TITLE: GCN CIRCULAR NUMBER: 35817 SUBJECT: Fermi GRB 240226A: Global MASTER-Net observations report DATE: 24/02/27 11:30:55 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich (Blagoveschensk Educational State University) 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 240226A ( Fermi GBM team, GCN 35804) errorbox 16246 sec after notice time and 16283 sec after trigger time at 2024-02-27 00:04:30 UT, with upper limit up to 16.8 mag. The observations began at zenith distance = 79 deg. The sun altitude is -45.7 deg. The galactic latitude b = -23 deg., longitude l = 355 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2386845 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 16314 | 2024-02-27 00:04:30 | MASTER-SAAO | (19h 06m 29.14s , -46d 29m 24.3s) | C | 60 | 16.3 | 16314 | 2024-02-27 00:04:30 | MASTER-SAAO | (18h 59m 24.88s , -46d 17m 34.7s) | C | 60 | 16.5 | 16393 | 2024-02-27 00:05:50 | MASTER-SAAO | (18h 56m 09.53s , -42d 41m 16.4s) | C | 60 | 16.0 | 16393 | 2024-02-27 00:05:50 | MASTER-SAAO | (18h 49m 32.02s , -42d 29m 23.5s) | C | 60 | 16.4 | 16473 | 2024-02-27 00:07:10 | MASTER-SAAO | (18h 49m 52.02s , -44d 33m 18.5s) | C | 60 | 16.5 | 16473 | 2024-02-27 00:07:10 | MASTER-SAAO | (18h 43m 01.98s , -44d 21m 24.2s) | C | 60 | 16.8 | 16633 | 2024-02-27 00:09:50 | MASTER-SAAO | (19h 04m 23.32s , -44d 22m 12.6s) | C | 60 | 16.7 | 16713 | 2024-02-27 00:11:09 | MASTER-SAAO | (19h 02m 49.54s , -48d 22m 23.9s) | C | 60 | 16.4 | 16713 | 2024-02-27 00:11:09 | MASTER-SAAO | (18h 55m 29.79s , -48d 10m 32.0s) | C | 60 | 16.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/35817. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...