GCN Circular 5117

J. R. Cummings (NASA/ORAU), M. M. Chester (PSU),
N. Gehrels (NASA/GSFC), O. Godet (U Leicester),
H. A. Krimm (GSFC/USRA), K. L. Page (U Leicester),
D. M. Palmer (LANL) and M. Stamatikos (NASA/GSFC/ORAU) report on
behalf of the Swift Team:

At 23:13:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060512 (trigger=209755).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA,Dec 195.772, +41.212 {13h 03m 05s, +41d 12' 43"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single peak
with a duration of about 20 sec.  The peak count rate
was ~500 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 23:15:02 UT, 102 seconds after the
BAT trigger. XRT found a bright, uncatalogued X-ray source
located at RA(J2000) = 13h 03m 05.8s, Dec(J2000) = +41d 11' 30.4", with an
estimated uncertainty of 7.6 arcseconds (90% confidence radius). 
This location is 73 arcseconds from the BAT on-board position, within
the BAT error circle. The initial flux in the 2.5s image was
2.6e-10 erg/cm2/s (0.2-10 keV). 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 112 seconds after the BAT trigger. There
is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image
at (RA,DEC) (J2000) of (195.7742,41.1909) or
(13h03m05.81s,+41o11'27.2")  with a 1-sigma error radius of about 0.5
arc sec. This position is 3.2 arc sec. from the center of the XRT
error circle. The estimated magnitude is 16.2 with a 1-sigma error of
about 0.5 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of  0.02.