TITLE:   GCN CIRCULAR
NUMBER:  29360
SUBJECT: Fermi  trigger No 633348010: Global MASTER-Net observations report 
DATE:    21/01/26 18:45:29 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@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 GRB210126.42 (trigger No 633348010,04h 42m 43.20s , -67d 56m 24.0s, R=3.85) errorbox  30650 sec after notice time and 30677 sec after trigger time at 2021-01-26 18:31:23 UT, with upper limit up to  17.8 mag. Observations started at twilight.  The observations began at zenith distance = 37 deg. The sun  altitude  is -9.8 deg. 

The galactic latitude b = -37 deg., longitude l = 279 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1533636

We obtain a following upper limits.  

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

   30708 | 2021-01-26 18:31:23 |         MASTER-SAAO | (04h 56m 00.76s , -68d 07m 33.7s) |   C |    60 | 16.6 |        
   30788 | 2021-01-26 18:32:43 |         MASTER-SAAO | (04h 32m 29.58s , -66d 08m 27.9s) |   C |    60 | 17.5 |        
   30867 | 2021-01-26 18:34:03 |         MASTER-SAAO | (04h 37m 21.61s , -70d 08m 15.9s) |   C |    60 | 17.1 |        
   30947 | 2021-01-26 18:35:23 |         MASTER-SAAO | (04h 13m 00.51s , -68d 07m 53.2s) |   C |    60 | 17.6 |        
   31027 | 2021-01-26 18:36:43 |         MASTER-SAAO | (05h 11m 57.07s , -66d 07m 23.3s) |   C |    60 | 17.4 |        
   31107 | 2021-01-26 18:38:03 |         MASTER-SAAO | (04h 49m 17.82s , -64d 08m 12.6s) |   C |    60 | 17.8 |        
   31187 | 2021-01-26 18:39:22 |         MASTER-SAAO | (04h 15m 15.48s , -72d 08m 35.2s) |   C |    60 | 17.7 |        
Filter C is a clear (unfiltred) band. 


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