TITLE:   GCN CIRCULAR
NUMBER:  29723
SUBJECT: Fermi GRB 210324C: Global MASTER-Net observations report 
DATE:    21/03/24 22:30:17 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 GRB 210324C ( Fermi GBM team, GCN 29718) errorbox  2759 sec after notice time and 2786 sec after trigger time at 2021-03-24 20:46:24 UT, with upper limit up to  17.1 mag. The observations began at zenith distance = 81 deg. The sun  altitude  is -48.8 deg. 

The galactic latitude b = -63 deg., longitude l = 263 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1576010

We obtain a following upper limits.  

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

    2876 | 2021-03-24 20:46:24 |         MASTER-SAAO | (02h 45m 04.74s , -47d 04m 20.4s) |   C |   180 | 17.1 |        
    3076 | 2021-03-24 20:49:44 |         MASTER-SAAO | (02h 44m 59.67s , -47d 05m 16.2s) |   C |   180 | 16.7 |        
Filter C is a clear (unfiltred) band. 


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