TITLE:   GCN CIRCULAR
NUMBER:  35504
SUBJECT: Swift GRB240109.17: Global MASTER-Net observations report
DATE:    24/01/09 10:34:27 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-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 Swift GRB240109.17 (trigger No 1207446,20h 05m 16.32s , +16d 34m 40.8s, R=0.05) errorbox  22878 sec after notice time and 22901 sec after trigger time at 2024-01-09 10:23:16 UT, with upper limit up to  15.7 mag. Observations started at twilight.  The observations began at zenith distance = 62 deg. The sun  altitude  is -9.6 deg. 

The galactic latitude b = -8 deg., longitude l = 57 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2351675

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   22905 |        MASTER-Tunka |   C |     5 | 15.4 |        
   22919 |        MASTER-Tunka |   C |     5 | 15.4 |        
   22985 |        MASTER-Tunka |   C |     1 | 15.0 |        
   23053 |        MASTER-Tunka |   C |     1 | 15.0 |        
   23127 |        MASTER-Tunka |   C |     5 | 15.7 |        
   23260 |        MASTER-Tunka |   C |     5 | 15.7 |        
Filter C is a clear (unfiltred) band. 


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