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

[vsnet-grb-info 41334] GRB 251226A: GECAM-B detection
by GCN Circulars 27 Dec '25

27 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43244 SUBJECT: GRB 251226A: GECAM-B detection DATE: 25/12/27 17:22:35 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> Chen-Wei Wang, Wen-Jun Tan, Xue-Yuan Zao, Shao-Lin Xiong (IHEP) report on behalf of GECAM team: GECAM-B was triggered in-flight by a long burst GRB 251226A, at 2025-12-26T08:01:02.550 UTC (denoted as T0), which is also detected by SVOM/GRM and HXMT. According to the GECAM-B light curve in about 70-6000 keV, this burst mainly consists of a precursor-like pulse followed by a multi-pulses main emission with a duration (T90) of 35.9 +3.4/-6.0 s. We note that the quiescent time between the precursor-like pulse and the main emission is relatively short. The GECAM-B light curve can be found here: https://www.bursthub.cn//admin/static/gecambgrb251226A.png GECAM-B in-flight localization of this burst is (J2000): Ra: 260.2 deg Dec: 47.0 deg Err: 9.1 deg (1-sigma, statistical only) We note that the localization may be improved since this burst is not detected by Fermi/GBM. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two micro-satellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS). View this GCN Circular online at https://gcn.nasa.gov/circulars/43244. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41333] SVOM GRB251227.07: Global MASTER-Net observations report
by GCN Circulars 27 Dec '25

27 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43243 SUBJECT: SVOM GRB251227.07: Global MASTER-Net observations report DATE: 25/12/27 03:56:36 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-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the SVOM GRB251227.07 (trigger No 1766799801,08h 24m 32.81s , +02d 47m 22.9s, R=1) errorbox 13 sec after notice time and 47 sec after trigger time at 2025-12-27 01:44:08 UT, with upper limit up to 16.9 mag. The observations began at zenith distance = 52 deg. The sun altitude is -31.3 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the SVOM GRB251227.07 errorbox 107 sec after notice time and 141 sec after trigger time at 2025-12-27 01:45:42 UT, with upper limit up to 19.4 mag. The observations began at zenith distance = 77 deg. The sun altitude is -22.1 deg. The galactic latitude b = 22 deg., longitude l = 222 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3086623 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 52 | 2025-12-27 01:44:08 | MASTER-Kislovodsk | (08h 23m 49.79s , +02d 54m 44.7s) | P- | 10 | 15.5 | 52 | 2025-12-27 01:44:08 | MASTER-Kislovodsk | (08h 23m 44.07s , +03d 16m 39.6s) | P| | 10 | 13.5 | 92 | 2025-12-27 01:44:42 | MASTER-Kislovodsk | (08h 24m 08.87s , +02d 54m 43.9s) | P- | 20 | 12.4 | 141 | 2025-12-27 01:45:27 | MASTER-Kislovodsk | (08h 24m 38.91s , +02d 54m 44.1s) | P- | 30 | 12.2 | 156 | 2025-12-27 01:45:42 | MASTER-OAFA | (08h 24m 30.53s , +02d 53m 39.1s) | C | 30 | 14.0 | 197 | 2025-12-27 01:46:18 | MASTER-OAFA | (08h 24m 30.76s , +02d 53m 43.8s) | C | 40 | 14.5 | 244 | 2025-12-27 01:47:05 | MASTER-OAFA | (08h 24m 30.96s , +02d 53m 48.7s) | C | 40 | 15.1 | 295 | 2025-12-27 01:47:51 | MASTER-OAFA | (08h 24m 31.13s , +02d 53m 53.9s) | C | 50 | 15.6 | 336 | 2025-12-27 01:48:26 | MASTER-Kislovodsk | (08h 24m 06.38s , +03d 13m 43.2s) | C | 60 | 16.7 | 336 | 2025-12-27 01:48:26 | MASTER-Kislovodsk | (08h 20m 01.59s , +03d 34m 00.8s) | C | 60 | 16.9 | 361 | 2025-12-27 01:48:47 | MASTER-OAFA | (08h 24m 31.36s , +02d 54m 00.5s) | C | 70 | 16.1 | 443 | 2025-12-27 01:50:03 | MASTER-OAFA | (08h 24m 31.60s , +02d 54m 07.7s) | C | 80 | 16.4 | 539 | 2025-12-27 01:51:29 | MASTER-OAFA | (08h 24m 31.92s , +02d 54m 16.2s) | C | 100 | 16.8 | 655 | 2025-12-27 01:53:15 | MASTER-OAFA | (08h 24m 32.18s , +02d 54m 25.7s) | C | 120 | 17.1 | 791 | 2025-12-27 01:55:21 | MASTER-OAFA | (08h 24m 32.48s , +02d 54m 36.5s) | C | 140 | 17.3 | 953 | 2025-12-27 01:57:48 | MASTER-OAFA | (08h 24m 32.88s , +02d 54m 49.4s) | C | 170 | 17.5 | 1074 | 2025-12-27 02:00:44 | MASTER-OAFA | (08h 24m 33.15s , +02d 54m 58.8s) | C | 60 | 17.7 | 1139 | 2025-12-27 02:01:50 | MASTER-OAFA | (08h 24m 33.27s , +02d 55m 03.5s) | C | 60 | 17.9 | 1205 | 2025-12-27 02:02:55 | MASTER-OAFA | (08h 24m 33.41s , +02d 55m 08.5s) | C | 60 | 17.9 | 1271 | 2025-12-27 02:04:01 | MASTER-OAFA | (08h 24m 33.56s , +02d 55m 13.6s) | C | 60 | 18.0 | 1336 | 2025-12-27 02:05:06 | MASTER-OAFA | (08h 24m 33.67s , +02d 55m 18.3s) | C | 60 | 18.0 | 1401 | 2025-12-27 02:06:12 | MASTER-OAFA | (08h 24m 33.79s , +02d 55m 23.2s) | C | 60 | 18.1 | 1467 | 2025-12-27 02:07:17 | MASTER-OAFA | (08h 24m 33.91s , +02d 55m 28.1s) | C | 60 | 18.1 | 1532 | 2025-12-27 02:08:23 | MASTER-OAFA | (08h 24m 34.04s , +02d 55m 33.0s) | C | 60 | 18.2 | 1598 | 2025-12-27 02:09:28 | MASTER-OAFA | (08h 24m 34.15s , +02d 