GRB241030B

This page lists all entries on GRB241030B in GRBweb

Summary Fermi GBM IPN Swift GCN 37980 GCN 37981 GCN 37983 GCN 37984 GCN 37985 GCN 37986 GCN 37987 GCN 37989 GCN 37991 GCN 37992 GCN 37995 GCN 37996 GCN 37998 GCN 37999 GCN 38001 GCN 38004 GCN 38008 GCN 38011 GCN 38012 GCN 38013 GCN 38020 GCN 38023 GCN 38024 GCN 38029 GCN 38158

Summary table
Variable Value Source
GRB_name_Fermi GRB241030774
T0 18:34:20 UTC GCN_circulars,Fermi GBM final loc
ra 50.7927° Swift
decl 34.4469° Swift
pos_error 2.46e-04° Swift
T90 6.848 s Fermi_GBM
T90_error 0.668 s Fermi_GBM
T90_start 18:34:20.200 UTC Fermi_GBM
fluence 2.51e-06 erg/cm² Fermi_GBM
fluence_error 2.72e-08 erg/cm² Fermi_GBM
redshift 2.8200
T100 7.048 s
GBM_located False
mjd 60613.77384259259 GCN_circulars,Fermi GBM final loc
Fermi GBM table
GRB_name_Fermi GRB241030774
trigger_name bn241030774
ra 50.7921°
decl 34.4461°
pos_error 3.61e+00°
datum 2024-10-30
t_trigger 18:34:20.392 UTC
T90 6.848 s
T90_error 0.668 s
T90_start 18:34:20.200 UTC
fluence 2.51e-06 erg/cm²
fluence_error 2.72e-08 erg/cm²
flux_1024 6.74e+00 erg/cm²/s
flux_1024_error 2.15e-01 erg/cm²/s
flux_1024_time 8.32e-01 erg/cm²/s
flux_64 8.71e+00 erg/cm²/s
flux_64_error 1.20e+00 erg/cm²/s
IPN table
GRB_name GRB241030B
ra 50.7875°
decl 34.4333°
pos_error 5.00e-02°
redshift 2.8200
Swift table
GRB_name GRB241030B
t_trigger 18:34:20 UTC
ra 50.7927°
decl 34.4469°
pos_error 2.46e-04°
GCN 37980 table
GRB_name GRB241030B
GCN_number 37980
Detection_method Fermi GBM final loc
t_trigger 18:34:20 UTC
ra 52.7000°
decl 36.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37980 SUBJECT: GRB 241030B: Fermi GBM Final Real-time Localization DATE: 24/10/30 18:45:28 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 18:34:20 UT on 30 Oct 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241030B (trigger 752006065.391554 / 241030774). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 52.7, Dec = 36.0 (J2000 degrees, equivalent to J2000 03h 30m, 36d 00'), with a statistical uncertainty of 3.0 degrees. The angle from the Fermi LAT boresight is 52.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241030774/quicklook/glg_skymap_all_bn241030774.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241030774/quicklook/glg_healpix_all_bn241030774.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241030774/quicklook/glg_lc_medres34_bn241030774.gif
GCN 37981 table
GRB_name GRB241030B
GCN_number 37981
Detection_method Swift Det
t_trigger 18:34:20 UTC
ra 50.7880°
decl 34.4320°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37981 SUBJECT: GRB 241030B: Swift detection of a burst DATE: 24/10/30 18:46:07 GMT FROM: David Palmer at LANL N. J. Klingler (GSFC/UMBC/CRESSTII), M. Ferro (INAF-OAB), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. M. Parsotan (GSFC), C. Salvaggio (INAF-OAB), T. Sbarrato (INAF-OAB) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 18:34:20 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 241030B (trigger=1263840). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 50.788, +34.432 which is RA(J2000) = 03h 23m 09s Dec(J2000) = +34d 25' 57" 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 8 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 18:36:58.0 UT, 157.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 50.79212, 34.44596 which is equivalent to: RA(J2000) = 03h 23m 10.11s Dec(J2000) = +34d 26' 45.5" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 51 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 https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.01 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 160 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 0.203. Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.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/)
GCN 37983 table
GRB_name GRB241030B
GCN_number 37983
Detection_method Swift-XRT Other
ra 50.7927°
decl 34.4469°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37983 SUBJECT: GRB 241030B: Prompt enhanced Swift-XRT position DATE: 24/10/30 19:05:42 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 241030B, we find an enhanced XRT position of the afterglow: RA, Dec: 50.79269, 34.44691 which is equivalent to: RA (J2000) = 03 23 10.24 Dec (J2000) = +34 26 48.9 with an uncertainty of 1.9 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/1263840. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team.
