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 12492

GRB 111020A: Chandra Observation
2011-10-24T20:28:14Z (13 years ago)
Edo Berger at Harvard <>
E. Berger, R. Margutti, and W. Fong (Harvard) report:

"We observed the field of the short GRB 111020A (GCN 12640) with the Chandra
X-ray Observatory + ACIS-S starting on 2011 October 23.14 UT (2.86 days
after the burst) for a total of 19.8 ksec.  We clearly detect a source in
coincidence with the enhanced XRT error circle (GCN 12463) at the following
coordinates (J2000):

RA = 19:08:12.502
DEC = -38:00:42.58

with an uncertainty of about 0.5".  The position includes a minor correction
to the Chandra astrometry using two X-ray sources with stellar counterparts
in our Gemini i-band images (which were astrometrically matched to the 2MASS
catalog; GCNs 12467, 12470).  The Chandra position is offset by 1.2" from
the centroid of the most recent XRT position (which has a 90% containment
uncertainty of 1.6").  Further analysis of the Chandra data is on-going.

We thank Harvey Tananbaum and the CXO scheduling staff for rapidly approving
and executing this observation."
Looking for U.S. government information and services? Visit