August 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 39446] GRB 250814C: SVOM/GRM observation of a short burst
by GCN Circulars 15 Aug '25

15 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41385 SUBJECT: GRB 250814C: SVOM/GRM observation of a short burst DATE: 25/08/15 09:18:33 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Hui Yang (IRAP), Stéphane Schanne (CEA) Report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by a short burst GRB 250814C (SVOM trigger reference: sb25081402) at 2025-08-14T03:24:23.000 UTC (T0), which is also detected by Konus-Wind and Swift/BAT. With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multi-pulses with a T90 of 1.20 +0.20/-0.30 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb250814C.png There is no indication of any subthreshold target from both CRT and IMT triggers onboard ECLAIRs close to the time of this event, suggesting that it is either too weak to be detected or outside the FoV of ECLAIRs. 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. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for this burst is: Chen-Wei Wang (IHEP)(cwwang(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/41385. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39445] LIGO/Virgo/KAGRA S250813k: Swift XRT observations, 2 X-ray sources
by GCN Circulars 15 Aug '25

15 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41384 SUBJECT: LIGO/Virgo/KAGRA S250813k: Swift XRT observations, 2 X-ray sources DATE: 25/08/15 07:26:06 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> K.L. Page (U. Leicester), P.A. Evans (U. Leicester), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), S.B. Cenko (NASA/GSFC), R.A.J. Eyles-Ferris (U. Leicester), A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), A.A. Breeveld (UCL-MSSL), S. Campana (INAF-OAB), J.J. Delaunay (PSU), M. De Pasquale (University of Messina), S. Dichiara (PSU), P. D’Avanzo (INAF-OAB), A. D’Aì (INAF-IASFPA) , V. D’Elia (ASI-SSDC & INAF-OAR), C. Gronwall (PSU), D. Hartmann (Clemson University), N. Klingler (NASA-GSFC / UMBC / CRESST II), N.P.M. Kuin (UCL-MSSL), S. Laha (NASA/GSFC), S.R. Oates (U. Birmingham), J.P. Osborne (U. Leicester), P. O’Brien (U. Leicester), M.J. Page (UCL-MSSL), G. Raman (PSU) S. Ronchini (PSU), T. Sbarrato (INAF-OAB), B. Sbarufatti (INAF-OAB), M.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), E. Troja (U Tor Vergata, INAF) report on behalf of the Swift team: Swift has carried out 109 observations of the LVK error region for the GW trigger S250813k convolved with the 2MPZ catalogue (Bilicki et al. 2014, ApJS, 210, 9), using the 'BAYESTAR' (version BAYESTAR.fits.gz) GW localisation map. As this is a 3D skymap, galaxy distances were taken into account in selecting which ones to observe. The observations currently span from 2.0 ks to 164 ks after the LVK trigger, and the XRT has covered 7.9 deg^2 on the sky (corrected for overlaps). This covers 70% of the probability in the 'ligo-skymap-from-samples' (version ligo-skymap-from-samples.fits.gz) skymap, and 71% after convolving with the 2MPZ galaxy catalogue, as described by Evans et al. (2016, MNRAS, 462, 1591). We have detected 2 X-ray sources. Each source is assigned a rank of 1-4 which describes how likely it is to be related to the GW trigger, with 1 being the most likely and 4 being the least likely. The ranks are described at https://www.swift.ac.uk/ranks.php. We have found: * 0 sources of rank 1 * 0 sources of rank 2 * 1 source of rank 3 * 1 source of rank 4 RANK 3 sources ============== These are uncatalogued X-ray sources, however they are not brighter than previous upper limits, so do not stand out as likely counterparts to the GW trigger. | Source ID | RA | Dec | Err90 | Detection Flag | | S250813k_X12 | 08h 54m 56.80s | +71d 23' 19.9" | 8.3" | GOOD | RANK 4 sources ============== These are catalogued X-ray sources, showing no signs of outburst compared to previous observations, so they are not likely to be related to the GW trigger. | Source ID | RA | Dec | Err90 | Detection Flag | | S250813k_X11 | 09h 17m 14.09s | +75d 30' 53.0" | 7.1" | GOOD | For all flux conversions and comparisons with catalogues and upper limits from other missions, we assumed a power-law spectrum with NH=3x10^20 cm^-2, and photon index (Gamma)=1.7, unless otherwise stated. The results of the XRT automated analysis, including details of the sources listed above, are online at https://www.swift.ac.uk/LVC/S250813k This circular is an official product of the Swift XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/41384. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39444] GRB 250813B: SVOM/GRM observation
by GCN Circulars 15 Aug '25

