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

[vsnet-grb-info 37648] GRB 250308A: SVOM/GRM observation of a bright short burst
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39632 SUBJECT: GRB 250308A: SVOM/GRM observation of a bright short burst DATE: 25/03/09 12:40:35 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Zheng-Hang Yu, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia (IRAP), Frédéric Piron (LUPM) Report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by GRB 250308A (SVOM trigger reference: sb25030804) at 2025-03-08T18:06:30.1 (T0), which is also detected by CALTE/GBM (TRIGGER ID: 1425492335) and Konus-Wind. 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 1.9 +0.9/-0.8 s in the 15-5000 keV band. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb250308A.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/GRM 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/39632. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37647] IceCube-250309A - IceCube observation of a high-energy neutrino candidate track-like event
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39631 SUBJECT: IceCube-250309A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 25/03/09 11:48:28 GMT FROM: A. Zegarelli at Ruhr University Bochum <azegarelli(a)icecube.wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2025-03-09 at 07:36:04.75 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_GOLD alert stream. The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 0.1759 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/140626_1288692.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2025-03-09 Time: 07:36:04.75 UT RA: 211.07 (+0.31 -0.30 deg 90% PSF containment) J2000 Dec: -10.73 (+0.26 -0.30 deg 90% PSF containment) J2000 The inferred neutrino energy of this alert is ~4 PeV, making it the fourth-highest energy known detection by IceCube over the past decade. The alert coincides with the Fermi GRB250309B (Fermi-GBM trigger 763198715 at 07:38:30.66 on 09 March 2025; https://gcn.gsfc.nasa.gov/other/763198715.fermi) with a time delay of 145.91 seconds relative to the GRB trigger time. The angular distance to the most updated reconstruction released by the GBM team, which has a 1σ statistical error of 1.60 deg, is 0.77 degrees. An alternative algorithm results in a shifted direction (https://gcn.nasa.gov/circulars/39629) with an angular distance from the best fit neutrino direction of 3.18 degrees and has a 1σ statistical error of 1.3 degree and a systematic error of 1 degree. We strongly encourage follow-up observations of the neutrino region of interest and the uncertainty region of GRB250309B. No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event. 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/39631. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37646] IceCube Alert 250309.32: Global MASTER-Net observations report
