A (Cummings et al., GCN Circ. 15440) with the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC, and subsequently with the ESO VLT using the optical acquisition camera of the X-shooter spectrograph, as well as with the HAWK-I near-infrared imager. A brief summary of our observations is reported below. For the NOT observation, the object was very low on the horizon (airmass = 4.56), hence we could only achieve a poor S/N.

At the position of the UVOT afterglow (Kuin et al., GCN Circ. 15443), a source is detected in all our images. It is clearly elongated in both R and J as seen in the VLT data, and we thus suggest that this is the host galaxy, though some afterglow contribution cannot be excluded. We note that a marginally significant object is visible in the DSS (R band) at the same position.

Instrument    Time (hr)  Filter  Magnitude
NOT/ALFOSC    1.29       R       20.07 +/- 0.12
VLT/X-shooter 4.48       R       20.48 +/- 0.01
VLT/HAWK-I    5.94       J       19.63 +/- 0.02

While the comparison of the two R-band magnitudes provides some evidence for fading, we note that both R-band measurements have an uncertain calibration, since no common star is available between the ALFOSC and X-shooter images. The two measurements are therefore tied to different USNO stars, which can introduce an error of ~0.1-0.2 mag. Specifically, we used the R1 magnitudes of stars 0453-0803362 and 0453-0803335 for ALFOSC and X-shooter, respectively. The HAWK-I observation was calibrated against five nearby 2MASS stars.


We kindly acknowledge excellent support by the observing staff at the VLT, in particular Claudia Reyes, Dimitri Gadotti, Julien Girard and Roger Wesson.

[GCN OPS NOTE(12nov13):  Per author's request, the observing time for the VLT/X-shooter
was changed from 5.84 to 4.48.]


GRB_name: GRB131105A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15446
SUBJECT: GRB 131105A: Swift detection of a burst
DATE:    13/11/05 02:17:27 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

J. R. Cummings (NASA/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), A. Y. Lien (NASA/GSFC/ORAU),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (AGU) and C. A. Swenson (PSU) report
on behalf of the Swift Team:

At 02:04:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131105A (trigger=576738).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 71.011, -62.981 which is 
   RA(J2000)  =  04h 44m 03s
   Dec(J2000) = -62d 58' 52"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multple peaks
with a total duration of about 120 sec.  The peak count rate
was ~1100 counts/sec (15-350 keV), at ~44 sec after the trigger. 

The XRT began observing the field at 02:09:35.6 UT, 290.9 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 70.96452, -62.99394 which
is equivalent to:
   RA(J2000)  = 04h 43m 51.48s
   Dec(J2000) = -62d 59' 38.2"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 89 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 (2.91 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.2
(+2.11/-1.84) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 294 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 5% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.03. 

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


GRB_name: GRB131105A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15447
SUBJECT: GRB 131105A: VLT/X-shooter optical afterglow candidate
DATE:    13/11/05 04:20:01 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu (DARK/NBI), D. Malesani (DARK/NBI), N. R. Tanvir (U. Leicester),
T. Kruehler (ESO), report on behalf of a larger collaboration:

We observed the field of GRB 131105A (Cummings et al., GCN 15446) with
the acquisition camera of the X-shooter spectrograph at the VLT. The
observation was taken around 03:24 UT on November 5, that is 1.3 hr
after the GRB. Inside the current XRT error circle (2.0" radius; see
http://www.swift.ac.uk/xrt_positions/), we detect a single source at
coordinates (J2000):

RA = 04:43:52.27
Dec = -62:59:43.7

with an uncertainty of <0.5". Its magnitude is R = 22.4 +- 0.1,
compared to three nearby bright USNO stars.

At the moment we cannot conclude whether this source is variable or
associated to the GRB, but we propose it as a candidate counterpart.

We acknowledge excellent support from the ESO staff in Paranal, in
particular Dimitri Gadotti and Roger Wesson.


GRB_name: GRB131105A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15448
SUBJECT: GRB 131105A: Enhanced Swift-XRT position
DATE:    13/11/05 07:15:56 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 704 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 131105A, 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 = 70.96782, -62.99505 which is equivalent
to:

RA (J2000): 04h 43m 52.28s
Dec (J2000): -62d 59' 42.2"

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

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

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


GRB_name: GRB131105A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15449
SUBJECT: GRB 131105A: TAROT La Silla observatory optical observations
DATE:    13/11/05 07:32:49 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D. (IRAP-CNRS-OMP), Gendre B.,
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 131105A detected by SWIFT
(trigger 576738) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 231s after the GRB trigger
(14s after the notice). The elevation of the field increased from
37 degrees above horizon and weather conditions
were good.

A first series of 30.0s exposure images was acquired in tracking mode.
We do not detect the afterglow candidate of Xu et al. (GCNC 15447)
with limiting magnitudes of:
t0+231s to t0+261s : Rlim = 18.3
t0+311s to t0+341s : Rlim = 18.3
t0+351s to t0+381s : Rlim = 18.3
t0+391s to t0+421s : Rlim = 18.3
t0+432s to t0+462s : Rlim = 18.3

Next series were co added by drizzling to increase the detectivity.
t0+ 472s to t0+1131s : Rlim = 19.0
t0+1141s to t0+1658s : Rlim = 19.0

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.

This message may be cited.


GRB_name: GRB131105A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15450
SUBJECT: GRB 131105A: VLT/X-shooter redshift
DATE:    13/11/05 09:48:07 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

D. Xu, D. Malesani (DARK/NBI), N. Tanvir (U. Leicester), T. Kruehler (ESO),
J. Fynbo (DARK/NBI) report on behalf of the X-shooter GRB
collaboration:

We have obtained spectroscopic observations of the afterglow of GRB 131105A
(Cummings et al., GCN 15446; Xu et al., GCN 15447), beginning at 03:46 UT,
approximately 102 minutes post-trigger.  We used the ESO VLT equipped
with the X-shooter spectrograph, covering the wavelength range 3000-20000 AA.

The exposure time was 8x600 s. In the NIR arm, we detect two emission lines,
interpreted as [O III] (5007) and H-alpha at a common redshift z = 1.686.
In the spectrum we also detect absorption lines at the same redshift, albeit at 
low signal-to-noise ratio. Furthermore, we measure significant fading of the source 
between two sets of acquisition images, confirming that we are seeing 
afterglow and host light.  Hence, we consider z = 1.686 the likely redshift of 
GRB 131105A. The afterglow appears to be red presumably due to dust extinction.

We acknowledge excellent support from the observing staff at Paranal, in
particular Dimitri Gadotti, Roger Wesson, and Claudia Reyes.


GRB_name: GRB131103A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15451
SUBJECT: GRB 131103A: VLT/X-shooter redshift
DATE:    13/11/05 10:08:47 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu, D. Malesani (DARK/NBI), S. Schulze (PUC, MCSS), A. de Ugarte
Postigo (IAA-CSIC, DARK/NBI), P. Jakobsson, Z. Cano(U Iceland), N. R.
Tanvir (U. Leicester), J. P. U. Fynbo, D. Watson (DARK/NBI), P.
Goldoni (APC, CEA/Irfu), S. Vergani (CNRS/GEPI), R. Wijers (U
Amsterdam) report on behalf of the X-shooter GRB collaboration:

We have obtained further observations of the afterglow of GRB 131103A
(Cummings et al., GCN Circ. 15440; Cano et al., GCN 15445) using the
ESO VLT equipped with the X-shooter spectrograph, covering the
wavelength range 3000-20000 AA.

The spectrum was secured on Nov. 5.2 with a total exposure time of
4x600 s. We detect a rich emission line spectrum from the underlying
host galaxy at a common redshift z = 0.5955. We also detect strong
absorption lines from FeII and
MgII at the same redshift in the blue part of the spectrum implying
that there is significant afterglow light superimposed on the host
light.