55m 37.9s) | C | 60 | 18.3 | 1664 | 2025-12-27 02:10:34 | MASTER-OAFA | (08h 24m 34.25s , +02d 55m 42.5s) | C | 60 | 18.4 | 1729 | 2025-12-27 02:11:40 | MASTER-OAFA | (08h 24m 34.40s , +02d 55m 47.4s) | C | 60 | 18.4 | 1795 | 2025-12-27 02:12:45 | MASTER-OAFA | (08h 24m 34.55s , +02d 55m 52.2s) | C | 60 | 18.4 | 1861 | 2025-12-27 02:13:51 | MASTER-OAFA | (08h 24m 34.63s , +02d 55m 56.7s) | C | 60 | 18.4 | 1926 | 2025-12-27 02:14:57 | MASTER-OAFA | (08h 24m 34.75s , +02d 56m 01.5s) | C | 60 | 18.5 | 1991 | 2025-12-27 02:16:02 | MASTER-OAFA | (08h 24m 34.86s , +02d 56m 05.9s) | C | 60 | 18.4 | 2061 | 2025-12-27 02:17:12 | MASTER-OAFA | (08h 24m 34.97s , +02d 56m 10.6s) | C | 60 | 18.5 | 2126 | 2025-12-27 02:18:17 | MASTER-OAFA | (08h 24m 35.09s , +02d 56m 15.1s) | C | 60 | 18.4 | 2192 | 2025-12-27 02:19:23 | MASTER-OAFA | (08h 24m 35.17s , +02d 56m 19.3s) | C | 60 | 18.6 | 2259 | 2025-12-27 02:20:29 | MASTER-OAFA | (08h 24m 35.30s , +02d 56m 24.0s) | C | 60 | 18.6 | 2324 | 2025-12-27 02:21:34 | MASTER-OAFA | (08h 24m 35.41s , +02d 56m 28.3s) | C | 60 | 18.6 | 2390 | 2025-12-27 02:22:40 | MASTER-OAFA | (08h 24m 35.47s , +02d 56m 32.6s) | C | 60 | 18.6 | 2456 | 2025-12-27 02:23:46 | MASTER-OAFA | (08h 24m 35.57s , +02d 56m 36.9s) | C | 60 | 18.7 | 2521 | 2025-12-27 02:24:52 | MASTER-OAFA | (08h 24m 35.68s , +02d 56m 41.3s) | C | 60 | 18.6 | 2586 | 2025-12-27 02:25:57 | MASTER-OAFA | (08h 24m 35.77s , +02d 56m 45.7s) | C | 60 | 18.6 | 2653 | 2025-12-27 02:27:03 | MASTER-OAFA | (08h 24m 35.87s , +02d 56m 49.9s) | C | 60 | 18.7 | 2718 | 2025-12-27 02:28:09 | MASTER-OAFA | (08h 24m 35.96s , +02d 56m 54.2s) | C | 60 | 18.7 | 2784 | 2025-12-27 02:29:14 | MASTER-OAFA | (08h 24m 36.07s , +02d 56m 58.5s) | C | 60 | 18.7 | 2850 | 2025-12-27 02:30:20 | MASTER-OAFA | (08h 24m 36.16s , +02d 57m 02.6s) | C | 60 | 18.7 | 2916 | 2025-12-27 02:31:26 | MASTER-OAFA | (08h 24m 36.25s , +02d 57m 06.7s) | C | 60 | 18.7 | 2981 | 2025-12-27 02:32:31 | MASTER-OAFA | (08h 24m 36.33s , +02d 57m 10.7s) | C | 60 | 18.8 | 3048 | 2025-12-27 02:33:38 | MASTER-OAFA | (08h 24m 36.42s , +02d 57m 14.8s) | C | 60 | 18.8 | 3113 | 2025-12-27 02:34:43 | MASTER-OAFA | (08h 24m 36.49s , +02d 57m 18.6s) | C | 60 | 18.9 | 3178 | 2025-12-27 02:35:49 | MASTER-OAFA | (08h 24m 36.57s , +02d 57m 22.4s) | C | 60 | 18.9 | 3244 | 2025-12-27 02:36:55 | MASTER-OAFA | (08h 24m 36.65s , +02d 57m 26.4s) | C | 60 | 18.8 | 3310 | 2025-12-27 02:38:01 | MASTER-OAFA | (08h 24m 36.72s , +02d 57m 30.5s) | C | 60 | 18.9 | 3376 | 2025-12-27 02:39:06 | MASTER-OAFA | (08h 24m 36.78s , +02d 57m 34.2s) | C | 60 | 18.9 | 3442 | 2025-12-27 02:40:13 | MASTER-OAFA | (08h 24m 36.85s , +02d 57m 38.0s) | C | 60 | 18.8 | 3507 | 2025-12-27 02:41:18 | MASTER-OAFA | (08h 24m 36.91s , +02d 57m 41.8s) | C | 60 | 18.9 | 3572 | 2025-12-27 02:42:23 | MASTER-OAFA | (08h 24m 36.98s , +02d 57m 45.5s) | C | 60 | 18.9 | 3638 | 2025-12-27 02:43:29 | MASTER-OAFA | (08h 24m 37.06s , +02d 57m 49.3s) | C | 60 | 18.9 | 3704 | 2025-12-27 02:44:34 | MASTER-OAFA | (08h 24m 37.10s , +02d 57m 53.0s) | C | 60 | 18.9 | 3769 | 2025-12-27 02:45:40 | MASTER-OAFA | (08h 24m 37.15s , +02d 57m 56.6s) | C | 60 | 18.9 | 3838 | 2025-12-27 02:46:49 | MASTER-OAFA | (08h 24m 37.22s , +02d 58m 00.5s) | C | 60 | 19.0 | 3904 | 2025-12-27 02:47:54 | MASTER-OAFA | (08h 24m 37.27s , +02d 58m 04.1s) | C | 60 | 18.9 | 3969 | 2025-12-27 02:49:00 | MASTER-OAFA | (08h 24m 37.34s , +02d 58m 07.8s) | C | 60 | 18.9 | 4035 | 2025-12-27 02:50:05 | MASTER-OAFA | (08h 24m 37.39s , +02d 58m 11.4s) | C | 60 | 18.9 | 4100 | 2025-12-27 02:51:11 | MASTER-OAFA | (08h 24m 37.44s , +02d 58m 14.8s) | C | 60 | 19.0 | 4166 | 2025-12-27 02:52:16 | MASTER-OAFA | (08h 24m 37.50s , +02d 58m 18.2s) | C | 60 | 19.0 | 4232 | 2025-12-27 02:53:22 | MASTER-OAFA | (08h 24m 37.55s , +02d 58m 21.4s) | C | 60 | 19.0 | 4297 | 2025-12-27 02:54:28 | MASTER-OAFA | (08h 24m 37.58s , +02d 58m 24.7s) | C | 60 | 19.0 | 4363 | 2025-12-27 02:55:33 | MASTER-OAFA | (08h 24m 37.62s , +02d 58m 27.9s) | C | 60 | 19.1 | 4428 | 2025-12-27 02:56:39 | MASTER-OAFA | (08h 24m 37.67s , +02d 58m 31.2s) | C | 60 | 19.1 | 4494 | 2025-12-27 02:57:44 | MASTER-OAFA | (08h 24m 37.71s , +02d 58m 34.4s) | C | 60 | 19.0 | 4559 | 2025-12-27 02:58:50 | MASTER-OAFA | (08h 24m 37.75s , +02d 58m 37.5s) | C | 60 | 19.1 | 4626 | 2025-12-27 02:59:57 | MASTER-OAFA | (08h 24m 37.78s , +02d 58m 40.7s) | C | 60 | 19.0 | 4692 | 2025-12-27 03:01:02 | MASTER-OAFA | (08h 24m 37.82s , +02d 58m 43.9s) | C | 60 | 19.1 | 4757 | 2025-12-27 03:02:08 | MASTER-OAFA | (08h 24m 37.84s , +02d 58m 47.0s) | C | 60 | 19.1 | 4823 | 2025-12-27 03:03:14 | MASTER-OAFA | (08h 24m 37.87s , +02d 58m 49.9s) | C | 60 | 19.1 | 4888 | 2025-12-27 03:04:19 | MASTER-OAFA | (08h 24m 37.91s , +02d 58m 52.8s) | C | 60 | 19.1 | 4954 | 2025-12-27 03:05:24 | MASTER-OAFA | (08h 24m 37.93s , +02d 58m 55.8s) | C | 60 | 19.1 | 5020 | 2025-12-27 03:06:30 | MASTER-OAFA | (08h 24m 37.96s , +02d 58m 58.7s) | C | 60 | 19.1 | 5085 | 2025-12-27 03:07:36 | MASTER-OAFA | (08h 24m 38.00s , +02d 59m 01.7s) | C | 60 | 19.1 | 5151 | 2025-12-27 03:08:41 | MASTER-OAFA | (08h 24m 38.00s , +02d 59m 04.3s) | C | 60 | 19.1 | 5217 | 2025-12-27 03:09:48 | MASTER-OAFA | (08h 24m 38.01s , +02d 59m 07.0s) | C | 60 | 19.1 | 5283 | 2025-12-27 03:10:53 | MASTER-OAFA | (08h 24m 38.04s , +02d 59m 09.9s) | C | 60 | 19.2 | 5348 | 2025-12-27 03:11:59 | MASTER-OAFA | (08h 24m 38.07s , +02d 59m 12.4s) | C | 60 | 19.1 | 5415 | 2025-12-27 03:13:05 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 15.0s) | C | 60 | 19.2 | 5480 | 2025-12-27 03:14:11 | MASTER-OAFA | (08h 24m 38.10s , +02d 59m 17.7s) | C | 60 | 19.1 | 5546 | 2025-12-27 03:15:16 | MASTER-OAFA | (08h 24m 38.10s , +02d 59m 20.4s) | C | 60 | 19.1 | 5613 | 2025-12-27 03:16:24 | MASTER-OAFA | (08h 24m 38.08s , +02d 59m 22.7s) | C | 60 | 19.2 | 5679 | 2025-12-27 03:17:29 | MASTER-OAFA | (08h 24m 38.08s , +02d 59m 25.1s) | C | 60 | 19.2 | 5744 | 2025-12-27 03:18:34 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 27.5s) | C | 60 | 19.2 | 5810 | 2025-12-27 03:19:40 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 29.9s) | C | 60 | 19.2 | 5876 | 2025-12-27 03:20:46 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 32.1s) | C | 60 | 19.2 | 5941 | 2025-12-27 03:21:52 | MASTER-OAFA | (08h 24m 38.07s , +02d 59m 34.4s) | C | 60 | 19.3 | 6007 | 2025-12-27 03:22:58 | MASTER-OAFA | (08h 24m 38.05s , +02d 59m 36.7s) | C | 60 | 19.3 | 6073 | 2025-12-27 03:24:04 | MASTER-OAFA | (08h 24m 38.03s , +02d 59m 39.0s) | C | 60 | 19.2 | 6139 | 2025-12-27 03:25:09 | MASTER-OAFA | (08h 24m 38.01s , +02d 59m 41.2s) | C | 60 | 19.3 | 6205 | 2025-12-27 03:26:15 | MASTER-OAFA | (08h 24m 37.99s , +02d 59m 43.3s) | C | 60 | 19.3 | 6270 | 2025-12-27 03:27:20 | MASTER-OAFA | (08h 24m 37.98s , +02d 59m 45.5s) | C | 60 | 19.3 | 6335 | 2025-12-27 03:28:26 | MASTER-OAFA | (08h 24m 37.94s , +02d 59m 47.5s) | C | 60 | 19.3 | 6401 | 2025-12-27 03:29:31 | MASTER-OAFA | (08h 24m 37.94s , +02d 59m 49.7s) | C | 60 | 19.3 | 6466 | 2025-12-27 03:30:36 | MASTER-OAFA | (08h 24m 37.93s , +02d 59m 51.8s) | C | 60 | 19.3 | 6531 | 2025-12-27 03:31:42 | MASTER-OAFA | (08h 24m 37.90s , +02d 59m 53.7s) | C | 60 | 19.3 | 6597 | 2025-12-27 03:32:48 | MASTER-OAFA | (08h 24m 37.86s , +02d 59m 55.7s) | C | 60 | 19.3 | 6663 | 2025-12-27 03:33:53 | MASTER-OAFA | (08h 24m 37.82s , +02d 59m 57.5s) | C | 60 | 19.3 | 6728 | 2025-12-27 03:34:59 | MASTER-OAFA | (08h 24m 37.78s , +02d 59m 59.3s) | C | 60 | 19.3 | 6794 | 2025-12-27 03:36:05 | MASTER-OAFA | (08h 24m 37.74s , +03d 00m 01.2s) | C | 60 | 19.3 | 6859 | 2025-12-27 03:37:10 | MASTER-OAFA | (08h 24m 37.70s , +03d 00m 03.1s) | C | 60 | 19.3 | 6925 | 2025-12-27 03:38:15 | MASTER-OAFA | (08h 24m 37.65s , +03d 00m 04.7s) | C | 60 | 19.4 | 6991 | 2025-12-27 03:39:21 | MASTER-OAFA | (08h 24m 37.61s , +03d 00m 06.5s) | C | 60 | 19.4 | 7056 | 2025-12-27 03:40:27 | MASTER-OAFA | (08h 24m 37.56s , +03d 00m 07.9s) | C | 60 | 19.4 | 7122 | 2025-12-27 03:41:33 | MASTER-OAFA | (08h 24m 37.53s , +03d 00m 09.5s) | C | 60 | 19.3 | 7188 | 2025-12-27 03:42:39 | MASTER-OAFA | (08h 24m 37.47s , +03d 00m 10.9s) | C | 60 | 19.3 | 7254 | 2025-12-27 03:43:44 | MASTER-OAFA | (08h 24m 37.42s , +03d 00m 12.3s) | C | 60 | 19.3 | 7320 | 2025-12-27 03:44:50 | MASTER-OAFA | (08h 24m 37.37s , +03d 00m 13.7s) | C | 60 | 19.3 | 7442 | 2025-12-27 03:46:53 | MASTER-OAFA | (08h 24m 37.49s , +03d 02m 16.4s) | C | 60 | 18.5 | 7508 | 2025-12-27 03:47:58 | MASTER-OAFA | (08h 24m 37.46s , +03d 02m 17.6s) | C | 60 | 19.4 | 7573 | 2025-12-27 03:49:04 | MASTER-OAFA | (08h 24m 37.40s , +03d 02m 18.7s) | C | 60 | 19.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/43243. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41332] SVOM GRB251227.07: Global MASTER-Net observations report
by GCN Circulars 27 Dec '25

27 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43243 SUBJECT: SVOM GRB251227.07: Global MASTER-Net observations report DATE: 25/12/27 03:56:36 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-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the SVOM GRB251227.07 (trigger No 1766799801,08h 24m 32.81s , +02d 47m 22.9s, R=1) errorbox 13 sec after notice time and 47 sec after trigger time at 2025-12-27 01:44:08 UT, with upper limit up to 16.9 mag. The observations began at zenith distance = 52 deg. The sun altitude is -31.3 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the SVOM GRB251227.07 errorbox 107 sec after notice time and 141 sec after trigger time at 2025-12-27 01:45:42 UT, with upper limit up to 19.4 mag. The observations began at zenith distance = 77 deg. The sun altitude is -22.1 deg. The galactic latitude b = 22 deg., longitude l = 222 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3086623 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 