V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov,
A.Kuznetsov, P.Balanutsa, A. Chasovnikov, V.Topolev, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C. Lopez, C.Francile, F. Podesta (Observatorio Astronomico Felix Aguilar OAFA, San Juan National University),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE, SJNU)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O. Gress, N.M. Budnev, O.Ershova, Yu.Ishmuhametova, S.Yazev (Applied Physics Institute, Irkutsk State University),
V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Educational State University),
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
MASTER-OAFA robotic telescope (Global MASTER-Net http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,vol. 2010, 30L)
located in Argentina (OAFA observatory of San JuanNational University)
was pointed to the GRB190324A (LaPorte et al. GCN 23993, Kunzweiler et al. GCN 23994, Perri et al. GCN 23997, Beardmore et al. GCN 24001, Hui et al. GCN 24002)
17 sec after notice time and 252 sec after trigger time at 2019-03-24 22:48:14 UT (Lipunov et al., GCN23995).
The SunAltitude was -1.09, so the GRB optical counterpart (MASTER OT J031827.61-471252.6 +-0.7arcsec)
light curve started at 2019-03-24 23:26:22UT (2541 sec after trigger time)
with m_OT=17.6 +-0.2(preliminary automatic light curve).
The OT became brighter (17.0) and then shows classical decay.
This OT was also detected by Swift (Marshall et al. GCN 23996), and the spectra was observed by Perley et al. GCN23999).
MASTER-SAAO was pointed 12s after notice time, but the alert altitude was -0.6deg.
Reduction will be continued.
The message may be cited.