GCN Circular 37238

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-Amur robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB240821.85 (trigger No 745964969,18h 05m 28.08s , -03d 34m 01.2s, R=5.05) errorbox  60376 sec after notice time and 60412 sec after trigger time at 2024-08-22 13:16:16 UT, with upper limit up to  16.6 mag. The observations began at zenith distance = 54 deg. The sun  altitude  is -21.5 deg. 

The galactic latitude b =  8 deg., longitude l = 25 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2570793

We obtain a following upper limits.  

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

   60443 | 2024-08-22 13:16:16 |         MASTER-Amur | (18h 01m 53.93s , +01d 07m 49.1s) |   C |    60 | 14.1 |        
   60443 | 2024-08-22 13:16:16 |         MASTER-Amur | (17h 54m 30.45s , +00d 38m 13.6s) |   C |    60 | 16.6 |        
   61371 | 2024-08-22 13:31:45 |         MASTER-Amur | (18h 01m 59.58s , +01d 09m 01.7s) |   C |    60 | 14.0 |        
   61371 | 2024-08-22 13:31:45 |         MASTER-Amur | (17h 54m 35.67s , +00d 39m 39.6s) |   C |    60 | 16.5 |        
Filter C is a clear (unfiltred) band. 


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