TITLE: GCN CIRCULAR NUMBER: 24241 SUBJECT: Baksan Neutrino Observatory Alert 190405.62: Global MASTER-Net:LIGO/Virgo S190425z: PanSTARR OT AT2019ebq/PS19qp DATE: 19/04/26 17:32:58 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov, A.Kuznetsov, P.Balanutsa, A. Chasovnikov, V.Topolev, D.Kuvshinov, F.Balakin (Lomonosov Moscow State University, SAI, Physics Department), V.B. Petkov, M.M. Boliev, A.N. Kurenya, Baksan Neutrino Observatory, Institute for Nuclear Research of RAS, Moscow, Russia 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), 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) MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010,Advances in Astronomy,vol. 2010, 30L) started LIGO/Virgo S190425z (Singer et al. GCN 24168) inspection at 2019-04-25 09:10:18 UT (Lipunov et al. GCN 24167) at MASTER-OAFA (Argentina). MASTER-OAFA started PS19qp (Smith et al., GCN 24210 ) at 2019-04-26 01:56:40. Looking at our old images AT2019ebq / PS19qp, we found a very recent inspection of this field due to the neutrino BNO alert 3 weeks ago and automatical Circular (not published yet). To establish a possible connection of this supernova with neutrinos, it is extremely important to determine the age of the supernova AT2019ebq / PS19qp . Thus the object is not associated with LIGO/Virgo S190425z but may be connected with BNO Alert190405.62 . Below you can find automatic Circular (not published yet): 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 BAKSAN Alert190405.62 ( 17h 25m 36.00s , - 2d 36m 00.00s, R=3) 19864 sec after trigger time at 2019-04-05 20:29:29 UT, with upper limit up to 19.2 mag. The observations began at zenit distance = 83 deg. The sun altitude is -39.9 deg. MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the BAKSAN Alert190405.62 28940 sec after trigger time at 2019-04-05 23:00:45 UT, with upper limit up to 19.1 mag. The observations began at zenit distance = 63 deg. The sun altitude is -37.1 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) was pointed to the BAKSAN Alert190405.62 1 days 39324 sec after trigger time at 2019-04-07 01:53:49 UT, with upper limit up to 19.2 mag. The observations began at zenit distance = 34 deg. The sun altitude is -38.5 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) was pointed to the BAKSAN Alert190405.62 1 days 54872 sec after trigger time at 2019-04-07 06:12:57 UT, with upper limit up to 18.0 mag. The observations began at zenit distance = 49 deg. The sun altitude is -56.9 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=991224 The follow up spectral and photometric observations of AT2019ebq/PS19qp are required. This message may be cited