GCN 37984 table
GRB_name GRB241030B
GCN_number 37984
Detection_method Swift-BAT Det
ra 50.7940°
decl 34.4390°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37984 SUBJECT: GRB 241030B: SVOM/ECLAIRs detection of a burst DATE: 24/10/30 19:10:53 GMT FROM: Stéphane Schanne at CEA Paris-Saclay/IRFU SVOM/ECLAIRs Commissioning Team: Donghua Zhao, Wenjin Xie (NAOC), Stéphane Schanne, Frédéric Chateau, Nicolas Dagoneau, Hervé Le Provost (CEA), Jean-Luc Atteia, Laurent Bouchet, Sebastien Guillot, Juliette Alaux (IRAP), Alexis Coleiro, Floriane Cangemi (APC), Tais Maiolino (LUPM), Karine Mercier, Marie-Claire Charmeau, Stefano Crepaldi (CNES) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Olivier Godet (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV) Report on behalf of the SVOM team: During the commissioning phase, the SVOM/ECLAIRs telescope triggered and localized GRB 241030B at 2024-10-30T18:34:19 UTC (Tb) which was also detected by Fermi GBM (Fermi GBM team, GCN 37980), Swift BAT (Klingler et al, GCN 37981) and Swift XRT (Evans et al, GCN 37983). The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. The burst was detected by both the on-board Count-Rate Trigger (CRT) and Image Trigger (IMT) and 15 alerts were received. The light-curve shows a single peak of about 8 s duration. The CRT detected the burst on time-windows from 2.56 to 20.48 s duration. The best detection is obtained by CRT with a signal-to-noise ratio of 37.6 in the 8-120 keV energy band over a time window of 5.12 s starting at Tb. The GRB localization is RA, Dec = 50.794, 34.439 (J2000). The statistical uncertainty on this position is 2.3 arcminutes, to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature. An automatic slew on this position was performed by SVOM upon request by the onboard trigger. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by APC, CEA, CNES, and IRAP. The SVOM point of contact for this burst is: stephane.schanne AT cea.fr
GCN 37985 table
GRB_name GRB241030B
GCN_number 37985
Detection_method Optical
ra 50.7927°
decl 34.4472°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37985 SUBJECT: GRB 241030B: Nanshan/HMT optical afterglow detection DATE: 24/10/30 19:17:38 GMT FROM: Dong Xu at NAOC/CAS S.Y. Fu, S.Q. Jiang, J. An, X. Liu, Z.P. Zhu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report on behalf of a large collaboration: We observed the field of GRB 241030B detected by Fermi/GBM (Fermi GBM team, GCN 37980), Swift/BAT (Klingler et al., GCN 37981), and SVOM/ECLAIRs (Zhao et al., GCN 37984), using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 18:36:30 UT on 2024-10-30, i.e., 2.17 mins after the Swift trigger, and a series of 20 s, 40 s , 60 s, 120 s frames have been obtained without any filter. An uncatalogued and varying optical transient (OT) is detected in our images, being consistent with the enhanced XRT position (Evans et al., GCN 37983), at coordinates (J2000) R.A. = 3:23:10.26 Dec. = +34:26:49.98 with an uncertainty of ~ 0.5 arcsec. The OT has R ~ 19.1 mag at 8.17 mins post-trigger, calibrated with nearby PanSTARRS stars and not corrected for Galactic extinction. Observations are ongoing.
GCN 37986 table
GRB_name GRB241030B
GCN_number 37986
Detection_method Swift-BAT Det
ra 50.7927°
decl 34.4472°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37986 SUBJECT: GRB 241030B: AKO Optical Afterglow Detection DATE: 24/10/30 19:37:04 GMT FROM: Mohammad Odeh at Al Khatim Observatory M44 Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International Astronomical Center in Abu Dhabi, UAE), and Shaikha Alshamsi, Nuha Manal Pattani, and Nidhal Guessoum (American University of Sharjah, UAE), report: We observed the field of GRB 241030B detected by Fermi/GBM (Fermi GBM team, GCN 37980), Swift/BAT (Klingler et al., GCN 37981), and SVOM/ECLAIRs (Zhao et al., GCN 37984), with our 0.36m f/7.7 robotic telescope. The observation started on 30 October 2024 at 18:58 (UT), 24 minutes from the trigger. We obtained multiple 180-sec exposures in Ic filter. We detected the optical afterglow at: R.A. (J2000): 03:23:10.26 Dec. (J2000): +34:26:50.1 Our detection is consistent with the results of (Fu et al., GCN 37985). The following observation was calculated using Atlas catalogue as a reference: ---------------------------------------------------------------------------- - ObsTime (mid), Exposure (sec), Filter, Mag ---------------------------------------------------------------------------- - 2024-10-30T19:08:23Z, 7x180s (stacked), Ic, 18.9 +/- 0.26 ---------------------------------------------------------------------------- - The magnitude is not corrected for galactic extinction.
