GCN Circular 7541
Subject
GRB 080330: error in reported XRT position
Event
Date
2008-03-30T04:36:19Z (18 years ago)
From
David Burrows at PSU/Swift <dnburrows@gmail.com>
D. N. Burrows (PSU) reports on behalf of the Swift XRT team:
The XRT position for GRB 080330 that was distributed in GCN Circ.
7537 was incorrect. The initial on-board XRT position determined
immediately after the spacecraft slew was
GRB_RA: 169.2707d {+11h 17m 04.9s} (J2000),
GRB_DEC: +30.6223d {+30d 37' 20.2"} (J2000),
with a nominal error circle radius of 5.0 arcseconds. This position
was 6.1 arcseconds from the UVOT position. It appears that shortly
after arriving on-target, the spacecraft began slowly drifting
because the star tracker did not lock properly on the star
field. The updated XRT position based on promptly downloaded data
was determined using inaccurate aspect information from the satellite
and was therefore incorrect. We apologize for any confusion that
this may have caused. We reiterate that the XRT position appears to
be consistent with the optical position.