TITLE: GCN CIRCULAR NUMBER: 44537 SUBJECT: Fermi GRB 260511A: Global MASTER-Net observations report DATE: 26/05/11 08:30:44 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 260511A ( Fermi GBM team, GCN 44529) errorbox 5184 sec after notice time and 5215 sec after trigger time at 2026-05-11 07:40:25 UT, with upper limit up to 20.5 mag. The observations began at zenith distance = 64 deg. The sun altitude is -45.2 deg. MASTER-OAGH robotic telescope located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 260511A errorbox 6822 sec after notice time and 6853 sec after trigger time at 2026-05-11 08:07:44 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 77 deg. The sun altitude is -39.6 deg. The galactic latitude b = 29 deg., longitude l = 310 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3306895 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 5246 | 2026-05-11 07:40:25 | MASTER-OAFA | (13h 10m 55.69s , -33d 35m 27.4s) | C | 60 | 19.5 | 5306 | 2026-05-11 07:40:25 | MASTER-OAFA | (13h 10m 55.69s , -33d 35m 27.5s) | C | 180 | 20.0 | Coadd 5366 | 2026-05-11 07:40:25 | MASTER-OAFA | (13h 10m 55.68s , -33d 35m 27.5s) | C | 300 | 20.0 | Coadd 5636 | 2026-05-11 07:40:25 | MASTER-OAFA | (13h 10m 55.69s , -33d 35m 27.5s) | C | 840 | 20.5 | Coadd 5322 | 2026-05-11 07:41:42 | MASTER-OAFA | (13h 10m 55.74s , -33d 37m 08.5s) | C | 60 | 19.4 | 5400 | 2026-05-11 07:43:00 | MASTER-OAFA | (13h 10m 59.00s , -33d 35m 34.7s) | C | 60 | 19.2 | 5475 | 2026-05-11 07:44:14 | MASTER-OAFA | (13h 10m 53.33s , -33d 36m 24.9s) | C | 60 | 19.5 | 5535 | 2026-05-11 07:44:14 | MASTER-OAFA | (13h 10m 53.33s , -33d 36m 24.9s) | C | 180 | 20.0 | Coadd 5554 | 2026-05-11 07:45:34 | MASTER-OAFA | (13h 10m 53.06s , -33d 35m 26.1s) | C | 60 | 19.3 | 5631 | 2026-05-11 07:46:51 | MASTER-OAFA | (13h 10m 59.98s , -33d 36m 26.7s) | C | 60 | 19.4 | 5708 | 2026-05-11 07:48:07 | MASTER-OAFA | (13h 10m 53.23s , -33d 37m 28.2s) | C | 60 | 19.3 | 5768 | 2026-05-11 07:48:07 | MASTER-OAFA | (13h 10m 53.23s , -33d 37m 28.1s) | C | 180 | 19.9 | Coadd 5781 | 2026-05-11 07:49:21 | MASTER-OAFA | (13h 11m 00.12s , -33d 37m 27.8s) | C | 60 | 19.3 | 5858 | 2026-05-11 07:50:37 | MASTER-OAFA | (13h 10m 56.28s , -33d 35m 51.6s) | C | 60 | 19.4 | 5935 | 2026-05-11 07:51:54 | MASTER-OAFA | (13h 10m 56.39s , -33d 37m 16.0s) | C | 60 | 19.3 | 5995 | 2026-05-11 07:51:54 | MASTER-OAFA | (13h 10m 56.39s , -33d 37m 16.0s) | C | 180 | 19.9 | Coadd 6012 | 2026-05-11 07:53:11 | MASTER-OAFA | (13h 10m 58.63s , -33d 35m 39.5s) | C | 60 | 19.3 | 6087 | 2026-05-11 07:54:27 | MASTER-OAFA | (13h 10m 52.96s , -33d 36m 32.8s) | C | 60 | 19.2 | 6163 | 2026-05-11 07:55:43 | MASTER-OAFA | (13h 10m 53.42s , -33d 35m 33.6s) | C | 60 | 19.2 | 6223 | 2026-05-11 07:55:43 | MASTER-OAFA | (13h 10m 53.41s , -33d 35m 33.6s) | C | 180 | 19.9 | Coadd 6239 | 2026-05-11 07:56:59 | MASTER-OAFA | (13h 10m 59.31s , -33d 36m 35.2s) | C | 60 | 19.2 | 6313 | 2026-05-11 07:58:13 | MASTER-OAFA | (13h 10m 52.93s , -33d 37m 36.1s) | C | 60 | 19.2 | 6391 | 2026-05-11 07:59:31 | MASTER-OAFA | (13h 11m 00.57s , -33d 37m 29.1s) | C | 60 | 19.2 | 6451 | 2026-05-11 07:59:31 | MASTER-OAFA | (13h 11m 00.57s , -33d 37m 29.2s) | C | 180 | 19.8 | Coadd 6464 | 2026-05-11 08:00:44 | MASTER-OAFA | (13h 10m 57.03s , -33d 35m 54.4s) | C | 60 | 19.1 | 6541 | 2026-05-11 08:02:01 | MASTER-OAFA | (13h 10m 57.13s , -33d 37m 22.1s) | C | 60 | 19.1 | 6617 | 2026-05-11 08:03:16 | MASTER-OAFA | (13h 10m 59.39s , -33d 35m 57.2s) | C | 60 | 19.2 | 6677 | 2026-05-11 08:03:16 | MASTER-OAFA | (13h 10m 59.40s , -33d 35m 57.2s) | C | 180 | 19.8 | Coadd 6692 | 2026-05-11 08:04:32 | MASTER-OAFA | (13h 10m 53.41s , -33d 36m 41.7s) | C | 60 | 19.2 | 6766 | 2026-05-11 08:05:46 | MASTER-OAFA | (13h 10m 54.96s , -33d 35m 42.7s) | C | 60 | 19.0 | 6840 | 2026-05-11 08:07:00 | MASTER-OAFA | (13h 10m 59.75s , -33d 36m 43.9s) | C | 60 | 19.1 | 6900 | 2026-05-11 08:07:00 | MASTER-OAFA | (13h 10m 59.75s , -33d 36m 43.9s) | C | 180 | 19.7 | Coadd 6884 | 2026-05-11 08:07:44 | MASTER-OAGH | (13h 11m 20.18s , -33d 45m 22.0s) | C | 60 | 18.2 | 6944 | 2026-05-11 08:07:44 | MASTER-OAGH | (13h 11m 20.19s , -33d 45m 21.9s) | C | 180 | 19.0 | Coadd 6884 | 2026-05-11 08:07:44 | MASTER-OAGH | (13h 09m 49.25s , -33d 12m 34.9s) | C | 60 | 18.8 | 6944 | 2026-05-11 08:07:44 | MASTER-OAGH | (13h 09m 49.25s , -33d 12m 34.9s) | C | 180 | 19.5 | Coadd 6917 | 2026-05-11 08:08:17 | MASTER-OAFA | (13h 10m 54.11s , -33d 37m 45.2s) | C | 60 | 19.0 | 6953 | 2026-05-11 08:08:52 | MASTER-OAGH | (13h 11m 26.44s , -33d 45m 03.2s) | C | 60 | 18.4 | 6953 | 2026-05-11 08:08:52 | MASTER-OAGH | (13h 09m 55.72s , -33d 12m 16.6s) | C | 60 | 18.8 | 6990 | 2026-05-11 08:09:30 | MASTER-OAFA | (13h 11m 01.38s , -33d 37m 35.3s) | C | 60 | 19.0 | 7021 | 2026-05-11 08:10:01 | MASTER-OAGH | (13h 11m 22.36s , -33d 43m 39.0s) | C | 60 | 18.3 | 7021 | 2026-05-11 08:10:01 | MASTER-OAGH | (13h 09m 51.74s , -33d 10m 53.0s) | C | 60 | 18.7 | 7066 | 2026-05-11 08:10:46 | MASTER-OAFA | (13h 10m 57.89s , -33d 36m 10.1s) | C | 60 | 19.1 | 7126 | 2026-05-11 08:10:46 | MASTER-OAFA | (13h 10m 57.89s , -33d 36m 10.1s) | C | 180 | 19.6 | Coadd 7091 | 2026-05-11 08:11:11 | MASTER-OAGH | (13h 11m 22.26s , -33d 45m 14.7s) | C | 60 | 18.2 | 7151 | 2026-05-11 08:11:11 | MASTER-OAGH | (13h 11m 22.26s , -33d 45m 14.7s) | C | 180 | 18.9 | Coadd 7091 | 2026-05-11 08:11:11 | MASTER-OAGH | (13h 09m 51.67s , -33d 12m 28.6s) | C | 60 | 18.5 | 7151 | 2026-05-11 08:11:11 | MASTER-OAGH | (13h 09m 51.67s , -33d 12m 28.5s) | C | 180 | 19.4 | Coadd 7143 | 2026-05-11 08:12:03 | MASTER-OAFA | (13h 10m 58.00s , -33d 37m 28.1s) | C | 60 | 19.1 | 7161 | 2026-05-11 08:12:21 | MASTER-OAGH | (13h 11m 25.40s , -33d 43m 36.4s) | C | 60 | 18.2 | 7161 | 2026-05-11 08:12:21 | MASTER-OAGH | (13h 09m 54.89s , -33d 10m 50.9s) | C | 60 | 18.6 | 7217 | 2026-05-11 08:13:17 | MASTER-OAFA | (13h 11m 02.04s , -33d 35m 52.5s) | C | 60 | 18.9 | 7231 | 2026-05-11 08:13:31 | MASTER-OAGH | (13h 11m 18.85s , -33d 44m 19.2s) | C | 60 | 18.2 | 7231 | 2026-05-11 08:13:31 | MASTER-OAGH | (13h 09m 48.37s , -33d 11m 33.8s) | C | 60 | 18.6 | 7294 | 2026-05-11 08:14:34 | MASTER-OAFA | (13h 10m 54.24s , -33d 36m 51.2s) | C | 60 | 18.9 | 7354 | 2026-05-11 08:14:34 | MASTER-OAFA | (13h 10m 54.24s , -33d 36m 51.1s) | C | 180 | 19.6 | Coadd 7300 | 2026-05-11 08:14:40 | MASTER-OAGH | (13h 11m 19.17s , -33d 43m 17.9s) | C | 60 | 18.3 | 7360 | 2026-05-11 08:14:40 | MASTER-OAGH | (13h 11m 19.17s , -33d 43m 17.9s) | C | 180 | 18.8 | Coadd 7300 | 2026-05-11 08:14:40 | MASTER-OAGH | (13h 09m 48.71s , -33d 10m 32.7s) | C | 60 | 18.6 | 7360 | 2026-05-11 08:14:40 | MASTER-OAGH | (13h 09m 48.71s , -33d 10m 32.5s) | C | 180 | 19.2 | Coadd 7370 | 2026-05-11 08:15:49 | MASTER-OAGH | (13h 11m 25.51s , -33d 44m 17.0s) | C | 60 | 18.2 | 7370 | 2026-05-11 08:15:49 | MASTER-OAGH | (13h 09m 55.12s , -33d 11m 31.7s) | C | 60 | 18.6 | 7371 | 2026-05-11 08:15:51 | MASTER-OAFA | (13h 10m 55.41s , -33d 35m 51.5s) | C | 60 | 18.9 | 7438 | 2026-05-11 08:16:58 | MASTER-OAGH | (13h 11m 19.31s , -33d 45m 15.5s) | C | 60 | 18.1 | 7438 | 2026-05-11 08:16:58 | MASTER-OAGH | (13h 09m 48.97s , -33d 12m 30.0s) | C | 60 | 18.5 | 7449 | 2026-05-11 08:17:09 | MASTER-OAFA | (13h 11m 00.93s , -33d 36m 53.0s) | C | 60 | 18.9 | 7507 | 2026-05-11 08:18:07 | MASTER-OAGH | (13h 11m 24.61s , -33d 45m 00.1s) | C | 60 | 18.2 | 7567 | 2026-05-11 08:18:07 | MASTER-OAGH | (13h 11m 24.62s , -33d 44m 60.0s) | C | 180 | 18.8 | Coadd 7507 | 2026-05-11 