[vsnet-grb-info 28419] Swift GRB210726.80: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30522
SUBJECT: Swift GRB210726.80: Global MASTER-Net observations report 
DATE:    21/07/26 19:24:23 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-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB210726.80 (trigger No 1061687,12h 53m 22.08s , +19d 11m 06.0s, R=0.05) errorbox  31 sec after notice time and 54 sec after trigger time at 2021-07-26 19:19:58 UT, with upper limit up to  15.0 mag. The observations began at zenith distance = 66 deg. The sun  altitude  is -18.0 deg. 

The galactic latitude b = 82 deg., longitude l = 310 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1671119

We obtain a following upper limits.  

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

      59 |      MASTER-Tavrida |  P\ |    10 | 14.1 |        
      94 |      MASTER-Tavrida |  P\ |    20 | 15.0 |        


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