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

[vsnet-grb-info 40394] GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart
by GCN Circulars 17 Oct '25

17 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42318 SUBJECT: GRB 251013C: SVOM/COLIBRÍ (FM-GFT) observations of a strong and late rebrightening of the optical counterpart DATE: 25/10/17 04:28:39 GMT FROM: enriquemm(a)astro.unam.mx Enrique Moreno Méndez (UNAM), Sarah Antier (OCA), Jean-Grégoire Ducoin (CPPM), Alan M. Watson (UNAM), Noémie Globus (UNAM), Ny Avo Rakotondrainibe (LAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Jean-Luc Atteia (IRAP), Dalya Akl (NYUAD), Camila Angulo (UNAM), Rosa L. Becerra (U Roma), Nathaniel R. Butler (ASU) , Damien Dornic (CPPM), Francis Fortin (IRAP), Leonardo García-García (UNAM), Ramandeep Gill (UNAM), Kin Ocelotl López (UNAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Margarita Pereyra (UNAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM), and Antonio de Ugarte Postigo (LAM) report: We imaged the field of the SVOM GRB 251013C (Rakotondrainibe et al., GCN Circ. 42222) using the DDRAGO wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2025-10-16 03:10 to 08:29 (57.51 to 62.83 hours after the trigger), obtaining 120 minutes of exposure in the r filter, and from 2025-10-17T03:17 to 03:28 UTC (81.64 to 81.98 hours after the trigger), obtaining 9 minutes of exposure in the r filter. The image was analyzed with STDWeb/STDPipe (Karpov 2025). The photometry was calibrated using nearby stars from the PanSTARRS catalog, is in the AB system, and is not corrected for Galactic extinction. We detect the optical counterpart, (Palmerio et al., GCN Circ. 42223; Perez-Garcia et al., GCN Circ. 42225; Konno et al., GCN Circ. 42226; Martin-Carrillo et al., GCN Circ. 42227; Masi et al., GCN Circ. 42228; Palmerio et al., GCN Circ. 42229; Moskvitin et al., GCN Circ. 42230; Gompertz et al., GCN Circ. 42231; Lipunov et al., GCN Circ. 42235; Garnavich et al., GCN Circ. 42240; Watson et al., GCN Circ. 42241; López-Cámara et al., GCN Circ. 42242; Zhang et al., GCN Circ. 42248; Brosio et al., GCN Circ. 42251; Reguitti et al., GCN Circ. 42253; Quintana-Ansaldo et al., Circ. GCN 42254; Maksut et al., GCN Circ. 42256; Ghosh et al., GCN Circ. 42261; Quadri et al., GCN Circ. 42262; Adami et al. GCN Circ. 42266; Peretto et al., GCN Circ. 42267; Ruocco et al., GCN Circ. 42269; Calapai, GCN Circ. 42275; Adami et al. GCN Circ. 42276; Globus et al., GCN Circ. 42279; Abidkhanov et al., GCN Circ. 42283; and Leonini et al., GCN Circ. 42301). Between our two epochs, the optical counterpart shows a rebrightening of Delta r = 0.97 +/- 0.05. Our observations show a strong and late rebrightening. Further observations and analysis are ongoing. We thank the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir and the COLIBRÍ and DDRAGO engineering teams. COLIBRÍ is an astronomical observatory developed and operated jointly by France (AMU, CNES and CNRS) and Mexico (UNAM and SECIHTI). It is located at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico. View this GCN Circular online at https://gcn.nasa.gov/circulars/42318. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40393] GRB 251007B: Swift-BAT refined analysis
by GCN Circulars 17 Oct '25

17 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42317 SUBJECT: GRB 251007B: Swift-BAT refined analysis DATE: 25/10/17 01:39:20 GMT FROM: Takanori Sakamoto at AGU <tsakamoto(a)phys.aoyama.ac.jp> C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), A. Melandri (INAF-OAR), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Because BAT triggered GRB 251007B (trigger #1402467) (Melandri, et al.GCN Circ. 42147) six minutes after GRB 251007A (Ambrosi, et al. GCN Circ. 42146), no BAT event data was generated on-board. Therefore, it is difficult to provide a detailed prompt emission analysis. According to the 1 s rate data (15-350 keV), the burst shows a double-peaked structure with a duration of ~25 sec. View this GCN Circular online at https://gcn.nasa.gov/circulars/42317. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40392] GRB 251007B: Swift-BAT refined analysis
by GCN Circulars 17 Oct '25

