TITLE:   GCN CIRCULAR
NUMBER:  35571
SUBJECT: Fermi GRB 240118B: Global MASTER-Net observations report
DATE:    24/01/19 00:31:43 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, 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 GRB 240118B ( Fermi GBM team, GCN 35562) errorbox  43321 sec after notice time and 43354 sec after trigger time at 2024-01-19 00:13:40 UT, with upper limit up to  18.5 mag. The observations began at zenith distance = 65 deg. The sun  altitude  is -33.7 deg. 

The galactic latitude b = -51 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=2359396

We obtain a following upper limits.  

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

   43385 | 2024-01-19 00:13:40 |         MASTER-SAAO | (03h 19m 56.04s , -54d 00m 56.6s) |   C |    60 | 18.4 |        
   43476 | 2024-01-19 00:15:11 |         MASTER-SAAO | (03h 30m 18.84s , -53d 48m 55.0s) |   C |    60 | 18.3 |        
   43476 | 2024-01-19 00:15:11 |         MASTER-SAAO | (03h 33m 26.11s , -54d 01m 50.8s) |   C |    60 | 18.1 |        
   43556 | 2024-01-19 00:16:31 |         MASTER-SAAO | (03h 06m 29.36s , -55d 42m 49.0s) |   C |    60 | 18.5 |        
   43556 | 2024-01-19 00:16:31 |         MASTER-SAAO | (03h 09m 45.21s , -55d 55m 46.4s) |   C |    60 | 18.5 |        
   43636 | 2024-01-19 00:17:51 |         MASTER-SAAO | (03h 33m 30.51s , -55d 40m 53.5s) |   C |    60 | 18.1 |        
Filter C is a clear (unfiltred) band. 


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