We acknowledge excellent support from the observing staff at Paranal,
in particular Dimitri Gadotti, Roger Wesson, and Claudia Reyes.

[GCN OPS NOTE(05nov13):  Per author's request, the typo in the redshift value
was changed from 0.599 to 0.5955.]


GRB_name: GRB131105A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15452
SUBJECT: Konus-Wind observation of GRB 131105A
DATE:    13/11/05 11:18:56 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration GRB 131105A
(Swift-BAT trigger 576738: Cummings et al., GCN 15446)
triggered Konus-Wind at T0=7527.233 s UT (02:05:27.233).

The burst light curve shows multiple peaks in the time
interval from ~T0-35 s till ~T0+90 s.
The emission is seen up to ~3 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131105_T07527/

As observed by Konus-Wind, the burst
had a fluence of (2.3  0.2)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.600 s,
of (2.0  0.2)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+90.368 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.88  0.38,
the high energy photon index beta = -2.33  0.33,
the peak energy Ep = 156  38 keV,
chi2 = 97/96 dof.

The spectrum near the maximum count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.04  0.27,
the high energy photon index beta = -2.64  0.76,
the peak energy Ep = 174  41 keV,
chi2 = 87.9/97 dof.

Assuming the redshift z=1.686 (Xu, et al., GCN 15450)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is (1.7  0.1)x10^53 erg,
the peak luminosity L_iso is (4.0  0.4)x10^52 erg/s,
and the rest-frame peak energy Ep,i = (420  100) keV

All the quoted values are preliminary.


GRB_name: GRB131024B
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15453
SUBJECT: GRB 131024B: Suzaku WAM observation of the prompt emission
DATE:    13/11/05 11:35:06 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro@phy.saitama-u.ac.jp>

Y. Ishida, M. Tashiro, Y. Terada, T. Yasuda, H. Ueno, S. Sugimoto
(Saitama U.), M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui,
Y. Fukazawa (Hiroshima U.), M. Yamauchi, N. Ohmori, M. Akiyama
(Univ. of Miyazaki), K. Yamaoka (Nagoya U.), S. Sugita (Ehime U.),
Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA), W. Iwakiri
(RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa,
K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report:

The long GRB 131024B (Krimm et al. GCN 15371) was detected by the the
Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of
50 keV - 5 MeV at 21:35:31 UT (=T0).

The observed light curve shows a single peak with a duration (T90) of
about 45 seconds.
The fluence in 100 - 1000 keV was 4.26 (+0.84/-2.27) x 10^-6 erg/cm^2.
The 1-s peak flux measured from T0+2 s was
0.73 (+0.26/-0.55) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-5 s to
T0+5 s is well fitted by a single power-law with a photon index of
2.13 (+0.28/-0.36) (chi^2/d.o.f = 12.4/14).

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

The light curves for this burst will be available at:

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


GRB_name: GRB131105A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15454
SUBJECT: GRB 131105A: Swift/UVOT Upper Limits
DATE:    13/11/05 11:40:36 GMT
FROM:    Massimiliano de Pasquale at MSSL-UCL  <m.depasquale@ucl.ac.uk>

M. De Pasquale (UCL-MSSL) and J. R. Cummings (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131105A
295 s after the BAT trigger (Cummings et al., GCN Circ. 15446).
No optical afterglow consistent with the optical position
(Xu et al. GCN Circ. 15447) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC           295          444          147         >21.5
white              295         1544          353         >22.0
v                  774         1594           97         >19.3
b                 1152         1520           58         >19.9
u                  848         1495           78         >19.8
w1                 823         1471           78         >19.4
m2                 798         1619           39         >18.4
w2                 750         1570           78         >19.5

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


GRB_name: GRB131105A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15455
SUBJECT: GRB 131105A: Fermi GBM observation
DATE:    13/11/05 16:18:25 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick@ucdconnect.ie>

G. Fitzpatrick (UCD) and P. Jenke (UAH) report on behalf of the Fermi GBM
Team:

At 02:04:53.49 UT on 05 November 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131105A (trigger 405309896/131105087), which
was also detected by Swift (Cummings et al., GCN 15446) and Konus-Wind
(Golenetskii et al, GCN 15452).  The GBM on-ground location is consistent
with the Swift/XRT position (Osborne et al., GCN 15448). The angle from
the Fermi LAT boresight is 37 degrees.

The GBM light curve consists of a multiple-peak structure with a duration
(T90) of about 112 s (50-300 keV). The time-averaged spectrum from
T0-3 s to T0+121 s is adequately fit by a Band function with Epeak =
203.9 +/- 31.1 keV, alpha = -1.2 +/- 0.1, and beta = -1.8 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(2.9 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+108 s in the 10-1000 keV band is 8.4 +/- 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: GRB131030A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15456
SUBJECT: GRB 131030A: Swift-BAT refined analysis
DATE:    13/11/05 16:32:59 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), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlinks,
we report further analysis of BAT GRB 131030A (trigger #576238)
(Troja, et al., GCN Circ. 15402).  The BAT ground-calculated position is
RA, Dec = 345.074, -5.380 deg which is 
   RA(J2000)  =  23h 00m 17.8s 
   Dec(J2000) = -05d 22' 46.4" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 37%.
 
The mask-weighted light curve shows at least two overlapping peaks starting
at ~T-8 sec, peaking at ~T+10 sec, and ending at ~T+180 sec with a low-level
tail out to at least T+800 sec.  T90 (15-350 keV) is 41.1 +- 4.0 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-6.04 to T+143.37 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.30 +- 0.03.  The fluence in the 15-150 keV band is 2.93 +- 0.04 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+6.40 sec in the 15-150 keV band
is 28.1 +- 0.7 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/576238/BA/


GRB_name: GRB131103A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15457
SUBJECT: GRB 131103A: Swift-BAT refined analysis
DATE:    13/11/05 16:40:45 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 131103A (trigger #576562)
(Cummings, et al., GCN Circ. 15440).  The BAT ground-calculated position is
RA, Dec = 348.948, -44.645 deg which is 
   RA(J2000)  =  23h 15m 47.5s 
   Dec(J2000) = -44d 38' 42.3" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.
 
The mask-weighted light curve shows a 2 or 3 overlapping peaks starting
at ~T-8 sec, peaking at ~T+0 sec, and ending at ~T+15 sec.
T90 (15-350 keV) is 17.3 +- 4.8 sec (estimated error including systematics).
 
The time-averaged spectrum from T-9.5 to T+13.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.97 +- 0.19.  The fluence in the 15-150 keV band is 8.2 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.62 sec in the 15-150 keV band
is 1.5 +- 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/576562/BA/


GRB_name: GRB131105A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15458
SUBJECT: GRB 131105A: Swift-XRT refined Analysis
DATE:    13/11/05 17:17:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

J.A. Kennea (PSU), V. Mangano (PSU), K.L. Page (U. Leicester), C.
Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), A. Maselli  (INAF-IASFPA), M.C. Stroh
(PSU) and J.R. Cummings report on behalf of the Swift-XRT team:

We have analysed 8.3 ks of XRT data for GRB 131105A (Cummings  et al.
GCN Circ. 15446),  from 276 s to 36.2 ks after the  BAT trigger. The
data comprise 7 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Osborne et al. (GCN. Circ
15448).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=8.0 (+0.0, -1.5). At T+353 s  the decay
flattens to an alpha of 0.62 (+/-0.04) before breaking again at T+21.4
ks to a final decay with index alpha=2.3 (+0.9, -0.8).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.22 (+0.16, -0.15). The
best-fitting absorption column is  2.2 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 2.9 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.5 x 10^-11 (5.9 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.2 (+0.5, -0.4) x 10^21 cm^-2
Galactic foreground: 2.9 x 10^20 cm^-2
Excess significance: 7.5 sigma
Photon index:      2.22 (+0.16, -0.15)

If the light curve continues to decay with a power-law decay index of
2.3, the count rate at T+24 hours will be 3.4 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-13 (2.0 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00576738.

