Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 11138

GRB 100823A: WHT observations
2010-08-24T04:28:24Z (14 years ago)
Andrew Levan at U.of Leicester <>
A.J. Levan (U. Warwick), N.R. Tanvir (U. Leicester), C. Copperwheat (U. Warwick)
report for a larger collaboration:

We observed the field of GRB 100823A (Mangano et al. GCN 11135) using the
William Herschel Telescope on La Palma with the ACAM instrument. Observations
were conducted in the z-band, and began at 00:37 UT, approximately 7.2 hours
after the burst.

Within the refined X-ray error circle (Goad et al. GCN 11136)  we identify a
source, at

RA(J2000): 01:22:48.97
DEC(J2000) 05:50:08.1

However, we note that a source is also present in the DSS2 images of the field
at this position.

Additionally we note the presence of a brighter source, not present in the DSS
images at

RA(J2000): 01:22:48.79
DEC(J2000) 05:50:10.9

This source may be the afterglow of GRB 100823A (offset approximately ~6 arcseconds
from the XRT position),  or alternatively could either be a red source, not visible in the
DSS2 red image, or a source with high proper motion.

Further observations will be required to assess the nature of any variability.

Images can be found at
Looking for U.S. government information and services? Visit