15 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41383 SUBJECT: GRB 250813B: SVOM/GRM observation DATE: 25/08/15 07:23:53 GMT FROM: tanwj(a)ihep.ac.cn SVOM/GRM team: Wen-Jun Tan, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Stéphane Schanne Report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by GRB 250813B (SVOM burst-id sb25081303) at 2025-08-13T22:51:12UTC (T0), which is also detected by SVOM/ECLAIRs (W.J. XIE et al., GCN #41354), Swift-XRT (K.L. Page et al., GCN #41359), EP-FXT (Q. Y. Wu et al., GCN #41361), SVOM/MXT (D. Götz et al., GCN #41368) and FERMI/GBM (Jacob Smith et al., GCN #41376) With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses with a T90 of 24.9 +/-0.76 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb250813B.png With this localization given by SVOM/ECLAIRs (RA= 336.728, DEC= 12.498, GCN #41354), the time-averaged spectrum from T0-6 to T0+35 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -0.84 +/-0.07 and the cutoff energy, parameterized as Epeak, is 109 +6/-5 keV. The event fluence (10-1000 keV) in this time interval is (1.35 +/-0.20)E-05 erg/cm^2. With the redshift z = 1.752 by VLT/X-shooter (B. Schneider et al., GCN#41363), the Eiso (from 1 keV to 10 MeV in rest frame) of this burst is (1.16 +0.20/-0.18)E53 erg. GRB 250813B is consistent with Type II GRBs in the 'Amati' relation diagram, as shown at: https://www.bursthub.cn//admin/static/grb250813B_amati.png 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. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for this burst is: Wen-Jun Tan (IHEP)(tanwj(a)ihep.ac.cn) View this GCN Circular online at https://gcn.nasa.gov/circulars/41383. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39443] GRB 250814A: P200/WIRC observations of the afterglow candidate
by GCN Circulars 15 Aug '25

15 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41382 SUBJECT: GRB 250814A: P200/WIRC observations of the afterglow candidate DATE: 25/08/15 06:11:05 GMT FROM: Tomas Ahumada Mena at Caltech <tahumada(a)caltech.edu> Tomás Ahumada (Caltech), Viraj Karambelkar (Caltech), Mansi Kasliwal (Caltech), Iver Warburton (Yale), Alessandro Peca (Yale), and Vishwajeet Swain (IITB) report: We observed the field of the Fermi and Swift GRB 250814A (Fermi team, GCN Circ. 41357; Caputo et al., GCN Circ. 41358, Salvaggio et al. GCN Circ. 41379), which is spatially coincident with the sub-threshold GW trigger S250814bg (GCN Circ. 41364), in the near-infrared J and Ks bands using the Wide-field Infrared Camera (WIRC; Wilson et al. 2003) on the Palomar 200-inch telescope. Observations began on 2025-08-15 at 03:20 UT and consisted of 1350 s in the Ks band, followed by J-band imaging starting at 04:00 UT with a total exposure time of 1200 s. We clearly detect the source announced in Karambelkar et al. (GCN Circ. 41337) and observed in i-band by Castro-Tirado et al. (GCN Circ. 41381) at RA = 20:25:13.9, Dec = +48:23:55.9 (J2000), in both bands. This position is consistent with the enhanced X-ray position reported by Salvaggio et al. (GCN Circ. 41379). Aperture photometry yields: Ks = 21.3 ± 0.2 mag (AB) J = 21.72 ± 0.15 mag (AB) These values are consistent, within the uncertainties, with those reported in Karambelkar et al. (GCN Circ. 41337) in both bands. We therefore conclude that this source shows no significant variability and is likely unrelated to the GRB. View this GCN Circular online at https://gcn.nasa.gov/circulars/41382. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39442] GRB 250814A: possible optical afterglow candidate at Spanish observatories
by GCN Circulars 15 Aug '25