GCN 37987 table
GRB_name GRB241030B
GCN_number 37987
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37987 SUBJECT: GRB 241030B: SAO RAS optical observations DATE: 24/10/30 20:41:05 GMT FROM: Moskvitin Alexander at SAO RAS A. S. Moskvitin (SAO RAS), V. P. Goranskij (SAI MSU), A. S. Vinokurov, V. S. Shergin (SAO RAS), A. S. Pozanenko (IKI), N. Pankov (IKI, HSE) report on behalf of the GRB follow-up team. We observed the field of GRB 241030B (Fermi GBM team, GCN 37980; Klingler et al., GCN 37981; Evans, GCN 37983; Zhao et al., GCN 37984), with the 1-m telescope of SAO RAS equipped with the CCD-photometer. We obtained a series of 300 and 600 sec. Rc images started 15 min after the trigger. The OT (Fu et al., GCN 37985; Odeh et al., GCN 37986) is clearly detected in our frames with the following brightness: R = 19.59 +/- 0.06 (18:49:32--19:00:55 UT, t_mid - T0 = 20.89 min); R = 20.61 +/- 0.07 (19:01:33--19:45:54 UT, t_mid - T0 = 49.39 min). This preliminary photometry is based on nearby PS1 stars (magnitudes converted with Lupton 2005 equations) and not corrected for the Galaxy extinction. Further observations are ongoing.
GCN 37989 table
GRB_name GRB241030B
GCN_number 37989
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37989 SUBJECT: GRB241030B: GRANDMA/TAROT Upper Limit DATE: 24/10/30 22:54:02 GMT FROM: Cristina Andrade at UMN A. Klotz (IRAP), C. Andrade (UMN), S. Antier, I. Abdi (AUS), Y. Rajabov (UBAI), M. Masek (FZU), E. de Bruin (UMN), M. Boer; C. Limonta (OCA), S. Karpov (FZU), M. Coughlin (UMN), I. Tosta e Melo (UniCT-DFA), P. Hello, N. Leroy (IJCLAB), P-A Duverne (APC), T. Pradier (Unistra/IPHC), N. Guessoum (AUS), M. Tanasan (NARIT), K. Noysena (NARIT), D.Turpin (CEA-Saclay/Irfu), on behalf of the GRANDMA collaboration: We observed the field of GRB 241030B, detected by SWIFT (GCN 37981) and SVOM/ECLAIRs (GCN 37984), using TAROT, TCA at Calern and TRE at La Réunion observatories. Observations began 1 minute after T0 for TCA and 10 minutes after the trigger for TRE and both without a filter. No afterglow candidate was detected the first min with an upper limit of 16.2 mag in r (5 sigma) and the first 15 min with an upper limit of 17.4 in r (5 sigma). It is consistent with Nanshan/HMT detection (GCN 37985), SAO RAS detection (GCN 37987) and AKO (GCN37986). All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). We use the SkyPortal application (skyportal.io) to monitor our observational campaign. GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).
GCN 37991 table
GRB_name GRB241030B
GCN_number 37991
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37991 SUBJECT: GRB 241030B: optical observations from the INAF Asiago Observatory DATE: 24/10/30 23:17:51 GMT FROM: Riccardo Brivio at INAF-OAB R. Brivio (INAF-OAB), D.B. Malesani (DAWN/NBI and Radboud Univ.), Y.-D. Hu (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Reguitti (INAF-OAB / INAF-OAPd), A. Melandri (INAF-OAR), M. Ferro (INAF-OAB), L. Tomasella (INAF -OAPd), E. Cappellaro (INAF -OAPd) report on behalf of the CIBO collaboration: We carried out follow-up optical observations of GRB 241030B detected by Fermi (Fermi GBM team, GCN 37980), Swift (Klingler et al., GCN 37981), and SVOM/ECLAIRs (Zhao et al., GCN 37984) from the INAF - Padova Astronomical Observatory located in Asiago (Italy) with the 67/92 Schmidt telescope starting on 2024-10-30 at 20:10:31 UT (~1.6 hours after the burst) with the r- and i-sdss filters. In our stacked images the optical afterglow (Fu et al., GCN 37985; Odeh et al., GCN 37986; Moskvitin et al., GCN 37987) is marginally detected in the i band, at the following AB magnitude: i = 20.8 +/- 0.3 (calibrated against the PanSTARRS catalog) at a mid-time of t - t0 = 1.71 hours after the trigger. The source is not detected in the r band down to the following 3 sigma upper limit: r > 21.5 (AB, calibrated against the PanSTARRS catalog) at a mid-time of t - t0 = 2.06 hours after the trigger.
