TITLE: GCN CIRCULAR NUMBER: 35240 SUBJECT: GRB 231129C: MASTER OT detection DATE: 23/11/30 19:18:20 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> G.Antipov, V.Lipunov, E.Gorbovskoy (Lomonosov MSU), D.Buckley (SAAO), D.Svinkin (Ioffe Institute, Konus-Wind), Ya.Kechin, K.Zhirkov, A.Kuznetsov, D.Vlasenko, P.Balanutsa, Yu.Tselik, N.Tiurina, I.Gorbunov, V.Vladimirov, D.Zimnukhov, V.Senik, A.Yudin,A.Chasovnikov, D.Cheryasov, A.Sosnovskij (Lomonosov MSU,SAI,PhysicsDepartment), O.A. Gres, N.M. Budnev (Irkutsk State University, API), C.Francile. F. Podesta, R.Podesta (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) MASTER Global robotic net (http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L) started GECAM-B (Ttrigger=2023-11-29 19:10:18.2, Tnotice_socket=2023-11-29 19:11:45.56 Zheng et al. GCN 35231) and Fermi very bright GRB 231129C (Ttrigger=2023-11-29 19:10:18.11, Tnotice_socket=2023-11-29 19:19:40.72 Sharma et al. GCN 35227, GCN 35238, also MAXI-GSC (GCN 35223), CALET (GCN 35228), AstroSat (GCN 35230)) 55 sec after notice time and 90 sec after trigger time at 2023-11-29 19:11:48 UT (Lipunov et al. GCN 35216) by MASTER-SAAO. There is OT source at R.A.,Dec(2000)=00:44:37.97 -81:59:48.75 +-4" with m_OT~17.6 at maximum (unfiltered) at first images with decay inside Swift XRT error-box (Evans et al. GCN 35225, Gropp et al. GCN 35234) Reduction will be continued. View this GCN Circular online at https://gcn.nasa.gov/circulars/35240. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...