Difference: GCNCIRCULAR20782 ( vs. 1)

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

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

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

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

D.Buckley, S. Potter, M. Kotze, South African Astronomical Observatory

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

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

MASTER Global robotic Net observed G275697 error-box synchronousely by very wide field cameras (MASTER-VWFC 2x400 square degrees) with m_lim=11mag on the single images, covering north (MASTER-Tunka) and south (MASTER-SAAO) parts of error-box.

MASTER-II G275697 inspection started 29min05s after the trigger time, covering 338 degrees for 24h after the trigger time up to 20.5mag, 640 for 36h after trigger time.

MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru) started inspection of the the LIGO/Virgo G275697 29min05s after the trigger time (18:57:31.375 Siellez et al GCN#20763) on 2017-02-27 19:26:36 UT.

The 5-sigma upper limit on the single images are 20.0-20.3, the summ are 20.8 mag

MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru) started inspection of the the LIGO/Virgo G275697 after sunset 49min28s after the trigger time on2017-02-27 19:46:59

The 5-sigma upper limit on the single images are 20.0-20.3, the summ are 20.8 mag

MASTER optical transients, detected during G275697 error-box inspection:

1) MASTER OT J225444.27+755459.8 discovery - not connected with trigger!

MASTER-IAC auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 22h 54m 44.27s +75d 54m 59.8s on 2017-02-26.93361 UT with unfiltered m_OT= 16.9m (mlimit=19.1m).

The OT is seen in 8 images. We have reference image without OT on 2015-08-18.99625 UT with unfiltered magnitude limit 19.6m.

There is no any sources in VIZIER inside 3", it means 22mag POSS limit in history and Amplitude of curent outburst more then 5.1mag (as minimum)

Spectral observations are required.

The discovery and reference images are available at:

2) MASTER OT J104304.78+020550.2 detection - QSO activity

MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 10h 43m 04.78s +02d 05m 50.2s on 2017-02-27.80508 UT.

The OT unfiltered magnitude is 18.5m (mlim=20.0).

The OT is seen in 4 images. We have reference image on 2015-04-22.74625 UT with unfiltered mlim=19.7m and m_QSO<~19.7.

-- ThomasKupfer - 01 Mar 2017