17 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42317 SUBJECT: GRB 251007B: Swift-BAT refined analysis DATE: 25/10/17 01:39:20 GMT FROM: Takanori Sakamoto at AGU <tsakamoto(a)phys.aoyama.ac.jp> C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), A. Melandri (INAF-OAR), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Because BAT triggered GRB 251007B (trigger #1402467) (Melandri, et al.GCN Circ. 42147) six minutes after GRB 251007A (Ambrosi, et al. GCN Circ. 42146), no BAT event data was generated on-board. Therefore, it is difficult to provide a detailed prompt emission analysis. According to the 1 s rate data (15-350 keV), the burst shows a double-peaked structure with a duration of ~25 sec. View this GCN Circular online at https://gcn.nasa.gov/circulars/42317. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40391] GRB 251016B: Fermi GBM Final Real-time Localization
by GCN Circulars 17 Oct '25

17 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42316 SUBJECT: GRB 251016B: Fermi GBM Final Real-time Localization DATE: 25/10/17 00:10:30 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 23:59:00 UT on 16 Oct 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251016B (trigger 782351945.722452 / 251016999). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 183.6, Dec = 59.6 (J2000 degrees, equivalent to J2000 12h 14m, 59d 36'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 46.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251016999/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251016999/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251016999/… View this GCN Circular online at https://gcn.nasa.gov/circulars/42316. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40390] GRB 251014D: Swift-BAT refined analysis
by GCN Circulars 16 Oct '25

16 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42315 SUBJECT: GRB 251014D: Swift-BAT refined analysis DATE: 25/10/16 23:04:28 GMT FROM: Rahul Gupta at NASA GSFC <rahul.gupta(a)nasa.gov> D. M. Palmer (LANL), 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), 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 251014D (trigger #1404126) (Klingler, et al., GCN Circ. 42274). The BAT ground-calculated position is RA, Dec = 323.933, -41.873 deg which is RA(J2000) = 21h 35m 43.9s Dec(J2000) = -41d 52' 23.0" with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 49%. The mask-weighted BAT light curve shows a main emission followed by weaker emission. T90 (15-350 keV) is 286.98 +- 70.09 sec (estimated error including systematics). The time-averaged spectrum from T+0.39 to T+310.10 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.74 +- 0.38. The fluence in the 15-150 keV band is 1.0 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+5.18 sec in the 15-150 keV band is 0.5 +- 0.2 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/1404126 View this GCN Circular online at https://gcn.nasa.gov/circulars/42315. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40389] GRB 251016A: BOOTES-6/DPRT optical upper limit
by GCN Circulars 16 Oct '25

16 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42314 SUBJECT: GRB 251016A: BOOTES-6/DPRT optical upper limit DATE: 25/10/16 21:13:12 GMT FROM: I. Perez-Garcia at Institute of Astrophysics of Andalusia <ipg(a)iaa.es> I. Perez-Garcia, E. Fernandez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S.-Y. Wu, S. Guziy and A. J. Castro-Tirado (IAA-CSIC, Granada), P. J. Meintjes and H. J. van Heerden (UFS, South Africa), A. Martin-Carrillo and L. Hanlon (UCD, Ireland), M. Gritsevich (Univ. of Helsinki), M. Jelinek (ASU-CAS), A. Kumar (ARIES) and C. J. Perez del Pulgar (UMA, Malaga), on behalf of a larger collaboration, report: Following the detection of GRB 251016A by Fermi/GBM (Smith et al., GCN 42309) and SVOM/ECLAIRs (Basa et al., GCN 42308), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) responded to this event starting on Oct 16, 17:35 UT (~ 2.6 h after trigger) with 60s images. No new source is detected within the Swift/XRT X-ray afterglow Source 1 position (Evans et al., GCN 42311) up to magnitude 17.14 using Gaia DR3 Gmag magnitude as reference on our first image. Further images were gathered and using ATLAS REFCAT2 as reference (Tonry et al. 2018) we get an upper limit of: | UT mid exposure | Mag limit | Filter | Exp time (sec) | | ------------------- | --------- | ------ | -------------- | | 2025-10-16 18:05:07 | 19.3 | clear | 60x7 | | 2025-10-16 18:37:07 | 17.6 | Z | 60x4 | | 2025-10-16 18:43:02 | 19.1 | g | 60x4 | | 2025-10-16 19:05:30 | 18.7 | r | 60x3 | | 2025-10-16 19:10:38 | 18.3 | i | 60x4 | We thank the staff at Boyden Observatory for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/42314. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40388] GRB 251016A: Glowbug gamma-ray detection of a short burst
by GCN Circulars 16 Oct '25