GCN 37992 table
GRB_name GRB241030B
GCN_number 37992
Detection_method Swift-XRT Det
ra 50.7925°
decl 34.4470°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37992 SUBJECT: GRB 241030B: Enhanced Swift-XRT position DATE: 24/10/30 23:31:00 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 1712 s of XRT Photon Counting mode data and 3 UVOT images for GRB 241030B, 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 = 50.79245, +34.44700 which is equivalent to: RA (J2000): 03h 23m 10.19s Dec (J2000): +34d 26' 49.2" with an uncertainty of 2.4 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.
GCN 37995 table
GRB_name GRB241030B
GCN_number 37995
Detection_method Fermi GBM Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37995 SUBJECT: GRB 241030B: BTA observations DATE: 24/10/31 00:19:17 GMT FROM: Moskvitin Alexander at SAO RAS A. S. Moskvitin, A. S. Vinokurov (SAO RAS), A. S. Pozanenko (IKI), N. Pankov (IKI, HSE) report on behalf of the GRB follow-up team. We observed the field of GRB 241030B (Fermi GBM team, GCN 37980; Klingler et al., GCN 37981; Evans, GCN 37983; Zhao et al., GCN 37984; Evans et al., GCN 37992), with the 6-m telescope of SAO RAS equipped with the focal reducer Scorpio-I. We obtained quasi-simultaneous 16 x 30 sec images both in B and Rc bands on October 30. The OT (Fu et al., GCN 37985; Odeh et al., GCN 37986; Brivio et al., GCN 37991; Moskvitin t al., GCN 37987) is clearly detected in the Rc stacked frame, but not presented in the B stacked frame: UT_start--UT_end t_mid - T0, h filter OT_mag limit (3sigma) 20:17:39--20:43:25 1.9367 R 22.10 +/- 0.08 24.0 20:18:28--20:44:15 1.9504 B n/d 24.0 This preliminary photometry is based on nearby PS1 stars (magnitudes converted with Lupton 2005 equations) and not corrected for the Galaxy extinction. We also obtained 2 x 1200 sec spectrum with VPHG550G grism (3500--7500 AA, FWHM resolution ~ 10A) on October 30, 19:34:07--20:14:23 UT (T-mid - T0 = 1.3319 hours). In the spectrum we do not find a continuum lower than 5200A. Due to non-detection in B filter and absence of continuum we conclude that redshift of the GRB z >~ 3.3.
GCN 37996 table
GRB_name GRB241030B
GCN_number 37996
Detection_method Fermi GBM Det
t_trigger 18:34:20.390 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 37996 SUBJECT: GRB241030B: Fermi GBM Observation DATE: 24/10/31 01:44:21 GMT FROM: oindabimukherjee@gmail.com O. Mukherjee (USRA), S. Dalessi (UAH), S. Bala (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 18:34:20.39 UT on 30 October 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB241030B (trigger 752006065/241030774). which was also detected by Swift/BAT (N. Klingler et al. 2024, GCN 37981), and SVOM/ECLAIRs (D. Zhao et al. 2024, GCN 37984). The Fermi GBM on-ground location is consistent with the Swift/BAT position. The angle from the Fermi LAT boresight is 54 degrees. The GBM light curve consists of a single bright peak with a duration (T90) of about 6.8 s (50-300 keV). The time-averaged spectrum from T0-1.0 to T0+9.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.04 +/- 0.07 and the cutoff energy, parameterized as Epeak, is 200 +/- 20 keV. The event fluence (10-1000 keV) in this time interval is (3.2 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.83 s in the 10-1000 keV band is 6.7 +/- 0.2 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak = 190 +/- 26 keV, alpha = -1.03 +/- 0.08 and beta = -2.81 +/- 1. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN 37998 table
GRB_name GRB241030B
GCN_number 37998
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37998 SUBJECT: GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart DATE: 24/10/31 07:49:59 GMT FROM: Alan Watson at UNAM Alan M. Watson (UNAM), S. Antier (OCA), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Dahlia Akl (AUS), Jean-Luc Atteia (IRAP), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), J.-G. Ducoin (CPPM), Francis Fortin (IRAP), Simona Lombardo (LAM), Francesco Magnani (CPPM), and Margarita Pereyra (UNAM) report: We imaged the field of GRB 241030B detected by Fermi/GBM, Swift/BAT, Swift/XRT, and SVOM/ECLAIRs (Fermi GBM Team, GCN Circ. 37980; Klingler et al., GCN Circ. 37981; Zhao et al., GCN Circ. 37984) during the commissioning of the COLIBRÍ (SVOM/F-GFT) telescope at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in Mexico. We observed with the engineering test camera in a red filter that approximates SDSS r. We observed from 2024-10-31 03:51 to 05:46 UTC (9.3 to 11.2 hours after the trigger) and obtained 5160 seconds of exposure. The data were reduced using custom software and then analyzed and calibrated against the PS1 catalog using the STDWeb service (Karpov et al., 2022). We do not detect the optical counterpart (Fu et al., GCN Circ. 37985; Odeh et al., GCN Circ. 37986; Moskvitin et al., GCN Circ. 37987; Brivio et al., GCN Circ. 37991; Moskvitin et al., GCN Circ. 37995) with a 3-sigma limiting AB magnitude of: r > 23.2 We warmly thank the COLIBRÍ engineering team and the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir.
