GCN Circular 35250

V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(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. Gress, N.M. Budnev, O.Ershova
(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),

V. Yurkov, A. Gabovich
(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 GRB231201.79 (trigger No 723149952,03h 17m 48.00s , -54d 56m 24.0s, R=1.34) errorbox  59 sec after notice time and 94 sec after trigger time at 2023-12-01 19:00:41 UT, with upper limit up to  18.1 mag. Observations started at twilight.  The observations began at zenith distance = 34 deg. The sun  altitude  is -16.9 deg. 

The galactic latitude b = -52 deg., longitude l = 269 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2321367

We obtain a following upper limits.  

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

     104 | 2023-12-01 19:00:41 |         MASTER-SAAO | (03h 24m 11.37s , -55d 13m 46.5s) |   C |    20 | 14.8 |        
     104 | 2023-12-01 19:00:41 |         MASTER-SAAO | (03h 09m 05.64s , -55d 03m 07.1s) |   C |    20 | 15.0 |        
     144 | 2023-12-01 19:01:21 |         MASTER-SAAO | (03h 09m 12.39s , -55d 04m 06.6s) |   C |    20 | 15.0 |        
     188 | 2023-12-01 19:02:00 |         MASTER-SAAO | (03h 24m 11.79s , -55d 15m 46.3s) |   C |    30 | 14.3 |        
     188 | 2023-12-01 19:02:00 |         MASTER-SAAO | (03h 09m 05.30s , -55d 05m 06.2s) |   C |    30 | 13.1 |        
    1682 | 2023-12-01 19:26:39 |         MASTER-SAAO | (03h 06m 37.02s , -54d 12m 09.5s) |   C |    60 | 13.5 |        
    1853 | 2023-12-01 19:29:30 |         MASTER-SAAO | (03h 27m 36.96s , -55d 55m 05.8s) |   C |    60 | 17.3 |        
    2795 | 2023-12-01 19:45:12 |         MASTER-SAAO | (03h 27m 32.84s , -55d 54m 01.7s) |   C |    60 | 13.8 |        
    5238 | 2023-12-01 20:25:55 |         MASTER-SAAO | (03h 17m 40.93s , -53d 59m 19.1s) |   C |    60 | 16.0 |        
    5238 | 2023-12-01 20:25:55 |         MASTER-SAAO | (03h 32m 23.55s , -54d 09m 55.9s) |   C |    60 | 16.0 |        
    5328 | 2023-12-01 20:27:25 |         MASTER-SAAO | (03h 06m 37.02s , -54d 11m 01.3s) |   C |    60 | 14.9 |        
    5408 | 2023-12-01 20:28:45 |         MASTER-SAAO | (03h 09m 46.68s , -57d 49m 05.2s) |   C |    60 | 12.3 |        
    5408 | 2023-12-01 20:28:45 |         MASTER-SAAO | (03h 26m 01.10s , -57d 59m 42.1s) |   C |    60 | 13.0 |        
    5499 | 2023-12-01 20:30:16 |         MASTER-SAAO | (03h 27m 29.14s , -55d 54m 35.9s) |   C |    60 | 18.1 |        
    5579 | 2023-12-01 20:31:36 |         MASTER-SAAO | (03h 09m 04.24s , -52d 05m 38.0s) |   C |    60 | 14.4 |        
    5579 | 2023-12-01 20:31:36 |         MASTER-SAAO | (03h 23m 08.79s , -52d 16m 13.7s) |   C |    60 | 14.8 |        
Filter C is a clear (unfiltred) band. 


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