TITLE: GCN CIRCULAR NUMBER: 38656 SUBJECT: Fermi GRB 241223A: Global MASTER-Net observations report DATE: 24/12/23 21:16:07 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 241223A ( Fermi GBM team, GCN 38650) errorbox 29603 sec after notice time and 29637 sec after trigger time at 2024-12-23 20:22:44 UT, with upper limit up to 18.4 mag. The observations began at zenith distance = 79 deg. The sun altitude is -25.8 deg. The galactic latitude b = 21 deg., longitude l = 275 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2719951 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 29667 | 2024-12-23 20:22:44 | MASTER-SAAO | (10h 31m 23.22s , -34d 45m 27.5s) | C | 60 | 17.9 | 31507 | 2024-12-23 20:53:23 | MASTER-SAAO | (10h 31m 16.29s , -34d 45m 04.3s) | C | 60 | 18.3 | 32074 | 2024-12-23 21:02:50 | MASTER-SAAO | (10h 40m 01.52s , -34d 44m 52.8s) | C | 60 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/38656. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...