TITLE: GCN CIRCULAR NUMBER: 38448 SUBJECT: Fermi GRB 241206A: Global MASTER-Net observations report DATE: 24/12/06 12:45:34 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 241206A ( Fermi GBM team, GCN 38447) errorbox 138 sec after notice time and 170 sec after trigger time at 2024-12-06 12:09:40 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 73 deg. The sun altitude is -28.5 deg. The galactic latitude b = 57 deg., longitude l = 99 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2698262 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 186 | 2024-12-06 12:09:40 | MASTER-Tunka | (13h 51m 49.84s , +53d 43m 36.3s) | C | 30 | 18.1 | 231 | 2024-12-06 12:09:40 | MASTER-Tunka | (13h 51m 49.88s , +53d 43m 35.4s) | C | 120 | 18.9 | Coadd 224 | 2024-12-06 12:10:13 | MASTER-Tunka | (13h 51m 49.88s , +53d 43m 33.9s) | C | 40 | 18.4 | 272 | 2024-12-06 12:10:57 | MASTER-Tunka | (13h 51m 49.94s , +53d 43m 31.7s) | C | 50 | 18.4 | 331 | 2024-12-06 12:11:50 | MASTER-Tunka | (13h 51m 49.97s , +53d 43m 28.4s) | C | 60 | 18.5 | 626 | 2024-12-06 12:16:21 | MASTER-Tunka | (14h 21m 06.04s , +56d 07m 49.0s) | C | 110 | 18.2 | 755 | 2024-12-06 12:18:14 | MASTER-Tunka | (14h 21m 06.00s , +56d 07m 43.3s) | C | 140 | 18.3 | 913 | 2024-12-06 12:20:38 | MASTER-Tunka | (14h 21m 05.87s , +56d 07m 35.0s) | C | 170 | 18.5 | 1092 | 2024-12-06 12:23:31 | MASTER-Tunka | (14h 21m 05.93s , +56d 07m 26.5s) | C | 180 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.