15 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41381 SUBJECT: GRB 250814A: possible optical afterglow candidate at Spanish observatories DATE: 25/08/15 00:40:01 GMT FROM: I. Perez-Garcia at Institute of Astrophysics of Andalusia <ipg(a)iaa.es> A.J. Castro-Tirado, I. Perez-Garcia, F. J. Aceituno, M. D. Caballero-Garcia, S. Guziy, R. Sanchez-Ramirez, E. Fernandez-Garcia, S.-Y. Wu (IAA-CSIC), Y.-D. Hu (GXU), J. Becerra (IAC), M. Gritsevich (Univ. of Helsinki), A. Sintes (Univ. Illes Balears), J. A. Font (Univ. de Valencia), S. B. Pandey (ARIES), B.-B. Zhang (NJU), J. Flores (CAHA), D. Garcia (GTC, IAC) and A. Romero (GTC), on behalf of a larger collaboration, report: We initially observed the field of the GRB 250814A detected by both Fermi (Fermi GBM team, GCNC 41357) and Swift (Caputo et al. GCNC 41358) using the 1.5m OSN telescope at Observatorio de Sierra Nevada in Granada (clear filter, starting on Aug 14, 20:30 UT). In addition to this facility, we also used both the 2.2m telescope at the Calar Alto Observatory (z-band, starting at 21:55 UT) and the 10.4 GTC telescope (griz-band, starting on Aug 15, 00:00 UT). This event was proposed to be temporally and spatially coincident with the subthreshold GW trigger S250814bg (the LVK Collaboration, GCNC 41364), which occurred 3.7 s prior to the Fermi GBM trigger (de Barra et al., GCNC 41378). At the position of the X-ray afterglow detected by Swift/XRT (Salvaggio et al. GCNC 41379), we identify an optical source in our data (in particular on the GTC i-band image) at coordinates (J2000): RA = 20:25:13.87 Dec = +48:23:56.5 (+/- 0.5"), for which we measure i = 23.3 +/- 0.3, which could be the optical counterpart to GRB250814A. This object is consistent with the proposed NIR candidate (Karambelkar et al. GCNC 41377). Further optical observations would be needed in order to confirm whether this object is the electromagnetic counterpart to S250814bg. View this GCN Circular online at https://gcn.nasa.gov/circulars/41381. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39441] GRB 250814A: KAIT optical upper limit
by GCN Circulars 14 Aug '25

14 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41380 SUBJECT: GRB 250814A: KAIT optical upper limit DATE: 25/08/14 22:30:47 GMT FROM: Weikang Zheng at UC Berkeley <weikang(a)berkeley.edu> WeiKang Zheng (UCB) and Alexei V. Filippenko (UCB) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, observed the field of GRB 250814A (Fermi GBM team, GCN 41357; Caputo et al., GCN 41358) starting at 07:50:38, Aug. 14 UT, 939 seconds after the burst. A set of 120x60s clear (roughly R) filter images were obtained. Preliminary analysis do not reveal any new optical counterpart candidate within the Swift/XRT error circles (Caputo et al., GCN 41358), neither in single image, nor in the co-add images. Also no object was found at the afterglow candidate position reported by Karambelkar et al. (GCN 41377). Our upper limit is about 21.5 (Vega) mag at a mid time of 1.27 hours after the burst. Our result is consistent with the upper limit reported by other groups (Becerra et al., GCN 41362; Postigo et al., GCN 41367; Karambelkar et al., GCN 41372; Salazar et al., GCN 41375). View this GCN Circular online at https://gcn.nasa.gov/circulars/41380. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39440] GRB 250814A: Swift-XRT refined Analysis
by GCN Circulars 14 Aug '25

14 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41379 SUBJECT: GRB 250814A: Swift-XRT refined Analysis DATE: 25/08/14 21:31:37 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> C. Salvaggio (INAF-OAB), M. Ferro (INAF-OAB), S. Dichiara (PSU), J.A. Kennea (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), R. Brivio (INAF-OAB) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.7 ks of XRT data for GRB 250814A, from 163 s to 40.1 ks after the trigger. The data comprise 184 s in Windowed Timing (WT) mode (the first 10 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The best available XRT position (using the promptly downlinked event data, the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 306.30792, 48.39903 which is equivalent to: RA (J2000): 20h 25m 13.90s Dec(J2000): +48d 23' 56.5" with an uncertainty of 2.2 arcsec (radius, 90% confidence). The light curve can be modelled with an initial power-law decay with an index of alpha=1.49 (+0.27, -0.28), followed by a break at T+338 s to an alpha of 3.15 (+0.26, -0.20). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.33 (+0.24, -0.22). The best-fitting absorption column is 1.2 (+0.4, -0.3) x 10^22 cm^-2, in excess of the Galactic value of 6.5 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.9 (+/-0.4) and a best-fitting absorption column of 1.0 (+0.4, -0.3) x 10^22 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.5 x 10^-11 (9.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.0 (+0.4, -0.3) x 10^22 cm^-2 Galactic foreground: 6.5 x 10^21 cm^-2 Excess significance: 1.8 sigma Photon index: 1.9 (+/-0.4) If the light curve continues to decay with a power-law decay index of 3.15, the count rate at T+24 hours will be 1.3 x 10^-7 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.0 x 10^-18 (1.2 x 10^-17) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01342439. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/41379. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39439] GRB 240814A: Fermi GBM Observation
by GCN Circulars 14 Aug '25