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


GRB_name: GRB131105A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15459
SUBJECT: GRB 131105A, Swift-BAT refined analysis
DATE:    13/11/06 03:02:25 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

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

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 131105A (trigger #576738)
(Cummings, et al., GCN Circ. 15446).  The BAT ground-calculated position is
RA, Dec = 70.973, -63.005 deg which is
  RA(J2000)  =  04h 43m 53.5s
  Dec(J2000) = -63d 00' 17.7"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 7%.

The mask-weighted light curve shows a multi-peak structure starts
at ~T+0 sec and ends at ~T+126 sec. The light curve consists of
~ 5 obvious peaks. T90 (15-350 keV) is 112.3 +- 4.1 sec (estimated
error including systematics).

The time-averaged spectrum from T+6.8 to T+125.6 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.45 +- 0.11.  The fluence in the 15-150 keV band is 7.1 +- 0.5 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+116.64 sec in the 15-150 keV band
is 3.5 +- 0.6 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/576738/BA/


GRB_name: GRB131029A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15460
SUBJECT: GRB 131029A: Suzaku WAM observation of the prompt emission
DATE:    13/11/06 03:23:09 GMT
FROM:    Makoto Tashiro at Saitama U/Swift  <tashiro@phy.saitama-u.ac.jp>

H. Ueno, M. Tashiro, Y. Terada, T. Yasuda, Y. Ishida, S. Sugimoto
(Saitama U.), M. Ohno, K. Takaki, T. Kawano, R. Nakamura, S. Furui,
Y. Fukazawa (Hiroshima U.), M. Yamauchi, N. Ohmori, M. Akiyama,
R. Kinoshita (Univ. of Miyazaki), K. Yamaoka (Nagoya U.), S. Sugita
(Ehime U.), Y. E. Nakagawa, M. Kokubun, T. Takahashi (ISAS/JAXA),
W. Iwakiri(RIKEN), Y. Hanabata (ICRR), Y. Urata (NCU), K. Nakazawa,
K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report:

The long GRB 131029A (Fermi-LAT detection: A. von Kienlin, et al., GCN
15401) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers 
an energy range of 50 keV - 5 MeV at UT 23:20:48.884 (=T0).

The observed light curve shows a two-peaked structure starting at
T0-5.0 s, ending at T0+110 s with a duration (T90) of about 84 seconds.
The fluence in 100 - 1000 keV was 1.51 (-0.36, +0.24) *10^-5 erg/cm^2.
The 1-s peak flux measured from T0+4.0 s was
1.55 (-0.92, +1.3) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from
T0-2 s to T0+110 s is well fitted by a single power-law with a photon
index of 1.87 (-0.17, +0.17) (chi2/d.o.f = 12.4/12).

Due to the brightness of this burst, a 3% systematic error was added
for low energy channels.
All the quoted errors are at statistical 90% confidence level.

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


GRB_name: GRB131031A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15461
SUBJECT: GRB 131031A: Swift-XRT afterglow confirmation
DATE:    13/11/06 15:13:36 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

P.A. Evans & B.P. Gompertz (U. Leicester) report on behalf of the 
Swift-XRT team:

Swift-XRT performed a second observation of GRB 131031A (Cummings, GCN 
15421) on 2013 Nov 5, for 4.7 ks. The XRT source reported by Gompertz & 
Page (GCN 15424) is undetected, with a 3-sigma upper limit of 2.5e-3 
ct/sec, well below the level of the previous detection. We therefore 
conclude that this was the afterglow of GRB 131031A.

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


GRB_name: GRB131030A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15462
SUBJECT: GRB 131030A: Continued RATIR Optical and NIR Observations
DATE:    13/11/06 19:36:04 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC),
Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos A. de
Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:

We again observed the field of GRB 131030A (Troja, et al., GCN Circ.
15402) with the Reionization and Transients Infrared Camera (RATIR;
www.ratir.org) on the 1.5m Harold Johnson Telescope at the
Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from
2013/11 5.08 to 2013/11 5.34 UTC (124.95 to 131.33 hours after the
BAT trigger), obtaining a total of 4.24 hours exposure in the r and
i bands and 0.92 hours exposure in the Z, Y, J, and H bands.

We continue to detect the previously reported source in the r and i
bands (Littlejohns, et al., GCN Circ. 15420; Troja, et al., GCN Circ.
15402). For a source within the Swift-XRT error circle, in comparison
with the SDSS DR9 and 2MASS, we obtain the following detections and
upper limits (3-sigma):

  r     23.17 +/- 0.14
  i     22.73 +/- 0.14
  Z     > 22.82
  Y     > 22.35
  J     > 20.05
  H     > 19.38

A further epoch of observations was also conducted from 2013/11 6.09
to 2013/11 6.34 UTC (149.15 to 155.17 hours after the BAT trigger),
obtaining a total of 3.73 hours exposure in the r and i bands and 1.53
hours exposure in the Z, Y, J, and H bands. The source was detected in
the r and i bands once more. For a source within the Swift-XRT error
circle, in comparison with the SDSS DR9 and 2MASS, we obtain the
following detections and upper limits (3-sigma):

  r     23.41 +/- 0.18
  i     23.06 +/- 0.18
  Z     > 22.74
  Y     > 22.25
  J     > 21.97
  H     > 21.39

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. In comparison with previous
epochs of RATIR observations, the source continues to fade in both the
r and i band.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131030A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15463
SUBJECT: GRB 131030A: RATIR Optical and NIR Upper Limits
DATE:    13/11/07 21:36:11 GMT
FROM:    Owen Littlejohns at Az State U  <olittlej@asu.edu>

Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC),
Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos A. de
Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM),
Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:

We again observed the field of GRB 131030A (Troja, et al., GCN
Circ. 15402) with the Reionization and Transients Infrared Camera
(RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the
Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from
2013/11 7.09 to 2013/11 7.33 UTC (173.34 to 178.87 hours after the
BAT trigger), obtaining a total of 3.40 hours exposure in the r
and i bands and 1.41 hours exposure in the Z, Y, J, and H bands.

For a source within the Swift-XRT error circle, in comparison
with the SDSS DR9 and 2MASS, we obtain the following upper limits
(3-sigma):

  r     > 23.52
  i     > 23.11
  Z     > 22.69
  Y     > 22.17
  J     > 21.87
  H     > 21.35

These magnitudes are in the AB system and are not corrected for
Galactic extinction in the direction of the GRB. The upper limits
obtained in the r and i bands are consistent with the reported
decay from previous epochs of RATIR observations (Littlejohns, et
al., GCN Circ. 15462).

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.

[GCN OPS NOTE(07nov13): Per operator's desire, I removed some email header detritus.]


GRB_name: GRB131108A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15464
SUBJECT: GRB 131108A: Fermi-LAT onboard detection of a burst 
DATE:    13/11/08 21:39:17 GMT
FROM:    Judith Racusin at GSFC  <judith.racusin@nasa.gov>

J. L. Racusin (NASA/GSFC), S. Zhu (NASA/GSFC/UMD), D. Kocevski (NASA/GSFC/ORAU), M. Ohno (Hiroshima), 
N. Omodei (Stanford), E. Troja (NASA/GSFC/CRESST) and G. Vianello (Stanford), report on behalf of the Fermi LAT 
team:

At 20:41:55.76 UTC on November 8, 2013, Fermi LAT triggered onboard on high energy emission from GRB 131108A.  
The burst was also detected by GBM (trigger 131108863/405636118), and triggered an autonomous repoint of the 
spacecraft.  This is the first onboard trigger since 2009, indicating a potentially rare and exciting event.

