[vsnet-grb-info 38639] Fermi GRB 250601A: Global MASTER-Net observations report

TITLE: GCN CIRCULAR NUMBER: 40603 SUBJECT: Fermi GRB 250601A: Global MASTER-Net observations report DATE: 25/06/02 04:45:45 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs lipunov@xray.sai.msu.ru

V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)

MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250601A ( Fermi GBM team, GCN 40596) errorbox 31266 sec after notice time and 31297 sec after trigger time at 2025-06-02 02:11:13 UT, with upper limit up to 18.8 mag. The observations began at zenith distance = 80 deg. The sun altitude is -41.7 deg.

The galactic latitude b = -31 deg., longitude l = 264 deg.

Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2888853

We obtain a following upper limits.

Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________

31328 | 2025-06-02 02:11:13 | MASTER-SAAO | (05h 23m 33.62s , -61d 25m 21.7s) | C | 60 | 18.1 | 31328 | 2025-06-02 02:11:13 | MASTER-SAAO | (05h 27m 12.25s , -61d 40m 47.0s) | C | 60 | 16.8 | 32079 | 2025-06-02 02:23:44 | MASTER-SAAO | (05h 23m 32.93s , -61d 25m 26.3s) | C | 60 | 18.2 | 32079 | 2025-06-02 02:23:44 | MASTER-SAAO | (05h 27m 11.81s , -61d 40m 51.9s) | C | 60 | 16.9 | 32832 | 2025-06-02 02:36:17 | MASTER-SAAO | (05h 23m 35.76s , -61d 24m 34.2s) | C | 60 | 18.2 | 32832 | 2025-06-02 02:36:17 | MASTER-SAAO | (05h 27m 14.94s , -61d 39m 58.9s) | C | 60 | 16.9 | 32926 | 2025-06-02 02:37:51 | MASTER-SAAO | (05h 01m 57.98s , -57d 37m 48.3s) | C | 60 | 18.3 | 32926 | 2025-06-02 02:37:51 | MASTER-SAAO | (05h 05m 13.56s , -57d 53m 13.1s) | C | 60 | 16.9 | 33492 | 2025-06-02 02:47:17 | MASTER-SAAO | (05h 23m 29.69s , -61d 25m 33.6s) | C | 60 | 18.3 | 33492 | 2025-06-02 02:47:17 | MASTER-SAAO | (05h 27m 09.27s , -61d 40m 57.8s) | C | 60 | 16.9 | 33586 | 2025-06-02 02:48:51 | MASTER-SAAO | (05h 01m 58.51s , -57d 38m 06.3s) | C | 60 | 18.6 | 33586 | 2025-06-02 02:48:51 | MASTER-SAAO | (05h 05m 14.44s , -57d 53m 30.3s) | C | 60 | 17.1 | 33679 | 2025-06-02 02:50:24 | MASTER-SAAO | (05h 17m 04.95s , -57d 38m 12.0s) | C | 60 | 18.3 | 33679 | 2025-06-02 02:50:24 | MASTER-SAAO | (05h 20m 20.73s , -57d 53m 36.1s) | C | 60 | 17.0 | 34244 | 2025-06-02 02:59:49 | MASTER-SAAO | (05h 23m 26.94s , -61d 25m 56.2s) | C | 60 | 18.2 | 34348 | 2025-06-02 03:01:33 | MASTER-SAAO | (05h 01m 56.88s , -57d 38m 26.6s) | C | 60 | 18.6 | 34348 | 2025-06-02 03:01:33 | MASTER-SAAO | (05h 05m 13.07s , -57d 53m 50.3s) | C | 60 | 17.2 | 34441 | 2025-06-02 03:03:06 | MASTER-SAAO | (05h 17m 02.63s , -57d 38m 31.9s) | C | 60 | 18.3 | 34441 | 2025-06-02 03:03:06 | MASTER-SAAO | (05h 20m 18.63s , -57d 53m 56.0s) | C | 60 | 17.0 | 35007 | 2025-06-02 03:12:32 | MASTER-SAAO | (05h 23m 27.32s , -61d 26m 18.0s) | C | 60 | 18.4 | 35101 | 2025-06-02 03:14:06 | MASTER-SAAO | (05h 01m 55.99s , -57d 38m 46.4s) | C | 60 | 18.6 | 35101 | 2025-06-02 03:14:06 | MASTER-SAAO | (05h 05m 12.55s , -57d 54m 10.0s) | C | 60 | 17.2 | 35194 | 2025-06-02 03:15:39 | MASTER-SAAO | (05h 17m 02.39s , -57d 38m 52.0s) | C | 60 | 18.4 | 35194 | 2025-06-02 03:15:39 | MASTER-SAAO | (05h 20m 18.72s , -57d 54m 16.2s) | C | 60 | 17.0 | 35288 | 2025-06-02 03:17:13 | MASTER-SAAO | (05h 02m 24.56s , -54d 08m 10.8s) | C | 60 | 17.0 | 35381 | 2025-06-02 03:18:46 | MASTER-SAAO | (05h 12m 59.55s , -53d 50m 37.6s) | C | 60 | 18.5 | 35381 | 2025-06-02 03:18:46 | MASTER-SAAO | (05h 15m 57.34s , -54d 06m 02.3s) | C | 60 | 16.7 | 35661 | 2025-06-02 03:23:26 | MASTER-SAAO | (05h 11m 01.98s , -51d 56m 40.6s) | C | 60 | 18.5 | 35661 | 2025-06-02 03:23:26 | MASTER-SAAO | (05h 13m 52.04s , -52d 12m 05.7s) | C | 60 | 16.8 | 35757 | 2025-06-02 03:25:02 | MASTER-SAAO | (05h 01m 55.75s , -57d 41m 01.1s) | C | 60 | 18.6 | 35757 | 2025-06-02 03:25:02 | MASTER-SAAO | (05h 05m 12.76s , -57d 56m 25.1s) | C | 60 | 17.3 | 35851 | 2025-06-02 03:26:36 | MASTER-SAAO | (05h 17m 02.21s , -57d 39m 55.6s) | C | 60 | 18.5 | 35851 | 2025-06-02 03:26:36 | MASTER-SAAO | (05h 20m 18.88s , -57d 55m 20.0s) | C | 60 | 17.2 | 36038 | 2025-06-02 03:29:43 | MASTER-SAAO | (05h 12m 58.98s , -53d 52m 22.2s) | C | 60 | 18.4 | 36038 | 2025-06-02 03:29:43 | MASTER-SAAO | (05h 15m 56.70s , -54d 07m 48.0s) | C | 60 | 17.0 | 36318 | 2025-06-02 03:34:23 | MASTER-SAAO | (05h 11m 01.70s , -51d 56m 54.3s) | C | 60 | 18.7 | 36318 | 2025-06-02 03:34:23 | MASTER-SAAO | (05h 13m 51.53s , -52d 12m 20.2s) | C | 60 | 17.0 | 36411 | 2025-06-02 03:35:56 | MASTER-SAAO | (05h 24m 08.15s , -51d 57m 10.8s) | C | 60 | 18.4 | 36411 | 2025-06-02 03:35:56 | MASTER-SAAO | (05h 26m 57.92s , -52d 12m 36.4s) | C | 60 | 17.0 | 36504 | 2025-06-02 03:37:29 | MASTER-SAAO | (05h 05m 10.11s , -57d 56m 43.4s) | C | 60 | 17.4 | 36504 | 2025-06-02 03:37:29 | MASTER-SAAO | (05h 01m 53.17s , -57d 41m 19.2s) | C | 60 | 18.7 | 36597 | 2025-06-02 03:39:02 | MASTER-SAAO | (05h 20m 17.51s , -57d 55m 46.9s) | C | 60 | 17.3 | 36597 | 2025-06-02 03:39:02 | MASTER-SAAO | (05h 17m 00.88s , -57d 40m 22.3s) | C | 60 | 18.6 | 36784 | 2025-06-02 03:42:09 | MASTER-SAAO | (05h 15m 55.94s , -54d 07m 49.4s) | C | 60 | 17.0 | 36784 | 2025-06-02 03:42:09 | MASTER-SAAO | (05h 12m 57.97s , -53d 52m 23.8s) | C | 60 | 18.6 | 36973 | 2025-06-02 03:45:18 | MASTER-SAAO | (05h 04m 12.35s , -56d 01m 02.3s) | C | 60 | 17.5 | 36973 | 2025-06-02 03:45:18 | MASTER-SAAO | (05h 01m 05.36s , -55d 45m 37.7s) | C | 60 | 18.8 | 37066 | 2025-06-02 03:46:51 | MASTER-SAAO | (05h 13m 57.11s , -52d 13m 36.4s) | C | 60 | 17.2 | 37066 | 2025-06-02 03:46:51 | MASTER-SAAO | (05h 11m 06.80s , -51d 58m 10.9s) | C | 60 | 18.7 | 37159 | 2025-06-02 03:48:24 | MASTER-SAAO | (05h 26m 51.17s , -52d 13m 53.2s) | C | 60 | 17.1 | Filter C is a clear (unfiltred) band.

The observation and reduction will continue. The message may be cited.

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