GCN Circular 35487

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) was pointed to the IceCube Alert 240105.52 (trigger No 46175426,04h 51m 34.32s , +11d 19m 33.6s, R=0.51) errorbox  19544 sec after notice time and 19590 sec after trigger time at 2024-01-05 17:54:12 UT, with upper limit up to  19.2 mag. The observations began at zenith distance = 53 deg. The sun  altitude  is -60.5 deg. 

The galactic latitude b = -20 deg., longitude l = 188 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2349706

We obtain a following upper limits.  

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

   19620 | 2024-01-05 17:54:12 |        MASTER-Tunka | (04h 50m 09.32s , +11d 20m 03.7s) |   C |    60 | 19.2 |        
   19692 | 2024-01-05 17:55:24 |        MASTER-Tunka | (04h 48m 31.89s , +10d 42m 29.0s) |   C |    60 | 19.2 |        
   19765 | 2024-01-05 17:56:37 |        MASTER-Tunka | (04h 56m 33.65s , +10d 41m 42.0s) |   C |    60 | 19.1 |        
   20781 | 2024-01-05 18:13:33 |        MASTER-Tunka | (04h 50m 07.23s , +11d 21m 11.9s) |   C |    60 | 19.1 |        
   20851 | 2024-01-05 18:14:43 |        MASTER-Tunka | (04h 48m 30.57s , +10d 42m 36.6s) |   C |    60 | 18.9 |        
   20922 | 2024-01-05 18:15:54 |        MASTER-Tunka | (04h 56m 33.87s , +10d 41m 52.7s) |   C |    60 | 18.9 |        
   21671 | 2024-01-05 18:28:23 |        MASTER-Tunka | (04h 50m 10.39s , +11d 19m 34.3s) |   C |    60 | 18.9 |        
   21832 | 2024-01-05 18:31:04 |        MASTER-Tunka | (04h 48m 24.56s , +10d 43m 53.3s) |   C |    60 | 18.9 |        
   21905 | 2024-01-05 18:32:17 |        MASTER-Tunka | (04h 56m 39.39s , +10d 43m 11.8s) |   C |    60 | 19.0 |        
Filter C is a clear (unfiltred) band. 


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