TITLE:   GCN CIRCULAR
NUMBER:  24341
SUBJECT: LIGO/Virgo S190426c: MASTER analysys of GRAWITA transients 
DATE:    19/04/29 11:47:01 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, D.Vlasenko, V.Vladimirov, D.Zimnukhov, A.Kuznetsov,
P.Balanutsa, I.Gorbunov, A. Chasovnikov, V.Grinshpun, F.Balakin, T.Pogrosheva (Lomonosov Moscow State University, SAI, Physics Department),

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres (The Instituto de Astrofisica de Canarias),

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)

D. Buckley (South African Astronomical Observatory),

O. Gress, N.M. Budnev, O.Ershova (Applied Physics Institute, Irkutsk Stat University),

V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk EducationState University),

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov (Kislovodsk Solar  Station of the Pulkovo Observatory),

MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
started inspect of GW190426 /  LIGO/Virgo S190426c errorbox (Chatterjee et al. GCN 24237 https://gcn.gsfc.nasa.gov/other/S190426c.gcn3 )
at 2019-04-26 16:15:47 UT  (Lipunov et al. GCN 24236) and continuied  several nights.

There is no OTs at GRAWITA positions ( Izzo et al. GCN 24340 ) several hours befor

1) 21 57 16.26 +83 22 39.4
Date_UT             unfiltmlim    MASTER_observatory
2019-04-26 20:38:02      19.6     MASTER-Kislovodsk
2019-04-26 18:38:53      19.6     MASTER-Tavrida
2019-04-26 16:41:15      19.2	  MASTER-Tunka

There is variable star in 5", presented in GSC2.3.2 (red fmag=19.9 in 1996), PanSTARR source with rmag=20.73(2010Dec30). It's not presented in 
USNO-B1, it means 22mPOSS limit in history.

2)  22:01:04.54    +83:48:36.9
Date_UT            unfiltmlim   MASTER_observatory
2019-04-26 20:38:02    19.6    MASTER-Kislovodsk
2019-04-26 18:38:53    19.6    MASTER-Tavrida
2019-04-26 16:25:18    19.6    MASTER-Tunka
2019-04-27 11:59:22    16.5    MASTER-Amur

there is also a star in 6.9" in PanSTARR catalogue with imag=21.14 (no  g,r)

3) 22 00 50.38 +84 44 36.5
Date_UT              unfiltmlim        MASTER_observatory
2019-04-26 20:56:51   20.0             MASTER-Tavrida
2019-04-26 20:38:02   19.7             MASTER-Kislovodsk
2019-04-26 16:25:18   19.5             MASTER-Tunka

There is a star in 4.3" in USNO-B1 (B1=20.77,R1=19.08) with proper motion .



The message may be cited.