[vsnet-grb-info 28606] Swift GRB 210824A: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30709
SUBJECT: Swift GRB 210824A: Global MASTER-Net observations report 
DATE:    21/08/25 04:10:10 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 GRB 210824A ( K. L. Page et al., GCN 30700) errorbox  45612 sec after notice time and 45332 sec after trigger time at 2021-08-24 16:50:54 UT, with upper limit up to  19.4 mag. Observations started at twilight.  The observations began at zenith distance = 46 deg. The sun  altitude  is -7.8 deg. 

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 210824A errorbox  48172 sec after notice time and 47892 sec after trigger time at 2021-08-24 17:33:34 UT, with upper limit up to  19.1 mag. Observations started at twilight.  The observations began at zenith distance = 47 deg. The sun  altitude  is -10.9 deg. 

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB 210824A errorbox  50320 sec after notice time and 50041 sec after trigger time at 2021-08-24 18:09:23 UT, with upper limit up to  17.4 mag. The observations began at zenith distance = 56 deg. The sun  altitude  is -21.7 deg. 

The galactic latitude b = 49 deg., longitude l = 17 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1698433

We obtain a following upper limits.  

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

   45363 |         MASTER-SAAO |   C |    60 | 16.0 |        
   45522 |         MASTER-SAAO |   C |    60 | 17.0 |        
   45602 |         MASTER-SAAO |   C |    60 | 17.2 |        
   46324 |         MASTER-SAAO |   C |    60 | 18.5 |        
   46483 |         MASTER-SAAO |   C |    60 | 18.7 |        
   46563 |         MASTER-SAAO |   C |    60 | 18.8 |        
   47281 |         MASTER-SAAO |   C |    60 | 19.4 |        
   47440 |         MASTER-SAAO |   C |    60 | 19.3 |        
   47520 |         MASTER-SAAO |   C |    60 | 19.4 |        
   47983 |      MASTER-Tavrida |   C |   180 | 17.8 |        
   49103 |      MASTER-Tavrida |   C |   180 | 19.1 |        
   49875 |      MASTER-Tavrida |   C |    60 | 18.7 |        
   50071 |   MASTER-Kislovodsk |   C |    60 | 15.8 |        
   50252 |      MASTER-Tavrida |   C |   180 | 19.0 |        
   50310 |   MASTER-Kislovodsk |   C |   180 | 15.1 |        
   50310 |   MASTER-Kislovodsk |   C |   180 | 15.3 |        
   51024 |      MASTER-Tavrida |   C |    60 | 18.4 |        
   51479 |      MASTER-Tavrida |   C |    60 | 18.4 |        
   51558 |      MASTER-Tavrida |   C |    60 | 18.4 |        
   52080 |   MASTER-Kislovodsk |   C |    60 | 16.6 |        
   52268 |         MASTER-SAAO |   C |    60 | 18.8 |        
   52527 |      MASTER-Tavrida |   C |    60 | 18.1 |        
   52605 |      MASTER-Tavrida |   C |    60 | 18.1 |        
   53102 |   MASTER-Kislovodsk |   C |   180 | 17.1 |        
   53102 |   MASTER-Kislovodsk |   C |   180 | 17.4 |        
   53227 |         MASTER-SAAO |   C |    60 | 18.6 |        
   53242 |   MASTER-Kislovodsk |   C |    60 | 17.0 |        
   53476 |      MASTER-Tavrida |   C |    60 | 17.9 |        
   53555 |      MASTER-Tavrida |   C |    60 | 17.9 |        
   54344 |   MASTER-Kislovodsk |   C |   180 | 17.0 |        
   54344 |   MASTER-Kislovodsk |   C |   180 | 17.1 |        
   54478 |      MASTER-Tavrida |   C |   180 | 18.0 |        
   54482 |         MASTER-SAAO |   C |   180 | 18.5 |        
   54617 |      MASTER-Tavrida |   C |    60 | 17.6 |        
   55565 |         MASTER-SAAO |   C |   180 | 17.0 |        
   55613 |      MASTER-Tavrida |   C |   180 | 17.8 |        
   55831 |      MASTER-Tavrida |   C |    60 | 17.5 |        
   56489 |   MASTER-Kislovodsk |   C |    60 | 12.8 |        
   56489 |   MASTER-Kislovodsk |   C |    60 | 14.0 |        
   56723 |         MASTER-SAAO |   C |   180 | 15.9 |        
Filter C is a clear (unfiltred) band. 


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