Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 11285

GRB 100915A: GRT Optical Observation
2010-09-16T00:11:56Z (14 years ago)
Takanori Sakamoto at NASA/GSFC <>
T. Sakamoto (UMBC/GSFC), D. Donato (UMCP/GSFC), N. Gehrels (GSFC),
T. Okajima (JHU/GSFC), Y. Urata (NCU), C.A. Wallace (FGCU)

We observed the field of GRB 100915A detected by Swift
(trigger #434178; Littlejohns et al., GCN Circ. 11277) with the 14-inch
Goddard Robotic Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (

A total 423 images of 5 sec (200 images), 30 sec (80 images), 
60 sec (120 images) and 100 sec (23 images) exposures were taken in 
the R filter starting from September 15 01:33:32 (UT) about 146 
seconds after the trigger (70 seconds after the BAT position notice) 
and stopped on September 15 05:49:30 (UT).  We do not detect 
the optical afterglow both in the individual images and the stacked 
image, which only combined good quality 418 images, inside the XRT 
position (Osborne et al., GCN #11279).  The estimated five sigma 
upper limit of the combined image (total exposure of 12500 sec) is 
~19.8 mag using the USNO-B1 catalog.
Looking for U.S. government information and services? Visit