[vsnet-grb-info 28157] Swift GRB210619.99: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30260
SUBJECT: Swift GRB210619.99: Global MASTER-Net observations report 
DATE:    21/06/20 00:10:13 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

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,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

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-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) was pointed to the Swift GRB210619.99 (trigger No 1056757,21h 18m 51.12s , +33d 51m 36.0s, R=0.05) errorbox  0 sec after notice time and 36 sec after trigger time at 2021-06-20 00:00:02 UT, with upper limit up to  16.7 mag. The observations began at zenith distance = 72 deg. The sun  altitude  is -70.4 deg. 

The galactic latitude b = -11 deg., longitude l = 81 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1640637

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

      42 |         MASTER-SAAO | P\  |    10 | 15.8 |        
      57 |         MASTER-SAAO | P\  |    40 | 16.5 |  Coadd 
      71 |         MASTER-SAAO | P\  |    10 | 15.6 |        
     106 |         MASTER-SAAO | P\  |    20 | 16.2 |        
     150 |         MASTER-SAAO | P\  |    30 | 16.5 |        
     205 |         MASTER-SAAO | P\  |    40 | 16.4 |        
     269 |         MASTER-SAAO | P\  |    50 | 16.7 |        
     344 |         MASTER-SAAO | P\  |    60 | 16.7 |        


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