The onboard location is R.A., Dec. 156.47, +9.90 (J2000) with an approximate error radius of 0.5 deg, seeded by the 
GBM detected position.  This was 27 deg from the LAT boresight at the time of the trigger. We anticipate providing a 
refined location within the next 12-15 hours when the LAT science data for this burst is downlinked and processed.

The Fermi LAT point of contact for this burst is Masanori Ohno (ohno@hep01.hepl.hiroshima-u.ac.jp).

A Swift TOO request has been approved.

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


GRB_name: GRB131108A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15465
SUBJECT: GRB 131108A Tiled Swift observations
DATE:    13/11/08 21:49:51 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a series of observations, tiled on the sky, of the
Fermi/LAT GRB 131108A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00021

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

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

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


GRB_name: GRB131108A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15466
SUBJECT: IPN triangulation of GRB 131108A
DATE:    13/11/08 22:58:31 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

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

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

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

report:

GRB 131108A (GCN 15464) has been observed by MESSENGER and INTEGRAL
(SPI-ACS) so far.  We have triangulated it to a preliminary annulus
centered at RA(2000)=211.006 degrees, Dec(2000)=-10.955 degrees, with
radius 57.980 +/- 0.055 degrees (3 sigma).  This annulus intersects the
LAT error circle, reducing its area by about a factor of 7, and forming
an error box whose area is approximately 390 sq. arcmin., and whose
corners are

          RA(2000)                      Dec(2000)
     156.363 o=10 h 25 m 27 s       9.411 o=  9 o 24 ' 40 "
     156.702 o=10 h 26 m 48 s      10.345 o= 10 o 20 ' 42 "
     156.477 o=10 h 25 m 54 s       9.400 o=  9 o 24 ' 00 "
     156.797 o=10 h 27 m 11 s      10.283 o= 10 o 16 ' 57 "


A map has been posted at ssl.berkeley.edu/ipn3/130811A.  This error box can be improved.


GRB_name: GRB131108A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15467
SUBJECT: IPN triangulation of GRB 131108A - correction
DATE:    13/11/08 23:20:38 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

The URL given in GCN 15466 was incorrect.  The correct URL is
ssl.berkeley.edu/ipn3/131108A.  I apologize for the confusion and
thank those of you who quickly pointed this out.


GRB_name: GRB131108A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15468
SUBJECT: GRB 131108A: Swift detection of a possible X-ray afterglow
DATE:    13/11/09 03:31:55 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M. C. Stroh and J. A. Kennea (PSU) report on behalf of the Swift/XRT team:

Swift-XRT has observed the error circle of the Fermi/LAT GRB 131108A (Racusin et al., GCN #15464, Evans, GCN #15465) in a series of observations tiled on the sky. In 621 s of data, beginning 3.9 ks after the Fermi/LAT trigger, we detect a bright, fading, uncatalogued X-ray source at RA, Dec = 156.50066, 9.66232 which is equivalent to:
RA (J2000) = 10h 26m 0.16s
Dec (J2000) = +09d 39' 44.4"
with an uncertainty of 3.6 arcsec (radius, 90% confidence). We note that this position lies 14.4' from the center of the Fermi/LAT
error circle (GCN #15464), consistant with that position, and inside the IPN error box (GCN #15466).

This previously uncatalogued source is significantly brighter than the RASS limit and fading, and we thus consider it the likely GRB afterglow.

The source was detected in 2 overlapping fields, with target IDs:
00020321, 00020322.

The results of the automated XRT processing of the source in these fields are available at: 
http://www.swift.ac.uk/xrt_products/TILED_GRB00021/00020321
http://www.swift.ac.uk/xrt_products/TILED_GRB00021/00020322

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


GRB_name: GRB131108A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15469
SUBJECT: GRB 131108A: 1.23m CAHA optical candidate
DATE:    13/11/09 03:59:02 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

J.  Gorosabel  (IAA-CSIC/UPV-EHU),  S.  Mottola (DLR),  A.  de  Ugarte Postigo  (IAA-CSIC/DARK-NBI),  S.  Hellmich  (DLR), G.  Proffe  (DLR), report on behalf of a large collaboration:

We imaged the  field of GRB 131108A (Racusin et  al.  GCNC 15464) with the 1.23m  CAHA telescope.  The  observations were carried out  in the V-band starting at  03:28:33 UT.  A bright V~18.5 object not present on the DSS is  detected consistent  with the  possible X-ray afterglow  position (Stroh & Kennea, GCNC 15468). Further observations are in progress.


GRB_name: GRB131108A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15470
SUBJECT: GRB 131108A: Redshift from 10.4m GTC
DATE:    13/11/09 05:35:00 GMT
FROM:    Antonio de Ugarte Postigo at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene (IAA-CSIC),
J. Gorosabel (IAA-CSIC), R. Sanchez-Ramirez (IAA-CSIC), 
J.P.U. Fynbo (DARK/NBI), N.R. Tanvir (U. Leicester), 
A. Cabrera-Lavers (ULL/IAC) and A. Garcia (ULL/IAC) report on 
behalf of a larger collaboration:

We have observed the afterglow of the Fermi-LAT GRB 131108A (Racusin 
et al. GCN 15464, Hurley et al. GCN 15466, Stroh et al. GCN 15468, Gorosabel 
et al. GCN 15469) with the 10.4m GTC telescope at Roque de los Muchachos 
Observatory (La Palma, Spain) starting at 04:50 UT (8.13 hr after the burst). 
The observation consisted of 3x600 s and was performed with the R1000B 
grism, that covers the range from 3700 to 7500 A at a resolution of ~1000.

Observations were performed with a poor seeing of ~2.2". The afterglow is 
detected in the acquisition frame with at a magnitude of r=18.9, as compared 
with the SDSS.

A preliminary reduction of the spectrum shows a strong trace and is 
characterised by a strong Ly-alpha absorption as well as absorption features 
which include SII, SiII, SiII*, OI, CII, SiIV, CIV and AlII at a common redshift of 
z=2.40, which we identify as the redshift of the GRB.


GRB_name: GRB131108A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15471
SUBJECT: GRB 131108A: NOT optical observations
DATE:    13/11/09 06:11:42 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu, D. Malesani (DARK/NBI), T. Pursimo (NOT) report on behalf of a
larger collaboration:

We observed the Swift/XRT field of Fermi-detected GRB 131108A (Racusin
et al., GCN 15464; Stroh & Kennea, GCN 15468) using the 2.5m Nordic
Optical Telescope (NOT) equipped with the MOSCA camera. We obtained
SDSS ugriz frames, starting at 04:46:48 UT on 2013-11-09 (i.e., 8.081
hr after the Fermi/LAT trigger).

The optical afterglow is detected at the border of the XRT error
circle reported in Stroh & Kennea (GCN 15468) at coordinates

R.A. (J2000)  = 10:26:00.48
Dec. (J2000) = +09:39:44.05

Error Radius: ~0.5 arcsec

thus being consistent with the XRT position, as reported in Gorosabel
et al. (GCN 15469). In particular, the ugriz SED shows a clear drop at
the wavelength range corresponding to the spectroscopic redshift of
z=2.40 in de Ugarte Postigo et al. (GCN 15470).


GRB_name: GRB131108A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15472
SUBJECT: GRB 131108A: Fermi-LAT refined analysis
DATE:    13/11/09 11:04:27 GMT
FROM:    Giacomo Vianello at SLAC  <giacomov@slac.stanford.edu>

G. Vianello (Stanford), N.Omodei (Stanford), J.Racusin (NASA/GSFC) and M.
Ohno (Hiroshima) report on behalf of the Fermi LAT team:

We have analyzed 1.5 ks of data for GRB 131108A which triggered onboard
Fermi/LAT (Racusin et al, GCN 15464) as well as Fermi/GBM.

