TITLE:   GCN CIRCULAR
NUMBER:  26594
SUBJECT: Swift GRB191227.07: Global MASTER-Net observations report 
DATE:    19/12/27 01:50:20 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev, O.Ershova 
(Irkutsk State University, API),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

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




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 Swift GRB191227.07 (trigger No 946344,21h 16m 40.68s , -16d 42m 15.8s, R=0.05) errorbox  19 sec after notice time and 51 sec after trigger time at 2019-12-27 01:40:28 UT, with upper limit up to  16.8 mag. The observations began at zenith distance = 83 deg. The sun  altitude  is -21.4 deg. 

The galactic latitude b = -40 deg., longitude l = 34 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1240958

We obtain a following upper limits.  

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

      56 |         MASTER-OAFA |   C |    10 | 15.8 |        
      97 |         MASTER-OAFA |   C |    10 | 15.7 |        
     144 |         MASTER-OAFA |   C |    20 | 16.1 |        
     201 |         MASTER-OAFA |   C |    30 | 16.4 |        
     274 |         MASTER-OAFA |   C |    50 | 16.8 |        
Filter C is a clear (unfiltred) band. 


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