[vsnet-grb-info 5129] GRB 071001: Swift detection of a burst

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6832
SUBJECT: GRB 071001: Swift detection of a burst
DATE:    07/10/01 16:54:59 GMT
FROM:    David Palmer at LANL  <palmer at lanl.gov>

M. De Pasquale (UCL-MSSL), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), S. Campana (INAF-OAB),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), C. Gronwall (PSU),
C. Guidorzi (Univ Bicocca&INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (GSFC/USRA),
V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), A. Moretti (INAF-OAB), C. Pagani (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL), J. L. Racusin (PSU),
G. Sato (GSFC/ISAS), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester), E. Troja (INAF-IASFPA),
T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the
Swift Team:

At 16:31:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 071001 (trigger=292826).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 149.766, -59.751 which is 
   RA(J2000) = 09h 59m 04s
   Dec(J2000) = -59d 45' 02"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows two isolated peaks
spanning a duration of about 50 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 16:33:10 UT, 83 seconds after the
BAT trigger. Using prompt downlinked data, we find a bright, variable, 
uncatalogued X-ray source located at RA, Dec 149.7302, -59.7819 which is
   RA(J2000)  = 09h 58m 55.25s
   Dec(J2000) = -59d 46' 54.8"
with an uncertainty of 6.0 arcsec (radius, 90% containment). 
This location is 129 arcseconds from the BAT on-board position,
within the BAT error circle. The initial flux in the 2.5s image
was 1.5e-09 erg/cm2/s (0.2-10 keV). 

The star tracker during the XRT observation has detected and
identified three valid stars, however the attitude solution quality
is worse than normal.  Therefore, there may be some additional 
systematic error in the quoted positions. 

Burst Advocate for this burst is M. De Pasquale (mdp AT mssl.ucl.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.)