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39630 SUBJECT: IceCube Alert 250309.32: Global MASTER-Net observations report DATE: 25/03/09 09:39:41 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the IceCube Alert 250309.32 (trigger No 1288692,14h 03m 12.24s , -10d 26m 24.0s, R=0.51) errorbox 9 sec after notice time and 109 sec after trigger time at 2025-03-09 07:37:54 UT, with upper limit up to 21.3 mag. The observations began at zenith distance = 21 deg. The sun altitude is -35.6 deg. The galactic latitude b = 48 deg., longitude l = 331 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2805613 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 120 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 12m 24.48s , -09d 45m 33.8s) | C | 20 | 18.1 | 135 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 12m 24.47s , -09d 45m 33.7s) | C | 50 | 18.7 | Coadd 120 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 03m 05.50s , -10d 07m 35.4s) | C | 20 | 20.1 | 155 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 03m 05.50s , -10d 07m 35.4s) | C | 90 | 21.1 | Coadd 490 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 03m 05.50s , -10d 07m 35.4s) | C | 760 | 21.0 | Coadd 154 | 2025-03-09 07:38:34 | MASTER-OAFA | (14h 12m 24.51s , -09d 45m 31.7s) | C | 10 | 17.5 | 165 | 2025-03-09 07:38:34 | MASTER-OAFA | (14h 03m 05.53s , -10d 07m 33.6s) | C | 30 | 20.4 | 196 | 2025-03-09 07:39:10 | MASTER-OAFA | (14h 12m 24.55s , -09d 45m 29.5s) | C | 20 | 18.1 | 206 | 2025-03-09 07:39:10 | MASTER-OAFA | (14h 03m 05.54s , -10d 07m 32.1s) | C | 40 | 20.6 | 247 | 2025-03-09 07:39:56 | MASTER-OAFA | (14h 12m 24.59s , -09d 45m 27.0s) | C | 30 | 18.6 | 292 | 2025-03-09 07:39:56 | MASTER-OAFA | (14h 12m 24.59s , -09d 45m 27.0s) | C | 120 | 19.6 | Coadd 257 | 2025-03-09 07:39:57 | MASTER-OAFA | (14h 03m 05.56s , -10d 07m 30.4s) | C | 50 | 20.7 | 322 | 2025-03-09 07:39:57 | MASTER-OAFA | (14h 03m 05.56s , -10d 07m 30.5s) | C | 180 | 21.0 | Coadd 308 | 2025-03-09 07:40:52 | MASTER-OAFA | (14h 12m 24.62s , -09d 45m 24.4s) | C | 40 | 18.7 | 318 | 2025-03-09 07:40:53 | MASTER-OAFA | (14h 03m 05.58s , -10d 07m 28.6s) | C | 60 | 20.8 | 379 | 2025-03-09 07:41:58 | MASTER-OAFA | (14h 12m 24.64s , -09d 45m 21.7s) | C | 50 | 18.9 | 389 | 2025-03-09 07:41:59 | MASTER-OAFA | (14h 03m 05.59s , -10d 07m 26.6s) | C | 70 | 20.8 | 466 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 12m 24.68s , -09d 45m 18.7s) | C | 70 | 19.0 | 566 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 12m 24.69s , -09d 45m 18.7s) | C | 270 | 20.2 | Coadd 476 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 03m 05.61s , -10d 07m 24.2s) | C | 90 | 20.9 | 596 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 03m 05.61s , -10d 07m 24.2s) | C | 330 | 21.3 | Coadd 572 | 2025-03-09 07:44:51 | MASTER-OAFA | (14h 12m 24.72s , -09d 45m 15.1s) | C | 90 | 19.3 | 582 | 2025-03-09 07:44:51 | MASTER-OAFA | (14h 03m 05.63s , -10d 07m 21.3s) | C | 110 | 20.9 | 698 | 2025-03-09 07:46:47 | MASTER-OAFA | (14h 12m 24.74s , -09d 45m 11.3s) | C | 110 | 19.5 | 708 | 2025-03-09 07:46:47 | MASTER-OAFA | (14h 03m 05.66s , -10d 07m 17.9s) | C | 130 | 20.8 | 849 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 12m 24.76s , -09d 45m 07.0s) | C | 140 | 19.5 | 1009 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 12m 24.76s , -09d 45m 07.0s) | C | 460 | 20.3 | Coadd 859 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 14.1s) | C | 160 | 20.7 | 1039 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 14.1s) | C | 520 | 20.5 | Coadd 1025 | 2025-03-09 07:51:50 | MASTER-OAFA | (14h 12m 24.78s , -09d 45m 02.4s) | C | 160 | 19.7 | 1036 | 2025-03-09 07:51:50 | MASTER-OAFA | (14h 03m 05.70s , -10d 07m 