Difference: GCNCIRCULAR20771 (1 vs. 2)

V.M. Lipunov, P.Balanutsa, E. Gorbovskoy, T.Pogrosheva, N.Tyurina, A.Kuznetsov, O.Gress, V.Shumkov, V.Kornilov, D.Vlasenko, M.I.Panchenko, A.V.Krylov, I.Gorbunov, Lomonosov Moscow State University, Sternberg Astronomical Institute

R. Rebolo, M. Serra-Ricart, G. Israelian, N.Lodiu, The Instituto de Astrofisica de Canarias

D.Buckley, South African Astronomical Observatory

N.M. Budnev, O. Gress, K. Ivanov, S.Yazev, Irkutsk State University

R.Podesta, C.Lopez, F. Podesta, Observatorio Astronomico Felix Aguilar (OAFA) , National University of San Juan, Argentina

H. Levato, C. Saffe, Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina

A. Tlatov, V.Sennik, Kislovodsk Solar Station of the Pulkovo Observatory

V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk

MASTER OT J192402.43+421720.0 - bright PSN in PGC2195963

MASTER-IAC auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 19h 24m 02.43s +42d 17m 20.0s on 2017-02-27 03:59:05.256UT during LIGO G275404 inspection (2017-02-25 18:30:51 UTC event time).

The OT unfiltered magnitude is ~16.6m (mlim=18.4). The OT is seen in 5 image. There is no minor planet at this place.

There is PGC2195963 disc galaxy in 12.3" of this PSN ( http://leda.univ-lyon1.fr/ledacat.cgi?o=PGC2195963 )

We have reference image on 2016-03-19 05:07:19UT with unfiltered mlim=19.8. Spectral observations are required.

The discovery and reference images are

The position of MASTER OT J173532.70+103810.5 (Lipunov et al. GCN #20740, Sollerman et al. GRC #20758) is inside G274296 (2017-02-17) LIGO localization (Shawhan et al. GCN #20689 )

-- ThomasKupfer - 28 Feb 2017