TITLE: GCN CIRCULAR NUMBER: 25948 SUBJECT: Swift GRB191004.9: Global MASTER-Net OT detection DATE: 19/10/04 21:44:00 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, F. Balakin Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University D. Buckley, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) Hugo Levato Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias 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) was pointed to the GRB191004.9 23 sec after notice time and 40 sec after trigger time at 2019-10-04 21:34:21 UT. On our first (10s exposure) set we found 1 optical transient within Swift error-box (ra=49.175 dec=-39.6125 r=0.05) brighter than 16.75. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 45 2019-10-04 21:34:21 10 (03h 16m 49.143s , -39d 38m 03.93s) 15.63 The 5-sigma upper limit has been about 16.75mag The message may be cited. ==================================================================== The galactic latitude b = -57 deg., longitude l = 244 deg. The observations made on zenit distance = 42 deg.The moon (42 % bright part) is 15 deg. above the horizon. The distance between moon and object is 106 The sun altitude is -51.4 deg. The object can be observed till sunrise at 2019-10-05 04:09:28