[vsnet-grb-info 8202] GRB 090726: GRT Optical Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9732
SUBJECT: GRB 090726: GRT Optical Observation
DATE:    09/07/29 10:22:47 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori at milkyway.gsfc.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 090726 detected by Swift
(trigger #358422; Page et al., GCN Circ. 9706) with the 14-inch
Goddard Robotic Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).

89 set of 30 sec exposures were taken in the R filter starting
from July 27 02:31:44 (UT) about 3.75 hours after the trigger and
stopped on July 27 03:22:10 (UT).  We do not detect the optical
afterglow (Moskvitin et al., GCN Circ. 9709; Fatkhullin et al.,
GCN Circ. 9712; Polasek et al., GCN Circ. 9714; Maticic et al.,
GCN Circ. 9715; Landsman et al., GCN Circ. 9717) both in the
individual images and the combined image.  The estimated three
sigma upper limit of the combined image (total exposure of 2670.0 sec)
is ~18.9 mag using the USNO-B1 catalog.