We confirm the detection of the GRB in our standard analysis at the
position of the afterglow candidate (Stroh and Kennea, GCN 15468; Gorosabel
et al., GCN 15469; de Ugarte Postigo et al., GCN 15470), with a very large
significance (>> 10 sigma).

As seen by Fermi/LAT the burst is bright, but relatively soft. In this
preliminary analysis the light curve appears well correlated with the
emission at lower energy, as seen by Fermi/GBM.
More than 118 photons above 100 MeV and more than 3 photons above 1 GeV are
observed within 1500 seconds. The highest energy photon is a 1.5 GeV event
which is observed 66 seconds after the GBM trigger, which at redshift 2.4
(GCN 15470) corresponds to 5 GeV rest-frame. The time-integrated spectrum
in the same time interval can be well described by a power law with photon
index -2.66 +/- 0.12, with a mean flux of 1.0e-08 +/- 1.3e-09 erg/cm2/s
(100 MeV - 100 GeV).

 Fermi-LAT pointed observations are ongoing.

The Fermi LAT point of contact for this burst is Masanori Ohno (
ohno@hep01.hepl.hiroshima-u.ac.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.


GRB_name: GRB131108A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15473
SUBJECT: GRB 131108A: TAROT-Calern optical observation
DATE:    13/11/09 11:51:06 GMT
FROM:    Bruce Gendre at ASDC  <bruce.gendre@gmail.com>

Klotz A., Turpin D. (IRAP-CNRS-OMP), Pelassa V. (UAH), Gendre B.,
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:


We imaged the field of GRB 131108A detected by Fermi-LAT and Fermi-GBM 
(Racusin et al., GCN 15646) with the TAROT robotic telescope (D=25cm)
located at the Calern Observatory, France.

The observations started about 22700s after the GRB trigger (3:00 UT on 
2013-11-09), when the object started to be visible. The weather 
conditions were poor, with only one sequence of 6 images being not cloudy.

We detect the afterglow reported by Stroh et al. (GCN 15468) and 
Gorosabel et al. (GCN 15469), with a magnitude of R = 17.8 +/- 0.2.

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.

This message may be cited.


GRB_name: GRB131108A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15474
SUBJECT: GRB 131108A: Swift-XRT observations
DATE:    13/11/09 15:26:33 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

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

We have analysed 7.9 ks of XRT data for the Fermi/LAT-detected burst:
GRB 131108A,  from 25.9 ks to 49.8 ks after the  Fermi/LAT trigger. The
data are entirely in Photon Counting (PC) mode.  An X-ray source is
detected within the Fermi/LAT error circle. Using 4560 s of PC mode
data and 6 UVOT images, we find an enhanced XRT position (using the
XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 156.50178, +9.66248 which is equivalent to:

RA (J2000): 10h 26m 00.43s
Dec(J2000): +09d 39' 44.9"

with an uncertainty of 1.6 arcsec (radius, 90% confidence). This
position is 14.4 arcmin from the center of the Fermi/LAT error circle
(GCN #15464), consistant with that position, and inside the   
IPN error box (GCN #15466).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.9 (+0.7, -0.6).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.2 (+0.4, -0.3). The
best-fitting absorption column is  9.9 (+7.6, -6.5) x 10^20 cm^-2, in
excess of the Galactic value of 3.2 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 3.2 x 10^-11 (4.5 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.9 (+7.6, -6.5) x 10^20 cm^-2
Galactic foreground: 3.2 x 10^20 cm^-2
Excess significance: 1.7 sigma
Photon index:      2.2 (+0.4, -0.3)

If the light curve continues to decay with a power-law decay index of
1.9, the count rate at T+24 hours will be 5.2 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x
10^-13 (2.4 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020326.

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


GRB_name: GRB131108A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15475
SUBJECT: GRB 131108A: RATIR Optical and NIR Observations
DATE:    13/11/09 16:32:22 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska
(UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen
Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM),
Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga
(UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:

We observed the field of the LAT GRB 131108A (Racusin, et al., GCN 15464,
Vianello et al., GCN 15472) with the Reionization and Transients Infrared
Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the
Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2013/11
9.41 to 2013/11 9.53 UTC (13.06 to 16.11 hours after the LAT trigger),
obtaining a total of 2.11 hours exposure in the r and i bands and 0.76 
hours
exposure in the Z, Y, J, and H bands.

For a source within the enhanced XRT error circle (Stroh & Kennea, GCN
15474) , in comparison with the SDSS DR9 and 2MASS, we obtain the
following detections:

   r    19.91  0.02
   i    19.70  0.02
   Z    19.57  0.04
   Y    19.23  0.05
   J    19.34  0.07
   H    19.09  0.08

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. We can confirm that this source 
fades
during our observations with a power-law decay index of approximately -2.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131108A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15476
SUBJECT: GRB 131108A: Swift/UVOT Detection 
DATE:    13/11/09 16:54:16 GMT
FROM:    Margaret Chester at PSU  <chester@astro.psu.edu>

M.M. Chester and M. C. Stroh (PSU) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of the Fermi/LAT-detected 
GRB 131108A 25920 s after the LAT trigger (Racusin et al., GCN Circ. 15464).
A source consistent with the XRT position (Stroh and Kennea GCN Circ. 15474)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  10:26:00.45 = 156.50187 (deg.)
   Dec (J2000) = +09:39:44.1  =   9.66225 (deg.)
with an estimated uncertainty of 0.58 arc sec. (radius, 90% confidence).

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

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

white            27746        28046          295         19.70 +/- 0.10
b                26833        27133          295         19.67 +/- 0.16
u                25920        26220          295         19.10 +/- 0.14
w1               31699        32599          886         20.96 +/- 0.33
m2               37465        37914          442        >20.6
w2               45446        49794         1069        >21.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.028 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB131108A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15477
SUBJECT: GRB 131108A: Fermi GBM observation
DATE:    13/11/09 17:50:57 GMT
FROM:    George A. Younes at USRA/NASA/MSFC  <younes.ge@gmail.com>

G. Younes (USRA/NASA-MSFC) reports on behalf of the Fermi GBM Team:

At 20:41:55.76 UT on 08 November 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 131108A (trigger 405636118/131108862), which also
triggered onboard the Fermi/LAT (Racusin et al, GCN 15464). The GBM on-ground
location is consistent with the Swift/XRT location of the candidate afterglow
(M. C. Stroh and J. A. Kennea, GCN 15468).

The burst was bright enough that it also resulted in an Autonomous Repoint Request (ARR).

The GBM light curve consists of a multiple-peak structure with a duration
(T90) of about 19 s (50-300 keV). The time-averaged spectrum from
T0 to T0+21 s is adequately fit by a Band function with Epeak =
373 +/- 14 keV, alpha = -0.91 +/- 0.02, and beta = -2.6 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(3.65 +/- 0.04)E-05  erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.1 s in the 10-1000 keV band is 19.8 +/- 0.4 ph/s/cm^2.

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


GRB_name: GRB131108A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15478
SUBJECT: GRB 131108A: CARMA 3mm detection
DATE:    13/11/09 19:27:44 GMT
FROM:    Daniel Perley at Caltech  <dperley@astro.caltech.edu>

D. A. Perley (Caltech) reports on behalf of a larger collaboration:

We observed the position of Fermi GRB 131108A (Racusin et al., GCN 
15464) with the Combined Array for Research in Millimeter Astronomy at a 
frequency of 93 GHz (3mm) starting at 13:26 UT on 2013-11-09, 16.7 hours 
after the burst.  Observations continued until 14:55 UT (midpoint t=17.5 
hours.)

A source is detected at a position consistent with the location of X-ray 
(Stroh & Kennea, GCN 15468) and optical (Xu et al., GCN 15471) 
afterglows at a flux of approximately ~2 mJy.  Follow-up observations 
are planned.

