TITLE: GCN CIRCULAR NUMBER: 31858 SUBJECT: Fermi GRB 220408B: Global MASTER-Net observations report DATE: 22/04/08 19:30:22 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 220408B ( Fermi GBM team, GCN 31854) errorbox 38858 sec after notice time and 38887 sec after trigger time at 2022-04-08 18:16:12 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 33 deg. The sun altitude is -24.1 deg. The galactic latitude b = -25 deg., longitude l = 259 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1936782 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 38918 | 2022-04-08 18:16:12 | MASTER-SAAO | (06h 12m 56.98s , -50d 05m 58.3s) | C | 60 | 17.8 | 39007 | 2022-04-08 18:17:42 | MASTER-SAAO | (06h 25m 30.38s , -50d 06m 55.8s) | C | 60 | 17.9 | 39088 | 2022-04-08 18:19:03 | MASTER-SAAO | (06h 04m 01.42s , -52d 01m 53.5s) | C | 60 | 17.5 | 39180 | 2022-04-08 18:20:34 | MASTER-SAAO | (06h 16m 56.43s , -52d 00m 18.7s) | C | 60 | 17.4 | 39498 | 2022-04-08 18:25:52 | MASTER-SAAO | (06h 33m 41.72s , -48d 11m 39.6s) | C | 60 | 17.5 | 39589 | 2022-04-08 18:27:23 | MASTER-SAAO | (06h 20m 15.24s , -53d 55m 36.6s) | C | 60 | 17.6 | 39669 | 2022-04-08 18:28:43 | MASTER-SAAO | (06h 33m 53.81s , -53d 55m 10.9s) | C | 60 | 17.6 | 39997 | 2022-04-08 18:34:11 | MASTER-SAAO | (06h 13m 03.64s , -50d 07m 10.9s) | C | 60 | 17.4 | 40088 | 2022-04-08 18:35:42 | MASTER-SAAO | (06h 25m 31.89s , -50d 05m 38.5s) | C | 60 | 17.6 | 40172 | 2022-04-08 18:37:07 | MASTER-SAAO | (06h 03m 58.08s , -52d 00m 16.1s) | C | 60 | 17.5 | 40263 | 2022-04-08 18:38:37 | MASTER-SAAO | (06h 16m 57.23s , -51d 59m 13.9s) | C | 60 | 17.3 | 40354 | 2022-04-08 18:40:09 | MASTER-SAAO | (06h 21m 52.59s , -48d 12m 07.9s) | C | 60 | 17.5 | 40434 | 2022-04-08 18:41:28 | MASTER-SAAO | (06h 33m 43.84s , -48d 13m 07.6s) | C | 60 | 17.5 | 40537 | 2022-04-08 18:43:11 | MASTER-SAAO | (06h 20m 24.77s , -53d 54m 58.6s) | C | 60 | 17.3 | 40669 | 2022-04-08 18:45:23 | MASTER-SAAO | (06h 33m 53.42s , -53d 53m 27.9s) | C | 60 | 17.4 | 40840 | 2022-04-08 18:48:14 | MASTER-SAAO | (06h 11m 00.85s , -48d 11m 45.8s) | C | 60 | 17.5 | 40919 | 2022-04-08 18:49:33 | MASTER-SAAO | (06h 13m 02.11s , -50d 04m 46.1s) | C | 60 | 17.4 | 41011 | 2022-04-08 18:51:05 | MASTER-SAAO | (06h 25m 34.52s , -50d 05m 46.3s) | C | 60 | 17.7 | 41106 | 2022-04-08 18:52:40 | MASTER-SAAO | (06h 04m 01.19s , -52d 00m 39.5s) | C | 60 | 17.1 | 41195 | 2022-04-08 18:54:09 | MASTER-SAAO | (06h 17m 05.09s , -52d 00m 21.5s) | C | 60 | 17.2 | 41291 | 2022-04-08 18:55:45 | MASTER-SAAO | (06h 21m 50.81s , -48d 10m 39.6s) | C | 60 | 17.8 | 41370 | 2022-04-08 18:57:05 | MASTER-SAAO | (06h 33m 49.29s , -48d 12m 25.5s) | C | 60 | 17.3 | 41474 | 2022-04-08 18:58:48 | MASTER-SAAO | (06h 20m 25.74s , -53d 52m 38.1s) | C | 60 | 17.2 | 41565 | 2022-04-08 19:00:19 | MASTER-SAAO | (06h 33m 52.54s , -53d 53m 31.3s) | C | 60 | 17.6 | 41738 | 2022-04-08 19:03:12 | MASTER-SAAO | (06h 36m 42.34s , -50d 06m 22.0s) | C | 60 | 17.6 | 41817 | 2022-04-08 19:04:32 | MASTER-SAAO | (06h 11m 06.65s , -48d 11m 50.7s) | C | 60 | 17.7 | 42081 | 2022-04-08 19:08:55 | MASTER-SAAO | (06h 01m 51.27s , -50d 04m 52.3s) | C | 60 | 17.6 | 42252 | 2022-04-08 19:11:46 | MASTER-SAAO | (06h 08m 09.12s , -53d 53m 57.1s) | C | 60 | 17.7 | 42785 | 2022-04-08 19:20:39 | MASTER-SAAO | (06h 36m 45.22s , -50d 05m 41.5s) | C | 60 | 17.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.