16 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42313 SUBJECT: GRB 251016A: Glowbug gamma-ray detection of a short burst DATE: 25/10/16 21:06:59 GMT FROM: richard.s.woolf.civ(a)us.navy.mil R. Woolf, C.C. Cheung, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report: The Glowbug gamma-ray telescope [1,2,3], operating on the International Space Station, reports the detection of GRB 251016A, which was also detected by SVOM/ECLAIRs (GCN 42308), Fermi/GBM (GCN 42309), and CALET (Trigger 1444661491). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2025-10-16 14:59:18.560 with a duration of 0.64 s and a total significance of about 76 sigma. The light curve comprises a single peak. The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS. Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS, and operated until 2024 April when it was put in safe storage on orbit. Glowbug was removed from storage and resumed operation on 2025 September 12. [1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959 [2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O [3] Woolf, R.S. et al. 2024, Proc. SPIE, 13151, id. 1315108 Distribution Statement A: Approved for public release. Distribution is unlimited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42313. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40387] GRB 251013C: VLA detection
by GCN Circulars 16 Oct '25

16 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42312 SUBJECT: GRB 251013C: VLA detection DATE: 25/10/16 20:08:06 GMT FROM: collinchristy(a)arizona.edu C. Christy (University of Arizona), T. Laskar (University of Utah), N. Franz (University of Arizona), K. D. Alexander (University of Arizona), E. Berger (Harvard University), R. Chornock (UC Berkeley), H. J. van Eerten (University of Bath), G. Farley (U. Utah), W. Fong (Northwestern University), R. Gill (UNAM), J. Granot (Open University), R. Margutti (UC Berkeley), and P. Schady (University of Bath) report: We observed GRB 251013C (Fermi GBM team, GCN 42221; Rakotondrainibe et al., GCN 42222) with the Karl G. Jansky Very Large Array (VLA) at multiple frequencies beginning on 2025 October 15 at 02:15 UT (1.36 days after the burst). In our preliminary analysis, we detect the radio counterpart (Laskar et al., GCN 42243; Rhodes et al., GCN 42294) at 10 GHz with a flux density of 0.111 +/- 0.012 mJy at the position: RA (J2000) = 23:03:20.56 +/- 0.03” Dec (J2000) = -0:12:37.22 +/- 0.03” This is consistent with the X-ray position (Rakotondrainibe et al., GCN 42222; Evans et al., GCN 42232), optical position (Palmerio et al., GCN 42223; Masi et al., GCN 42228), and radio position (Laskar et al., GCN 42243; Rhodes et al., GCN 42294). Further observations are planned. We thank the VLA staff for scheduling and executing these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/42312. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40386] sb25101602: Swift-XRT counterpart detection
by GCN Circulars 16 Oct '25