GCN 37999 table
GRB_name GRB241030B
GCN_number 37999
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37999 SUBJECT: GRB 241030B: SVOM/VT optical afterglow observations DATE: 24/10/31 08:29:09 GMT FROM: SVOM_group SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), H. Zhou (PMO). SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV) report on behalf of the SVOM team: VT started to observe the field of GRB 241030B (Fermi GBM team, GCN 37980; Klingler et al., GCN 37981; Evans, GCN 37983; Zhao et al., GCN 37984; Evans et al., GCN 37992; Mukherjee et.al, GCN 37996) after the automatic slew of the platform. The VT conducted observation in B band (400nm-650nm) channel. The optical counterpart (Fu et al., GCN 37985; Odeh et al., GCN 37986; Brivio et al., GCN 37991; Moskvitin et al., GCN 37987; Moskvitin et.al GCN 37995) was detected at 2024-10-30T18:39:52 in VT_B band image with a exposure time of 100s . The brightness was 19.47+-0.05 mag, at a mid time of 382 s after the burst. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS.
GCN 38001 table
GRB_name GRB241030B
GCN_number 38001
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 38001 SUBJECT: GRB 241030B : MITSuME Akeno optical upper limits DATE: 24/10/31 08:55:47 GMT FROM: hagio.h.ffca@m.isct.ac.jp H. Hagio, Y. Kubo, N. Higuchi, I. Takahashi, M. Niwano, M. Sasada, S. Hayatsu, H. Seki, S. Joshima, Y. Yatsu and N. Kawai (Science Tokyo) report on behalf of the MITSuME collaboration: We observed the field of GRB 241030B (Fermi GBM Team, GCN 37980, Klingler et al. GCN 37981) with the optical three-color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50-cm telescope Akeno. The observation started at 2024-10-30 18:44:33.72 UT (10.2 minutes after the Swift/BAT trigger). We stacked the images with good conditions. We did not detect any uncatalogued sources within the enhanced Swift/XRT error region(Evans et al. GCN 37992). We obtained the 5-sigma limits of the stacked images as follows. T0+[min] | MID-UT | T-EXP[sec] | 5-sigma limits ------------------------------------------------------------------------------------------------ 15.9 | 2024-10-30 18:50:13.75 | 480 | g'>18.7, Rc>18.6, Ic>18.1 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the trigger T-EXP: Total Exposure time We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g', Rc and Ic band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ; https://github.com/MNiwano/Eclaire).
GCN 38004 table
GRB_name GRB241030B
GCN_number 38004
Detection_method Optical
redshift 2.8200
Circular_text TITLE: GCN CIRCULAR NUMBER: 38004 SUBJECT: GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82 DATE: 24/10/31 11:54:00 GMT FROM: Antonio Martin-Carrillo at UCD,Space Science Group N. R. Tanvir (U. Leicester), C. C. Thoene (ASU-CAS, AbAO), J. P. U. Fynbo (DAWN/NBI), A. de Ugarte Postigo (LAM/OCA, CNRS), L. Izzo (INAF-OACn & DARK/NBI), D. B. Malesani (DAWN/NBI and Radboud Univ.), A. Martin-Carrillo (UCD), J. F. Agui Fernandez (CAHA), G. Lombardi (GTC), S. Geier (GTC) and G. Gómez Velarde (GTC) report: We observed the optical counterpart (Fu et al., GCN 37985) of GRB 241030B (Fermi GBM team, GCN 37980; Klingler et al., GCN 37981; Zhao et al., GCN 37984) using OSIRIS+ on the 10.4 m GTC telescope, at the Roque de los Muchachos Observatory (La Palma, Spain). The observation consisted of 4 spectra of 1200 s each, obtained with grism R1000B, covering the spectral range between 3650 and 7800 AA, at a resolving power of 600. The acquisition image, obtained on 2024-10-31 at 02:42:33 UT, 8.14 hr since the trigger, shows the afterglow at r(AB) = 23.53 +/- 0.12 mag, as compared to Pan-STARRS field stars. The spectrum shows a faint continuum over the complete spectral range, though a drop in flux is observed blueward of ~4700 AA, suggesting the onset of the Lyman-alpha forest. No clear DLA trough is visible, but several, low S/N absorption features are present to the red of the drop, which we tentatively interpret as Si II 1526, Si IV 1393, C IV 1548,1550 (blended), Al II 1670, Al III 1854,1862 at z = 2.82, which we propose as the redshift of GRB 241030B.
