[vsnet-grb-info 28323] Swift GRB 210708B: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30426
SUBJECT: Swift GRB 210708B: Global MASTER-Net observations report 
DATE:    21/07/08 23:21:27 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-IAC robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Spain (IAC Teide Observatory) was pointed to the Swift GRB 210708B ( B. Sbarufatti et al., GCN 30417) errorbox  27094 sec after notice time and 27800 sec after trigger time at 2021-07-08 21:06:45 UT, with upper limit up to  16.5 mag. Observations started at twilight.  The observations began at zenith distance = 79 deg. The sun  altitude  is -13.0 deg. 

MASTER-OAFA robotic telescope  located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 210708B errorbox  34540 sec after notice time and 35247 sec after trigger time at 2021-07-08 23:10:51 UT, with upper limit up to  17.2 mag. The observations began at zenith distance = 77 deg. The sun  altitude  is -17.6 deg. 

The galactic latitude b = 42 deg., longitude l = 218 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1655856

We obtain a following upper limits.  

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

   27891 |          MASTER-IAC |   C |   180 | 16.5 |        
   35337 |         MASTER-OAFA |   C |   180 | 17.2 |        
Filter C is a clear (unfiltred) band. 


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