TITLE: GCN CIRCULAR NUMBER: 33428 SUBJECT: Fermi GRB 230307A: Global MASTER-Net observations report DATE: 23/03/08 22:20:57 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 230307A ( Fermi GBM team, GCN 33405) errorbox 1 days 7520 sec after notice time and 1 days 7572 sec after trigger time at 2023-03-08 17:50:19 UT, with upper limit up to 19.0 mag. Observations started at twilight. The observations began at zenith distance = 46 deg. The sun altitude is -10.1 deg. The galactic latitude b = -37 deg., longitude l = 292 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2202708 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 94063 | 2023-03-08 17:50:19 | MASTER-SAAO | (04h 06m 50.07s , -74d 51m 54.3s) | C | 180 | 17.4 | 94063 | 2023-03-08 17:50:19 | MASTER-SAAO | (04h 09m 51.53s , -74d 51m 58.1s) | C | 180 | 17.1 | 94274 | 2023-03-08 17:53:51 | MASTER-SAAO | (04h 06m 44.57s , -76d 46m 43.0s) | C | 180 | 17.9 | 94274 | 2023-03-08 17:53:51 | MASTER-SAAO | (04h 10m 11.69s , -76d 46m 46.6s) | C | 180 | 17.7 | 94909 | 2023-03-08 18:04:25 | MASTER-SAAO | (03h 08m 23.27s , -74d 51m 18.2s) | C | 180 | 18.5 | 94909 | 2023-03-08 18:04:25 | MASTER-SAAO | (03h 11m 26.50s , -74d 51m 25.8s) | C | 180 | 18.5 | 95120 | 2023-03-08 18:07:56 | MASTER-SAAO | (04h 06m 35.42s , -76d 44m 20.5s) | C | 180 | 19.0 | 95120 | 2023-03-08 18:07:56 | MASTER-SAAO | (04h 10m 04.25s , -76d 44m 25.9s) | C | 180 | 18.8 | 95754 | 2023-03-08 18:18:31 | MASTER-SAAO | (03h 08m 25.33s , -74d 51m 41.6s) | C | 180 | 18.7 | 95754 | 2023-03-08 18:18:31 | MASTER-SAAO | (03h 11m 30.09s , -74d 51m 50.8s) | C | 180 | 18.7 | 106819 | 2023-03-08 21:23:55 | MASTER-SAAO | (03h 03m 53.63s , -76d 38m 21.4s) | C | 60 | 18.5 | 106819 | 2023-03-08 21:23:55 | MASTER-SAAO | (03h 00m 21.60s , -76d 38m 10.8s) | C | 60 | 18.6 | 107112 | 2023-03-08 21:28:48 | MASTER-SAAO | (03h 38m 39.03s , -76d 38m 02.4s) | C | 60 | 18.5 | 107112 | 2023-03-08 21:28:48 | MASTER-SAAO | (03h 35m 05.28s , -76d 37m 50.0s) | C | 60 | 18.5 | 107204 | 2023-03-08 21:30:20 | MASTER-SAAO | (03h 34m 06.25s , -78d 31m 42.8s) | C | 60 | 18.4 | 107204 | 2023-03-08 21:30:20 | MASTER-SAAO | (03h 29m 57.72s , -78d 31m 30.2s) | C | 60 | 18.4 | 107284 | 2023-03-08 21:31:41 | MASTER-SAAO | (04h 14m 36.07s , -78d 32m 15.3s) | C | 60 | 18.5 | 107284 | 2023-03-08 21:31:41 | MASTER-SAAO | (04h 10m 26.79s , -78d 32m 04.8s) | C | 60 | 18.5 | 107714 | 2023-03-08 21:37:50 | MASTER-SAAO | (03h 39m 18.35s , -76d 34m 01.4s) | C | 180 | 18.9 | 107714 | 2023-03-08 21:37:50 | MASTER-SAAO | (03h 35m 45.53s , -76d 33m 46.1s) | C | 180 | 19.0 | 107926 | 2023-03-08 21:41:22 | MASTER-SAAO | (03h 24m 25.90s , -76d 32m 40.7s) | C | 180 | 18.7 | 107926 | 2023-03-08 21:41:22 | MASTER-SAAO | (03h 20m 53.73s , -76d 32m 24.2s) | C | 180 | 18.9 | 108138 | 2023-03-08 21:44:54 | MASTER-SAAO | (03h 24m 23.20s , -76d 33m 24.5s) | C | 180 | 18.7 | 108138 | 2023-03-08 21:44:54 | MASTER-SAAO | (03h 20m 50.60s , -76d 33m 07.7s) | C | 180 | 18.8 | 108349 | 2023-03-08 21:48:25 | MASTER-SAAO | (03h 39m 21.23s , -76d 32m 07.5s) | C | 180 | 18.7 | 108349 | 2023-03-08 21:48:25 | MASTER-SAAO | (03h 35m 48.38s , -76d 31m 51.0s) | C | 180 | 18.9 | 108559 | 2023-03-08 21:51:55 | MASTER-SAAO | (03h 39m 29.26s , -76d 33m 05.1s) | C | 180 | 18.7 | 108559 | 2023-03-08 21:51:56 | MASTER-SAAO | (03h 35m 56.14s , -76d 32m 48.9s) | C | 180 | 18.9 | 108771 | 2023-03-08 21:55:27 | MASTER-SAAO | (03h 38m 53.42s , -74d 34m 06.9s) | C | 180 | 18.6 | 108771 | 2023-03-08 21:55:27 | MASTER-SAAO | (03h 35m 47.35s , -74d 33m 50.3s) | C | 180 | 18.8 | 108982 | 2023-03-08 21:58:58 | MASTER-SAAO | (03h 35m 55.42s , -74d 33m 24.8s) | C | 180 | 18.6 | 108982 | 2023-03-08 21:58:58 | MASTER-SAAO | (03h 39m 01.23s , -74d 33m 41.8s) | C | 180 | 18.5 | 109194 | 2023-03-08 22:02:30 | MASTER-SAAO | (03h 39m 51.43s , -77d 32m 08.3s) | C | 180 | 18.6 | 109194 | 2023-03-08 22:02:30 | MASTER-SAAO | (03h 36m 01.98s , -77d 31m 51.5s) | C | 180 | 18.8 | 109405 | 2023-03-08 22:06:01 | MASTER-SAAO | (03h 36m 04.38s , -77d 33m 31.5s) | C | 180 | 18.8 | 109405 | 2023-03-08 22:06:01 | MASTER-SAAO | (03h 39m 54.39s , -77d 33m 48.0s) | C | 180 | 18.7 | 109617 | 2023-03-08 22:09:33 | MASTER-SAAO | (03h 49m 04.44s , -77d 31m 38.2s) | C | 180 | 18.7 | 109617 | 2023-03-08 22:09:33 | MASTER-SAAO | (03h 52m 54.28s , -77d 31m 54.1s) | C | 180 | 18.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.