GCN Circular 10881
Subject
GRB 100621A: IRSF/SIRIUS NIR Observation
Date
2010-06-22T15:37:21Z (14 years ago)
From
Hiroyuki Naito at Nagoya U <naito@stelab.nagoya-u.ac.jp>
H. Naito, T. Sako, D. Suzuki, S. Kobara and K. Omori (Nagoya Univ.) on
behalf of the MOA Collaboration,
T. Nagayama, M. Kurita (Nagoya Univ.) and N. Oi (The Graduate
University for Advanced Studies/NAOJ)
on behalf of the IRSF Collabration report:
We searched for a NIR afterglow of GRB 100621A (Ukwatta et al., GCN
10870) starting from
04:02 to 04:51 UT on 2010 June 21 with the SIRIUS on the IRSF 1.4m
telescope at SAAO in
South Africa. In images of a 300 sec exposure with J, H and Ks filter,
we detected an new source
within the error circle of the enhanced Swift XRT position (Evans et
al., GCN 10873) and at the
location of the GROND source (Updike et al., GCN 10874) . The
estimated magnitudes are the
followings.
---------------------------------------------------------------
Mid time from Total Exp. J-mag* H-mag* K-mag*
trigger (min) (s)
---------------------------------------------------------------
61.41 300 16.56 15.22 14.18
67.61 300 16.24 14.63 13.84
73.84 300 15.27 13.78 12.63
80.14 300 15.07 13.57 12.40
86.36 300 14.93 13.45 12.23
92.56 300 14.90 13.45 12.32
98.81 300 14.93 13.47 12.34
105.0 300 15.04 13.55 12.36
---------------------------------------------------------------
*Typical error is ~ 0.1 mag
This photometry was done by using the DoPhot and calibrated against
the 2MASS catalog stars,
and not corrected for the Galactic extinction. The source was
brightened up by >1mag during our
observation period while the other field stars were reasonably stable.