GCN Circular 25752

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, 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-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) started inspect of the LIGO/Virgo S190915ak errorbox  20 sec after notice time and 488 sec after trigger time at 2019-09-16 00:05:10 UT, with upper limit up to  18.0 mag. The observations began at zenit distance = 66 deg. The sun  altitude  is -28.9 deg. 

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the LIGO/Virgo S190915ak errorbox  42 sec after notice time and 510 sec after trigger time at 2019-09-16 00:05:32 UT, with upper limit up to  17.9 mag. The observations began at zenit distance = 66 deg. The sun  altitude  is -32.6 deg. 

MASTER-IAC robotic telescope  located in Spain (IAC Teide Observatory) started inspect of the LIGO/Virgo S190915ak errorbox  58 sec after notice time and 526 sec after trigger time at 2019-09-16 00:05:48 UT, with upper limit up to  15.4 mag. The observations began at zenit distance = 80 deg. The sun  altitude  is -56.6 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/ligo_1.php?id=10805

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     538 | 2019-09-16 00:05:10 |   MASTER-Kislovodsk | (12h 28m 43.081s , +69d 10m 37.29s) |   C |   100 | 17.9 |        
     538 | 2019-09-16 00:05:10 |   MASTER-Kislovodsk | (12h 51m 21.032s , +68d 43m 30.04s) |   C |   100 | 18.0 |        
     561 | 2019-09-16 00:05:32 |      MASTER-Tavrida | (12h 37m 08.804s , +69d 06m 05.53s) |   C |   100 | 16.9 |        
     561 | 2019-09-16 00:05:32 |      MASTER-Tavrida | (12h 39m 58.560s , +69d 11m 14.24s) |   C |   100 | 17.9 |        
     582 | 2019-09-16 00:05:48 |          MASTER-IAC | (12h 38m 17.588s , +69d 16m 19.88s) |  P| |   110 | 14.9 |        
     582 | 2019-09-16 00:05:48 |          MASTER-IAC | (12h 40m 14.677s , +69d 12m 29.84s) |  P- |   110 | 15.4 |        
Filter C is a clear (unfiltred) band. 


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