TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5464 SUBJECT: GRB060814: Break in the XRT light curve DATE: 06/08/17 17:21:36 GMT FROM: Alberto Moretti at Obs Brera Merate A. Moretti (INAF-OAB), C. Guidorzi (Univ. Bicocca & INAF-OAB), P. Romano (INAF-OAB), D.N. Burrows (PSU), N. Gehrels (GSFC) report on behalf of the Swift-XRT team: Based on the most recent downlinked data on GRB060814 (trigger number 224552) we find clear evidence of a break in the light curve at 42(+/-6) ks from the burst trigger (see the light curve at http://www.brera.inaf.it/~moretti/grbplot/xrt060814.gif ) which could be a jet break. The light curve slope steepens from 1.04+/-0.05 to 1.9+/-0.3 (errors are quoted at 90% confidence level). In order to convert the XRT count rate to absorbed (unabsorbed) flux the conversion factor is 4.9E-11 (8.5E-11) Therefore we encourage optical data collection on this GRB in order to measure the redshift and to test whether this break is achromatic. This circular is an official product of the Swift-XRT team.