GCN Circular 8884

M. Perri (ASDC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), O. Godet (U Leicester), C. Gronwall (PSU),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
W.B Landsman (GSFC), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
M. Stamatikos (NASA/ORAU), G. Stratta (ASDC), M. C. Stroh (PSU) and
L. Vetere (PSU) report on behalf of the Swift Team:

At 23:03:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090205 (trigger=342121).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 220.925, -27.864 which is 
   RA(J2000) = 14h 43m 42s
   Dec(J2000) = -27d 51' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
with a duration of about 10 sec.  The peak count rate
was ~900 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 23:04:42.4 UT, 87.6 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 220.91150, -27.85298 which is
equivalent to:
   RA(J2000)  = 14h 43m 38.76s
   Dec(J2000) = -27d 51' 10.7"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 58 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
7.72e+20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 92 seconds after the BAT trigger. No credible
afterglow candidate has  been found in the initial data products. 
The 8'x8' region for the list of sources generated on-board covers
100% of the BAT error circle and 100% of the XRT error circle.   The
list of sources is typically complete to about 18 mag. No correction
has been made for the expected extinction corresponding to E(B-V) of
0.12. 

Burst Advocate for this burst is M. Perri (perri AT asdc.asi.it). 
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.)