GCN 38008 table
GRB_name GRB241030B
GCN_number 38008
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 38008 SUBJECT: GRB 241030B: Swift/UVOT Detection DATE: 24/10/31 12:56:29 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and N. J. Klingler (GSFC/UMBC/CRESSTII) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 241030B 162 s after the BAT trigger (Klingler et al., GCN Circ. 37981). The optical counterpart (Fu et al., GCN Circ. 37985; Odeh et al., GCN Circ. 37986; Moskvitin et al., GCN Circ. 37987; Brivio et al., GCN Circ. 37991; Moskvitin et.al GCN Circ. 37995 and Qui et al. GCN Circ. 37999) is detected in the initial UVOT exposure in the white filter only. 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 162 538 167 21.00 ± 0.30 v 395 4817 255 >19.4 b 494 857 58 >19.3 u 469 5380 203 >20.2 w1 444 5228 255 >21.1 m2 4822 5021 197 >19.7 w2 371 4612 255 >19.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.204 in the direction of the burst (Schlegel et al. 1998).
GCN 38011 table
GRB_name GRB241030B
GCN_number 38011
Detection_method Swift-BAT Det
ra 50.7870°
decl 34.4390°
Circular_text TITLE: GCN CIRCULAR NUMBER: 38011 SUBJECT: GRB 241030B: Swift-BAT refined analysis DATE: 24/10/31 14:06:42 GMT FROM: Takanori Sakamoto at AGU S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), R. Gupta (GSFC), N. J. Klingler (GSFC/UMBC/CRESSTII), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (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 241030B (trigger #1263840) (Klingler, et al., GCN Circ. 37981). The BAT ground-calculated position is RA, Dec = 50.787, 34.439 deg which is RA(J2000) = 03h 23m 08.8s Dec(J2000) = +34d 26' 21.9" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 11%. The mask-weighted light curve shows a single-pulse structure that starts at T-2 sec, peaks at T+1 sec, and ends at T+9 sec. T90 (15-350 keV) is 6.7 +- 1.6 sec (estimated error including systematics). The time-averaged spectrum from T-1.58 to T+7.10 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.40 +- 0.16. 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+0.68 sec in the 15-150 keV band is 3.2 +- 0.6 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1263840
GCN 38012 table
GRB_name GRB241030B
GCN_number 38012
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 38012 SUBJECT: GRB 241030B: LCOGT Optical Upper Limits DATE: 24/10/31 14:09:14 GMT FROM: Robert Strausbaugh at Eastern Illinois University R. Strausbaugh (Eastern Illinois University), A. Cucchiara (NASA) report on behalf of a larger collaboration: We observed the Fermi/Swift GRB 241030B field (Fermi GBM Team, GCN 37980; Klingler et al., GCN 37981) with the LCOGT 1-meter Sinistro instrument at the Teide Observatory, Tenerife site, on October 30, from 21:50 to 22:22 UT (corresponding to 3.27 to 3.8 hours after the GRB trigger time) with the sdss r and i filters. We performed a series of 3x300s exposures in i- and r-bands. We do not detect a source within the enhanced Swfit XRT error region (Evans et al., GCN 37983) in either band. This result is consistent with fading from early optical detections (Fu et al., GCN 37985; Odeh et al, GCN 37986; Moskvitin et al., GCN 37987, Brivio et al., GCN 37991; Moskvitin et al., GCN 37995; Qiu et al., GCN 37999; Tanvir et al., GCN 38004; Breeveld et al., GCN 38008) and other optical upper limits (Klotz et al., GCN 37989; Hagio et al., GCN 38001). The following 5-sigma upper limits are calculated using the PanSTARRS catalog as reference: r > 22.5 i > 22.0 These magnitudes are not corrected for galactic extinction.
