TITLE:   GCN CIRCULAR
NUMBER:  33446
SUBJECT: Fermi GRB 230310A: Global MASTER-Net observations report 
DATE:    23/03/10 01:15:14 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(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 230310A ( Fermi GBM team, GCN 33445) errorbox  187 sec after notice time and 218 sec after trigger time at 2023-03-10 00:48:39 UT, with upper limit up to  18.0 mag. The observations began at zenith distance = 54 deg. The sun  altitude  is -43.8 deg. 

The galactic latitude b =  9 deg., longitude l =  1 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2203155

We obtain a following upper limits.  

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

     249 | 2023-03-10 00:48:39 |         MASTER-SAAO | (17h 11m 56.73s , -17d 55m 16.0s) |   C |    60 | 18.0 |        
     249 | 2023-03-10 00:48:39 |         MASTER-SAAO | (17h 11m 04.28s , -17d 54m 58.3s) |   C |    60 | 17.9 |        
     339 | 2023-03-10 00:50:09 |         MASTER-SAAO | (17h 20m 26.28s , -17d 55m 05.0s) |   C |    60 | 17.4 |        
     339 | 2023-03-10 00:50:09 |         MASTER-SAAO | (17h 19m 33.91s , -17d 54m 48.7s) |   C |    60 | 17.3 |        
     418 | 2023-03-10 00:51:29 |         MASTER-SAAO | (17h 17m 28.93s , -16d 01m 23.8s) |   C |    60 | 18.0 |        
     418 | 2023-03-10 00:51:29 |         MASTER-SAAO | (17h 16m 37.06s , -16d 01m 07.8s) |   C |    60 | 17.7 |        
     510 | 2023-03-10 00:53:01 |         MASTER-SAAO | (17h 25m 51.99s , -15d 59m 37.5s) |   C |    60 | 17.7 |        
     510 | 2023-03-10 00:53:01 |         MASTER-SAAO | (17h 25m 00.18s , -15d 59m 22.0s) |   C |    60 | 17.6 |        
     604 | 2023-03-10 00:54:34 |         MASTER-SAAO | (17h 07m 28.98s , -19d 47m 03.3s) |   C |    60 | 18.0 |        
     604 | 2023-03-10 00:54:34 |         MASTER-SAAO | (17h 06m 35.75s , -19d 46m 48.4s) |   C |    60 | 17.9 |        
     684 | 2023-03-10 00:55:54 |         MASTER-SAAO | (17h 16m 04.51s , -19d 48m 20.0s) |   C |    60 | 17.8 |        
     684 | 2023-03-10 00:55:54 |         MASTER-SAAO | (17h 15m 11.34s , -19d 48m 05.3s) |   C |    60 | 17.6 |        
Filter C is a clear (unfiltred) band. 


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