[vsnet-grb-info 27136] Fermi GRB 210104A: Global MASTER-Net observations report

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29239
SUBJECT: Fermi GRB 210104A: Global MASTER-Net observations report 
DATE:    21/01/04 15:30:28 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-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 210104A ( Fermi GBM team, GCN 29232) errorbox  13896 sec after notice time and 13949 sec after trigger time at 2021-01-04 15:19:29 UT, with upper limit up to  18.0 mag. Observations started at twilight.  The observations began at zenith distance = 51 deg. The sun  altitude  is -10.7 deg. 

The galactic latitude b = 27 deg., longitude l = 149 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1518462

We obtain a following upper limits.  

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

   13980 | 2021-01-04 15:19:29 |      MASTER-Tavrida | (06h 52m 09.73s , +68d 11m 37.6s) |   C |    60 | 17.7 |        
   13980 | 2021-01-04 15:19:29 |      MASTER-Tavrida | (07h 08m 11.29s , +68d 09m 51.0s) |   C |    60 | 17.9 |        
   14060 | 2021-01-04 15:20:49 |      MASTER-Tavrida | (06h 59m 02.10s , +66d 11m 00.3s) |   C |    60 | 17.7 |        
   14060 | 2021-01-04 15:20:49 |      MASTER-Tavrida | (07h 13m 46.16s , +66d 09m 08.7s) |   C |    60 | 18.0 |        
Filter C is a clear (unfiltred) band. 


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