TITLE: GCN CIRCULAR NUMBER: 33994 SUBJECT: Swift GRB 230618A: Global MASTER-Net observations report DATE: 23/06/18 06:40:49 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 230618A ( K. L. Page (U Leicester) and S. Laha (GSFC/UMBC) report on behalf of et al., GCN 33989) errorbox 10 sec after notice time and 42 sec after trigger time at 2023-06-18 03:54:03 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 67 deg. The sun altitude is -78.0 deg. The galactic latitude b = 66 deg., longitude l = 314 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2224051 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 48 | MASTER-OAFA | C | 10 | 16.9 | 79 | MASTER- | C | 10 | 15.6 | 89 | MASTER-OAFA | C | 10 | 16.9 | 113 | MASTER- | C | 20 | 16.1 | 135 | MASTER-OAFA | C | 20 | 17.3 | 158 | MASTER- | C | 30 | 16.5 | 191 | MASTER-OAFA | C | 30 | 17.7 | 241 | MASTER-OAFA | C | 130 | 18.7 | Coadd 213 | MASTER- | C | 40 | 16.6 | 258 | MASTER-OAFA | C | 40 | 17.9 | 278 | MASTER- | C | 50 | 16.7 | 339 | MASTER-OAFA | C | 60 | 18.2 | 353 | MASTER- | C | 60 | 17.1 | 440 | MASTER-OAFA | C | 80 | 18.5 | 555 | MASTER-OAFA | C | 310 | 19.3 | Coadd 443 | MASTER- | C | 80 | 17.1 | 553 | MASTER- | C | 100 | 17.1 | 561 | MASTER-OAFA | C | 100 | 18.6 | 683 | MASTER- | C | 120 | 17.1 | 708 | MASTER-OAFA | C | 130 | 18.7 | 838 | MASTER- | C | 150 | 17.2 | 884 | MASTER-OAFA | C | 160 | 18.7 | 1064 | MASTER-OAFA | C | 520 | 19.5 | Coadd 1023 | MASTER- | C | 180 | 17.5 | 1085 | MASTER-OAFA | C | 180 | 18.6 | 1222 | MASTER- | C | 180 | 17.1 | 1297 | MASTER-OAFA | C | 180 | 18.8 | 1422 | MASTER- | C | 180 | 17.1 | 1508 | MASTER-OAFA | C | 180 | 18.6 | 1688 | MASTER-OAFA | C | 540 | 19.3 | Coadd 1622 | MASTER- | C | 180 | 17.1 | 1822 | MASTER- | C | 180 | 17.1 | 1902 | MASTER-OAFA | C | 180 | 18.5 | 2097 | MASTER- | C | 180 | 17.0 | 2114 | MASTER-OAFA | C | 180 | 18.5 | 2325 | MASTER-OAFA | C | 180 | 18.3 | 2505 | MASTER-OAFA | C | 540 | 19.0 | Coadd 2438 | MASTER- | C | 180 | 17.5 | 2536 | MASTER-OAFA | C | 180 | 18.5 | 2747 | MASTER-OAFA | C | 180 | 18.3 | 2778 | MASTER- | C | 180 | 17.4 | 2958 | MASTER-OAFA | C | 180 | 18.1 | 3118 | MASTER- | C | 180 | 17.4 | 3170 | MASTER-OAFA | C | 180 | 17.9 | 3381 | MASTER-OAFA | C | 180 | 17.9 | 3458 | MASTER- | C | 180 | 17.4 | 3799 | MASTER- | C | 180 | 17.5 | 3947 | MASTER-OAFA | C | 180 | 17.7 | 4138 | MASTER- | C | 180 | 17.5 | 4158 | MASTER-OAFA | C | 180 | 17.7 | 4477 | MASTER- | C | 180 | 17.5 | 4551 | MASTER-OAFA | C | 180 | 17.4 | 4763 | MASTER-OAFA | C | 180 | 17.3 | 4817 | MASTER- | C | 180 | 17.4 | 5011 | MASTER-OAFA | C | 180 | 17.0 | 5158 | MASTER- | C | 180 | 17.5 | 5222 | MASTER-OAFA | C | 180 | 16.9 | 5499 | MASTER- | C | 180 | 17.4 | 5795 | MASTER-OAFA | C | 180 | 16.5 | 5837 | MASTER- | C | 180 | 17.5 | 6177 | MASTER- | C | 180 | 17.5 | 6516 | MASTER- | C | 180 | 17.5 | 6856 | MASTER- | C | 180 | 17.5 | 7197 | MASTER- | C | 180 | 17.5 | 7537 | MASTER- | C | 180 | 17.5 | 7877 | MASTER- | C | 180 | 17.5 | 8218 | MASTER- | C | 180 | 17.5 | 8558 | MASTER- | C | 180 | 17.5 | 8899 | MASTER- | C | 180 | 17.5 | 9240 | MASTER- | C | 180 | 17.5 | 9581 | MASTER- | C | 180 | 17.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.