GCN Circular 25378

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

V.B. Petkov, M.M. Boliev, A.N. Kurenya,
(Baksan Neutrino Observatory, Institute for Nuclear Research of RAS, Moscow, Russia),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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

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)

MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Baksan Neutrino Observatory Alert 190816.83 (  5h  9m 36.00s , -62d  6m 00.00s, R=3) errorbox  14744 sec after trigger time at 2019-08-16 23:55:26 UT, with upper limit up to  17.7 mag. The observations began at zenit distance = 60 deg. The sun  altitude  is -65.3 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/observ.php?id=1108240

We obtain a following upper limits.  

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

   14774 | 2019-08-16 23:55:26 |         MASTER-SAAO | (  4h 43m 27.27s , -64d  0m 27.80s) |   C |    60 | 17.7 |        
   15890 | 2019-08-17 00:14:02 |         MASTER-SAAO | (  4h 40m 33.80s , -60d  1m 01.09s) |   C |    60 | 17.5 |        
   16252 | 2019-08-17 00:20:03 |         MASTER-SAAO | (  4h 40m 34.61s , -60d  0m 23.16s) |   C |    60 | 17.2 |        
   16348 | 2019-08-17 00:21:40 |         MASTER-SAAO | (  4h 56m 33.46s , -59d 59m 48.25s) |   C |    60 | 17.3 |        
   16643 | 2019-08-17 00:26:35 |         MASTER-SAAO | (  5h  5m 35.75s , -66d  0m 04.93s) |   C |    60 | 17.1 |        
   16741 | 2019-08-17 00:28:12 |         MASTER-SAAO | (  4h 56m 33.08s , -60d  0m 10.76s) |   C |    60 | 17.0 |        
   17267 | 2019-08-17 00:36:59 |         MASTER-SAAO | (  5h  5m 36.37s , -65d 59m 50.10s) |   C |    60 | 16.9 |        
Filter C is a clear (unfiltred) band. 


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