We thank the CARMA staff for their support in executing these observations.


GRB_name: GRB131108A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15479
SUBJECT: GRB 131108A: AGILE/GRID observation
DATE:    13/11/09 21:41:41 GMT
FROM:    Andrea Giuliani at IASF/INAF  <giuliani@iasf-milano.inaf.it>

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


GRB 131108A (GCN 15464) transited in the field of view of AGILE
approximately between t0-20 and t0+150 sec (with t0 = 08:41:55 UT).

A preliminary analysis of the Gamma-Ray Imaging Detector (GRID) data in
temporal and spatial coincidence with the GRB shows a significant excess of
gamma-ray events above 30 MeV at the location of the event.

During the first 80 seconds after t0 the GRID instrument detected 66
photons compatible with the GRB, most of which below 100 MeV, corresponding
to a fluence of  2.56 +- 0.32 1e-5  erg / cm^2 in the  energy band 30 MeV -
1 GeV.

The energy distribution of photons in the same energy band is compatible
with a power-law of index -2.35 +-0.2 .

An analysis of the AGILE/MCAL data is also in progress.
More observations of this interesting burst are strongly encouraged.

This message may be cited.

[GCN OPS NOTE(09nov13):  This was delayed by ~1 hour because the submitor's
new account had to added to the Circulars list.]
 


GRB_name: GRB131108A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15480
SUBJECT: Konus-Wind observation of GRB 131108A
DATE:    13/11/10 12:05:37 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration, bright, hard-spectrum GRB 131108A
(Fermi-LAT detection: Racusin, et al., GCN 15464; Vianello, et al., GCN 15472;
IPN triangulation: Hurley at al., GCN 15466;
Fermi-GBM observation: Younes, GCN 15477;
AGILE/GRID observation: Giuliani, et al., GCN 15479)
triggered Konus-Wind at T0=74512.947 s UT (20:41:52.947).

The light curve shows a mult-peaked structure from ~T0 to ~T0+20 s.
The emission is seen up to ~12 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131108_T74512/

As observed by Konus-Wind, the burst
had a fluence of (4.15  0.25)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0,
of (2.10  0.15)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+23.04 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.11  0.05,
the high energy photon index beta = -2.72  0.06,
the peak energy Ep = 340  11 keV,
chi2 = 69.2/95 dof.

The spectrum of the brightest initial spike
(measured from T0 to T0+0.256 s)
is best fit in the 50 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -1.21  0.11,
and the peak energy Ep = 1326  382 keV,
chi2 = 52.9/70 dof.

Assuming the redshift z=2.40 (de Ugarte Postigo, et al., GCN 15470;
Xu, et al., GCN 15471),
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is (5.8  0.4)x10^53 erg,
the peak luminosity L_iso is (1.0  0.07)x10^54 erg/s,
and the rest-frame peak energy Ep,i = (1160  40) keV

All the quoted results are preliminary.


GRB_name: GRB131030A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15481
SUBJECT: GRB 131030A: MITSuME Akeno Optical observation 
DATE:    13/11/11 06:15:29 GMT
FROM:    Taketoshi Yoshii at Tokyo Tech  <yoshii.t.ac@m.titech.ac.jp>

T.Tanigawa, T. Yoshii, K. Ito, Y. Saito, Y. Yano, R. Usui, Y. Tachibana, 

S. Kurita, Y. Yatsu, and N. Kawai (Tokyo Tech)

report on behalf of the MITSuME collaboration:



We observed the field of GRB 131030A (E. Troja et al., GCN Circular #15402) with the 

optical three color (g, Rc, and Ic) CCD cameras attached to the MITSuME 50 cm

telescope of Akeno Observatory, Yamanashi, Japan.



The observation started on 2013-10-31 09:37:51 UT ( 12.68h after the burst).

We detected the previously reported optical afterglow of GRB131013A (E. Troja et al., GCN Circular #15402) in the Rc and Ic band.



The measured magnitudes were listed below.


T0+[sec]     MID-UT        T-EXP[sec]              g'                          Rc                          Ic

-------------------------------------------------------------------------------------------------------------------------------------

43334       10:45:52        2940                >19.92                19.37+/-0.31          18.94+/-0.27

49357       12:14:44        5760                >20.72                20.05+/-0.30          19.25+/-0.24

57097       14:23:40        3780                >20.38                19.57+/-0.22          >19.51

-------------------------------------------------------------------------------------------------------------------------------------

T0+ : Elapsed time after the burst [sec]

T-EXP: Total Exposure time [sec]

We used GSC2.3 catalog for flux calibration.


GRB_name: GRB131108A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15482
SUBJECT: GRB 131108A: Continued RATIR Optical and NIR Observations
DATE:    13/11/11 18:15:07 GMT
FROM:    Eleonora Troja at GSFC  <eleonora.troja@nasa.gov>

Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska
(UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Owen
Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM),
Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga
(UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:

We observed the field of GRB 131108A (Racusin et al., GCN 15464,
Vianello et al., GCN 15472 ) with the Reionization and Transients Infrared
Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the
Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2013/11
11.40 to 2013/11 11.53 UTC (61.01 to 64.03 hours after the LAT trigger),
obtaining a total of 2.04 hours exposure in the r and i bands and
0.89 hours exposure in the Z, Y, J, and H bands.

We continue to detect the previously reported source (Troja et al.,
GCN 15475).  In comparison with the SDSS DR9 and 2MASS, we obtain
the following detections and upper limits (3-sigma):

   r    22.4  0.12
   i    22.03  0.11
   Z   21.95  0.22
   Y   21.6  0.3
   J    > 21.5
   H   > 21.0

These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. A comparison with our earlier
observations suggests a decay index of approximately -1.6 between our
observations of 2013 Nov 9 and these observations.

We thank the staff of the Observatorio Astronmico Nacional in San Pedro
Mrtir.


GRB_name: GRB131110A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15483
SUBJECT: GRB 131110A found in ground analysis of BAT slew event data
DATE:    13/11/14 04:11:17 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings and D. M Palmer report on behalf of the Swift-BAT science team:

At 11:53:11 Swift was slewing.  A rate increase during the slew was noticed in
ground post-processing.  The BAT lightcurve shows a slow rise and decay peak
with about 90 seconds duration.  A mosaic of BAT images from the slew shows
a significant source at RA, Dec 69.264, -17.258 which is

RA (J2000)    04h 37m 3.4s
Dec (J2000)  -17d 15' 30"

with an estimated error radius of 4 arcmin.

A Swift TOO has been requested.


GRB_name: GRB131108A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15484
SUBJECT: GRB 131108A: optical observations
DATE:    13/11/14 06:19:25 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss@gmail.com>

A. Volnova (IKI), Yu. Krugly (IA KhNU), R. Inasaridze (AAO), I.
Slyusarev (IA KhNU),  G. Inasaridze (AAO), V. Zhuzhunadze (AAO),  I.
Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB
follow-up collaboration:

We observed the field of Swift GRB 131108A (Racusin et al., GCN 15464,
Hurley et al. GCN 15466) with  AZT-8  telescope of Institute of
Astronomy, Kharkiv National University and with AS-32 telescope of
Abastumani Observatory. We obtained several images in R-filter and
also non-fileterd images.   Within the enhanced XRT circle (Stroth &
Kennea, GCN 15474) we detect the optical counterpart reported by
Gorosabel et al. (GCN 15469).

