TITLE: GCN CIRCULAR NUMBER: 24058 SUBJECT: Hard Fermi GRB190404.29/TriggNum576054086: MASTER optical counterpart discovery near PGC020455 DATE: 19/04/07 18:19:41 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, T.Pogrosheva, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov, A.Kuznetsov, P.Balanutsa, I.Gorbunov, 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 (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-Tavrida robotic telescope (Global MASTER-Net http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) automatically was pointed to the FERMI GRB190404.29 (trigger 576054086 07h 09m 04.08s , +55d 16m 01.20s, R=11.45 Ttrig=2019-04-04 07:01:21.93UT) 40918 sec after trigger time at 2019-04-04 18:23:19 UT, with upper limit up to 20.2 mag. The observations started at zenit distance = 25deg. The sun altitude was -22.6 deg. MASTER OT J071404.52+550304.2 discovery in PGC020455 MASTER-Tavrida auto-detection system discovered OT source at (RA, Dec) = 07h 14m 04.52s +55d 03m 04.2s on 2019-04-04.78094 UT. The OT unfiltered magnitude is 18.5 (limit 19.8m). There is 15 mag (B) galaxy PGC020455 at 160 Mpc. OT offset is 21.2W 55.1N arcsec from PGC020455 center. The OT is seen in 2 inspection images (there is no minor planet at this place): 2019-04-04 18:36:58.335 18.5 +-0.2 2019-04-04 18:44:33.528 18.3 +-0.2 There is no OT in 24h at 2019-04-05 19:02:36UT at MASTER-Tavrida image with mlim=19.8. We have also reference image (without OT) on 2017-08-03.00720 UT with unfiltered magnitude limit 19.6m. Deep photometry and spectroscopy are required. The discovery and reference images are available at http://observ.pereplet.ru/images/MASTEROTJ071404.52+550304.2.jpg MASTER cover map is http://observ.pereplet.ru/images/MASTERGRB180404.29map/jpg The message may be cited. [GCN OPS NOTE(21apr19): Per autor's request, the GB name in the Subject-line was changed from "GRB1904204.29" to "GRB190404.29".]