TITLE:   GCN CIRCULAR
NUMBER:  30014
SUBJECT: Swift GRB210514.71: Global MASTER-Net observations report 
DATE:    21/05/15 09:42:53 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@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-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB210514.71 (trigger No 20210514,00h 11m 52.08s , -21d 52m 30.0s, R=0.2) errorbox  33660 sec after notice time and 50658 sec after trigger time at 2021-05-15 07:12:18 UT, with upper limit up to  19.6 mag. The observations began at zenith distance = 79 deg. The sun  altitude  is -51.7 deg. 

The galactic latitude b = -80 deg., longitude l = 64 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1613204

We obtain a following upper limits.  

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

   50748 |         MASTER-OAFA |   C |   180 | 17.9 |        
   51348 |         MASTER-OAFA |   C |   180 | 17.0 |        
   53441 |         MASTER-OAFA |   C |   180 | 17.5 |        
   56400 |         MASTER-OAFA |   C |   180 | 18.5 |        
   56580 |         MASTER-OAFA |   C |   540 | 19.6 |  Coadd 
   56600 |         MASTER-OAFA |   C |   180 | 18.8 |        
   56800 |         MASTER-OAFA |   C |   180 | 19.1 |        
   56999 |         MASTER-OAFA |   C |   180 | 19.0 |        
   57199 |         MASTER-OAFA |   C |   180 | 19.1 |        
Filter C is a clear (unfiltred) band. 


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