GCN Circular 37710

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-Tunka robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB241004.49 (trigger No 749735279,18h 29m 16.08s , -09d 33m 00.0s, R=3.45) errorbox  668 sec after notice time and 689 sec after trigger time at 2024-10-04 11:59:23 UT, with upper limit up to  19.4 mag. Observations started at twilight.  The observations began at zenith distance = 63 deg. The sun  altitude  is -13.6 deg. 

The galactic latitude b = -0 deg., longitude l = 22 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2625150

We obtain a following upper limits.  

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

     720 | 2024-10-04 11:59:23 |        MASTER-Tunka | (18h 27m 32.98s , -10d 06m 12.9s) |   C |    60 | 19.0 |        
     792 | 2024-10-04 12:00:36 |        MASTER-Tunka | (18h 35m 37.61s , -10d 05m 20.4s) |   C |    60 | 18.9 |        
     997 | 2024-10-04 12:04:01 |        MASTER-Tunka | (18h 21m 30.92s , -08d 11m 15.5s) |   C |    60 | 19.4 |        
    1069 | 2024-10-04 12:05:13 |        MASTER-Tunka | (18h 29m 35.60s , -08d 10m 42.9s) |   C |    60 | 19.1 |        
    1266 | 2024-10-04 12:08:30 |        MASTER-Tunka | (18h 19m 15.89s , -11d 59m 33.6s) |   C |    60 | 19.0 |        
    1338 | 2024-10-04 12:09:42 |        MASTER-Tunka | (18h 27m 22.68s , -11d 58m 49.2s) |   C |    60 | 18.7 |        
    1536 | 2024-10-04 12:13:00 |        MASTER-Tunka | (18h 12m 00.83s , -10d 04m 25.0s) |   C |    60 | 19.2 |        
    1609 | 2024-10-04 12:14:13 |        MASTER-Tunka | (18h 20m 09.83s , -10d 03m 52.0s) |   C |    60 | 19.2 |        
    1681 | 2024-10-04 12:15:25 |        MASTER-Tunka | (18h 27m 33.82s , -10d 05m 16.8s) |   C |    60 | 19.2 |        
    1753 | 2024-10-04 12:16:37 |        MASTER-Tunka | (18h 35m 34.49s , -10d 06m 44.0s) |   C |    60 | 18.9 |        
Filter C is a clear (unfiltred) band. 


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