GRB 231117A
GCN Circular 35201
Subject
GRB 231117A: MeerKAT 1.3GHz detection
Date
2023-11-27T16:10:58Z (2 years ago)
From
Lauren Rhodes at Oxford <lauren.rhodes@physics.ox.ac.uk>
Via
Web form
L. Rhodes (Oxford), G. Schroeder (Northwestern), G. Anderson (Curtin), W. Fong (Northwestern), S. Chastain (UNM), A. Gulati (USyd), A. van der Horst(GWU), C. Kilpatrick (Northwestern), N. Klinger (NASA/GSFC), T. Laskar (Utah), J. K. Leung (UofT/HUJI), A. Nugent (Northwestern), J. Rastinejad (Northwestern), S. D. Ryder (Macquarie) on behalf of a larger collaboration.
We observed GRB 231117A (GCN 35071) with the MeerKAT radio telescope at 1.3GHz for a total of 2 hours starting on 26 November 2023 at 12:47 UTC. The observations used J1939-6342 and J2232+1143 as flux and phase calibrators, respectively. Using the SARAO SDP image we find an unresolved source at the position of the afterglow candidate (GCN 35083) with a flux density of ~100uJy/beam. The rms noise in the field is 7uJy/beam. We note that the measured flux density may have a substantial contribution from the host galaxy reported in GCN 35083 but said contribution cannot be quantified until the afterglow has faded.
We thank the staff at the South African Radio Astronomy Observatory for scheduling these observations.
GCN Circular 35172
Subject
GRB 231117A: Mondy optical observations
Date
2023-11-23T23:07:40Z (2 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We observed the field of GRB 231117A (Laha et al., GCN 35071; Navaneeth et al., GCN 35072; Beardmore et al., GCN3574; Cattaneo et al., GCN 35075; Svinkin et al., GCN 35079; Cheung et al., GCN 35081; Dafcikova et al., GCN 53095; Busman et al. GCN 35138; O'Connor et al., GCN 35139; Watson et al., GCN 35153, Kuin et al., GCN 35154; Dichiara et al., GCN 35160; Fong et al., GCN 35163) with AZT-33IK telescope of Mondy observatory in R-filter on 2023-11-17, 2023-11-18 and 2023-11-20. Using image subtraction and the image on 2023-11-20 as a template we obtained preliminary photometry of the optical transient
Date UT start t-T0 Exp. Filter OT Err.
(mid, days) (s)
2023-11-17 11:45:33 0.38349 30x120 R 21.00 0.16
2023-11-18 12:09:46 1.41142 46x120 R 21.59 0.16
The photometry is based on nearby USNO-B1.0 R2 stars. The index of power law (t-T0)^-alpha between the two epochs is alpha = 0.8 (+0.13 -0.2).
However, photometry may be biased due to the template contamination by a still decaying optical transient, so we caution against using this index for any physical assessments.
GCN Circular 35163
Subject
GRB 231117A: Chandra afterglow detection
Date
2023-11-23T03:12:50Z (2 years ago)
From
Wen-fai Fong at Northwestern University <wfong@northwestern.edu>
Via
Web form
W. Fong, T. Eftekhari, G. Schroeder (Northwestern), A. Rouco Escorial (ESA/ESAC) report:
"The Chandra X-ray Observatory observed the position of the short-duration GRB 231117A (Laha et al., GCN 35071, Navaneeth et al., GCN 35072, Cattaneo et al., GCN 35075, Svinkin et al., GCN 35079, Cheung et al., GCN 35081) starting on 2023 November 21 at 06:22:13 UT. We obtained an ACIS-S observation under Proposal 24400307 (PI: Fong), with an effective exposure time of ~27 ksec, for a mid-time of 4.3 days post-burst.
The X-ray afterglow is clearly detected at high significance. The source is spatially coincident with the optical (e.g., Yang et al., GCN 35083, Rastinejad et al., GCN 35087, Gompertz et al., GCN 35088) and radio (Rhodes et al., GCN 35097, Schroeder et al., GCN 35114) afterglows at the position:
RA (J2000) = 22:09:33.37
Dec (J2000) = 13:31:20.0
We note that, similar to the reported optical positions, the Chandra source is just outside the 90% confidence region of the latest XRT position. We measure a 0.3-10 keV flux for the Chandra afterglow of FX ~ 2e-13 erg/s/cm^2. We find that the XRT light curve beyond ~300 seconds post-burst can be modeled with a single power-law with FX ~ t^-0.6, and that the Chandra observation is fully consistent with this power law.
We thank the Chandra staff for rapid approval and planning of these observations."