09.7s) | C | 180 | 20.6 | 1212 | 2025-03-09 07:54:56 | MASTER-OAFA | (14h 12m 24.76s , -09d 44m 57.9s) | C | 160 | 19.6 | 1222 | 2025-03-09 07:54:56 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 05.4s) | C | 180 | 20.6 | 1398 | 2025-03-09 07:58:02 | MASTER-OAFA | (14h 12m 24.74s , -09d 44m 53.3s) | C | 160 | 19.8 | 1558 | 2025-03-09 07:58:02 | MASTER-OAFA | (14h 12m 24.74s , -09d 44m 53.3s) | C | 480 | 20.3 | Coadd 1408 | 2025-03-09 07:58:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 00.9s) | C | 180 | 20.6 | 1588 | 2025-03-09 07:58:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 00.9s) | C | 540 | 20.5 | Coadd 1584 | 2025-03-09 08:01:08 | MASTER-OAFA | (14h 12m 24.74s , -09d 44m 49.1s) | C | 160 | 19.7 | 1594 | 2025-03-09 08:01:08 | MASTER-OAFA | (14h 03m 05.70s , -10d 06m 56.7s) | C | 180 | 20.6 | 1770 | 2025-03-09 08:04:15 | MASTER-OAFA | (14h 12m 24.73s , -09d 44m 44.9s) | C | 160 | 19.6 | 1781 | 2025-03-09 08:04:15 | MASTER-OAFA | (14h 03m 05.73s , -10d 06m 52.4s) | C | 180 | 20.7 | 1957 | 2025-03-09 08:07:21 | MASTER-OAFA | (14h 12m 24.72s , -09d 44m 40.7s) | C | 160 | 19.7 | 2117 | 2025-03-09 08:07:21 | MASTER-OAFA | (14h 12m 24.72s , -09d 44m 40.7s) | C | 480 | 20.3 | Coadd 1967 | 2025-03-09 08:07:22 | MASTER-OAFA | (14h 03m 05.75s , -10d 06m 48.3s) | C | 180 | 20.5 | 2147 | 2025-03-09 08:07:22 | MASTER-OAFA | (14h 03m 05.76s , -10d 06m 48.4s) | C | 540 | 20.5 | Coadd 2143 | 2025-03-09 08:10:27 | MASTER-OAFA | (14h 12m 24.71s , -09d 44m 36.8s) | C | 160 | 19.6 | 2153 | 2025-03-09 08:10:28 | MASTER-OAFA | (14h 03m 05.79s , -10d 06m 44.3s) | C | 180 | 20.6 | 2329 | 2025-03-09 08:13:34 | MASTER-OAFA | (14h 12m 24.71s , -09d 44m 33.2s) | C | 160 | 19.7 | 2340 | 2025-03-09 08:13:34 | MASTER-OAFA | (14h 03m 05.84s , -10d 06m 40.6s) | C | 180 | 20.8 | 2515 | 2025-03-09 08:16:39 | MASTER-OAFA | (14h 12m 24.68s , -09d 44m 29.5s) | C | 160 | 19.7 | 2675 | 2025-03-09 08:16:39 | MASTER-OAFA | (14h 12m 24.68s , -09d 44m 29.5s) | C | 480 | 20.3 | Coadd 2526 | 2025-03-09 08:16:40 | MASTER-OAFA | (14h 03m 05.85s , -10d 06m 36.6s) | C | 180 | 20.6 | 2706 | 2025-03-09 08:16:40 | MASTER-OAFA | (14h 03m 05.85s , -10d 06m 36.6s) | C | 540 | 20.7 | Coadd 2702 | 2025-03-09 08:19:46 | MASTER-OAFA | (14h 12m 24.68s , -09d 44m 25.6s) | C | 160 | 19.6 | 2712 | 2025-03-09 08:19:46 | MASTER-OAFA | (14h 03m 05.90s , -10d 06m 32.8s) | C | 180 | 20.7 | 2888 | 2025-03-09 08:22:52 | MASTER-OAFA | (14h 12m 24.64s , -09d 44m 22.0s) | C | 160 | 19.6 | 2898 | 2025-03-09 08:22:52 | MASTER-OAFA | (14h 03m 05.91s , -10d 06m 28.7s) | C | 180 | 20.7 | 3074 | 2025-03-09 08:25:58 | MASTER-OAFA | (14h 12m 24.59s , -09d 44m 18.7s) | C | 160 | 19.6 | 3234 | 2025-03-09 08:25:58 | MASTER-OAFA | (14h 12m 24.59s , -09d 44m 18.6s) | C | 480 | 20.5 | Coadd 3084 | 2025-03-09 08:25:59 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 25.4s) | C | 180 | 20.8 | 3264 | 2025-03-09 08:25:59 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 25.3s) | C | 540 | 20.6 | Coadd 3260 | 2025-03-09 08:29:05 | MASTER-OAFA | (14h 12m 24.55s , -09d 44m 15.1s) | C | 160 | 19.7 | 3271 | 2025-03-09 08:29:05 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 21.3s) | C | 180 | 20.6 | 3447 | 2025-03-09 08:32:11 | MASTER-OAFA | (14h 12m 24.52s , -09d 44m 11.8s) | C | 160 | 19.6 | 3457 | 2025-03-09 08:32:11 | MASTER-OAFA | (14h 03m 05.91s , -10d 06m 17.9s) | C | 180 | 20.6 | 3633 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 12m 24.48s , -09d 44m 08.4s) | C | 160 | 19.7 | 3793 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 12m 24.48s , -09d 44m 08.5s) | C | 480 | 20.4 | Coadd 3644 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 03m 05.92s , -10d 06m 14.4s) | C | 180 | 20.6 | 3824 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 03m 05.92s , -10d 06m 14.3s) | C | 540 | 20.5 | Coadd 3819 | 2025-03-09 08:38:24 | MASTER-OAFA | (14h 12m 24.44s , -09d 44m 05.3s) | C | 160 | 19.7 | 3830 | 2025-03-09 08:38:24 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 11.1s) | C | 180 | 20.6 | 4006 | 2025-03-09 08:41:30 | MASTER-OAFA | (14h 12m 24.42s , -09d 44m 02.4s) | C | 160 | 19.7 | 4016 | 2025-03-09 08:41:30 | MASTER-OAFA | (14h 03m 05.95s , -10d 06m 07.8s) | C | 180 | 20.6 | 4192 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 12m 24.38s , -09d 43m 59.5s) | C | 160 | 19.7 | 4352 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 12m 24.38s , -09d 43m 59.4s) | C | 480 | 20.4 | Coadd 4202 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 03m 05.96s , -10d 06m 04.4s) | C | 180 | 20.6 | 4382 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 03m 05.96s , -10d 06m 04.4s) | C | 540 | 20.6 | Coadd 4378 | 2025-03-09 08:47:42 | MASTER-OAFA | (14h 12m 24.33s , -09d 43m 56.5s) | C | 160 | 19.6 | 4388 | 2025-03-09 08:47:42 | MASTER-OAFA | (14h 03m 05.98s , -10d 06m 01.1s) | C | 180 | 20.6 | 4564 | 2025-03-09 08:50:48 | MASTER-OAFA | (14h 12m 24.26s , -09d 43m 53.8s) | C | 160 | 19.7 | 4574 | 2025-03-09 08:50:48 | MASTER-OAFA | (14h 03m 06.00s , -10d 05m 58.2s) | C | 180 | 20.6 | 4750 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 12m 24.22s , -09d 43m 51.1s) | C | 160 | 19.8 | 4910 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 12m 24.22s , -09d 43m 51.1s) | C | 480 | 20.4 | Coadd 4760 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 03m 06.02s , -10d 05m 55.4s) | C | 180 | 20.7 | 4940 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 03m 06.02s , -10d 05m 55.4s) | C | 540 | 20.7 | Coadd 4936 | 2025-03-09 08:57:00 | MASTER-OAFA | (14h 12m 24.13s , -09d 43m 48.7s) | C | 160 | 19.6 | 4946 | 2025-03-09 08:57:00 | MASTER-OAFA | (14h 03m 06.02s , -10d 05m 52.7s) | C | 180 | 20.6 | 5122 | 2025-03-09 09:00:06 | MASTER-OAFA | (14h 12m 24.08s , -09d 43m 46.1s) | C | 160 | 19.7 | 5132 | 2025-03-09 09:00:06 | MASTER-OAFA | (14h 03m 06.03s , -10d 05m 50.1s) | C | 180 | 20.6 | 5307 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 12m 24.05s , -09d 43m 43.6s) | C | 160 | 19.7 | 5467 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 12m 24.05s , -09d 43m 43.6s) | C | 480 | 20.3 | Coadd 5318 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 03m 06.04s , -10d 05m 47.4s) | C | 180 | 20.7 | 5498 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 03m 06.04s , -10d 05m 47.4s) | C | 540 | 20.6 | Coadd 5493 | 2025-03-09 09:06:18 | MASTER-OAFA | (14h 12m 24.00s , -09d 43m 41.3s) | C | 160 | 19.6 | 5504 | 2025-03-09 09:06:18 | MASTER-OAFA | (14h 03m 06.04s , -10d 05m 44.8s) | C | 180 | 20.6 | 5680 | 2025-03-09 09:09:24 | MASTER-OAFA | (14h 12m 23.93s , -09d 43m 39.2s) | C | 160 | 19.6 | 5690 | 2025-03-09 09:09:24 | MASTER-OAFA | (14h 03m 