52 | 2025-12-27 01:44:08 | MASTER-Kislovodsk | (08h 23m 49.79s , +02d 54m 44.7s) | P- | 10 | 15.5 | 52 | 2025-12-27 01:44:08 | MASTER-Kislovodsk | (08h 23m 44.07s , +03d 16m 39.6s) | P| | 10 | 13.5 | 92 | 2025-12-27 01:44:42 | MASTER-Kislovodsk | (08h 24m 08.87s , +02d 54m 43.9s) | P- | 20 | 12.4 | 141 | 2025-12-27 01:45:27 | MASTER-Kislovodsk | (08h 24m 38.91s , +02d 54m 44.1s) | P- | 30 | 12.2 | 156 | 2025-12-27 01:45:42 | MASTER-OAFA | (08h 24m 30.53s , +02d 53m 39.1s) | C | 30 | 14.0 | 197 | 2025-12-27 01:46:18 | MASTER-OAFA | (08h 24m 30.76s , +02d 53m 43.8s) | C | 40 | 14.5 | 244 | 2025-12-27 01:47:05 | MASTER-OAFA | (08h 24m 30.96s , +02d 53m 48.7s) | C | 40 | 15.1 | 295 | 2025-12-27 01:47:51 | MASTER-OAFA | (08h 24m 31.13s , +02d 53m 53.9s) | C | 50 | 15.6 | 336 | 2025-12-27 01:48:26 | MASTER-Kislovodsk | (08h 24m 06.38s , +03d 13m 43.2s) | C | 60 | 16.7 | 336 | 2025-12-27 01:48:26 | MASTER-Kislovodsk | (08h 20m 01.59s , +03d 34m 00.8s) | C | 60 | 16.9 | 361 | 2025-12-27 01:48:47 | MASTER-OAFA | (08h 24m 31.36s , +02d 54m 00.5s) | C | 70 | 16.1 | 443 | 2025-12-27 01:50:03 | MASTER-OAFA | (08h 24m 31.60s , +02d 54m 07.7s) | C | 80 | 16.4 | 539 | 2025-12-27 01:51:29 | MASTER-OAFA | (08h 24m 31.92s , +02d 54m 16.2s) | C | 100 | 16.8 | 655 | 2025-12-27 01:53:15 | MASTER-OAFA | (08h 24m 32.18s , +02d 54m 25.7s) | C | 120 | 17.1 | 791 | 2025-12-27 01:55:21 | MASTER-OAFA | (08h 24m 32.48s , +02d 54m 36.5s) | C | 140 | 17.3 | 953 | 2025-12-27 01:57:48 | MASTER-OAFA | (08h 24m 32.88s , +02d 54m 49.4s) | C | 170 | 17.5 | 1074 | 2025-12-27 02:00:44 | MASTER-OAFA | (08h 24m 33.15s , +02d 54m 58.8s) | C | 60 | 17.7 | 1139 | 2025-12-27 02:01:50 | MASTER-OAFA | (08h 24m 33.27s , +02d 55m 03.5s) | C | 60 | 17.9 | 1205 | 2025-12-27 02:02:55 | MASTER-OAFA | (08h 24m 33.41s , +02d 55m 08.5s) | C | 60 | 17.9 | 1271 | 2025-12-27 02:04:01 | MASTER-OAFA | (08h 24m 33.56s , +02d 55m 13.6s) | C | 60 | 18.0 | 1336 | 2025-12-27 02:05:06 | MASTER-OAFA | (08h 24m 33.67s , +02d 55m 18.3s) | C | 60 | 18.0 | 1401 | 2025-12-27 02:06:12 | MASTER-OAFA | (08h 24m 33.79s , +02d 55m 23.2s) | C | 60 | 18.1 | 1467 | 2025-12-27 02:07:17 | MASTER-OAFA | (08h 24m 33.91s , +02d 55m 28.1s) | C | 60 | 18.1 | 1532 | 2025-12-27 02:08:23 | MASTER-OAFA | (08h 24m 34.04s , +02d 55m 33.0s) | C | 60 | 18.2 | 1598 | 2025-12-27 02:09:28 | MASTER-OAFA | (08h 24m 34.15s , +02d 55m 37.9s) | C | 60 | 18.3 | 1664 | 2025-12-27 02:10:34 | MASTER-OAFA | (08h 24m 34.25s , +02d 55m 42.5s) | C | 60 | 18.4 | 1729 | 2025-12-27 02:11:40 | MASTER-OAFA | (08h 24m 34.40s , +02d 55m 47.4s) | C | 60 | 18.4 | 1795 | 2025-12-27 02:12:45 | MASTER-OAFA | (08h 24m 34.55s , +02d 55m 52.2s) | C | 60 | 18.4 | 1861 | 2025-12-27 02:13:51 | MASTER-OAFA | (08h 24m 34.63s , +02d 55m 56.7s) | C | 60 | 18.4 | 1926 | 2025-12-27 02:14:57 | MASTER-OAFA | (08h 24m 34.75s , +02d 56m 01.5s) | C | 60 | 18.5 | 1991 | 2025-12-27 02:16:02 | MASTER-OAFA | (08h 24m 34.86s , +02d 56m 05.9s) | C | 60 | 18.4 | 2061 | 2025-12-27 02:17:12 | MASTER-OAFA | (08h 24m 34.97s , +02d 56m 10.6s) | C | 60 | 18.5 | 2126 | 2025-12-27 02:18:17 | MASTER-OAFA | (08h 24m 35.09s , +02d 56m 15.1s) | C | 60 | 18.4 | 2192 | 2025-12-27 02:19:23 | MASTER-OAFA | (08h 24m 35.17s , +02d 56m 19.3s) | C | 60 | 18.6 | 2259 | 2025-12-27 02:20:29 | MASTER-OAFA | (08h 24m 35.30s , +02d 56m 24.0s) | C | 60 | 18.6 | 2324 | 2025-12-27 02:21:34 | MASTER-OAFA | (08h 24m 35.41s , +02d 56m 28.3s) | C | 60 | 18.6 | 2390 | 2025-12-27 02:22:40 | MASTER-OAFA | (08h 24m 35.47s , +02d 56m 32.6s) | C | 60 | 18.6 | 2456 | 2025-12-27 02:23:46 | MASTER-OAFA | (08h 24m 35.57s , +02d 56m 36.9s) | C | 60 | 18.7 | 2521 | 2025-12-27 02:24:52 | MASTER-OAFA | (08h 24m 35.68s , +02d 56m 41.3s) | C | 60 | 18.6 | 2586 | 2025-12-27 02:25:57 | MASTER-OAFA | (08h 24m 35.77s , +02d 56m 45.7s) | C | 60 | 18.6 | 2653 | 2025-12-27 02:27:03 | MASTER-OAFA | (08h 24m 35.87s , +02d 56m 49.9s) | C | 60 | 18.7 | 2718 | 2025-12-27 02:28:09 | MASTER-OAFA | (08h 24m 35.96s , +02d 56m 54.2s) | C | 60 | 18.7 | 2784 | 2025-12-27 02:29:14 | MASTER-OAFA | (08h 24m 36.07s , +02d 56m 58.5s) | C | 60 | 18.7 | 2850 | 2025-12-27 02:30:20 | MASTER-OAFA | (08h 24m 36.16s , +02d 57m 02.6s) | C | 60 | 18.7 | 2916 | 2025-12-27 02:31:26 | MASTER-OAFA | (08h 24m 36.25s , +02d 57m 06.7s) | C | 60 | 18.7 | 2981 | 2025-12-27 02:32:31 | MASTER-OAFA | (08h 24m 36.33s , +02d 57m 10.7s) | C | 60 | 18.8 | 3048 | 2025-12-27 02:33:38 | MASTER-OAFA | (08h 24m 36.42s , +02d 57m 14.8s) | C | 60 | 18.8 | 3113 | 2025-12-27 02:34:43 | MASTER-OAFA | (08h 24m 36.49s , +02d 57m 18.6s) | C | 60 | 18.9 | 3178 | 2025-12-27 02:35:49 | MASTER-OAFA | (08h 24m 36.57s , +02d 57m 22.4s) | C | 60 | 18.9 | 3244 | 2025-12-27 02:36:55 | MASTER-OAFA | (08h 24m 36.65s , +02d 57m 26.4s) | C | 60 | 18.8 | 3310 | 2025-12-27 02:38:01 | MASTER-OAFA | (08h 24m 36.72s , +02d 57m 30.5s) | C | 60 | 18.9 | 3376 | 