GRB 121117A
GCN Circular 13967
Subject
GRB 121117A: Swift detection of a burst
Date
2012-11-17T09:07:42Z (13 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
J. R. Cummings (NASA/UMBC), A. P. Beardmore (U Leicester),
V. D'Elia (ASDC), C. Gronwall (PSU), C. Guidorzi (U Ferrara),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and T. N. Ukwatta (MSU) report on behalf of the
Swift Team:
At 08:50:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 121117A (trigger=538696). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 31.635, +7.379 which is
RA(J2000) = 02h 06m 32s
Dec(J2000) = +07d 22' 44"
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 20 sec. The peak count rate
was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 08:51:49.2 UT, 52.2 seconds after
the BAT trigger. No source was detected in the 2.5-s promptly available
image. We are waiting for the full dataset to detect and localise the
XRT counterpart.
UVOT prompt data are not available at this time. We are waiting for
the full dataset to search for an UVOT counterpart.
This burst occurred as the Swift spacecraft was approaching the
South Atlantic Anomaly and the source was approaching the
Earth Limb observing constraint. As a result, only a brief exposure
under high background conditions is available for the
narrow-field instruments during the first orbit.
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.)
GCN Circular 13968
Subject
GRB 121117A: BOOTES-3 early optical upper limit
Date
2012-11-17T10:42:15Z (13 years ago)
From
Juan Carlos Tello at IAA-CSIC <jtello@iaa.es>
J.C. Tello (IAA-CSIC), J. Gorosabel (IAA-CSIC), A.J. Castro-Tirado
(IAA-CSIC), W. Allen (Vintage Lane Obs.), Ph. Yock and Kuan-Yu Lin
(Auckland Univ.), P. Kubanek (IP AS CR & IAA-CSIC), report on behalf of a
larger collaboration:
"We observed the field of GRB 121117A (Cummings et al., GCNC 13967) ,
detected by Swift/BAT, with the 0.6m Yock-Allen robotic telescope
(BOOTES-3) located in Blenheim, New Zealand. Unfiltered images were
obtained starting 09:04:07UT (13m after the burst, limited by clouds). An
exposure of 30 seconds resulted in a limiting magnitude of 16.0 when
calibrated with the R1Mag value of USNO-B1.0 catalogue stars. Due to
clouds, combining images did not provide a deeper limiting magnitude"
This message may be cited.
GCN Circular 13969
Subject
GRB 121117A: ROTSE-III Optical Limits
Date
2012-11-17T13:05:41Z (13 years ago)
From
Weikang Zheng at U.of Michigan <zwk@umich.edu>
W. Zheng (U Mich), report on behalf of the ROTSE collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 121117A
(Swift trigger 538696; Cummings et al., GCN 13967), producing images
beginning 9.1 s after the GCN notice time. An automated response took the
first image at 08:51:21.1 UT, 24.1 s after the burst, under fair conditions.
We took 10 5-sec, 10 20-sec and 20 60-sec exposures. These unfiltered images
are calibrated relative to USNO A2.0 (R).
Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle. Individual images have limiting magnitudes
ranging from 14.9-16.4; we set the following specific limits.
start UT end UT t_exp(s) mlim Coadd?
---------------------------------------------------
08:50:57.0 08:55:57.0 5 15.0 N
08:51:32.0 08:51:37.0 5 15.0 N
08:51:43.0 08:51:48.0 5 15.4 N
08:51:55.0 08:52:00.0 5 15.2 N
08:52:07.0 08:52:12.0 5 15.2 N
08:50:57.0 08:53:04.0 50 16.8 Y
08:53:18.0 08:57:59.0 200 17.2 Y
GCN Circular 13970
Subject
GRB 121117A, Swift-BAT refined analysis
Date
2012-11-17T21:31:41Z (13 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <james.r.cummings@nasa.gov>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
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-61 to T+191 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 121117A (trigger #538696)
(Cummings, et al., GCN Circ. 13967). The BAT ground-calculated position is
RA, Dec = 31.617, 7.432 deg which is
RA(J2000) = 02h 06m 28.1s
Dec(J2000) = +07d 25' 55.6"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a single FRED peak. Swift was close to
the SAA and BAT entered SAA mode about 250 seconds after the trigger. T90
(15-350 keV) is 30 +- 5 sec (estimated error including systematics).
