TITLE: GCN CIRCULAR NUMBER: 43637 SUBJECT: Fermi GRB 260208A: Global MASTER-Net observations report DATE: 26/02/08 06:45:32 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 260208A ( Fermi GBM team, GCN 43635) errorbox 829 sec after notice time and 866 sec after trigger time at 2026-02-08 05:21:55 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 82 deg. The sun altitude is -43.2 deg. The galactic latitude b = 78 deg., longitude l = 64 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3125988 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 952 | 2026-02-08 05:21:55 | MASTER-OAFA | (13h 38m 21.97s , +33d 02m 05.7s) | C | 170 | 15.2 | 1073 | 2026-02-08 05:24:51 | MASTER-OAFA | (13h 38m 22.08s , +33d 02m 10.6s) | C | 60 | 15.9 | 1133 | 2026-02-08 05:24:51 | MASTER-OAFA | (13h 38m 22.14s , +33d 02m 11.3s) | C | 180 | 16.9 | Coadd 1139 | 2026-02-08 05:25:57 | MASTER-OAFA | (13h 38m 22.25s , +33d 02m 15.0s) | C | 60 | 16.1 | 1205 | 2026-02-08 05:27:02 | MASTER-OAFA | (13h 38m 22.38s , +33d 02m 19.9s) | C | 60 | 16.5 | 1271 | 2026-02-08 05:28:08 | MASTER-OAFA | (13h 38m 22.48s , +33d 02m 24.1s) | C | 60 | 16.6 | 1331 | 2026-02-08 05:28:08 | MASTER-OAFA | (13h 38m 22.48s , +33d 02m 24.0s) | C | 180 | 17.2 | Coadd 1336 | 2026-02-08 05:29:14 | MASTER-OAFA | (13h 38m 22.62s , +33d 02m 28.3s) | C | 60 | 16.7 | 1401 | 2026-02-08 05:30:19 | MASTER-OAFA | (13h 38m 22.73s , +33d 02m 32.6s) | C | 60 | 16.8 | 1467 | 2026-02-08 05:31:25 | MASTER-OAFA | (13h 38m 22.83s , +33d 02m 36.7s) | C | 60 | 17.0 | 1527 | 2026-02-08 05:31:25 | MASTER-OAFA | (13h 38m 22.83s , +33d 02m 36.7s) | C | 180 | 17.7 | Coadd 1532 | 2026-02-08 05:32:30 | MASTER-OAFA | (13h 38m 22.91s , +33d 02m 40.5s) | C | 60 | 17.1 | 1598 | 2026-02-08 05:33:36 | MASTER-OAFA | (13h 38m 22.99s , +33d 02m 44.5s) | C | 60 | 17.2 | 1664 | 2026-02-08 05:34:42 | MASTER-OAFA | (13h 38m 23.00s , +33d 02m 48.1s) | C | 60 | 17.2 | 1724 | 2026-02-08 05:34:42 | MASTER-OAFA | (13h 38m 23.01s , +33d 02m 48.1s) | C | 180 | 17.9 | Coadd 1730 | 2026-02-08 05:35:48 | MASTER-OAFA | (13h 38m 23.04s , +33d 02m 51.5s) | C | 60 | 17.2 | 1796 | 2026-02-08 05:36:53 | MASTER-OAFA | (13h 38m 23.05s , +33d 02m 54.5s) | C | 60 | 17.3 | 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/43637. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...