06.09s , -10d 05m 42.5s) | C | 180 | 20.6 | 5866 | 2025-03-09 09:12:30 | MASTER-OAFA | (14h 12m 23.88s , -09d 43m 37.0s) | C | 160 | 19.6 | 6026 | 2025-03-09 09:12:30 | MASTER-OAFA | (14h 12m 23.88s , -09d 43m 37.0s) | C | 480 | 20.3 | Coadd 5876 | 2025-03-09 09:12:31 | MASTER-OAFA | (14h 03m 06.10s , -10d 05m 40.2s) | C | 180 | 20.6 | 6056 | 2025-03-09 09:12:31 | MASTER-OAFA | (14h 03m 06.10s , -10d 05m 40.2s) | C | 540 | 20.4 | Coadd 6052 | 2025-03-09 09:15:36 | MASTER-OAFA | (14h 12m 23.83s , -09d 43m 35.0s) | C | 160 | 19.6 | 6062 | 2025-03-09 09:15:36 | MASTER-OAFA | (14h 03m 06.11s , -10d 05m 38.0s) | C | 180 | 20.6 | 6238 | 2025-03-09 09:18:42 | MASTER-OAFA | (14h 12m 23.77s , -09d 43m 33.0s) | C | 160 | 19.6 | 6248 | 2025-03-09 09:18:42 | MASTER-OAFA | (14h 03m 06.11s , -10d 05m 35.8s) | C | 180 | 20.7 | 6424 | 2025-03-09 09:21:48 | MASTER-OAFA | (14h 12m 23.72s , -09d 43m 31.3s) | C | 160 | 19.5 | 6584 | 2025-03-09 09:21:48 | MASTER-OAFA | (14h 12m 23.72s , -09d 43m 31.3s) | C | 480 | 20.3 | Coadd 6434 | 2025-03-09 09:21:49 | MASTER-OAFA | (14h 03m 06.12s , -10d 05m 33.9s) | C | 180 | 20.6 | 6610 | 2025-03-09 09:24:54 | MASTER-OAFA | (14h 12m 23.65s , -09d 43m 29.5s) | C | 160 | 19.5 | 6620 | 2025-03-09 09:24:55 | MASTER-OAFA | (14h 03m 06.14s , -10d 05m 31.9s) | C | 180 | 20.6 | 6796 | 2025-03-09 09:28:00 | MASTER-OAFA | (14h 12m 23.59s , -09d 43m 27.9s) | C | 160 | 19.4 | 6806 | 2025-03-09 09:28:01 | MASTER-OAFA | (14h 03m 06.16s , -10d 05m 30.1s) | C | 180 | 20.5 | 6983 | 2025-03-09 09:31:07 | MASTER-OAFA | (14h 12m 23.52s , -09d 43m 26.7s) | C | 160 | 19.2 | 6993 | 2025-03-09 09:31:07 | MASTER-OAFA | (14h 03m 06.19s , -10d 05m 28.9s) | C | 180 | 20.4 | 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/39630. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37645] GRB 250309B: BALROG localization (Fermi Trigger 763198715 / GRB 250309318)
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39629 SUBJECT: GRB 250309B: BALROG localization (Fermi Trigger 763198715 / GRB 250309318) DATE: 25/03/09 08:04:59 GMT FROM: Jochen Greiner at MPE <jcgrog(a)mpe.mpg.de> T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 763198715 at 07:38:30 on 09 March 2025 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position is: RA(2000.0) = 210.5 deg Decl.(2000.0) = -7.6 deg The 1 sigma statistical error radius is 1.3 deg. We estimate an additional systematic error of 1 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB250309318/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB250309318/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB250309318/json View this GCN Circular online at https://gcn.nasa.gov/circulars/39629. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37644] EP250308a: Global MASTER-Net observations report
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39628 SUBJECT: EP250308a: Global MASTER-Net observations report DATE: 25/03/09 06:09:33 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP250308a ( EP Team et al., GCN 39625) errorbox 194 sec after notice time and 44884 sec after trigger time at 2025-03-09 05:32:01 UT, with upper limit up to 20.4 mag. The observations began at zenith distance = 57 deg. The sun altitude is -52.8 deg. The galactic latitude b = 71 deg., longitude l = 9 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2805476 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 44915 | 2025-03-09 05:32:01 | MASTER-OAFA | (14h 02m 29.31s , +18d 46m 58.8s) | C | 60 | 20.4 | 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/39628. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37643] EP250308a: GSP optical upper limit