GCN Circular 35160
Subject
GRB 231117A: Continued GTC Observations
Date
2023-11-22T20:56:27Z (2 years ago)
From
Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>
Via
Web form
Simone Dichiara (PSU), Alan M. Watson (UNAM), Nathaniel R. Butler (ASU), Eleonora Troja (Università di Roma Tor Vergata), Brendan O’Connor (CMU), Rosa L. Becerra (UNAM), Nissim Fraija (UNAM), William Lee (UNAM), Kin López (UNAM), and Margarita Pereyra (UNAM) report:
We observed the field of GRB 231117A (Laha et al., GCN 35071; Navaneeth et al., GCN 35072; Beardmore et al., GCN3574; Cattaneo et al., GCN 35075; Svinkin et al., GCN 35079; Cheung et al., GCN 35081; Dafcikova et al., GCN 53095; Busman et al. GCN 35138; O'Connor et al., GCN 35139; Watson et al., GCN 35153, Kuin et al., GCN 35154) with the OSIRIS instrument on the GTC telescope from 2023-11-21 20:34 to 21:16 UTC (113.5 to 114.2 hours after the trigger). We obtained total integrations of 480 s in r and 960 s in z with a seeing of about 0.9 arcsec.
We detect the source in both bands but, even with our good seeing, reliable photometry will require image subtraction. We measure r = 21.8 +/- 0.1 AB, with an uncertain contribution from the host galaxy. This value is not corrected for Galactic extinction.
Further observations are planned.
We thank the staff of the GTC, especially David García Álvarez and Antonio Cabrera, for their help with these observations.
GCN Circular 35154
Subject
GRB 231117A: Swift/UVOT late time observations
Date
2023-11-21T22:05:33Z (2 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Via
email
N.P.M. Kuin (MSSL/UCL) and S. L. Laha (GSFC/UMBC)
report on behalf of the Swift/UVOT team:
The initial Swift/UVOT observations of the field of GRB 231117A
(Laha et al., GCN Circ. 35071) have been reported by Kuin and
Laha (GCN Circ. 35134) based on the enhanced XRT position (Beardmore
et al. GCN Circ. 35074). A refined position was published by
Yang et al. (GCN Circ. 35083) which we use for the current
circular.
We report here exposures taken over the specified period and summed for
better S/N. We also report here in AB magnitudes (Breeveld et al. 2011,
AIP Conf. Proc. 1358, 373):
Filter T_start(s) T_stop(s) Exp(s) AB-Mag
white 106 1713 392 22.3 +/- 0.5
u 5863 18,406 917 20.9 +/- 0.2
white 67,725 68,529 675 21.7 +/- 0.2
white 210,209 223,742 4848 22.4 +/- 0.4
Considering that these are AB magnitudes, we can compare the white and u
values to see a likely peak around the time of the u magnitude with a
subsequent decay.
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.071 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 35153
Subject
GRB 231117A: GTC Near-Infrared Observations
Date
2023-11-21T21:05:30Z (2 years ago)
From
Alan M Watson at UNAM <alan@astro.unam.mx>
Via
legacy email
Alan M. Watson (UNAM), Simone Dichiara (PSU), Eleonora Troja
(Università di Roma Tor Vergata), Brendan O’Connor (CMU), Rosa L.
Becerra (UNAM), Nathaniel R. Butler (ASU), Nissim Fraija (UNAM),
William Lee (UNAM), Océlotl López (UNAM), and Margarita Pereyra (UNAM)
report:
We observed the field of GRB 231117A (Laha et al., GCN 35071;
Navaneeth et al., GCN 35072; Beardmore et al., GCN3574; Cattaneo et
al., GCN 35075; Svinkin et al., GCN 35079; Cheung et al., GCN 35081;
Dafcikova et al., GCN 53095; Busman et al. GCN 35138; O'Connor et al.,
GCN 35139) with the EMIR instrument on the GTC telescope from
2023-11-19 19:33 to 19:57 UTC (64.5 to 64.9 hours after the trigger).
We obtained total integrations of 420 in J and 252 in Ks with a seeing
of about 0.8 arcsec.
From our preliminary analysis, the source is detected in all filters
with brightness J = 20.9 +/- 0.1 AB, with an uncertain contribution
from the host galaxy. This value is not corrected for Galactic
extinction.
Further observations are planned.
We thank the staff of the GTC, including Riccardo Scarpa and Antonio
Cabrera, for their help with these observations.
GCN Circular 35152
Subject
GRB 231117A: Swift-BAT refined analysis
Date
2023-11-21T19:58:25Z (2 years ago)
From
Tyler Parsotan at NASA GSFC <tyler.parsotan@nasa.gov>
Via
email
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), M. J. Moss (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
T. Sakamoto (AGU), M. Stamatikos (OSU)
(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 231117A (trigger #1197027)
(Laha, et al., GCN Circ. 35071). The BAT ground-calculated position is
RA, Dec = 332.404, 13.516 deg which is
RA(J2000) = 22h 09m 37.0s
Dec(J2000) = +13d 30' 58.1"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 83%.
The mask-weighted light curve shows a very strong fast rise exponential decay profile
with potential precursor emission prior to the main pulse.