2025-12-27 02:39:06 | MASTER-OAFA | (08h 24m 36.78s , +02d 57m 34.2s) | C | 60 | 18.9 | 3442 | 2025-12-27 02:40:13 | MASTER-OAFA | (08h 24m 36.85s , +02d 57m 38.0s) | C | 60 | 18.8 | 3507 | 2025-12-27 02:41:18 | MASTER-OAFA | (08h 24m 36.91s , +02d 57m 41.8s) | C | 60 | 18.9 | 3572 | 2025-12-27 02:42:23 | MASTER-OAFA | (08h 24m 36.98s , +02d 57m 45.5s) | C | 60 | 18.9 | 3638 | 2025-12-27 02:43:29 | MASTER-OAFA | (08h 24m 37.06s , +02d 57m 49.3s) | C | 60 | 18.9 | 3704 | 2025-12-27 02:44:34 | MASTER-OAFA | (08h 24m 37.10s , +02d 57m 53.0s) | C | 60 | 18.9 | 3769 | 2025-12-27 02:45:40 | MASTER-OAFA | (08h 24m 37.15s , +02d 57m 56.6s) | C | 60 | 18.9 | 3838 | 2025-12-27 02:46:49 | MASTER-OAFA | (08h 24m 37.22s , +02d 58m 00.5s) | C | 60 | 19.0 | 3904 | 2025-12-27 02:47:54 | MASTER-OAFA | (08h 24m 37.27s , +02d 58m 04.1s) | C | 60 | 18.9 | 3969 | 2025-12-27 02:49:00 | MASTER-OAFA | (08h 24m 37.34s , +02d 58m 07.8s) | C | 60 | 18.9 | 4035 | 2025-12-27 02:50:05 | MASTER-OAFA | (08h 24m 37.39s , +02d 58m 11.4s) | C | 60 | 18.9 | 4100 | 2025-12-27 02:51:11 | MASTER-OAFA | (08h 24m 37.44s , +02d 58m 14.8s) | C | 60 | 19.0 | 4166 | 2025-12-27 02:52:16 | MASTER-OAFA | (08h 24m 37.50s , +02d 58m 18.2s) | C | 60 | 19.0 | 4232 | 2025-12-27 02:53:22 | MASTER-OAFA | (08h 24m 37.55s , +02d 58m 21.4s) | C | 60 | 19.0 | 4297 | 2025-12-27 02:54:28 | MASTER-OAFA | (08h 24m 37.58s , +02d 58m 24.7s) | C | 60 | 19.0 | 4363 | 2025-12-27 02:55:33 | MASTER-OAFA | (08h 24m 37.62s , +02d 58m 27.9s) | C | 60 | 19.1 | 4428 | 2025-12-27 02:56:39 | MASTER-OAFA | (08h 24m 37.67s , +02d 58m 31.2s) | C | 60 | 19.1 | 4494 | 2025-12-27 02:57:44 | MASTER-OAFA | (08h 24m 37.71s , +02d 58m 34.4s) | C | 60 | 19.0 | 4559 | 2025-12-27 02:58:50 | MASTER-OAFA | (08h 24m 37.75s , +02d 58m 37.5s) | C | 60 | 19.1 | 4626 | 2025-12-27 02:59:57 | MASTER-OAFA | (08h 24m 37.78s , +02d 58m 40.7s) | C | 60 | 19.0 | 4692 | 2025-12-27 03:01:02 | MASTER-OAFA | (08h 24m 37.82s , +02d 58m 43.9s) | C | 60 | 19.1 | 4757 | 2025-12-27 03:02:08 | MASTER-OAFA | (08h 24m 37.84s , +02d 58m 47.0s) | C | 60 | 19.1 | 4823 | 2025-12-27 03:03:14 | MASTER-OAFA | (08h 24m 37.87s , +02d 58m 49.9s) | C | 60 | 19.1 | 4888 | 2025-12-27 03:04:19 | MASTER-OAFA | (08h 24m 37.91s , +02d 58m 52.8s) | C | 60 | 19.1 | 4954 | 2025-12-27 03:05:24 | MASTER-OAFA | (08h 24m 37.93s , +02d 58m 55.8s) | C | 60 | 19.1 | 5020 | 2025-12-27 03:06:30 | MASTER-OAFA | (08h 24m 37.96s , +02d 58m 58.7s) | C | 60 | 19.1 | 5085 | 2025-12-27 03:07:36 | MASTER-OAFA | (08h 24m 38.00s , +02d 59m 01.7s) | C | 60 | 19.1 | 5151 | 2025-12-27 03:08:41 | MASTER-OAFA | (08h 24m 38.00s , +02d 59m 04.3s) | C | 60 | 19.1 | 5217 | 2025-12-27 03:09:48 | MASTER-OAFA | (08h 24m 38.01s , +02d 59m 07.0s) | C | 60 | 19.1 | 5283 | 2025-12-27 03:10:53 | MASTER-OAFA | (08h 24m 38.04s , +02d 59m 09.9s) | C | 60 | 19.2 | 5348 | 2025-12-27 03:11:59 | MASTER-OAFA | (08h 24m 38.07s , +02d 59m 12.4s) | C | 60 | 19.1 | 5415 | 2025-12-27 03:13:05 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 15.0s) | C | 60 | 19.2 | 5480 | 2025-12-27 03:14:11 | MASTER-OAFA | (08h 24m 38.10s , +02d 59m 17.7s) | C | 60 | 19.1 | 5546 | 2025-12-27 03:15:16 | MASTER-OAFA | (08h 24m 38.10s , +02d 59m 20.4s) | C | 60 | 19.1 | 5613 | 2025-12-27 03:16:24 | MASTER-OAFA | (08h 24m 38.08s , +02d 59m 22.7s) | C | 60 | 19.2 | 5679 | 2025-12-27 03:17:29 | MASTER-OAFA | (08h 24m 38.08s , +02d 59m 25.1s) | C | 60 | 19.2 | 5744 | 2025-12-27 03:18:34 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 27.5s) | C | 60 | 19.2 | 5810 | 2025-12-27 03:19:40 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 29.9s) | C | 60 | 19.2 | 5876 | 2025-12-27 03:20:46 | MASTER-OAFA | (08h 24m 38.09s , +02d 59m 32.1s) | C | 60 | 19.2 | 5941 | 2025-12-27 03:21:52 | MASTER-OAFA | (08h 24m 38.07s , +02d 59m 34.4s) | C | 60 | 19.3 | 6007 | 2025-12-27 03:22:58 | MASTER-OAFA | (08h 24m 38.05s , +02d 59m 36.7s) | C | 60 | 19.3 | 6073 | 2025-12-27 03:24:04 | MASTER-OAFA | (08h 24m 38.03s , +02d 59m 39.0s) | C | 60 | 19.2 | 6139 | 2025-12-27 03:25:09 | MASTER-OAFA | (08h 24m 38.01s , +02d 59m 41.2s) | C | 60 | 19.3 | 6205 | 2025-12-27 03:26:15 | MASTER-OAFA | (08h 24m 37.99s , +02d 59m 43.3s) | C | 60 | 19.3 | 6270 | 2025-12-27 03:27:20 | MASTER-OAFA | (08h 24m 37.98s , +02d 59m 45.5s) | C | 60 | 19.3 | 6335 | 2025-12-27 03:28:26 | MASTER-OAFA | (08h 24m 37.94s , +02d 59m 47.5s) | C | 60 | 19.3 | 6401 | 2025-12-27 03:29:31 | MASTER-OAFA | (08h 24m 37.94s , +02d 59m 49.7s) | C | 60 | 19.3 | 6466 | 2025-12-27 03:30:36 | MASTER-OAFA | (08h 24m 37.93s , +02d 59m 51.8s) | C | 60 | 19.3 | 6531 | 2025-12-27 03:31:42 | MASTER-OAFA | (08h 24m 37.90s , +02d 59m 53.7s) | C | 60 | 19.3 | 6597 | 2025-12-27 03:32:48 | MASTER-OAFA | (08h 24m 37.86s , +02d 59m 55.7s) | C | 60 | 19.3 | 6663 | 2025-12-27 03:33:53 | MASTER-OAFA | (08h 24m 37.82s , +02d 59m 57.5s) | C | 60 | 19.3 | 6728 | 2025-12-27 03:34:59 | MASTER-OAFA | (08h 24m 37.78s , +02d 59m 59.3s) | C | 60 | 19.3 | 6794 | 2025-12-27 03:36:05 | MASTER-OAFA | (08h 24m 37.74s , +03d 00m 01.2s) | C | 60 | 19.3 | 6859 | 2025-12-27 03:37:10 | MASTER-OAFA | (08h 24m 37.70s , +03d 00m 03.1s) | C | 60 | 19.3 | 6925 | 2025-12-27 03:38:15 | MASTER-OAFA | (08h 24m 37.65s , +03d 00m 04.7s) | C | 60 | 19.4 | 6991 | 2025-12-27 03:39:21 | MASTER-OAFA | (08h 24m 37.61s , +03d 00m 06.5s) | C | 60 | 19.4 | 7056 | 2025-12-27 03:40:27 | MASTER-OAFA | (08h 24m 37.56s , +03d 00m 07.9s) | C | 60 | 19.4 | 7122 | 2025-12-27 03:41:33 | MASTER-OAFA | (08h 24m 37.53s , +03d 00m 09.5s) | C | 60 | 19.3 | 7188 | 2025-12-27 03:42:39 | MASTER-OAFA | (08h 24m 37.47s , +03d 00m 10.9s) | C | 60 | 19.3 | 7254 | 2025-12-27 03:43:44 | MASTER-OAFA | (08h 24m 37.42s , +03d 00m 12.3s) | C | 60 | 19.3 | 7320 | 2025-12-27 03:44:50 | MASTER-OAFA | (08h 24m 37.37s , +03d 00m 13.7s) | C | 60 | 19.3 | 7442 | 2025-12-27 03:46:53 | MASTER-OAFA | (08h 24m 37.49s , +03d 02m 16.4s) | C | 60 | 18.5 | 7508 | 2025-12-27 03:47:58 | MASTER-OAFA | (08h 24m 37.46s , +03d 02m 17.6s) | C | 60 | 19.4 | 7573 | 2025-12-27 03:49:04 | MASTER-OAFA | (08h 24m 37.40s , +03d 02m 18.7s) | C | 60 | 19.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/43243. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41331] IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 27 Dec '25

27 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43242 SUBJECT: IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube DATE: 25/12/27 03:54:10 GMT FROM: Yuhua Yao at IceCube/UW-Madison <yyao255(a)icecube.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-251225A (https://gcn.nasa.gov/circulars/43239) in a time range of 1000 seconds centered on the alert event time (2025-12-25 20:05:46.800 UTC to 2025-12-25 20:22:26.800 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-251225A. We report a p-value of 1.00 in this time window. IceCube’s sensitivity to neutrino point sources with an E^-2.5 spectrum, expressed as E^2 dN/dE evaluated at 1 TeV, is 1.4e-01 GeV cm^-2 within the 90% spatial containment region of IceCube-251225A 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 2e+02 GeV and 8e+04 GeV. A subsequent search was performed including 2 days of data centered on the alert event time (2025-12-24 20:14:06.800 UTC to 2025-12-26 20:14:06.800 UTC). In this case, we report a p-value of 1.00, consistent with no significant excess of track events. IceCube’s sensitivity to neutrino point sources with an E^-2.5 spectrum, expressed as E^2 dN/dE evaluated at 1 TeV, is 1.7e-01 GeV cm^-2 within the 90% spatial containment region of IceCube-251225A 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/43242. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41330] The EP-WXT trigger 01709250617 is likely a flaring star
by GCN Circulars 26 Dec '25

26 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43241 SUBJECT: The EP-WXT trigger 01709250617 is likely a flaring star DATE: 25/12/26 03:59:58 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> C. Wang (IHEP, CAS), J. P. Feng, B. Zhang (USTC), T. Wu, H. C. Ding (AHNU), W. J. Zhang, H. Sun (NAO, CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709250617 at the time of 2025-12-26T02:55:13, is likely a stellar flare associated with G 177-25. The estimated flux of the flare is around 1.0×10^(-10) erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 1.8×10^30 erg/s. 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/43241. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41329] IceCube Alert 251225.84: Global MASTER-Net observations report
by GCN Circulars 26 Dec '25

26 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43240 SUBJECT: IceCube Alert 251225.84: Global MASTER-Net observations report DATE: 25/12/26 00:39:34 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-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the IceCube Alert 251225.84 (trigger No 19814286,19h 49m 58.80s , +22d 27m 50.4s, R=0.51) errorbox 12800 sec after notice time and 12867 sec after trigger time at 2025-12-25 23:48:34 UT, with upper limit up to 15.5 mag. Observations started at twilight. The observations began at zenith distance = 80 deg. The sun altitude is -11.8 deg. The galactic latitude b = -2 deg., longitude l = 60 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3085150 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 12873 | 2025-12-25 23:48:34 | MASTER-Tunka | (19h 49m 23.32s , +22d 04m 38.1s) | C | 10 | 15.4 | 12873 | 2025-12-25 23:48:34 | MASTER-Tunka | (19h 49m 40.90s , +21d 58m 08.5s) | C | 10 | 14.5 | 12896 | 2025-12-25 23:48:57 | MASTER-Tunka | (19h 49m 29.45s , +22d 03m 37.1s) | C | 10 | 15.3 | 12896 | 2025-12-25 23:48:57 | MASTER-Tunka | (19h 49m 46.97s , +21d 57m 07.9s) | C | 10 | 14.6 | 12921 | 2025-12-25 23:49:23 | MASTER-Tunka | (19h 49m 23.66s , +22d 02m 37.8s) | C | 10 | 15.2 | 12921 | 2025-12-25 23:49:23 | MASTER-Tunka | (19h 49m 41.14s , +21d 56m 09.7s) | C | 10 | 14.5 | 12945 | 2025-12-25 23:49:46 | MASTER-Tunka | (19h 49m 28.63s , +22d 02m 56.0s) | C | 10 | 15.1 | 12945 | 2025-12-25 23:49:46 | MASTER-Tunka | (19h 49m 46.21s , +21d 56m 26.8s) | C | 10 | 14.5 | 12972 | 2025-12-25 23:50:13 | MASTER-Tunka | (19h 49m 26.49s , +22d 04m 32.3s) | C | 10 | 15.2 | 12972 | 2025-12-25 23:50:13 | MASTER-Tunka | (19h 49m 44.04s , +21d 58m 04.3s) | C | 10 | 14.5 | 12997 | 2025-12-25 23:50:39 | MASTER-Tunka | (19h 49m 26.25s , +22d 02m 54.0s) | C | 10 | 15.2 | 12997 | 2025-12-25 23:50:39 | MASTER-Tunka | (19h 49m 43.95s , +21d 56m 23.9s) | C | 10 | 14.6 | 13020 | 2025-12-25 23:51:03 | MASTER-Tunka | (19h 49m 28.47s , +22d 04m 31.8s) | C | 5 | 15.0 | 13025 | 2025-12-25 23:51:03 | MASTER-Tunka | (19h 49m 28.47s , +22d 04m 31.7s) | C | 15 | 15.5 | Coadd 13020 | 2025-12-25 23:51:03 | MASTER-Tunka | (19h 49m 46.18s , +21d 58m 01.8s) | C | 5 | 14.4 | 13042 | 2025-12-25 23:51:25 | MASTER-Tunka | (19h 49m 23.36s , +22d 03m 41.2s) | C | 5 | 14.9 | 13042 | 2025-12-25 23:51:25 | MASTER-Tunka | (19h 49m 42.53s , +21d 57m 20.8s) | C | 5 | 14.4 | 13062 | 2025-12-25 23:51:46 | MASTER-Tunka | (19h 49m 22.30s , +22d 04m 41.4s) | C | 5 | 14.9 | 13062 | 2025-12-25 23:51:46 | MASTER-Tunka | (19h 49m 39.99s , +21d 58m 14.0s) | C | 5 | 14.3 | 13080 | 2025-12-25 23:52:03 | MASTER-Tunka | (19h 49m 28.75s , +22d 03m 40.6s) | C | 5 | 14.9 | 13080 | 2025-12-25 23:52:03 | MASTER-Tunka | (19h 49m 46.63s , +21d 57m 10.8s) | C | 5 | 14.4 | 13101 | 2025-12-25 23:52:25 | MASTER-Tunka | (19h 49m 23.26s , +22d 02m 41.2s) | C | 5 | 15.0 | 13101 | 2025-12-25 23:52:25 | MASTER-Tunka | (19h 49m 41.16s , +21d 56m 11.7s) | C | 5 | 14.4 | 13247 | 2025-12-25 23:54:24 | MASTER-Tunka | (19h 49m 22.94s , +22d 04m 41.5s) | C | 60 | 15.5 | 13247 | 2025-12-25 23:54:24 | MASTER-Tunka | (19h 49m 41.00s , +21d 58m 11.0s) | C | 60 | 14.8 | Coadd Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/43240. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41328] IceCube-251225A - IceCube observation of a high-energy neutrino candidate track-like event
by GCN Circulars 25 Dec '25

25 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43239 SUBJECT: IceCube-251225A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 25/12/25 22:27:35 GMT FROM: Giacomo Sommani at Ruhr-Universität Bochum <gsommani(a)icecube.wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 25-12-25 at 20:14:06.80 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_BRONZE alert stream. The average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 1.0705 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/141764_19814286.amon) more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 25-12-25 Time: 20:14:06.80 UT RA: 297.42 (+0.54/-0.49 deg 90% PSF containment) J2000 Dec: 22.47 (+0.46/-0.48 deg 90% PSF containment) J2000 We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino. 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/43239. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41327] Fermi Gamma-ray Burst Monitor trigger 788368008/251225630 is not a GRB
by GCN Circulars 25 Dec '25

25 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43238 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 788368008/251225630 is not a GRB DATE: 25/12/25 16:54:22 GMT FROM: Bagrat Mailyan at Florida Tech <mbagrat(a)gmail.com> B. Mailyan (Florida Tech) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 788368008/251225630 at 15:06:43.51 UT on 25 December 2025, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to particle activity." View this GCN Circular online at https://gcn.nasa.gov/circulars/43238. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41326] GRB 251222A: NUTTelA-TAO Early Measurements
by GCN Circulars 25 Dec '25

25 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43237 SUBJECT: GRB 251222A: NUTTelA-TAO Early Measurements DATE: 25/12/25 13:23:54 GMT FROM: Zhanat Maksut at Nazarbayev University <zhanat.maksut(a)nu.edu.kz> Z. Maksut (NU), B. Grossan (UCB, NU), T. Komesh (NU), D. Berdikhan (NU), E. Abdikamalov (NU), M. Krugov (FAI), K. Baigarin (NU), M. Coughlin (UNM), P. Hello (IJCLAB), S. Antier (IJCLAB), and S. Karpov (FZU) on behalf of the GRANDMA/NUTTelA-TAO: The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) pointed at GRB 251222A on receipt of an automated SVOM/ECLAIRs position alert. Observations started at 17:07:10 UT on 2025-12-22, 84 s after the SVOM/ECLAIRs trigger (Yang et al., GCN 43188). We observe in Sloan g' and i' bands simultaneously with the Burst Simultaneous Three-Channel Imager (Grossan, Kumar & Smoot 2019, JHEA, 32, 14). A new optical counterpart reported previously (Palmerio et al., GCN 43189; An et. al, GCN 43194; Calapai et. al, GCN 43195; Durbak et. al, GCN 43197; Li et. al, GCN 43203; Saccardi