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GCN Circular 41736

Subject
EP250905b: Global MASTER-Net observations report
Event
EP250905b
Date
2025-09-06T08:27:35Z (4 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, 
G.Antipov,  A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile,  F. Podesta, R.Podesta, E. Gonzalez  (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A.Sosnovskij (CrAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) 

MASTER-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP250905b ( EP Team et al., GCN 41735Loading...
 
 ) errorbox  2238 sec after notice time and 46512 sec after trigger time at 2025-09-06 08:13:40 UT, with upper limit up to  19.5 mag. The observations began at zenith distance = 43 deg. The sun  altitude  is -33.0 deg. 

The galactic latitude b = -28 deg., longitude l = 262 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2985909

We obtain a following upper limits.  

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

   46542 | 2025-09-06 08:13:40 |         MASTER-OAFA | (06h 03m 11.78s , -54d 19m 04.9s) |   C |    60 | 19.5 |        
   46618 | 2025-09-06 08:14:56 |         MASTER-OAFA | (06h 03m 19.42s , -54d 18m 45.3s) |   C |    60 | 19.5 |        
   46697 | 2025-09-06 08:16:14 |         MASTER-OAFA | (06h 03m 15.86s , -54d 17m 05.6s) |   C |    60 | 19.5 |        
   46771 | 2025-09-06 08:17:29 |         MASTER-OAFA | (06h 03m 15.93s , -54d 18m 30.1s) |   C |    60 | 19.5 |        
   46837 | 2025-09-06 08:18:35 |         MASTER-OAFA | (06h 03m 15.94s , -54d 18m 27.8s) |   C |    60 | 19.5 |        
   46903 | 2025-09-06 08:19:41 |         MASTER-OAFA | (06h 03m 15.97s , -54d 18m 25.3s) |   C |    60 | 19.5 |        
   46981 | 2025-09-06 08:20:59 |         MASTER-OAFA | (06h 03m 19.09s , -54d 17m 19.1s) |   C |    60 | 19.5 |        
   47047 | 2025-09-06 08:22:05 |         MASTER-OAFA | (06h 03m 19.11s , -54d 17m 16.9s) |   C |    60 | 19.5 |        
Filter C is a clear (unfiltred) band. 


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