08:18:07 | MASTER-OAGH | (13h 09m 54.39s , -33d 12m 14.6s) | C | 60 | 18.6 | 7567 | 2026-05-11 08:18:07 | MASTER-OAGH | (13h 09m 54.39s , -33d 12m 14.6s) | C | 180 | 19.4 | Coadd 7523 | 2026-05-11 08:18:23 | MASTER-OAFA | (13h 10m 55.99s , -33d 37m 53.5s) | C | 60 | 18.9 | 7583 | 2026-05-11 08:18:23 | MASTER-OAFA | (13h 10m 55.99s , -33d 37m 53.5s) | C | 180 | 19.6 | Coadd 7577 | 2026-05-11 08:19:17 | MASTER-OAGH | (13h 11m 21.64s , -33d 43m 38.5s) | C | 60 | 18.0 | 7577 | 2026-05-11 08:19:17 | MASTER-OAGH | (13h 09m 51.53s , -33d 10m 53.2s) | C | 60 | 18.5 | 7598 | 2026-05-11 08:19:38 | MASTER-OAFA | (13h 11m 00.75s , -33d 37m 31.6s) | C | 60 | 18.8 | 7647 | 2026-05-11 08:20:26 | MASTER-OAGH | (13h 11m 21.58s , -33d 44m 48.6s) | C | 60 | 18.1 | 7647 | 2026-05-11 08:20:26 | MASTER-OAGH | (13h 09m 51.49s , -33d 12m 02.7s) | C | 60 | 18.6 | 7676 | 2026-05-11 08:20:55 | MASTER-OAFA | (13h 10m 58.71s , -33d 36m 14.3s) | C | 60 | 18.9 | 7722 | 2026-05-11 08:21:42 | MASTER-OAGH | (13h 11m 24.04s , -33d 43m 24.1s) | C | 60 | 18.1 | 7782 | 2026-05-11 08:21:42 | MASTER-OAGH | (13h 11m 24.03s , -33d 43m 24.0s) | C | 180 | 18.6 | Coadd 7722 | 2026-05-11 08:21:42 | MASTER-OAGH | (13h 09m 54.00s , -33d 10m 38.6s) | C | 60 | 18.5 | 7782 | 2026-05-11 08:21:42 | MASTER-OAGH | (13h 09m 54.00s , -33d 10m 38.5s) | C | 180 | 19.1 | Coadd 7752 | 2026-05-11 08:22:12 | MASTER-OAFA | (13h 10m 58.85s , -33d 37m 45.7s) | C | 60 | 18.9 | 7792 | 2026-05-11 08:22:51 | MASTER-OAGH | (13h 11m 17.55s , -33d 44m 06.7s) | C | 60 | 18.0 | 7792 | 2026-05-11 08:22:52 | MASTER-OAGH | (13h 09m 47.49s , -33d 11m 21.0s) | C | 60 | 18.3 | 7826 | 2026-05-11 08:23:26 | MASTER-OAFA | (13h 11m 02.50s , -33d 36m 10.9s) | C | 60 | 18.9 | 7861 | 2026-05-11 08:24:01 | MASTER-OAGH | (13h 11m 18.56s , -33d 43m 05.0s) | C | 60 | 18.0 | 7861 | 2026-05-11 08:24:01 | MASTER-OAGH | (13h 09m 48.54s , -33d 10m 19.5s) | C | 60 | 18.4 | 7903 | 2026-05-11 08:24:43 | MASTER-OAFA | (13h 10m 56.54s , -33d 36m 58.6s) | C | 60 | 18.9 | 7931 | 2026-05-11 08:25:11 | MASTER-OAGH | (13h 11m 24.27s , -33d 44m 03.0s) | C | 60 | 18.1 | 7931 | 2026-05-11 08:25:11 | MASTER-OAGH | (13h 09m 54.32s , -33d 11m 17.1s) | C | 60 | 18.5 | 8000 | 2026-05-11 08:26:20 | MASTER-OAGH | (13h 11m 17.71s , -33d 45m 00.9s) | C | 60 | 18.1 | 8000 | 2026-05-11 08:26:20 | MASTER-OAGH | (13h 09m 47.79s , -33d 12m 14.9s) | C | 60 | 18.5 | 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/44537. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...