TITLE:   GCN CIRCULAR
NUMBER:  24664
SUBJECT: Fermi GRB190525.67 Global MASTER-Net observations report 
DATE:    19/05/25 17:31:31 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, 
V.Vladimirov, D. Vlasenko, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov 
(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-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) started inspect of the Fermi GRB190525.67 (trigger No 580493060,  8h 41m 12.00s , +22d 40m 58.80s, R=29.13) errorbox  1933 sec after trigger time at 2019-05-25 16:36:28 UT, with upper limit up to  19.0 mag. Observations started at twilight.  The observations began at zenit distance = 59 deg. The sun  altitude  is -11.1 deg. 

The galactic latitude b = -60 deg., longitude l = 98 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1028461

We obtain a following upper limits.  

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

    2023 | 2019-05-25 16:36:28 |         MASTER-SAAO | (  8h 34m 40.26s , - 3d 55m 34.32s) |   V |   180 | 17.4 |        
    2236 | 2019-05-25 16:40:00 |         MASTER-SAAO | (  8h 35m 28.29s , - 3d 55m 19.81s) |   C |   180 | 18.0 |        
    2416 | 2019-05-25 16:40:00 |         MASTER-SAAO | (  8h 35m 28.30s , - 3d 55m 19.73s) |   C |   540 | 19.0 |  Coadd 
    3094 | 2019-05-25 16:54:19 |         MASTER-SAAO | (  8h 35m 28.52s , - 3d 55m 56.34s) |   V |   180 | 18.2 |        
    3306 | 2019-05-25 16:57:50 |         MASTER-SAAO | (  8h 35m 28.55s , - 3d 55m 44.06s) |   C |   180 | 18.7 |        
Filter C is a clear (unfiltred) band. 


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