GCN 38013 table
GRB_name GRB241030B
GCN_number 38013
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 38013 SUBJECT: GRB 241030B : GIT optical upper limits DATE: 24/10/31 14:28:02 GMT FROM: V. Swain at IIT Bombay V. Swain, A.P. Saikia, T. Mohan, R. Kumar, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team: We observed the field of GRB 241030B (Fermi GBM Team, GCN 37980, Klingler et al. GCN 37981) with 0.7m GROWTH-India Telescope (GIT) in g', r', and i' filters. We started the observation at 2024-10-30 18:42:39 UT, i.e., 8.3 mins after the Fermi GBM trigger. We took multiple exposures and obtained upper limits at the position reported by Fu et. al., (GCN 37985). The photometry results follow as: ------------------------------------------------------------------------------ | JD (mid) | t-t0 (mins) | Filter | Exposure (s) | Upper limit (AB) | | ----------------- | ----------- |------- | ------------ | -------------- | | 2460614.279618055 | 8.32 | r' | 20 | 18.9 | | 2460614.281053241 | 10.38 | g' | 20 | 18.7 | | 2460614.282048611 | 11.82 | i' | 30 | 18.0 | | 2460614.434398148 | 231.2 | g' | 440 | 21.2 | | 2460614.439745370 | 238.9 | r' | 440 | 21.3 | | 2460614.445185185 | 246.7 | i' | 400 | 20.2 | ------------------------------------------------------------------------------ Our results are consistent with Fu et al.; (GCN 37985), Odeh et al.; (GCN 37986), Moskvitin et al.; (GCN 37987), Brivio et al.; (GCN 37991), Moskvitin et al.; (GCN 37995), Watson et al.; (GCN 37998), Qiu et al.; (GCN 37999), Hagio et al.; (GCN 38001), Tanvir et. al.; (GCN 38004), Breeveld et. al.; (GCN 38008), Strausbaugh et. al.; (GCN 38012). The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN 38020 table
GRB_name GRB241030B
GCN_number 38020
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 38020 SUBJECT: GRB 241030B: Montarrenti Observatory optical upper limit DATE: 24/10/31 23:48:16 GMT FROM: Simone Leonini at Montarrenti Observatory (Siena, Italy) S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez (Montarrenti Observatory, Siena, Italy, part of UAI/SSV-GRB section), M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy) and B. De Simone (Universita' degli Studi Di Salerno) report: We performed follow-up observations of the field of GRB 241030B with the automated and remoted 0.53m Ritchey-Chretien telescope at Montarrenti Observatory (Siena, Italy, IAU code C88). Observations were started at 2024-10-30 21:55:28 UT, 3.33 hours after burst (Fermi-GBM team, GCN 37980; Swift trigger 1263840, GCN 37981 Klingler et al.; SVOM/ECLAIRs, GCN 37984 Zhao et al.) stacking 140x40s Rc-band CCD images. In our preliminary analysis, we have not found any optical transient candidate within the error-box (2.4 arcmin.) of the Neil Gehrels Swift Observatory enhanced position (RA 03h 23m 10.19s, Dec. +34d 26m 49.2s - J2000) down to the following 3-sigma optical upper limits: MJD Exp. Filter UL (3-sigma) 60614.4476 140x40s Rc > 20.91 Magnitude was calibrated with the nearby PanSTARRS stars converted using Lupton (2005) equations. No correction for galactic dust extinction was applied. Our observations are consistent with other fading detection and upper limits already reported (Fu et al., GCN 37985; Odeh et al., GCN 37986; Moskvitin et al., GCN 37987; Klotz et al., GCN 37989; Brivio et al., GCN 37991; Moskvitin et al., GCN 37995; Watson et al., GCN 37998; Qiu et al., GCN 37999; Hagio et al., GCN 38001; Tanvir et. al., GCN 38004; Strausbaugh et. al., GCN 38012; Swain et al., GCN 38013).
GCN 38023 table
GRB_name GRB241030B
GCN_number 38023
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 38023 SUBJECT: GRB 241030B: NUTTelA-TAO / BSTI Optical Limits DATE: 24/11/01 04:57:48 GMT FROM: Toktarkhan Komesh at Nazarbayev University Zh. Abdullayev (NU), Zh. Maksut (NU), T. Komesh (NU), B. Grossan (UCB, NU), D. Berdikhan (NU), M. Krugov (FAI) and E. Abdikamalov (NU) report on behalf of the Energetic Cosmos Laboratory: The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) observed the field of GRB 241030B observing in Sloan g' and r' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14). We started observations at 20:15:59 UT on 2024-10-30, 1.7 h after the BAT trigger. Observations were made in partly cloudy conditions. No source consistent with the XRT (P.A. Evans 2024, GCN Circ. 37983) was detected. We report the following results: start time t-t0(s) end time UL g' UL r' exposure_time (s) ----------------------------------------------------------------- 20:15:59 6100 20:16:59 19.2 19.0 60 start time is in UT. t-t0(s) gives the time since trigger, in seconds. UL g' and UL r' give the 5 sigma upper limit sensitivity in magnitudes, for images co-added to the given exposure time. The results in in the table corresponds to co-adds of an initial short exposure image sequence of 0.5 s (these sub-second exposures are read-noise suppressed by our EMCCD cameras, with high gain electron multiplication active). Calibration was done with the 3 bright Pan-STARRS catalog stars on our images. ---------------------------------- NU = Nazarbayev University, Astana, Kazakhstan UCB = University of California, Berkeley, USA FAI = Fesenkov Astrophysical Institute, Kazakhstan This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14870504). The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.
