TITLE: GCN CIRCULAR NUMBER: 44482 SUBJECT: Fermi GRB 260506A: Global MASTER-Net observations report DATE: 26/05/06 07:00:25 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-OAGH robotic telescope [1] located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 260506A ( Fermi GBM team, GCN 44481) errorbox 224 sec after notice time and 230 sec after trigger time at 2026-05-06 06:32:38 UT, with upper limit up to 19.3 mag. The observations began at zenith distance = 58 deg. The sun altitude is -41.5 deg. The galactic latitude b = 36 deg., longitude l = 136 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3296217 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 260 | 2026-05-06 06:32:38 | MASTER-OAGH | (08h 44m 39.72s , +75d 23m 45.7s) | C | 60 | 18.5 | 260 | 2026-05-06 06:32:38 | MASTER-OAGH | (08h 37m 44.58s , +75d 59m 45.8s) | C | 60 | 18.7 | 333 | 2026-05-06 06:33:51 | MASTER-OAGH | (09h 16m 22.00s , +75d 24m 42.7s) | C | 60 | 18.8 | 333 | 2026-05-06 06:33:51 | MASTER-OAGH | (09h 09m 15.33s , +76d 01m 00.1s) | C | 60 | 18.9 | 406 | 2026-05-06 06:35:04 | MASTER-OAGH | (08h 52m 23.52s , +77d 19m 08.0s) | C | 60 | 19.1 | 406 | 2026-05-06 06:35:04 | MASTER-OAGH | (08h 44m 14.66s , +77d 55m 18.4s) | C | 60 | 19.3 | 479 | 2026-05-06 06:36:17 | MASTER-OAGH | (09h 28m 38.58s , +77d 18m 24.2s) | C | 60 | 18.3 | 479 | 2026-05-06 06:36:17 | MASTER-OAGH | (09h 20m 26.78s , +77d 54m 22.8s) | C | 60 | 18.6 | 553 | 2026-05-06 06:37:31 | MASTER-OAGH | (09h 32m 43.22s , +73d 30m 24.2s) | C | 60 | 18.8 | 553 | 2026-05-06 06:37:31 | MASTER-OAGH | (09h 26m 27.66s , +74d 06m 31.2s) | C | 60 | 18.9 | 626 | 2026-05-06 06:38:44 | MASTER-OAGH | (10h 00m 45.91s , +73d 28m 55.8s) | C | 60 | 18.7 | 626 | 2026-05-06 06:38:44 | MASTER-OAGH | (09h 54m 25.86s , +74d 05m 06.5s) | C | 60 | 19.0 | 699 | 2026-05-06 06:39:57 | MASTER-OAGH | (09h 44m 54.95s , +75d 25m 08.4s) | C | 60 | 19.0 | 699 | 2026-05-06 06:39:57 | MASTER-OAGH | (09h 37m 45.79s , +76d 01m 15.0s) | C | 60 | 19.2 | 773 | 2026-05-06 06:41:11 | MASTER-OAGH | (10h 16m 39.45s , +75d 23m 04.3s) | C | 60 | 19.0 | 773 | 2026-05-06 06:41:11 | MASTER-OAGH | (10h 09m 25.61s , +75d 59m 15.1s) | C | 60 | 19.2 | 1010 | 2026-05-06 06:45:08 | MASTER-OAGH | (08h 44m 32.03s , +75d 26m 03.2s) | C | 60 | 18.9 | 1010 | 2026-05-06 06:45:08 | MASTER-OAGH | (08h 37m 39.30s , +75d 57m 59.1s) | C | 60 | 18.9 | 1083 | 2026-05-06 06:46:21 | MASTER-OAGH | (09h 16m 23.42s , +75d 24m 39.6s) | C | 60 | 18.8 | 1083 | 2026-05-06 06:46:21 | MASTER-OAGH | (09h 09m 18.88s , +76d 00m 58.5s) | C | 60 | 19.0 | 1156 | 2026-05-06 06:47:34 | MASTER-OAGH | (08h 52m 15.20s , +77d 18m 04.3s) | C | 60 | 19.1 | 1156 | 2026-05-06 06:47:34 | MASTER-OAGH | (08h 44m 14.12s , +77d 54m 09.0s) | C | 60 | 19.1 | 1230 | 2026-05-06 06:48:47 | MASTER-OAGH | (09h 28m 45.20s , +77d 17m 37.2s) | C | 60 | 18.7 | 1230 | 2026-05-06 06:48:47 | MASTER-OAGH | (09h 20m 32.90s , +77d 53m 53.1s) | C | 60 | 19.0 | 1303 | 2026-05-06 06:50:00 | MASTER-OAGH | (09h 32m 40.96s , +73d 31m 11.3s) | C | 60 | 18.9 | 1303 | 2026-05-06 06:50:00 | MASTER-OAGH | (09h 26m 24.09s , +74d 07m 34.1s) | C | 60 | 19.0 | 1376 | 2026-05-06 06:51:14 | MASTER-OAGH | (10h 00m 49.53s , +73d 29m 34.1s) | C | 60 | 18.9 | 1376 | 2026-05-06 06:51:14 | MASTER-OAGH | (09h 54m 31.45s , +74d 05m 45.0s) | C | 60 | 19.2 | 1448 | 2026-05-06 06:52:26 | MASTER-OAGH | (09h 44m 56.50s , +75d 25m 43.2s) | C | 60 | 19.0 | 1448 | 2026-05-06 06:52:26 | MASTER-OAGH | (09h 37m 49.83s , +76d 01m 49.5s) | C | 60 | 19.1 | 1523 | 2026-05-06 06:53:41 | MASTER-OAGH | (10h 16m 36.92s , +75d 24m 10.7s) | C | 60 | 18.9 | 1523 | 2026-05-06 06:53:41 | MASTER-OAGH | (10h 09m 24.89s , +76d 00m 21.4s) | 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/44482. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...