14 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41378 SUBJECT: GRB 240814A: Fermi GBM Observation DATE: 25/08/14 20:20:15 GMT FROM: Cuán de Barra at UCD <cuan.debarra(a)ucdconnect.ie> C. de Barra (University College Dublin), P. McDermott (University College Dublin), and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 07:35:09.28 UT on 14 August 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250814A (trigger 776849714/250814316) which was also detected by Swift BAT (R. Caputo et al. 2025, GCN 41358). The Fermi GBM on-ground location is consistent with the Swift BAT position. The GBM trigger was temporally coincident with the non-significant compact binary merger candidate S250814bg (LVK Collaboration, GCN 41364) with GBM triggering 3.7s after S250814bg. The angle from the Fermi LAT boresight is 25 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 22 s (50-300 keV). The time-averaged spectrum from T0-6.1 to T0+16.4 s is best fit by a simple power law function with index -1.63 +/- 0.04.The spectrum is equally well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.15+/- 0.15 and the cutoff energy, parameterized as Epeak, is 132 +/- 24 keV. The event fluence (10-1000 keV) in this time interval is (2.9 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.6 s in the 10-1000 keV band is 1.4 +/- 0.2 ph/s/cm^2. 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/" View this GCN Circular online at https://gcn.nasa.gov/circulars/41378. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39438] GRB 250814A: Possible afterglow candidate from P200/WIRC
by GCN Circulars 14 Aug '25

14 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41377 SUBJECT: GRB 250814A: Possible afterglow candidate from P200/WIRC DATE: 25/08/14 19:35:32 GMT FROM: Viraj Karambelkar at Indian Inst of Tech,Bombay <karambelkarvraj21197(a)gmail.com> Viraj Karambelkar (Caltech), Mansi Kasliwal (Caltech), Steven Giacalone (Caltech), Emily Gilbert (IPAC), Matt Lastovka (UMD), Vishwajeet Swain (IITB), Gaurav Waratkar (IITB), Tomas Ahumada (Caltech) report: We observed the field of the Fermi and Swift GRB 250814A (Fermi team, GCN Circ. 41357, Caputo et al. GCN Circ. 41358) coincident with the sub-threshold GW trigger S250814bg (GCN Circ. 41364) in the near-infrared J and Ks bands with the Wide-field infrared Camera (WIRC, Wilson et al. 2003) on the Palomar 200-inch telescope. Observations started on 2025-08-14 at 11:31:29 UT and lasted for 1665 seconds in the J-band, and started at 12:09:12 UT and lasted for 810 seconds in the Ks-band. We marginally detect a faint source in the Ks-band image at RA=20:25:13.9, Dec=48:23:55.9 (J2000), ~0.6 arcsec from the enhanced position of the X-ray counterpart reported by Caputo et al (GCN 41358). We also detect a marginal source at this location in the more sensitive J-band image, however, it is blended with several faint sources and is near the detection limit of the image. We performed aperture photometry at the location of this source and measured the following magnitudes Ks ~ 21.2 +/- 0.35 mag (AB), J ~ 21.6 mag +/- 0.4 mag (AB) We encourage deep NIR observations to trace the brightness evolution and confirm the nature of this source. View this GCN Circular online at https://gcn.nasa.gov/circulars/41377. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 39437] GRB 250813B: Fermi GBM Observation
by GCN Circulars 14 Aug '25

14 Aug '25

TITLE: GCN CIRCULAR NUMBER: 41376 SUBJECT: GRB 250813B: Fermi GBM Observation DATE: 25/08/14 19:17:11 GMT FROM: Jacob Smith at Fermi-GBM Team <jrs0118(a)uah.edu> Jacob Smith (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: At 22:51:11.24 UT on 13 August 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250813B (trigger 776818276/250813952), which was also detected by SVOM/ECLAIRs (W.J. Xie, et al. 2025, GCN 41354). The Fermi GBM on-ground location is consistent with the SVOM/ECLAIRs position. An optical afterglow was first reported by Ondrejov D50 (M. Jelinek, et al. 2025, GCN 41353) which also reports an extremely rapid decay (M. Jelinek, et al. 2025, GCN 41355). A redshift of z=1.752 was report by the VLT (B. Schneider, et al. 2025, GCN 41363). The angle from the Fermi LAT boresight is 99 degrees. The GBM light curve consists of multiple emission episodes with a duration (T90) of about 24.1 s (50-300 keV). The time-averaged spectrum from T0-3.8 to T0+31.0 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.82 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 114 +/- 3 keV. A Band function fits equally well with Epeak = 112 +/- 4, alpha = -0.81 +/- 0.04, and beta = -3.67 +/- 0.79. The event fluence (10-1000 keV) in this time interval is (1.30 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+11 s in the 10-1000 keV band is 8.1 +/- 0.3 ph/s/cm^2. 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/ View this GCN Circular online at https://gcn.nasa.gov/circulars/41376. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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