16 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42311 SUBJECT: sb25101602: Swift-XRT counterpart detection DATE: 25/10/16 20:00:35 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P.A. Evans (U. Leicester), J.A. Kennea (PSU), E. Ambrosi (INAF-IASFPA) , A.P. Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), R. Brivio (INAF-OAB), D.N. Burrows (PSU), S. Campana (INAF-OAB), M. Capalbi (INAF-OAR), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), M. Ferro (INAF-OAB), A. Melandri (INAF-OAR), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M. Perri (SSDC & INAF-OAR), C. Salvaggio (INAF-OAB), T. Sbarrato (INAF-OAB), B. Sbarufatti (INAF-OAB), M.A. Williams (PSU) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the SVOM/ECLAIRs-detected GRB251016A (sb25101602), collecting 749 s of Photon Counting (PC) mode data between T0+6.6 ks and T0+7.4 ks after the trigger. A likely counterpart has been found. The details of this source are: Source 1 (SWIFT J174512.5-393337): ================================== RA (J2000.0): 266.3024 = 17 45 12.58 Dec (J2000.0): -39.5606 = -39 33 38.2 Error: 4.6 (arcsec, radius, 90% confidence). Detect flag: GOOD Distance: 4.5 arcmin from the SVOM/ECLAIRs position. Mean rate: 0.057 +/- 0.011 ct s^-1 Mean flux: (3.41 +/- 0.64)e-12 erg cm^-2 s^-1 Peak rate: 0.072 +/- 0.019 ct s^-1 Peak flux: (4.4 +/- 1.1)e-12 erg cm^-2 s^-1 ECF: 6.02e-11 erg cm^-2 ct^-1 assuming NH=7.85e+21 cm^-2, gamma=1.55 determined from a spectral fit. XMM UL: 6.5e-13 erg cm^-2 s^-1, (0.3-10 keV) so the source is 3.2-sigma above this 3-sigma upper limit. The source may be fading, at the 1.1-sigma level. There are 2 2MASS objects within the source's 3-sigma error radius. We have detected a total of 9 sources. These have been automatically classified as follows: * 1 likely counterpart * 0 candidate counterparts * 8 uncatalogued X-ray sources * 0 known X-ray sources Uncatalogued X-ray sources -------------------------- Source 2 (SWIFT J174439.5-394550): ================================== RA (J2000.0): 266.1646 = 17 44 39.50 Dec (J2000.0): -39.7642 = -39 45 51.1 Error: 6.1 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 11.4 arcmin from the SVOM/ECLAIRs position. Mean rate: 0.0300 [+0.0096, -0.0079] ct s^-1 Mean flux: (1.29 [+0.41, -0.34])e-12 erg cm^-2 s^-1 Peak rate: 0.0300 [+0.0096, -0.0079] ct s^-1 Peak flux: (1.29 [+0.41, -0.34])e-12 erg cm^-2 s^-1 XMM UL: 7.9e-13 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. There are 5 2MASS objects within the source's 3-sigma error radius. Source 3 (SWIFT J174431.8-393913): ================================== RA (J2000.0): 266.1326 = 17 44 31.82 Dec (J2000.0): -39.6537 = -39 39 13.3 Error: 5.9 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 5.7 arcmin from the SVOM/ECLAIRs position. Mean rate: (-1.0 +/- -1.0)e0 ct s^-1 Mean flux: (-4.3 +/- -4.3)e-11 erg cm^-2 s^-1 Peak rate: 0.0123 [+0.0069, -0.0053] ct s^-1 Peak flux: (5.3 [+2.9, -2.3])e-13 erg cm^-2 s^-1 XMM UL: 1.3e-12 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. There are 5 2MASS objects within the source's 3-sigma error radius. Source 4 (SWIFT J174456.1-392739): ================================== RA (J2000.0): 266.2340 = 17 44 56.16 Dec (J2000.0): -39.4609 = -39 27 39.2 Error: 14.0 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 7.1 arcmin from the SVOM/ECLAIRs position. Mean rate: (-1.0 +/- -1.0)e0 ct s^-1 Mean flux: (-3.5 +/- -3.5)e-9 erg cm^-2 s^-1 Peak rate: (6.3 [+5.6, -4.0])e-3 ct s^-1 Peak flux: (2.2 [+1.9, -1.4])e-11 erg cm^-2 s^-1 ECF: 3.48e-09 erg cm^-2 ct^-1 assuming NH=3.52e+22 cm^-2, gamma=5.05 determined from a spectral fit. XMM UL: 1.0e-12 erg cm^-2 s^-1, (0.3-10 keV) so the source is 1.3-sigma above this 3-sigma upper limit. There is no evidence for fading. There are 34 2MASS objects within the source's 3-sigma error radius. Source 5 (SWIFT J174354.6-392827): ================================== RA (J2000.0): 265.9777 = 17 43 54.65 Dec (J2000.0): -39.4743 = -39 28 27.5 Error: 9.8 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 12.2 arcmin from the SVOM/ECLAIRs position. Mean rate: 0.0128 [+0.0066, -0.0050] ct s^-1 Mean flux: (5.5 [+2.8, -2.1])e-13 erg cm^-2 s^-1 Peak rate: 0.0128 [+0.0066, -0.0050] ct s^-1 Peak flux: (5.5 [+2.8, -2.1])e-13 erg cm^-2 s^-1 XMM UL: 7.2e-13 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. There are 22 2MASS objects within the source's 3-sigma error radius. Source 6 (SWIFT J174500.5-394402): ================================== RA (J2000.0): 266.2523 = 17 45 00.55 Dec (J2000.0): -39.7341 = -39 44 02.8 Error: 11.1 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 9.7 arcmin from the SVOM/ECLAIRs position. Mean rate: 0.0156 [+0.0070, -0.0055] ct s^-1 Mean flux: (6.7 [+3.0, -2.4])e-13 erg cm^-2 s^-1 Peak rate: 0.0156 [+0.0070, -0.0055] ct s^-1 Peak flux: (6.7 [+3.0, -2.4])e-13 erg cm^-2 s^-1 XMM UL: 1.3e-12 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. There are 18 2MASS objects within the source's 3-sigma error radius. Source 7 (SWIFT J174411.2-392428): ================================== RA (J2000.0): 266.0470 = 17 44 11.28 Dec (J2000.0): -39.4079 = -39 24 28.4 Error: 13.9 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 12.5 arcmin from the SVOM/ECLAIRs position. Mean rate: 0.0167 [+0.0073, -0.0057] ct s^-1 Mean flux: (7.2 [+3.2, -2.4])e-13 erg cm^-2 s^-1 Peak rate: 0.0167 [+0.0073, -0.0057] ct s^-1 Peak flux: (7.2 [+3.2, -2.4])e-13 erg cm^-2 s^-1 XMM UL: 1.1e-12 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. A SIMBAD object `OGLE BLG-DSCT-13120' is 43.9" away. There are 33 2MASS objects within the source's 3-sigma error radius. Source 8 (SWIFT J174427.1-393500): ================================== RA (J2000.0): 266.1131 = 17 44 27.14 Dec (J2000.0): -39.5835 = -39 35 00.6 Error: 11.9 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 4.3 arcmin from the SVOM/ECLAIRs position. Mean rate: (-1.0 +/- -1.0)e0 ct s^-1 Mean flux: (-4.3 +/- -4.3)e-11 erg cm^-2 s^-1 Peak rate: (8.7 [+6.1, -4.5])e-3 ct s^-1 Peak flux: (3.7 [+2.6, -1.9])e-13 erg cm^-2 s^-1 XMM UL: 6.6e-13 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. There are 28 2MASS objects within the source's 3-sigma error radius. Source 9 (SWIFT J174502.9-392734): ================================== RA (J2000.0): 266.2622 = 17 45 02.93 Dec (J2000.0): -39.4596 = -39 27 34.6 Error: 8.8 (arcsec, radius, 90% confidence). Detect flag: POOR Distance: 7.5 arcmin from the SVOM/ECLAIRs position. Mean rate: (-1.0 +/- -1.0)e0 ct s^-1 Mean flux: (-4.3 +/- -4.3)e-11 erg cm^-2 s^-1 Peak rate: (8.9 [+6.4, -4.7])e-3 ct s^-1 Peak flux: (3.8 [+2.7, -2.0])e-13 erg cm^-2 s^-1 XMM UL: 7.1e-13 erg cm^-2 s^-1, (0.3-10 keV) so the source is not above this 3-sigma upper limit. There is no evidence for fading. There are 11 2MASS objects within the source's 3-sigma error radius. All fluxes are 0.3-10 keV, observed. 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-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/SVOM/SVOM_FIELD00042. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/42311. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40385] Fermi GRB 251016A: Global MASTER-Net observations report
by GCN Circulars 16 Oct '25