The time-averaged spectrum from T+0.0 to T+158.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.16 +- 0.18. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+7.06 sec in the 15-150 keV band
is 1.1 +- 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/538696/BA/
GCN Circular 13971
Subject
GRB 121117A: MASTER prompt optical limit
Date
2012-11-18T07:56:13Z (13 years ago)
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
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.Krushinski, I.Zalozhnih, A. Popov
Ural Federal University, Kourovka
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 GRB121117A 47 sec after
GRB time at 2012-11-17 08:51:43.208 UT. On our first (10s exposure) set we
haven`t found optical transient within SWIFT error-box (Cummings et
al., GCN Circ. 13967).
The 5-sigma upper limit has been about 13.7 mag
This is the prompt limit because our observations was done during
Gamma-ray activity (Cummings et al., GCN Circ. 13970).
The message may be cited.
GCN Circular 13972
Subject
GRB 121117A: Swift-XRT refined Analysis
Date
2012-11-18T08:37:46Z (13 years ago)
From
Andy Beardmore at U Leicester <apb@star.le.ac.uk>
A.P. Beardmore (U. Leicester) and J. R. Cummings (NASA/UMBC) report on
behalf of the Swift-XRT team:
We have analysed 13 ks of XRT data for GRB 121117A (Cummings et al.
GCN Circ. 13967), from 41 s to 62.7 ks after the BAT trigger. The data
comprise 204 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. Using 3463 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 = 31.61064, +7.41954
which is equivalent to:
RA (J2000): 02h 06m 26.55s
Dec(J2000): +07d 25' 10.4"
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.27 (+/-0.04).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.55 (+0.22, -0.19). The
best-fitting absorption column is 8.4 (+7.2, -3.2) x 10^20 cm^-2,
consistent with the Galactic value of 5.2 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 4.2 x 10^-11 (4.7 x
10^-11) erg cm^-2 count^-1.
A summary of the WT-mode spectrum is thus:
Total column: 8.4 (+7.2, -3.2) x 10^20 cm^-2
Galactic foreground: 5.2 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.55 (+0.22, -0.19)
If the light curve continues to decay with a power-law decay index of
1.27, the count rate at T+24 hours will be 9.9 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.2 x
10^-14 (4.7 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00538696.
This circular is an official product of the Swift-XRT team.
GCN Circular 13973
Subject
GRB 121117A: Swift/UVOT Observations
Date
2012-11-18T12:41:31Z (13 years ago)
From
Samantha Oates at MSSL <sro@mssl.ucl.ac.uk>
S. R. Oates (MSSL-UCL) 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 121117A
s after the BAT trigger (Cummings et al., GCN Circ. 13967).
We find an optical afterglow consistent with the XRT position
(Beardmore et al. GCN Circ. 13972) in the initial UVOT white exposure.
The refined UVOT position is (RA,DEC) = 31.61063, 7.41956 (J2000),
which is equivalent to:
RA (J2000) = 02:06:26.56
Dec (J2000) = +07:25:10.5
with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence).
Preliminary magnitudes and 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 (FC) 57 205 146 19.17 +/- 0.10
white 4606 10267 1150 >21.9
v 3580 11882 1077 >20.3
b 4400 6037 393 >20.6
u 4195 5831 393 >20.3
w1 3990 5627 393 >20.3
m2 3785 5421 393 >20.2
w2 4811 11174 1082 >21.3
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).