T90 (15-350 keV) is 0.67 +- 0.07 sec (estimated error including systematics).
The time-averaged spectrum from T-0.42 to T+1.30 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.55 +- 0.04. The fluence in the 15-150 keV band is 2.3 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-0.05 sec in the 15-150 keV band
is 28.9 +- 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/1197027/BA/
GCN Circular 35142
Subject
GRB 231117A: AMI-LA radio observations
Date
2023-11-20T20:44:23Z (2 years ago)
From
Lauren Rhodes at Oxford <lauren.rhodes@physics.ox.ac.uk>
Via
Web form
Lauren Rhodes, Rob Fender (Oxford), Dave Green, Dave Titterington (Cambridge) report:
We observed the field of the afterglow candidate GRB 231117A (GCN 35071) with the Arcminute Microkelvin Imager Large-Array (AMI-LA) at 15.5 GHz beginning at UT 15:30:45 on 17-Nov-2023 for a total of 4 hours. The flux standard 3c286 was used to calibrate the bandpass response and flux scale of the AMI-LA and J2232+1143 was used as an interleaved complex gain calibrator.
We do not detect any radio emission at the position of the afterglow candidate as reported in GCN 35083 with a 3-sigma upper limit of 230uJy/beam.
We thank the staff at the Mullard Radio Astronomy Observatory for carrying out these observations and operating the AMI-LA.
GCN Circular 35139
Subject
GRB 231117A: LDT Confirmation of Optical Fading
Date
2023-11-20T17:19:39Z (2 years ago)
From
Brendan O'Connor at Carnegie Mellon University <boconno2@andrew.cmu.edu>
Via
Web form
B. O'Connor (CMU), I. Andreoni (JSI/UMD/NASA-GSFC), G. Srinivasaragavan (UMD), T. Ahumada (Caltech), S. B. Cenko (NASA-GSFC), J. Durbak (UMD), E. Hammerstein (UMD), N. Klingler (UMBC/NASA-GSFC), A. Kutyrev (NASA-GSFC), L. Singer (NASA-GSFC), S. Veilleux (UMD):
We performed additional observations of GRB 231117A (Laha et al., GCN 35071; Navaneeth et al., GCN 35072; Beardmore et al., GCN3574; Cattaneo et al., GCN 35075; Svinkin et al., GCN 35079; Cheung et al., GCN 35081, Dafcikova et al., GCN 53095) with the Large Monolithic Imager (LMI) mounted at the 4-m Lowell Discovery Telescope (LDT) located in Flagstaff, AZ, under program M01 (PI: Andreoni). The observations began on 2023-11-20 02:50:02 UT (~3 d after the GRB) under seeing of ~2.2". We performed observations in the riz bands with 750 s exposure in each band.
At the location of the optical afterglow (Yang et al., GCN 35083; Rastinejad et al., GCN 35087; Gompertz et al., GCN 35088; Kumar et al., GCN 35089, Ahumada et al., GCN 35093; Andreoni et al., GCN 35099; Kilpatrick et al., GCN 35102; Chen et al., GCN 35105; Odeh et al., GCN 35118; Takahashi et al., GCN 35133; Schneider et al., GCN 35124; Busmann et al., GCN 35138), we clearly detect a source.
Preliminary photometry (including some contribution from the host) suggests fading by ~0.85 magnitudes in i-band from our previous observations obtained 2.0 days before (Andreoni et al., GCN 35099). Our observations confirm the fading of the optical afterglow candidate, as first reported by Fulton et al. (GCN 35121) and later by Busmann et al. (GCN 35138).
We thank the staff of the Lowell Observatory for their support during the observations.
GCN Circular 35138
Subject
GRB 231117A: Wendelstein Confirmation of Fading of the Optical Afterglow
Date
2023-11-20T17:16:21Z (2 years ago)
From
m.busmann@physik.lmu.de
Via
Web form
Malte Busmann (LMU), Daniel Gruen (LMU), Brendan O’Connor (CMU), Antonella Palmese (CMU), Lei Hu (CMU), Arno Riffeser (LMU/MPE), Ananya Shankar (LMU) report:
We observed GRB 231117A (Laha et al., GCN 35071; Navaneeth et al., GCN 35072; Beardmore et al., GCN3574; Cattaneo et al., GCN 35075; Svinkin et al., GCN 35079; Cheung et al., GCN 35081, Dafcikova et al., GCN 53095) with the 2m Fraunhofer telescope at Wendelstein Observatory, Germany. Observations were obtained using the 3kk imager in the r, i, and J bands simultaneously. The data were obtained starting at 2023-11-19 18:11:39 UT (~2.6 d after the GRB) under ~2” seeing.
At the location of the optical transient (Yang et al., GCN 35083; Rastinejad et al., GCN 35087; Gompertz et al., GCN 35088; Kumar et al., GCN 35089, Ahumada et al., GCN 35093; Andreoni et al., GCN 35099; Kilpatrick et al., GCN 35102