[vsnet-grb-info 28034] Fermi trigger No 644712030: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30137
SUBJECT: Fermi  trigger No 644712030: Global MASTER-Net observations report 
DATE:    21/06/07 04:34:33 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) started inspect of the Fermi GRB210606.94 (trigger No 644712030,05h 11m 04.08s , -31d 39m 00.0s, R=3.88) errorbox  10334 sec after notice time and 20370 sec after trigger time at 2021-06-07 04:19:55 UT, with upper limit up to  17.1 mag. Observations started at twilight.  The observations began at zenith distance = 77 deg. The sun  altitude  is -15.4 deg. 

The galactic latitude b = -34 deg., longitude l = 234 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1630093

We obtain a following upper limits.  

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

   20400 | 2021-06-07 04:19:55 |         MASTER-SAAO | (04h 51m 51.22s , -29d 20m 05.6s) |   C |    60 | 17.1 |        
   20480 | 2021-06-07 04:21:15 |         MASTER-SAAO | (05h 01m 07.65s , -29d 19m 39.3s) |   C |    60 | 16.7 |        
Filter C is a clear (unfiltred) band. 


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