TITLE:   GCN CIRCULAR
NUMBER:  36969
SUBJECT: Fermi GRB 240727A: Global MASTER-Net observations report
DATE:    24/07/29 03:15:38 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 240727A ( Fermi GBM team, GCN 36958) errorbox  1 days 9913 sec after notice time and 1 days 9945 sec after trigger time at 2024-07-29 02:37:31 UT, with upper limit up to  16.9 mag. The observations began at zenith distance = 79 deg. The sun  altitude  is -36.5 deg. 

The galactic latitude b = -5 deg., longitude l = 248 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2543175

We obtain a following upper limits.  

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

   96376 | 2024-07-29 02:37:31 |         MASTER-SAAO | (07h 08m 02.69s , -36d 44m 01.5s) |   C |    60 | 16.4 |        
   96534 | 2024-07-29 02:40:10 |         MASTER-SAAO | (07h 07m 41.05s , -34d 48m 14.6s) |   C |    60 | 16.9 |        
   97030 | 2024-07-29 02:48:26 |         MASTER-SAAO | (07h 06m 42.54s , -32d 56m 19.5s) |   C |    60 | 16.2 |        
   97110 | 2024-07-29 02:49:45 |         MASTER-SAAO | (07h 16m 18.00s , -32d 54m 03.9s) |   C |    60 | 15.9 |        
   97190 | 2024-07-29 02:51:05 |         MASTER-SAAO | (07h 16m 22.47s , -34d 47m 53.9s) |   C |    60 | 15.8 |        
   97269 | 2024-07-29 02:52:25 |         MASTER-SAAO | (07h 08m 03.99s , -36d 44m 12.2s) |   C |    60 | 16.1 |        
   97349 | 2024-07-29 02:53:44 |         MASTER-SAAO | (07h 19m 20.58s , -38d 35m 56.4s) |   C |    60 | 15.9 |        
   97428 | 2024-07-29 02:55:03 |         MASTER-SAAO | (07h 29m 35.38s , -38d 36m 57.4s) |   C |    60 | 15.7 |        
   97507 | 2024-07-29 02:56:23 |         MASTER-SAAO | (07h 18m 08.43s , -36d 41m 46.8s) |   C |    60 | 15.9 |        
   97666 | 2024-07-29 02:59:01 |         MASTER-SAAO | (07h 07m 36.44s , -34d 48m 22.6s) |   C |    60 | 15.7 |        
   97745 | 2024-07-29 03:00:20 |         MASTER-SAAO | (07h 27m 02.23s , -36d 43m 25.0s) |   C |    60 | 15.0 |        
   97826 | 2024-07-29 03:01:42 |         MASTER-SAAO | (07h 37m 08.56s , -36d 42m 39.8s) |   C |    60 | 14.6 |        
   98064 | 2024-07-29 03:05:40 |         MASTER-SAAO | (07h 06m 44.88s , -32d 55m 02.4s) |   C |    60 | 15.5 |        
   98143 | 2024-07-29 03:06:59 |         MASTER-SAAO | (07h 16m 11.65s , -32d 55m 09.9s) |   C |    60 | 15.2 |        
Filter C is a clear (unfiltred) band. 


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