The details of preliminary photometry are following:

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

2013-11-10T02:00:12 1.24560 R       15x300  20.92 +/- 0.12
2013-11-11T00:44:00 2.21609 None    36x120  21.20 +/- 0.11

The photometry is based the SDSS stars, R magnitude (gri -> R
transformations by Lupton 2005):

SDSS id                           R
J102559.54+093904.1   16.928 +/- 0.014
J102609.18+093958.8   17.999 +/- 0.021
J102610.10+093859.6   17.339 +/- 0.014


GRB_name: GRB131108A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15485
SUBJECT: GRB 131108A: ISON Blagoveshensk upper limit
DATE:    13/11/14 06:21:44 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss@gmail.com>

A. Volnova (IKI), D. Varda (ISON), E. Sinyakov (ISON), I. Molotov
(KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:

We observed the field of GRB 131108A (Racusin et al., GCN 15464,
Hurley et al., GCN 15466) with ORI-25 telescope of ISON-Blagoveshensk
observatory starting Nov., 9 (UT) 16:40:45. We took several unfiltered
images with exposures of 30 seconds. In the combined images in the
enhanced XRT circle (Stroth & Kennea, GCN 15474) we do not detect the
OT reported by Gorosabel et al. (GCN 15469).

The details of the photometry are the following:

UT start      t-T0     Filter    Exp.    OT         UL (3sigma)
               (mid, days)           (s)
16:40:45   0.85072  None  95x30  n/d   17.1

The photometry is based on a nearby bright SDSS star, R (gri -> R
transformations by Lupton 2005):

SDSS id                      R
J102613.43+094109.5  13.318 +/- 0.013


GRB_name: GRB131031A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15486
SUBJECT: GRB 131031A: Mondy optical observations
DATE:    13/11/15 00:06:28 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss@gmail.com>

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

We observed the field of the Swift GRB 131031A (Cummings et al., GCN
15421) with AZT-33IK telescope of Sayan observatory (Mondy). We took
several images in R-filter of 60 s exposure on Nov., 01, 02, and 05.
In the stacked images from Nov. 01 and 02 in the XRT error circle
(Gompertz & Page, GCN 15424) we detected a source which is coincident
with the source reported by Gorosabel et al. (GCN 15426).

The details of the photometry are the following:

date         UT start  t-T0            Filter   Exp.    OT
                            (mid, days)             (s)
20131101 15:50:21 1.23918       R      147x60 22.23 +/- 0.14
20131102 14:59:29 2.17988       R      106x60 22.43 +/- 0.16
20131105 15:59:53 5.21974       R        91x60 >22.3 (UL 3 sigma)

The photometry is based 3 SDSS stars, R (gri -> R transformations by
Lupton 2005):

SDSS id                       R
J015828.04-013339.6  19.230
J015828.59-013429.3  17.299
J015835.16-013313.8  18.742


GRB_name: GRB131110A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15487
SUBJECT: GRB 131110A BAT refined analysis
DATE:    13/11/15 02:24:09 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)

We report further analysis of the ground-detected Swift-BAT slew GRB 131110A
(Cummings and Palmer, GCN circ # 15483).  The best BAT position is
RA, Dec 69.268, -17.259 which is

RA (J2000)    04h 37m 4.4s
Dec (J2000)  -17d 15' 34"

with an estimated 90% containment radius of 0.8 arcmin.

The BAT mask-weighted lightcurve shows a single broad peak with a slow rise to a
plateau at T+25 seconds, lasting about 70 seconds, and a slow decay.  T90 is about
100 +- 10 seconds.

The average spectrum from T0 to T+90 (after which the source had a low mask coding
factor in BAT) is best fit by a simple power law function with a photon index of
1.61 +- 0.09.  The fluence from 15-150 keV during this interval was
(3.53 +- 0.10) x 10^-6 ergs/cm^2/sec.  Errors are 90% confidence.

A Swift TOO has been approved with the observation number 20327, to be performed
11/15/2013.


GRB_name: GRB131110A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15488
SUBJECT: GRB 131110A: Swift-XRT and UVOT upper limits
DATE:    13/11/15 15:29:45 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

K.L. Page, P.A. Evans (U. Leicester) and N.P.M. Kuin (UCL-MSSL) report on
behalf of the Swift-XRT and UVOT teams:

The Swift-XRT began observing the field of GRB 131011A 397 ks after the
event (Cummings & Palmer, GCN Circ. 15483). In 2.8 ks of Photon Counting
(PC)  mode data, no source was found in the BAT error circle; the 3-sigma
upper limit (0.3-10 keV) is 3.6e-3 count s^-1

The Swift-UVOT also began observations of the field of GRB 131110Aat the
same time. No optical afterglow was found in the image. Preliminary
3-sigma upper limits using the UVOT photometric system (Breeveld et al.
2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:

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

white      397556    409058     892     >20.2
v        398095    409489     938     >18.6
u        397018    408678     892     >19.2

This circular is an official product of the Swift team.


GRB_name: GRB130925A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15489
SUBJECT: GRB 130925A: HST imaging
DATE:    13/11/16 09:22:23 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), R. Hounsell,
A. S. Fruchter (STScI), S. B. Cenko (NASA/GSFC), D. A. Perley (Caltech),
P. T. O'Brien (U. Leicester) report:

We imaged the location of GRB 130925A (Evans et al. GCN 15251;
Sudilovsky et al. GCN 15247) with HST at two epochs, at 20 days and
47 days post-burst respectively, in the F814W (I-band), F110W (J-band)
and F160W (H-band) filters.

The host galaxy is well resolved and appears to be an almost edge-on spiral.
The galaxy shows signs of disturbance: specifically the disk shows asymmetry
and the bulge appears to be extended perpendicular to the disk, suggestive
of a polar-ring morphology.

Image subtraction reveals evidence of faint transient light in the first epoch
in all three filters.  The location is in good agreement with that from prior 
ground-based imaging of the GRB.  The transient position is close to the disk 
plane, which likely accounts for the high extinction and X-ray column for this 
event (Evans et al. GCN 15254).  It is, however, slightly offset from the 
nucleus of the galaxy by about 0.12 arcsec (~600pc in projection).  This 
would initially seem to be in conflict with a possible tidal disruption origin 
for this event, although if the galaxy morphology is indicative of a recent 
major merger, then it is plausible that the system currently contains more 
than one super-massive black hole.

Further analysis is ongoing.

We thank the staff at STScI for approving and expediting
these ToO observations.


GRB_name: GRB131117A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15490
SUBJECT: GRB 131117A: Swift detection of a burst
DATE:    13/11/17 00:43:57 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. J. Page (UCL-MSSL), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL) and C. A. Swenson (PSU)
report on behalf of the Swift Team:

At 00:34:04 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 131117A (trigger=577968).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 332.339, -31.722 which is 
   RA(J2000) = 22h 09m 21s
   Dec(J2000) = -31d 43' 19"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 20 sec.  The peak count rate
was ~1750 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 00:35:10.8 UT, 66.1 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 332.33119, -31.76055 which
is equivalent to:
   RA(J2000)  = 22h 09m 19.49s
   Dec(J2000) = -31d 45' 38.0"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 140 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 1.41
x 10^20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 69 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.02. 

Burst Advocate for this burst is M. J. Page (m.page AT 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: GRB131117A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15491
SUBJECT: GRB 131117A: Skynet PROMPT optical detection of an afterglow
DATE:    13/11/17 02:21:48 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter@physics.unc.edu>

A.Trotter, D. Reichart, J. Haislip, N. Frank, A. LaCluyze, J. Moore, T. 
Berger, H. T. Cromartie, R. Egger, A. Foster, K. Ivarsen, M. Maples, M. 
Nysewander, and J. A. Crain report:

Skynet observed the Swift/XRT localization of GRB 131117A (Page et al., 
GCN 15490, Swift trigger 577968) with four 14" telescopes of the PROMPT 
array at Cerro Tololo, Chile, beginning 91s after the trigger, 
simultaneously in the BVRI bands. We detect a fading optical source in 
V, R and I bands at:
RA 22:09:19.3
Dec -31:45:44.4 (J2000)
which is within the error circle reported by the Swift XRT.  The 
afterglow fades from R~17.2 at t=1.5min to R~19.7 at t=24min.

