[vsnet-grb-info 27990] Fermi GRB 210528A: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30093
SUBJECT: Fermi GRB 210528A: Global MASTER-Net observations report 
DATE:    21/05/28 23:15:13 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) started inspect of the Fermi GRB 210528A ( Fermi GBM team, GCN 30090) errorbox  23846 sec after notice time and 23874 sec after trigger time at 2021-05-28 20:41:40 UT, with upper limit up to  18.1 mag. Observations started at twilight.  The observations began at zenith distance = 61 deg. The sun  altitude  is -10.4 deg. 

The galactic latitude b = 19 deg., longitude l = 244 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1623301

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   23904 | 2021-05-28 20:41:40 |          MASTER-IAC | (09h 02m 44.74s , -13d 49m 49.9s) |   C |    60 | 16.3 |        
   24064 | 2021-05-28 20:44:20 |          MASTER-IAC | (09h 07m 35.44s , -15d 45m 51.5s) |   C |    60 | 16.7 |        
   24224 | 2021-05-28 20:46:59 |          MASTER-IAC | (09h 00m 12.10s , -15d 50m 05.1s) |   C |    60 | 17.2 |        
   24224 | 2021-05-28 20:46:59 |          MASTER-IAC | (08h 51m 50.12s , -15d 44m 39.9s) |   C |    60 | 16.6 |        
   24463 | 2021-05-28 20:50:59 |          MASTER-IAC | (08h 55m 21.79s , -13d 57m 05.7s) |   C |    60 | 17.5 |        
   24463 | 2021-05-28 20:50:59 |          MASTER-IAC | (08h 47m 03.96s , -13d 51m 40.4s) |   C |    60 | 17.0 |        
   24623 | 2021-05-28 20:53:38 |          MASTER-IAC | (09h 05m 43.99s , -17d 44m 47.2s) |   C |    60 | 17.8 |        
   24623 | 2021-05-28 20:53:38 |          MASTER-IAC | (08h 57m 16.72s , -17d 39m 23.2s) |   C |    60 | 17.4 |        
   24863 | 2021-05-28 20:57:39 |          MASTER-IAC | (09h 02m 46.24s , -13d 50m 39.8s) |   C |    60 | 17.5 |        
   25423 | 2021-05-28 21:06:59 |          MASTER-IAC | (09h 07m 34.43s , -15d 44m 11.1s) |   C |    60 | 17.9 |        
   28711 | 2021-05-28 22:01:46 |          MASTER-IAC | (09h 00m 07.99s , -15d 52m 31.3s) |   C |    60 | 18.1 |        
   28950 | 2021-05-28 22:05:46 |          MASTER-IAC | (08h 55m 24.26s , -13d 58m 30.1s) |   C |    60 | 18.1 |        
   29110 | 2021-05-28 22:08:26 |          MASTER-IAC | (09h 05m 38.03s , -17d 45m 24.2s) |   C |    60 | 18.1 |        
   29670 | 2021-05-28 22:17:46 |          MASTER-IAC | (09h 00m 15.02s , -15d 50m 52.6s) |   C |    60 | 18.0 |        
   29910 | 2021-05-28 22:21:45 |          MASTER-IAC | (08h 55m 27.00s , -13d 57m 44.5s) |   C |    60 | 17.9 |        
   30070 | 2021-05-28 22:24:25 |          MASTER-IAC | (09h 05m 44.96s , -17d 46m 24.8s) |   C |    60 | 18.0 |        
Filter C is a clear (unfiltred) band. 


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