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39627 SUBJECT: EP250308a: GSP optical upper limit DATE: 25/03/09 05:36:15 GMT FROM: Wenxiong Li at NAOC <liwenxiong1992(a)gmail.com> W. X. Li, S. J. Xue (NAOC), M. Andrews, J. Farah, D. A. Howell, M. Newsome, E. Padilla Gonzalez, C. McCully, and G. Terreran (Las Cumbres Observatory), on behalf of a larger collaboration, report: Following the detection of the fast X-ray transient EP250308a by the Einstein Probe (trigger ID: 01709132392; Yin et al., GCN 39625), we initiated observations of its location starting on 2025 March 9th at 05:07 UT (~12 hours after the EP/WXT trigger) in the i band. These observations were conducted using the 1-meter telescope at the Las Cumbres Observatory node located at Cerro Tololo Inter-American Observatory in Chile. No new optical source was detected in the co-added images within the EP/FXT error box down to ~21.5 mag. These observations were taken as part of the Global Supernova Project. View this GCN Circular online at https://gcn.nasa.gov/circulars/39627. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37642] EP250308a: FTW optical and NIR upper limits
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39626 SUBJECT: EP250308a: FTW optical and NIR upper limits DATE: 25/03/09 05:35:45 GMT FROM: Brendan O'Connor at Carnegie Mellon University <boconno2(a)andrew.cmu.edu> Malte Busmann (LMU), Brendan O’Connor (Carnegie Mellon U.), Daniel Gruen (LMU) and Antonella Palmese (Carnegie Mellon U.) report: We observed the 90% of EP-WXT trigger 01709132392, corresponding to EP250308a, with the Three Channel Imager (3KK) at the Fraunhofer Telescope at Wendelstein Observatory (FTW) in the r, i and J band simultaneously for 19 x 180 s starting at 2025-03-09T03:27:28 UT (0.43 days after the trigger). We performed difference imaging in the i-band with templates from Legacy Survey and detect no new or changing source. The 3 sigma mean depth of our observations are: r > 24.0 AB mag i > 23.8 AB mag The magnitudes are calibrated against the PS1 catalog and not corrected for Galactic extinction. We thank Michael Schmidt from the Wendelstein Observatory staff for obtaining these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/39626. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37641] EP250308a: Einstein Probe detection of an X-ray transient
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39625 SUBJECT: EP250308a: Einstein Probe detection of an X-ray transient DATE: 25/03/09 05:27:54 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.