16 Oct '25

TITLE: GCN CIRCULAR NUMBER: 42310 SUBJECT: Fermi GRB 251016A: Global MASTER-Net observations report DATE: 25/10/16 19:00:45 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 251016A ( Fermi GBM team, GCN 42309) errorbox 9753 sec after notice time and 9784 sec after trigger time at 2025-10-16 17:42:24 UT, with upper limit up to 16.8 mag. Observations started at twilight. The observations began at zenith distance = 38 deg. The sun altitude is -11.4 deg. The galactic latitude b = -12 deg., longitude l = 344 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3016116 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 9814 | 2025-10-16 17:42:24 | MASTER-SAAO | (17h 41m 59.48s , -48d 04m 09.1s) | C | 60 | 14.4 | 9814 | 2025-10-16 17:42:24 | MASTER-SAAO | (17h 44m 44.95s , -48d 19m 26.1s) | C | 60 | 16.5 | 9909 | 2025-10-16 17:43:58 | MASTER-SAAO | (17h 39m 01.22s , -50d 11m 14.5s) | C | 60 | 16.8 | 9909 | 2025-10-16 17:43:58 | MASTER-SAAO | (17h 36m 07.40s , -49d 55m 40.2s) | C | 60 | 15.2 | 10004 | 2025-10-16 17:45:33 | MASTER-SAAO | (17h 48m 32.79s , -46d 10m 37.6s) | C | 60 | 14.6 | 10004 | 2025-10-16 17:45:33 | MASTER-SAAO | (17h 51m 12.71s , -46d 25m 54.6s) | C | 60 | 16.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42310. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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