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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."
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