TITLE:   GCN CIRCULAR
NUMBER:  25855
SUBJECT: LIGO/Virgo S190923y: MASTER OT outburst detection inside NSBH merger error-box
DATE:    19/09/27 15:44:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tiurina, P.Balanutsa,A.Kuznetsov, V.Vladimirov, D. Vlasenko, I.Gorbunov,D.Zimnukhov,
V.Senik, T.Pogrosheva, K.Pozdnyakov, A.Chasovnikov, V.Topolev, F.Balakin, D.Kuvshinov(Lomonosov Moscow State University, SAI,Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix Aguilar OAFA),
H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova(Irkutsk State University, API),
A. Tlatov, D. Dormidontov(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational State University)


MASTER Global Robotic Net started LIGO/Virgo S190923y (Minazzoli et al. LVC GCN 25814, Ttrig = 2019-09-23 12:55:59.646 UT)
inspection 374 sec after notice time (798 sec after trigger time) at 2019-09-23 13:09:17 UT
(Lipunov et al. GCN 25812) https://master.sai.msu.ru/site/master2/ligo_1.php?id=10825 .


MASTER OT J162250.41-482250.3 discovery

MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L )
discovered OT source at (RA, Dec) = 16h 22m 50.41s -48d 22m 50.3s on 2019-09-26.80632 UT   (AT 2019rfj).

The OT unfiltered magnitude is 17.0m (mlim=18.6).

The OT is seen on 2 images on 2019-09-26 19:33:10,  19:21:06UT in MASTER-SAAO
and on 4 images on 2019-09-27 00:12:12-00:30:55 in MASTER-OAFA.
  There is no minor planet at this place.

We have reference images on 2019-09-23.89472 UT (nearest in time) with unfiltered mlim=18.2m.

Spectral observations are required.

The discovery and reference images are available at:

http://master.sai.msu.ru/static/OT/162250.41-482250.3.png



The observation and reduction will be continued.
The message may be cited.