TITLE:   GCN CIRCULAR
NUMBER:  38353
SUBJECT: Swift GRB241127.91: Global MASTER-Net observations report
DATE:    24/11/27 21:55:40 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V.Lipunov, E.Gorbovskoy, N.Tiurina,  P.Balanutsa, , D.Vlasenko, I.Panchenko,
A.Kuznetsov,  G.Antipov,  A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, 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. 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-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB241127.91 (trigger No 1270788,21h 51m 41.28s , -56d 41m 06.0s, R=0.05) errorbox  11 sec after notice time and 35 sec after trigger time at 2024-11-27 21:43:51 UT, with upper limit up to  18.3 mag. The observations began at zenith distance = 61 deg. The sun  altitude  is -35.8 deg. 

The galactic latitude b = -47 deg., longitude l = 337 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2686277

We obtain a following upper limits.  

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

      41 |         MASTER-SAAO |   C |    10 | 13.0 |        
      56 |         MASTER-SAAO |   C |    40 | 17.9 |  Coadd 
      70 |         MASTER-SAAO |   C |    10 | 17.5 |        
     104 |         MASTER-SAAO |   C |    20 | 17.9 |        
     143 |         MASTER-SAAO |   C |    20 | 16.7 |        
     178 |         MASTER-SAAO |   C |    90 | 18.3 |  Coadd 
     187 |         MASTER-SAAO |   C |    30 | 17.7 |        
     241 |         MASTER-SAAO |   C |    40 | 17.9 |        
     305 |         MASTER-SAAO |   C |    50 | 15.7 |        
     379 |         MASTER-SAAO |   C |    60 | 14.9 |        
Filter C is a clear (unfiltred) band. 


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