-H. I. Yin (NJU), Q. Y. Wu (NAO, CAS), J. H. Wu (GZHU), H. W. Pan (NAO, CAS) report on behalf of the Einstein Probe team: We report on the detection of an X-ray transient by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP250308a. The transient triggered EP-WXT (ID: 01709132392) at 2025-03-08T17:03:57 (UTC). The WXT position of the source is R.A. = 210.581 deg, DEC = 18.515 deg (J2000) with an uncertainty of 2.9 arcmin in radius (90% C.L. statistical and systematic). The average WXT 0.5-4 keV spectrum can be fitted with an absorbed power law with a Galactic hydrogen column density of 2.37 x 10^20 cm^-2 and a photon index of 2.36 (-0.59/+0.61). The derived average unabsorbed 0.5-4 keV flux is 3.62 (-0.82/+1.18) x 10^(-10) erg/s/cm^2. The Follow-up X-ray Telescope (FXT) on board EP observed this source autonomously about 165 seconds after the trigger with an exposure time of 5.5 ks. On-ground analysis of the FXT data found an uncatalogued source at R.A. = 210.5875, DEC = 18.4967 (J2000) with an uncertainty of about 10 arcsec (radius, 90% C.L. statistical and systematic), which is consistent positionally with the WXT transient. The average 0.5-10 keV spectrum can be fitted with an absorbed power law with a Galactic hydrogen column density of 2.37 x 10^20 cm^-2 and a photon index of 2.59 (-0.07/+0.08). The derived average unabsorbed 0.5-10 keV flux is 9.71 (-0.42/+0.45) x 10^(-13) erg/s/cm^2. The uncertainties are at the 90% confidence level for the above parameters. No previously known bright X-ray sources are found within the error circle around the transient position. Further follow-up observations are encouraged to identify the nature of this X-ray transient. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/39625. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37640] EP250308a: NOT optical upper limit
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39624 SUBJECT: EP250308a: NOT optical upper limit DATE: 25/03/09 05:18:36 GMT FROM: Zipei Zhu at NAOC <zpzhu(a)nao.cas.cn> Z.P. Zhu, X. Liu, Jie An, S.Q. Jiang, D. Xu (NAOC), S.Y. Fu (HUST, NAOC), D. B. Malesani (DAWN/NBI and Radboud U.), P. Jonker (Radboud U.), A. H. Fuente (NOT) report on behalf of a large collaboration: We observed the field of EP250308a detected by EP/WXT (Trigger ID: 01709132392), using the ALFOSC instruments mounted on the Nordic Optical Telescope (NOT), with 3 x 300 s in the SDSS-r band. Preliminary analysis shows that no new source is detected within the EP/WXT error circle, down to the 5-sigma upper limits of r > ~ 22.7 (AB) at ~ 0.41 day after the EP trigger, calibrated with nearby Pan-STARRS stars and without Galactic extinction correction. View this GCN Circular online at https://gcn.nasa.gov/circulars/39624. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 37639] GRB 250309A: Fermi GBM Final Real-time Localization
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39623 SUBJECT: GRB 250309A: Fermi GBM Final Real-time Localization DATE: 25/03/09 00:53:02 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 SHORT GRB At 00:42:03 UT on 9 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250309A (trigger 763173728.785018 / 250309029). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 46.7, Dec = 58.0 (J2000 degrees, equivalent to J2000 03h 06m, 58d 00'), with a statistical uncertainty of 22.9 degrees. The angle from the Fermi LAT boresight is 22.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250309029/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250309029/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250309029/… View this GCN Circular online at https://gcn.nasa.gov/circulars/39623. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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