GCN Circular 9541
Subject
GRB 090618: BOAO V-band Observation
Date
2009-06-21T06:09:55Z (15 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im (CEOU/Seoul National Univ), Y.-B. Jeon (KASI), and
Y. Urata (NCU)
We observed GRB090618 (Schady et al. GCN 9512) in V using
a 15.5cm refractor at Bohyunsan Optical Astronomical Observatory
in Korea, operarted by the Korea Astronomy Space Science Institute.
A series of exposures were taken starting at 2009 June 18, 11:54:19.
The afterglow, identified earlier by many groups
(GCN 9513, 9514, 9515, 9520, 9522), was clearly detected
at V=17.9 +- 0.1 magnitude at mid-time of 2009 12:55:07
(about 4hr 26.6min after the BAT trigger).
The photometry was calibrated against nearby SDSS stars
where the transformation of SDSS magnitude to V-band magnitude
was carried out using the recipe of Chonis & Gaskell (2008).