[vsnet-grb-info 28393] Swift GRB210724.84: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30496
SUBJECT: Swift GRB210724.84: Global MASTER-Net observations report 
DATE:    21/07/24 20:34:20 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 GRB210724.84 (trigger No 1061482,15h 09m 37.68s , -06d 16m 26.4s, R=0.05) errorbox  21 sec after notice time and 566 sec after trigger time at 2021-07-24 20:23:35 UT, with upper limit up to  17.2 mag. The observations began at zenith distance = 46 deg. The sun  altitude  is -56.0 deg. 

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB210724.84 errorbox  28 sec after notice time and 573 sec after trigger time at 2021-07-24 20:23:42 UT, with upper limit up to  15.3 mag. The observations began at zenith distance = 71 deg. The sun  altitude  is -23.3 deg. 

The galactic latitude b = 42 deg., longitude l = 354 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1669395

We obtain a following upper limits.  

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

     621 |         MASTER-SAAO | P\  |   110 | 17.1 |        
     629 |      MASTER-Tavrida |  P\ |   110 | 15.3 |        
     758 |         MASTER-SAAO | P\  |   140 | 17.2 |        
     773 |      MASTER-Tavrida |  P\ |   140 | 15.3 |        


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