TITLE:   GCN CIRCULAR
NUMBER:  34272
SUBJECT: Integral GRB230726.26: Global MASTER-Net observations report
DATE:    23/07/26 18:57:58 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, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(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. Gres, N.M. Budnev
(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),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Integral GRB230726.26 (trigger No 10345,02h 43m 39.77s , +61d 39m 22.3s, R=50) errorbox  43577 sec after notice time and 43585 sec after trigger time at 2023-07-26 18:16:08 UT, with upper limit up to  18.3 mag. Observations started at twilight.  The observations began at zenith distance = 42 deg. The sun  altitude  is -10.0 deg. 

The galactic latitude b =  2 deg., longitude l = 136 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2245361

We obtain a following upper limits.  

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

   43676 |      MASTER-Tavrida |   C |   180 | 17.6 |        
   43868 |      MASTER-Tavrida |   C |   180 | 17.6 |        
   44059 |      MASTER-Tavrida |   C |   180 | 17.8 |        
   44251 |      MASTER-Tavrida |   C |   180 | 17.9 |        
   44444 |      MASTER-Tavrida |   C |   180 | 18.3 |        
   44635 |      MASTER-Tavrida |   C |   180 | 18.2 |        
   44828 |      MASTER-Tavrida |   C |   180 | 18.1 |        
   45019 |      MASTER-Tavrida |   C |   180 | 18.2 |        
   45211 |      MASTER-Tavrida |   C |   180 | 18.2 |        
   45403 |      MASTER-Tavrida |   C |   180 | 18.1 |        
   45594 |      MASTER-Tavrida |   C |   180 | 18.3 |        
Filter C is a clear (unfiltred) band. 


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