TITLE: GCN CIRCULAR NUMBER: 12492 SUBJECT: GRB 111020A: Chandra Observation DATE: 11/10/24 20:28:14 GMT FROM: 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."