TITLE: GCN CIRCULAR NUMBER: 36370 SUBJECT: Integral GRB240502.23: Global MASTER-Net observations report DATE: 24/05/02 12:19:45 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (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. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich (Blagoveschensk Educational State University) MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the Integral GRB240502.23 (trigger No 10671,07h 34m 35.27s , +16d 45m 27.8s, R=0.0545) errorbox 23897 sec after notice time and 23928 sec after trigger time at 2024-05-02 12:07:33 UT, with upper limit up to 17.3 mag. Observations started at twilight. The observations began at zenith distance = 56 deg. The sun altitude is -11.1 deg. The galactic latitude b = 17 deg., longitude l = 203 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2441081 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 24018 | MASTER-Amur | C | 180 | 17.3 | 24018 | MASTER-Amur | C | 180 | 15.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.