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

[vsnet-grb-info 36807] GRB 250103B: LCOGT Optical Upper Limit
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38805 SUBJECT: GRB 250103B: LCOGT Optical Upper Limit DATE: 25/01/03 19:44:52 GMT FROM: Robert Strausbaugh at Eastern Illinois University <rstrausbaugh(a)eiu.edu> R. Strausbaugh (Eastern Illinois University), A. Cucchiara (NASA) report on behalf of a larger collaboration: We observed the Swift GRB 250103B field (Eyles-Ferris et al., GCN 38796) with the LCOGT 1-meter Sinistro instrument at the South African Astronomical Observatory site, on January 3, from 18:51 to 19:23 UT (corresponding to 4.12 to 4.65 hours after the GRB trigger time) with the Bessel I and R filters. We performed a series of 3x300s exposures in I-band and R-band. We do not detect a source within the XRT error region in either band. The following 5-sigma upper limits are calculated using the USNO-B1.0 catalog as reference: R > 23.0 I > 22.1 These magnitudes are not corrected for galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/38805. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36806] IceCube-250102A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38804 SUBJECT: IceCube-250102A: Upper limits from a search for additional neutrino events in IceCube DATE: 25/01/03 19:16:59 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison <thwaites(a)wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-250102A (https://gcn.nasa.gov/circulars/38781) in a time range of 1000 seconds centered on the alert event time (2025-01-02 13:39:41.920 UTC to 2025-01-02 13:56:21.920 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-250102A. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-250102A ranges from 1.3e-01 to 1.4e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 3e+02 GeV and 1e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2025-01-01 13:48:01.920 UTC to 2025-01-03 13:48:01.920 UTC). In this case, we report a p-value of 1.00, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-250102A is 1.5e-01 GeV cm^-2 in a 2 day time window. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu. [1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021) View this GCN Circular online at https://gcn.nasa.gov/circulars/38804. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36805] Swift GRB 250103B: Global MASTER-Net observations report
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38803 SUBJECT: Swift GRB 250103B: Global MASTER-Net observations report DATE: 25/01/03 18:51:27 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, 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. 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) was pointed to the Swift GRB 250103B ( R. A. J. Eyles-Ferris et al., GCN 38796) errorbox 10372 sec after notice time and 10451 sec after trigger time at 2025-01-03 18:38:29 UT, with upper limit up to 18.0 mag. Observations started at twilight. The observations began at zenith distance = 10 deg. The sun altitude is -9.9 deg. The galactic latitude b = -53 deg., longitude l = 234 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2732251 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 10542 | MASTER-SAAO | C | 180 | 18.0 | 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/38803. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36804] GRB 250103A: SVOM/VT optical counterpart confirmation
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38802 SUBJECT: GRB 250103A: SVOM/VT optical counterpart confirmation DATE: 25/01/03 16:59:13 GMT FROM: Liping Xin at NAOC, SVOM <xlp(a)nao.cas.cn> 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, D. H. Zhao (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), R.-Z. Li, J. X. Cao, D. F. Kong (GXU) and Y. Wang (PMO, CAS) 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: GRB 250103A (Wang et al., GCN 38786) was observed by on-board VT after the automatic slew of the platform. The VT conducted observations in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously. With the X band downlinked data, the optical candidate reported (Li et al., GCN 38795) was detected in VT_B and VT_R band images. Its brightness was rising for 1.0 mag from 500 sec to 2000 sec after the burst and then decays. The magnitude was VT_B=21.8+/0.1 mag and VT_R=20.1+/0.1 mag in AB magnitude, at about 8000 seconds post the trigger. We confirm that this source is the optical counterpart of 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/38802. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36803] EP250101a: Liverpool Telescope optical upper limit
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38801 SUBJECT: EP250101a: Liverpool Telescope optical upper limit DATE: 25/01/03 16:39:44 GMT FROM: A. Bochenek at Liverpool John Moores University <a.m.bochenek(a)2023.ljmu.ac.uk> A. Bochenek and D. A. Perley (LJMU) report: We observed the field of the fast X-ray transient EP250101a (Liang et al., GCN 38778) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 6x200s exposures in the SDSS i’ filter starting at 2025-01-02 22:39:43 UT, approximately 1.7 days after the trigger. Four of the images had to be discarded due to autoguider issues. We do not detect any new sources in the EP/WXT confidence region (Liang et al., GCN 38778). The 3-sigma limiting magnitude on the stacked images is i > 21.6 mag, calculated using the nearby PanSTARRS secondary standards as reference. The photometry was not corrected for extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/38801. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36802] GRB 250103A: Swift ToO observations
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38800 SUBJECT: GRB 250103A: Swift ToO observations DATE: 25/01/03 16:39:21 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the SVOM/ECLAIRs GRB 250103A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021752 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the SVOM/ECLAIRs event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38800. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36801] IceCube-250101A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38799 SUBJECT: IceCube-250101A: Upper limits from a search for additional neutrino events in IceCube DATE: 25/01/03 16:39:06 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison <thwaites(a)wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-250101A (https://gcn.nasa.gov/circulars/38770) in a time range of 1000 seconds centered on the alert event time (2025-01-01 20:56:37.730 UTC to 2025-01-01 21:13:17.730 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-250101A. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-250101A is 1.5e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate energy range between 3e+02 GeV and 2e+05 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2024-12-31 21:04:57.730 UTC to 2025-01-02 21:04:57.730 UTC). In this case, we report a p-value of 1.00, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-250101A is 1.6e-01 GeV cm^-2 in a 2 day time window. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu. [1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021) View this GCN Circular online at https://gcn.nasa.gov/circulars/38799. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36800] GRB 250101a: Liverpool Telescope optical follow-up
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38798 SUBJECT: GRB 250101a: Liverpool Telescope optical follow-up DATE: 25/01/03 16:31:30 GMT FROM: A. Bochenek at Liverpool John Moores University <a.m.bochenek(a)2023.ljmu.ac.uk> A. Bochenek and D. A. Perley (LJMU) report: We observed the field of GRB250101a (Page et. al., GCN 38752) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 6x200s exposures in the SDSS r’ filter starting at 2025-01-02 23:03:59 UT, approximately 1.4 days after the trigger. Three of the images had to be discarded due to autoguider issues. We report a faint detection in the stacked images of r = 22.8 ± 0.2 mag, at a position consistent with the Swift/UVOT position (Page et. al., GCN 38752). The photometry was obtained using nearby PanSTARRS standards and was not corrected for extinction. The object continues to decline after re-brightening (Moskvitin et al., GCN 38765, Escudero-Coca et al., GCN 38769, Leonini et al., GCN 38771), consistent with the observations reported by Ghosh et al., GCN 38779 and Moskvitin et al., GCN 38780. View this GCN Circular online at https://gcn.nasa.gov/circulars/38798. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36799] GRB 250103B: SVOM detection of a long burst
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38797 SUBJECT: GRB 250103B: SVOM detection of a long burst DATE: 25/01/03 16:30:29 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> T. Bouchet, D. Turpin (CEA), S. Guillot (IRAP), H. Goto (CEA), F. Daigne (IAP), L. Zhang (IHEP) report on behalf of the SVOM team: The SVOM/ECLAIRs telescope triggered (sb25010303) at 2025-01-03T15:44:04.223 UTC (Tb) and located the long duration GRB 250103B also detected by Swift (Eyles-Ferris et al. GCN 38796). 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 7 alerts were received. The best detection is obtained by IMT with a signal-to-noise ratio of 10.6 in the 5-8 keV energy band over a time window of 41 s starting at Tb. The localization of the best Alert is RA, Dec = 54.660, -33.769 (J2000). R.A. = 03:38:38.46 Dec = -33:46:09.67 The uncertainty on this position is 7.6 arcminutes at 90% C.L., which includes a systematic uncertainty of 2 arcminutes in quadrature. The light curve shows a main single episode in the GRM data with a preliminary T90 duration of about 25 s below 550 keV. Further analysis will be conducted once the X-band telemetry data of ECLAIRs and GRM are received. SVOM did not slew on this burst. 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. The SVOM point of contact for this burst is: Tristan Bouchet (tristan.bouchet(a)cea.fr) View this GCN Circular online at https://gcn.nasa.gov/circulars/38797. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36798] GRB 250103B: Swift detection of a burst
by GCN Circulars 03 Jan '25

