TITLE:   GCN CIRCULAR
NUMBER:  31819
SUBJECT: Fermi GRB 220403A: Global MASTER-Net observations report 
DATE:    22/04/03 20:30:33 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 220403A ( Fermi GBM team, GCN 31818) errorbox  25928 sec after notice time and 25957 sec after trigger time at 2022-04-03 17:22:40 UT, with upper limit up to  19.0 mag. Observations started at twilight.  The observations began at zenith distance = 40 deg. The sun  altitude  is -11.4 deg. 

The galactic latitude b = -51 deg., longitude l = 251 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1931107

We obtain a following upper limits.  

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

   25988 | 2022-04-03 17:22:40 |         MASTER-SAAO | (04h 20m 06.06s , -55d 00m 19.5s) |   V |    60 | 17.1 |        
   26067 | 2022-04-03 17:23:59 |         MASTER-SAAO | (04h 20m 11.62s , -55d 00m 16.9s) |   C |    60 | 17.3 |        
   26931 | 2022-04-03 17:38:24 |         MASTER-SAAO | (04h 20m 10.16s , -54d 59m 21.9s) |   V |    60 | 17.2 |        
   27011 | 2022-04-03 17:39:44 |         MASTER-SAAO | (04h 20m 13.25s , -54d 58m 04.9s) |   C |    60 | 17.7 |        
   32778 | 2022-04-03 19:15:50 |         MASTER-SAAO | (04h 16m 32.90s , -29d 11m 52.6s) |   C |    60 | 18.4 |        
   32858 | 2022-04-03 19:17:10 |         MASTER-SAAO | (04h 25m 45.28s , -29d 10m 01.4s) |   C |    60 | 19.0 |        
   33896 | 2022-04-03 19:34:28 |         MASTER-SAAO | (04h 16m 37.18s , -29d 11m 05.9s) |   C |    60 | 18.0 |        
   33976 | 2022-04-03 19:35:48 |         MASTER-SAAO | (04h 25m 49.01s , -29d 09m 49.4s) |   C |    60 | 18.5 |        
   34928 | 2022-04-03 19:51:41 |         MASTER-SAAO | (04h 16m 45.67s , -29d 10m 04.1s) |   C |    60 | 17.5 |        
   35008 | 2022-04-03 19:53:00 |         MASTER-SAAO | (04h 25m 46.29s , -29d 10m 59.4s) |   C |    60 | 18.1 |        
Filter C is a clear (unfiltred) band. 


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