et. al, GCN 43208; Gupta et. al, GCN 43207; Saccardi et. al, GCN 43204; Kumar et. al, GCN 43209; Pérez-Fournon et. al, GCN 43212; Gupta et al., GCN 43224; Globus et al., GCN 43225; Pankov et al., GCN 43226; Freeberg et al., GCN 43229) was detected. We observe a rapid decay during the first ∼100 s, followed by a gradual rise leading to the first bump at around 500 s. The light curve then exhibits a decay until ∼4000 s, after which it rises again, reaching a second bump at around 10 ks. The total duration of the observations was about 4.5 hours. We report the following preliminary, uncorrected, selected photometric values: tc-t0(s) t_exp i'(mag) err(mag) g’(mag) err(mag) -------- ------ ------- -------- 85.5 3.0 16.2 0.08 17.02 0.09 117 30.0 17.58 0.07 19.45 0.09 519 30.0 17.32 0.08 18.22 0.07 3161 180.0 19.3 0.09 19.95 0.08 tc-t0 = trigger time minus image center time. Calibration was done with 5 bright Pan-STARRS catalog stars (see Komesh, T. et al. 2023, MNRAS 520, 6104). We caution that these are preliminary results, without color or other corrections. This research has been funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP26103591). The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazakhstan. GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/) View this GCN Circular online at https://gcn.nasa.gov/circulars/43237. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41325] GRB 251222A/EP251222b: Optical detection with Kinder observations
by GCN Circulars 25 Dec '25

25 Dec '25

TITLE: GCN CIRCULAR NUMBER: 43236 SUBJECT: GRB 251222A/EP251222b: Optical detection with Kinder observations DATE: 25/12/25 09:54:37 GMT FROM: Amar Aryan at National Central University, Institute of Astronomy (NCUIA) <amararyan941(a)gmail.com> M.-H. Lee, A. Aryan, T.-W. Chen, W.-J. Hou, H.-Y. Hsiao (all NCU), A. K. H. Kong (NTHU), J. Gillanders, S. J. Smartt (both Oxford), Y. J. Yang (NYUAD), Y.-H. Lee, A. Sankar.K, Y.-C. Pan, C.-C. Ngeow, C.-H. Lai, C.-S. Lin, H.-C. Lin, J.-K. Guo (all NCU), S. Yang, Z. N. Wang, L. L. Fan, G. H. Sun (all HNAS), H.-W. Lin (UMich), H. F. Stevance, S. Srivastav, L. Rhodes (all Oxford), M. Nicholl, M. Fulton, T. Moore, K. W. Smith, C. Angus, A. Aamer (all QUB), A. Schultz and M. Huber (both IfA, Hawaii) report: We observed the field of the GRB/fast X-ray transient GRB 251222A/EP251222ba (Fermi/GBM team, GCN#43186; Yang et al., GCN#43188; Guo et al., GCN#43201; Shi et al., GCN#43215; Neights et al., GCN#43222) using the 40cm SLT at Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al., 2025, ApJ, 983, 86, doi:10.3847/1538-4357/adb428). The first SLT epoch of observations started at 10:39 UTC on the 23rd of December 2025 (MJD 61032.444), 17.55 hr after the Fermi/GBM detection. We utilized the astroalign (Beroiz et al., 2020, A&C, 32, 100384) and astropy (Astropy Collaboration et al., 2022, ApJ, 935, 167) packages to align and stack the individual frames. In the stacked image, we clearly detected the optical counterpart candidate proposed by Palmerio et al. (GCN#43189) at a spectroscopic redshift of z = 3.171 (Saccardi et al., GCN#43204). The optical counterpart candidate was confirmed by several observations, including An et al. (GCN#43194); Calapai et al. (GCN#43195); Durbak et al. (NIR detection, GCN#43197); Li et al. (optical rebrightening, GCN#43203); Gupta et al. (GCN#43207, GCN#43224); Saccardi et al. (GCN#43208); Kumar et al. (GCN#43209); Pérez-Fournon et al. (GCN#43212); Globus et al. (GCN#43225); Pankov et al. (GCN#43226); Freeberg et al. (GCN#43229); Volnova et al. (GCN#43230) and Busmann et al. (GCN#43233). Moreover, we further utilized AutoPhOT to perform the PSF photometry. The details of the observations and the measured magnitude (in the AB system) are as follows: Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude. | avg. Seeing | med. Airmass SLT | i | 61032.444 | 17.55 | 300 * 12 | 19.48 +/- 0.07 | 3".7 | 2.27 The BALROG localization of the transient was reported by Preis et al. (GCN#43190), the Swift/XRT counterpart candidate was reported by Beardmore et al. (GCN#43213), and Frederiks et al. (GCN#43214) reported the Konus-Wind detection. The presented magnitude is calibrated using the field stars from the ATLAS-RefCat2 catalog from MAST (Tonry et al., 2018, ApJ, 867, 105) and is not corrected for the expected Galactic foreground extinction of A_i = 0.17 mag in the direction of the transient (Schlafly & Finkbeiner, 2011). The methodology, details on the Lulin observatory telescopes, and a compilation of our optical follow-up campaign for FXTs discovered within the first year of operation of the Einstein-Probe mission are presented in Aryan et al., 2025, ApJS, 281, 20, doi:10.3847/1538-4365/adfc69. View this GCN Circular online at https://gcn.nasa.gov/circulars/43236. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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