TITLE: GCN CIRCULAR NUMBER: 34389 SUBJECT: Fermi GRB 230812B: Global MASTER-Net observations report DATE: 23/08/12 22:31:08 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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. Gres, N.M. Budnev (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), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 230812B ( Fermi GBM team, GCN 34386) errorbox 10680 sec after notice time and 10713 sec after trigger time at 2023-08-12 21:56:45 UT, with upper limit up to 19.3 mag. The observations began at zenith distance = 50 deg. The sun altitude is -31.0 deg. The galactic latitude b = 41 deg., longitude l = 72 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2253499 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 10804 | 2023-08-12 21:56:45 | MASTER-Tavrida | (16h 41m 41.24s , +46d 23m 36.1s) | C | 180 | 19.3 | 10992 | 2023-08-12 21:59:54 | MASTER-Tavrida | (16h 41m 46.04s , +46d 22m 29.1s) | C | 180 | 19.1 | 11111 | 2023-08-12 22:03:07 | MASTER-Tavrida | (16h 41m 40.73s , +46d 21m 24.6s) | C | 30 | 17.8 | 11151 | 2023-08-12 22:03:47 | MASTER-Tavrida | (16h 41m 47.62s , +46d 21m 41.9s) | C | 30 | 17.8 | 11189 | 2023-08-12 22:04:25 | MASTER-Tavrida | (16h 41m 44.53s , +46d 23m 10.6s) | C | 30 | 17.9 | 11227 | 2023-08-12 22:05:04 | MASTER-Tavrida | (16h 41m 44.48s , +46d 21m 32.8s) | C | 30 | 17.8 | 11267 | 2023-08-12 22:05:43 | MASTER-Tavrida | (16h 41m 47.52s , +46d 22m 59.5s) | C | 30 | 17.8 | 11304 | 2023-08-12 22:06:21 | MASTER-Tavrida | (16h 41m 40.68s , +46d 22m 18.0s) | C | 30 | 17.8 | 11343 | 2023-08-12 22:06:59 | MASTER-Tavrida | (16h 41m 41.50s , +46d 23m 16.6s) | C | 30 | 18.0 | 11381 | 2023-08-12 22:07:38 | MASTER-Tavrida | (16h 41m 47.28s , +46d 22m 15.3s) | C | 30 | 17.8 | 11495 | 2023-08-12 22:08:17 | MASTER-Tavrida | (16h 39m 42.09s , +46d 39m 09.7s) | C | 180 | 19.0 | 11683 | 2023-08-12 22:11:25 | MASTER-Tavrida | (16h 39m 49.58s , +46d 39m 04.4s) | C | 180 | 19.0 | 11874 | 2023-08-12 22:14:36 | MASTER-Tavrida | (16h 41m 28.89s , +45d 40m 34.6s) | C | 180 | 19.0 | 12063 | 2023-08-12 22:17:44 | MASTER-Tavrida | (16h 41m 29.14s , +45d 39m 21.9s) | C | 180 | 19.0 | 12251 | 2023-08-12 22:20:53 | MASTER-Tavrida | (16h 41m 31.63s , +45d 40m 21.9s) | C | 180 | 19.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.