TITLE: GCN CIRCULAR NUMBER: 28760 SUBJECT: Swift GRB201024A: Global MASTER-Net OT detection DATE: 20/10/24 03:09:25 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (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) was pointed to the Swift GRB201024A (trigger 1001514) 36 sec after notice time and 66 sec after trigger time at 2020-10-24 02:51:20 UT. On our first (10s exposure) set we found 1 optical transient within Swift error-box (ra=125.95 dec=3.35444 r=0.05) brighter than 16.5. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|----- 229 2020-09-25 21:54:16 40 (08h 23m 48.58s, +03d 21m 13.8s) 14.9 The 5-sigma upper limit has been about 17mag The message may be cited.