TITLE: GCN CIRCULAR NUMBER: 34363 SUBJECT: Fermi GRB 230807A: Global MASTER-Net observations report DATE: 23/08/08 00:45:47 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-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 230807A ( Fermi GBM team, GCN 34361) errorbox 740 sec after notice time and 775 sec after trigger time at 2023-08-07 22:37:57 UT, with upper limit up to 18.1 mag. The observations began at zenith distance = 80 deg. The sun altitude is -74.3 deg. The galactic latitude b = -39 deg., longitude l = 258 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2251439 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 805 | 2023-08-07 22:37:57 | MASTER-SAAO | (04h 52m 47.80s , -51d 03m 55.2s) | C | 60 | 17.3 | 865 | 2023-08-07 22:37:57 | MASTER-SAAO | (04h 52m 47.80s , -51d 03m 55.2s) | C | 180 | 17.9 | Coadd 805 | 2023-08-07 22:37:57 | MASTER-SAAO | (04h 51m 35.23s , -51d 03m 20.2s) | C | 60 | 17.4 | 865 | 2023-08-07 22:37:57 | MASTER-SAAO | (04h 51m 35.21s , -51d 03m 20.2s) | C | 180 | 18.1 | Coadd 885 | 2023-08-07 22:39:16 | MASTER-SAAO | (04h 52m 47.69s , -51d 02m 55.7s) | C | 60 | 17.2 | 885 | 2023-08-07 22:39:16 | MASTER-SAAO | (04h 51m 35.14s , -51d 02m 20.1s) | C | 60 | 17.3 | 977 | 2023-08-07 22:40:48 | MASTER-SAAO | (04h 52m 53.74s , -51d 03m 56.6s) | C | 60 | 17.3 | 977 | 2023-08-07 22:40:48 | MASTER-SAAO | (04h 51m 41.02s , -51d 03m 21.5s) | C | 60 | 17.4 | 1067 | 2023-08-07 22:42:19 | MASTER-SAAO | (04h 52m 46.43s , -51d 04m 58.9s) | C | 60 | 16.9 | 1067 | 2023-08-07 22:42:19 | MASTER-SAAO | (04h 51m 33.61s , -51d 04m 23.3s) | C | 60 | 17.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.