TITLE:   GCN CIRCULAR
NUMBER:  37210
SUBJECT: Fermi  trigger No 745873283: Global MASTER-Net observations report
DATE:    24/08/20 19:17:01 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-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB240820.79 (trigger No 745873283,18h 26m 24.00s , -13d 30m 00.0s, R=9.07) errorbox  227 sec after notice time and 275 sec after trigger time at 2024-08-20 19:05:53 UT, with upper limit up to  17.2 mag. The observations began at zenith distance = 60 deg. The sun  altitude  is -23.1 deg. 

The galactic latitude b = -1 deg., longitude l = 18 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2569661

We obtain a following upper limits.  

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

     305 | 2024-08-20 19:05:53 |      MASTER-Tavrida | (18h 22m 48.57s , -14d 40m 05.3s) |   C |    60 | 17.1 |        
     305 | 2024-08-20 19:05:54 |      MASTER-Tavrida | (18h 22m 43.82s , -14d 35m 54.1s) |   C |    60 | 17.2 |        
     380 | 2024-08-20 19:07:09 |      MASTER-Tavrida | (18h 31m 08.80s , -14d 38m 30.2s) |   C |    60 | 16.6 |        
     601 | 2024-08-20 19:10:24 |      MASTER-Tavrida | (18h 41m 17.80s , -05d 00m 28.1s) |  P\ |   110 | 15.4 |        
Filter C is a clear (unfiltred) band. 


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