TITLE: GCN CIRCULAR NUMBER: 29004 SUBJECT: Swift GRB201209.24: Global MASTER-Net observations report DATE: 20/12/09 05:52:09 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, 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. 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, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (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 GRB201209.24 (trigger No 1011980,01h 32m 25.44s , -01d 45m 46.8s, R=0.05) errorbox 29 sec after notice time and 51 sec after trigger time at 2020-12-09 05:45:44 UT, with upper limit up to 16.8 mag. The observations began at zenith distance = 75 deg. The sun altitude is -33.0 deg. The galactic latitude b = -62 deg., longitude l = 147 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1499038 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 57 | MASTER-OAFA | C | 10 | 16.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.