03 Jan '25

TITLE: GCN CIRCULAR NUMBER: 38796 SUBJECT: GRB 250103B: Swift detection of a burst DATE: 25/01/03 15:58:32 GMT FROM: P.A. Evans at U. Leicester <pae9(a)leicester.ac.uk> R. A. J. Eyles-Ferris (U Leicester), S. Dichiara (PSU), P. A. Evans (U Leicester), R. Gupta (NASA GSFC), N. P. M. Kuin (UCL-MSSL), M. J. Moss (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 15:44:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 250103B (trigger=1278865). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 54.651, -33.772 which is RA(J2000) = 03h 38m 36s Dec(J2000) = -33d 46' 18" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 30 sec. The peak count rate was ~600 counts/sec (15-350 keV), at ~3 sec after the trigger. The XRT began observing the field at 15:46:48.8 UT, 151.2 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 54.66403, -33.74965 which is equivalent to: RA(J2000) = 03h 38m 39.37s Dec(J2000) = -33d 44' 58.7" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 89 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (9.99 x 10^19 cm^-2, Willingale et al. 2013), with an excess column of 4.1 (+3.96/-3.24) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 155 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 none of the XRT error circle. 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 0.008. Burst Advocate for this burst is R. A. J. Eyles-Ferris (raje1 AT leicester.ac.uk). 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/) View this GCN Circular online at https://gcn.nasa.gov/circulars/38796. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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