[vsnet-grb-info 3151] GRB(?)060421:MASTER optical limit

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4988
SUBJECT: GRB(?)060421:MASTER optical limit
DATE:    06/04/21 11:50:19 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc at observ.inetcomm.ru>

V. Lipunov, V.Kornilov, N.Tyurina, A.Belinski, D.Kuvshinov, E.Gorbovskoy,
A.Krylov, G.Borisov, A.Sankovich,  V.Vladimirov, P.Gritsyk, S.Korobkin

Sternberg Astronomical Institute, Moscow Union 'Optic'
MASTER  robotic system (http://observ.pereplet.ru) responded
to GRB060421 (GRB_TIME is 2006-04-21 00:39:23.33, M. R. Goad et al. 
GCN4985).

Unfortunaly 2 minutes before notice time roof closed roboticaly due to 
meteo alert "cloudy". The first image was at 2006-04-21 00:48:45 UT,
562 s  after the GRB time.
The unfiltered image is calibrated relative to USNO A2.0 (0.8 R + 0.2 B).
The robot not find OT-candidate in error box brighter then  16.8 (s/n=3) 
at Swift XRT position (Mike Goad, Kim Page GCN4987).
This work is supported by RFFI  04-02-16411 grant.
This message can be cited.
Mailto: lipunov at sai.msu.ru