TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4519 SUBJECT: GRB 060116: Swift-BAT detection of a burst DATE: 06/01/16 09:06:54 GMT FROM: Scott Barthelmy at NASA/GSFC S. Campana (INAF-OAB), S. Barthelmy (GSFC), N. Gehrels (GSFC), C. Gronwall (PSU), J. Kennea (PSU), C. Markwardt (GSFC/UMD), K. Page (U Leicester), D. Palmer (LANL), M. Perri (ASDC) on behalf of the Swift team: At 08:37:27 UT, Swift-BAT triggered and located GRB 060116 (trigger=177533). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 84.699d,-5.449d {05h 38m 48s,-05d 26' 54"} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve shows a multi-peak structure with a total duration of ~35 sec. The peak count rate was ~600 counts/sec (15-350 keV), at several times after the trigger. XRT began observing the field at 08:40:00.75 UT, 154 sec after the BAT trigger. The on-board detection algorithm did not centroid on a source due to insufficient counts so no prompt X-ray position is available. The XRT prompt spectrum and lightcurve show no signficant X-ray emission in the field, suggesting that any X-ray counterpart to this burst is faint. Further analysis will require processing of the XRT full telemetry data following the next ground station contact at 09:32 UT. UVOT took a finding chart exposure of 200 seconds with the V filter starting 153 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 18th mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18.0 mag. No correction has been made for the expected visual extinction of about 0.9 magnitudes.