TITLE:   GCN CIRCULAR
NUMBER:  11629
SUBJECT: GRB 110205A: Swift detection of a burst with an optical candidate
DATE:    11/02/05 02:17:32 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. P. Beardmore (U Leicester), W. H. Baumgartner (GSFC/UMBC),
D. N. Burrows (PSU), M. M. Chester (PSU), J. M. Gelbord (PSU),
S. T. Holland (CRESST/USRA/GSFC), N. P. M. Kuin (UCL-MSSL),
O. M. Littlejohns (U Leicester), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC), C. J. Saxton (UCL-MSSL),
M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.),
M. Stamatikos (OSU/NASA/GSFC), C. A. Swenson (PSU) and
T. N. Ukwatta (MSU) report on behalf of the Swift Team:

At 02:02:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110205A (trigger=444643).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 164.589, +67.516 which is 
   RA(J2000) = 10h 58m 21s
   Dec(J2000) = +67d 30' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT lightcurve shows activity
with multiple peaks until at least T+300 seconds, with a
peak count rate of 4500 counts/s (15-150 keV) at T+210 s. 

The XRT began observing the field at 02:05:16.8 UT, 155.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 164.6321, +67.5230 which is equivalent to:
   RA(J2000)  = 10h 58m 31.70s
   Dec(J2000) = +67d 31' 22.7"
with an uncertainty of 6.2 arcseconds (radius, 90% containment). This
location is 64 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 164 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
   RA(J2000) = 10:58:31.12 = 164.62965
   DEC(J2000) = +67:31:31.2 = 67.52532
with a 90%-confidence error radius of about 0.63 arc sec. This position is 9.0
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.71 with a 1-sigma error of about 0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01. 

Burst Advocate for this burst is A. P. Beardmore (apb AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)