GCN Circular 13976
Subject
GRB 121117A: GROND confirmation of the UVOT afterglow candidate
Date
2012-11-19T22:35:54Z (13 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg), M. Nardini
(Universita degli studi di Milano-Bicocca), and J.Greiner (MPE Garching)
report on behalf of the GROND team:
We observed the field of GRB 121117A (Swift trigger 538696, Cummings et
al., GCN #13967) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla
Observatory (Chile).
First-epoch observations started on November 18, 2012, at 00:16 UT, about
15.5 hrs after the GRB trigger. Second-epoch observations were performed
the following night. On the first-epoch images we find a faint source
within the r=1.7 arcsec XRT error circle (Beardmore et al., GCN 13972) at
coordinates RA(J2000) = 02:06:26.58, Dec. = 07:25:10.2 (+/- 0".3). Within
the astrometric error this is consistent with the object seen by UVOT in
the white band during the first 200 seconds after the GRB trigger (Oates
et al., GCN 13973). For this source we measure the following preliminary
AB magnitudes:
g' > 24.0,
r' = 23.6 +/- 0.2,
i' = 23.0 +/- 0.2,
z' > 23.1,
J > 21.3,
H > 20.8,
K > 19.5,
calibrated against SDSS and 2MASS field stars. On the second-epoch images
the object had faded to r'=24.5 +/- 0.2 and i'>24.3, implying that this
was the GRB afterglow.
GCN Circular 13978
Subject
GRB 121117A: optical upper limit
Date
2012-11-21T07:21:38Z (13 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (SAI MSU, 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 121117A (Cummings et al., GCN 13967) with
ORI-25 telescope of ISON-Blagoveshensk observatory starting on Nov.17
(UT) 09:05:39. We took several unfiltered exposures within 2 hours after
the start. We do not detect the OT (Oates et al., GCN 13973) in the XRT
error circle (Beardmore et al. GCN 13972) in any stacked images. A
photometry is based on nearby USNO-B1.0 stars (R2):
T_start T0+, Filter, exposure, UL (3 sigma)
(UT) mid (d) (s)
09:05:39 0.03105 none 80 x 40 18.3
10:05:44 0.07483 none 88 x 40 18.4
09:05:39 0.05397 none 168 x 40 18.9
GCN Circular 13980
Subject
GRB 121117A: Optical observations
Date
2012-11-21T11:24:44Z (13 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
Brajesh Kumar, Ram Kesh Yadav, S.B. Pandey and V.K. Bhatt (ARIES, Nainital,
India, on behalf of larger Indian GRB collaboration).
GRB 121117A (Cummings et al., GCN 13967) field was observed with the 1.3m
Devasthal Fast Optical Telescope at Nainital. Three images in R_c pass-band
(300 sec each) starting at 2012-11-17 14:35:26 (UT) were acquired. In the
co-added R_c frame (300sec x 3), we did not detect the optical source
(Oates et al., GCN 13973) down to a limiting magnitude of ~20.5 mag
(in comparison to nearby USNO- B1 stars).
This massage may be cited.
GCN Circular 14004
Subject
GRB 121117A: Terskol obseravtions
Date
2012-11-27T08:45:18Z (13 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
I. V. Sokolov, A. V. Sergeev, M. V. Andreev (TB INASAN, Russia),
V. B. Petkov (BNO INR RAS, Russia),
A. S. Moskvitin, V. N. Komarova (SAO RAS, Russia), on behalf of larger GRB
collaboration report:
GRB 121117A (Cummings et al., GCN 13967) field was observed with the 2-m
telescope
at the Mt. Peak Terskol since 6 hours after the trigger (2012-11-17,
14:50:02 -- 15:05:20 UT).
We obtained 3 x 300 sec. images in R and did not detect any source
(reported in Oates et al.,
GCN 13973 and in Nicuesa Guelbenzuet al., GCN 13976) down to a limiting
magnitude of ~21.1 mag
as well as the Indian team observing at the same time (Kumar et al., GCN
13980).
Calibrations were done by the same nearby USNO-B1 stars as in Volnova et
al., GCN 13978.
The magnitude was not corrected for the Galactic extinction E(B-V) = 0.06.