GCN Circular 9564
Subject
GRB 090621A: GRT Optical Observation
Date
2009-06-23T02:08:36Z (15 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori.sakamoto-1@nasa.gov>
T. Sakamoto (UMBC/GSFC), D. Donato (ORAU/GSFC), N. Gehrels (GSFC),
T. Okajima (JHU/GSFC), T.N. Ukwatta (GWU/GSFC), Y. Urata (NCU),
C.A. Wallace (FGCU)
We observed the field of GRB 090621A detected by Swift
(trigger #355303; Curran et al., GCN #9540) with the 14-inch
Goddard Robotic Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).
100 set of 30 sec exposures were taken in the R filter starting
from June 21 05:00:15 (UT) about 37.3 min after the trigger and
stopped on June 21 05:56:22 (UT). We do not detect the optical
afterglow both in the individual images and the combined image
inside the XRT position (Page et al., GCN #9543). The estimated
three sigma upper limit of the combined image (total exposure
of 2850 sec; excluding five bad quality images) is ~17.9 mag using
the USNO-B1 catalog.