GCN Circular 36073

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-Kislovodsk robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the IceCube Alert 240412.23 (trigger No 10803235,06h 55m 08.64s , +05d 52m 19.2s, R=1.15) errorbox  40744 sec after notice time and 40796 sec after trigger time at 2024-04-12 16:53:43 UT, with upper limit up to  17.9 mag. Observations started at twilight.  The observations began at zenith distance = 47 deg. The sun  altitude  is -11.9 deg. 

The galactic latitude b =  4 deg., longitude l = 208 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2419799

We obtain a following upper limits.  

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

   40886 | 2024-04-12 16:53:43 |   MASTER-Kislovodsk | (06h 55m 36.89s , +05d 54m 23.4s) |   C |   180 | 17.3 |        
   40886 | 2024-04-12 16:53:43 |   MASTER-Kislovodsk | (06h 51m 27.09s , +06d 15m 59.5s) |   C |   180 | 17.9 |        
   41027 | 2024-04-12 16:57:03 |   MASTER-Kislovodsk | (06h 52m 33.46s , +05d 02m 23.9s) |   C |    60 | 16.3 |        
   41027 | 2024-04-12 16:57:03 |   MASTER-Kislovodsk | (06h 48m 24.53s , +05d 23m 56.6s) |   C |    60 | 17.1 |        
Filter C is a clear (unfiltred) band. 


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