Photometry is calibrated to six APASS-DR7 stars in the field, and has 
not been corrected for Galactic foreground extinction.

A preliminary light curve is at: http://skynet.unc.edu/grb/grb131117a.png

Skynet observations are ongoing.


GRB_name: GRB131117A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15492
SUBJECT: GRB 131117A: Enhanced Swift-XRT position
DATE:    13/11/17 03:13:23 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Using 599 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 131117A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 332.33113, -31.76237 which is equivalent
to:

RA (J2000): 22h 09m 19.47s
Dec (J2000): -31d 45' 44.5"

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

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

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


GRB_name: GRB131117A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15493
SUBJECT: GRB 131117A: GROND confirmation of the afterglow and  photo-z.
DATE:    13/11/17 06:17:20 GMT
FROM:    Mohit Tanga at MPE/GROND  <mohit@mpe.mpg.de>

GRB 131117A: GROND confirmation of the afterglow and  photo-z.

M. Tanga (MPE Garching), S. Schmidl, S. Klose (both TLS Tautenburg), K.
Varela (MPE Garching) and J.Greiner (MPE Garching) report on behalf of the
GROND team:

We observed the field of GRB 131117A (Swift trigger 577968, Page et al.,
GCN 15490) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started on November 17, 2013, at 00:36:34 UT, 150 s after the
GRB trigger. They were performed at an average seeing of 1".0 and at an
average airmass of 1.2 .

We detect the fading afterglow discovered by Trotter et al. (GCN 15491).

Based on a total exposure time of 460 s in g'r'i'z' and 480 s in JHK, at a
midtime of 0.80 hrs after the burst, we measure the following preliminary
AB magnitudes:

g' = 20.9 +/- 0.1,
r' = 19.6 +/- 0.1,
i' = 19.1 +/- 0.1,
z' = 19.0 +/- 0.1,
J =  19.0 +/- 0.1,
H =  18.9 +/- 0.1 and
K =  18.7 +/- 0.3.

Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
reddening of E(B-V) = 0.02 mag in the direction of the burst (Schlegel et
al. 1998).

On the basis of the preliminary analysis we estimate the photometric
redshift to be z = 4.18 +/-0.16.


GRB_name: GRB131117A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15494
SUBJECT: GRB 131117A: VLT/X-shooter redshift
DATE:    13/11/17 08:38:15 GMT
FROM:    Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>

O. E. Hartoog (U. Amsterdam), D. Xu (DARK/NBI), D. Malesani (DARK/NBI),
N. R. Tanvir (U. Leicester), J. P. U. Fynbo (DARK/NBI), L. Kaper (U. Amsterdam)
and V. D'Elia (ASI/ASDC) report:

We observed the afterglow of GRB 131117A (Page et al. GCN 15490,
Trotter et al. GCN 15491, Tanga et al. GCN 15493) with the VLT
X-shooter spectrograph covering a spectral range 3200A to 18000A.
Poor conditions meant that observations could not start until 01:42 UT,
68 minutes post-burst.

The continuum level is faint, but we see a strong break corresponding
to Ly-alpha at a redshift of z=4.042.  This is supported by the detection
of absorption lines corresponding to SiII 1259/1260, SiIV 1393/1402
and SiII 1526.  There is also a clear Ly-a forest blueward of the break.
We therefore propose this as the redshift of the GRB, noting it
is consistent with the photometric redshift of Tanga et al. (GCN15493).

We thank the staff at Paranal, particularly Christophe Martayan,
for their support in obtaining these observations.


GRB_name: GRB131117A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15495
SUBJECT: GRB 131117A: Swift-XRT refined Analysis
DATE:    13/11/17 14:44:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

V. Mangano (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. Maselli 
(INAF-IASFPA), A. Melandri (INAF-OAB), M.C. Stroh (PSU), D.N. Burrows
(PSU) and M.J. Page report on behalf of the Swift-XRT team:

We have analysed 7.2 ks of XRT data for GRB 131117A (Page  et al. GCN
Circ. 15490),  from 51 s to 34.0 ks after the  BAT trigger. The data
comprise 82 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 15492).

The late-time light curve (from T0+4.1 ks) can be modelled with  a
power-law decay with a decay index of alpha=0.88 (+0.23, -0.20).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.03 (+0.31, -0.28). The
best-fitting absorption column is  2.0 (+0.6, -0.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.4 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.27 (+0.28, -0.26)
and a best-fitting absorption column of 5.9 (+5.2, -4.5) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.2 x 10^-11 (4.0 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      5.9 (+5.2, -4.5) x 10^20 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.27 (+0.28, -0.26)

If the light curve continues to decay with a power-law decay index of
0.88, the count rate at T+24 hours will be 4.2 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x
10^-13 (1.7 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00577968.

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


GRB_name: GRB131117A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15496
SUBJECT: GRB 131117A: Swift/UVOT Detection
DATE:    13/11/17 14:57:25 GMT
FROM:    Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and M. J. Page (UCL-MSSL) report on behalf of 
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 131117A 
70s after the BAT trigger (Page et al., GCN Circ. 15490).
A fading source consistent with the afterglow position found by Trotter 
et al. (GCN Circ. 15491) is found in the white filter only. This is 
consistent with the redshift of z=4.042 given by Hartoog et al. (GCN 
Circ. 15494).

The preliminary UVOT position is:
     RA  (J2000) =  22:09:19.36 = 332.33067 (deg.)
     Dec (J2000) = -31:45:44.3  = -31.76231 (deg.)
with an estimated uncertainty of 0.64 arc sec. (radius, 90% confidence).

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

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

white               70          219          147         20.13  0.17
v                  611         5157          216        >20.0
b                  537         4542          216        >20.6
u                  282         4336          442        >20.7
w1                 660         5567          216        >20.4
m2                 636         5362          216        >20.0
w2                 587         4952          216        >20.5

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


GRB_name: GRB131117A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  15497
SUBJECT: GRB 131117A: TAROT La Silla observatory optical observations
DATE:    13/11/17 16:32:51 GMT
FROM:    Alain Klotz at IRAP-CNRS-OMP  <Alain.Klotz@free.fr>

Klotz A., Turpin D. (IRAP-CNRS-OMP), Gendre B.,
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 131117 detected by SWIFT
(trigger 577968) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 40s after the GRB trigger
(14s after the notice). The elevation of the field decreased from
71 degrees above horizon and weather conditions
were good.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We detect the OT discovered by Trotter et al. (GCNC 15491)
and confirmed by Tanga et al. (GCNC 15493). The OT is seen
at a constant level considering the 2 sigma error of +/- 0.5
mag.

t0+40s to t0+46s  R=17.0 +/-0.5
t0+46s to t0+52s  R=17.0 +/-0.5
t0+52s to t0+58s  R=17.0 +/-0.5
t0+58s to t0+64s  R=17.0 +/-0.5
t0+64s to t0+70s  R=17.0 +/-0.5
t0+70s to t0+76s  R=17.0 +/-0.5
t0+76s to t0+82s  R=17.0 +/-0.5
t0+82s to t0+88s  R=17.0 +/-0.5
t0+88s to t0+94s  R=17.0 +/-0.5
t0+94s to t0+100s R=17.0 +/-0.5

Then series of image acquired in tracking mode
shows the decay of the OT:

t0+113s to t0+173s   R=17.2  +/-0.1
t0+194s to t0+464s   R=18.8  +/-0.2
t0+630s to t0+1080s  R=19.0  +/-0.2
t0+1472s to t0+2192s R=19.1  +/-0.2
t0+2524s to t0+4324s Rlim=20.0

Magnitudes were estimated with the nearby NOMAD1 stars
and are not corrected for galactic dust extinction.