GCN 38024 table
GRB_name GRB241030B
GCN_number 38024
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 38024 SUBJECT: GRB 241030B: NUTTelA-TAO / BSTI Optical Limits DATE: 24/11/01 04:57:52 GMT FROM: Toktarkhan Komesh at Nazarbayev University Zh. Abdullayev (NU), Zh. Maksut (NU), T. Komesh (NU), B. Grossan (UCB, NU), D. Berdikhan (NU), M. Krugov (FAI) and E. Abdikamalov (NU) report on behalf of the Energetic Cosmos Laboratory: The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) observed the field of GRB 241030B observing in Sloan g' and r' bands, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14). We started observations at 20:15:59 UT on 2024-10-30, 1.7 h after the BAT trigger. Observations were made in partly cloudy conditions. No source consistent with the XRT (P.A. Evans 2024, GCN Circ. 37983) was detected. We report the following results: start time t-t0(s) end time UL g' UL r' exposure_time (s) ----------------------------------------------------------------- 20:15:59 6100 20:16:59 19.2 19.0 60 start time is in UT. t-t0(s) gives the time since trigger, in seconds. UL g' and UL r' give the 5 sigma upper limit sensitivity in magnitudes, for images co-added to the given exposure time. The results in in the table corresponds to co-adds of an initial short exposure image sequence of 0.5 s (these sub-second exposures are read-noise suppressed by our EMCCD cameras, with high gain electron multiplication active). Calibration was done with the 3 bright Pan-STARRS catalog stars on our images. ---------------------------------- NU = Nazarbayev University, Astana, Kazakhstan UCB = University of California, Berkeley, USA FAI = Fesenkov Astrophysical Institute, Kazakhstan This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14870504). The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.
GCN 38029 table
GRB_name GRB241030B
GCN_number 38029
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 38029 SUBJECT: GRB 241030B: Swift-XRT refined Analysis DATE: 24/11/01 10:30:01 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: We have analysed 5.6 ks of XRT data for GRB 241030B, from 168 s to 51.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The light curve can be modelled with a power-law decay with a decay index of alpha=1.17 (+/-0.07). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.00 (+0.31, -0.28). The best-fitting absorption column is 2.9 (+1.3, -0.9) x 10^21 cm^-2, consistent with the Galactic value of 2.0 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (5.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.9 (+1.3, -0.9) x 10^21 cm^-2 Galactic foreground: 2.0 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 2.00 (+0.31, -0.28) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01263840. This circular is an official product of the Swift-XRT team.
GCN 38158 table
GRB_name GRB241030B
GCN_number 38158
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 38158 SUBJECT: GRB 241030B: TESS detection of optical counterpart DATE: 24/11/10 22:10:21 GMT FROM: Rahul Jayaraman at MIT R. Jayaraman (MIT), M.M. Fausnaugh (TTU), and G.R. Ricker (MIT) report: The Transiting Exoplanet Survey Satellite (TESS; Ricker et al. JATIS 1 2015) observed GRB 241030B (Klingler et al., GCN 37981; Fermi GBM Team, GCN 37980) during its scheduled sky survey. TESS observed this region continuously from 3.72 days before the trigger to 2.71 days after the trigger, at a cadence of 200 seconds. The GRB occurred during TESS observational Sector 85, and the localization fell within Camera 1, CCD 4. We performed forced difference-imaging photometry at the location of the confirmed X-ray afterglow (Evans et al., GCN 37992) using the full-frame images from the publicly available TICA data archived at MAST (https://archive.stsci.edu/hlsp/tica). Our data reduction routine is described in Fausnaugh et al. 2023 (ApJ 956(2):108). We detect an optical transient at the location of the GRB in the 3 exposures during and after the time of trigger from Klingler et al. The trigger occurred 115 seconds before the end of a concurrent 200-second TESS exposure. The optical transient has a magnitude of 16.40 ± 0.14 in the TESS band in this image. The magnitude falls to 16.50 ± 0.15 in the next exposure, and then 17.08 ± 0.25 mag in the third exposure. These values are in line with the upper limits of 16.2 (r) at T0+1 min, and 17.4 at T0+15 min from Klotz et al., GCN 37989. This circular includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.