TITLE: GCN CIRCULAR NUMBER: 36163 SUBJECT: Swift GRB240418.85: Global MASTER-Net observations report DATE: 24/04/18 20:37:07 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB240418.85 (trigger No 1222885,15h 57m 17.26s , +23d 36m 26.3s, R=0.05) errorbox 18 sec after notice time and 78 sec after trigger time at 2024-04-18 20:25:26 UT, with upper limit up to 17.8 mag. The observations began at zenith distance = 41 deg. The sun altitude is -34.9 deg. The galactic latitude b = 48 deg., longitude l = 39 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2426906 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 88 | MASTER-Kislovodsk | P| | 20 | 17.0 | 98 | MASTER-Kislovodsk | P| | 40 | 17.3 | Coadd 171 | MASTER-Kislovodsk | P| | 10 | 16.5 | 202 | MASTER-Kislovodsk | P| | 10 | 16.5 | 236 | MASTER-Kislovodsk | P| | 20 | 17.0 | 275 | MASTER-Kislovodsk | P| | 30 | 17.3 | 331 | MASTER-Kislovodsk | P| | 40 | 17.5 | 395 | MASTER-Kislovodsk | P| | 50 | 17.5 | 470 | MASTER-Kislovodsk | P| | 60 | 17.8 | The observation and reduction will continue. The message may be cited.