GCN Circular 11886
A.J. Levan (U. Warwick), N. Butler, J. Bloom (U.C. Berkeley), N.R. Tanvir (U. Leicester), A.S. Fruchter (STScI) report for a larger collaboration: "We observed GRB 110328/Swift J164449.3+573451 (Cummings et al. GCN 11823) with the Chandra X-ray Observatory on 4 April 2011, beginning at 02:30UT. A total of 15 ks of observation were obtained with the High Resolution Camera (HRC-I). The X-ray counterpart is strongly detected at a mean observed flux of ~5e-11 ergs/s/cm^2, and continues to show strong variability, with flaring of a factor two in flux over the duration of the observations. Utilizing three additional point sources in common to both our Chandra observations, and those taken with Gemini and UKIRT (e.g. Levan et al. GCN 11846) we performed relative astrometry between the optical/IR and X-ray sources. Preliminary analysis suggests the location of the X-ray counterpart is offset 0.07 +/- 0.25 arcseconds from the optical/IR counterpart in our Gemini images. We thank the staff of CXC, in particular Harvey Tannenbaum and Ping Zhao, for their assistance in obtaining this data"