[vsnet-grb-info 5938] GRB 080330: Swift-XRT refined position retraction

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7583
SUBJECT: GRB 080330: Swift-XRT refined position retraction
DATE:    08/04/11 14:32:16 GMT
FROM:    Jirong Mao at INAF-OAB  <jirong.mao at brera.inaf.it>

J. Mao and C. Guidorzi (INAF-OAB) on behalf of the Swift-XRT team report:

A re-examination of the XRT data on GRB080330 (Mao et al.
GCN Circ. 7537) taken during the first orbit revealed that
the XRT improved position distributed by Mao (GCN Circ. 7561)
is incorrect due to star tracker loss-of-lock problems already
mentioned by Burrows (GCN Circ. 7541).
We re-processed the first orbit PC data and extracted the following
refined position from 136 to 311 s after the burst,
when the star tracker drifting seems to have little impact:
RA, Dec = 169.26950, +30.62355 which is equivalent to:

RA (J2000): 11h 17m 04.68s
Dec (J2000): +30d 37' 24.78"

with an uncertainty of 4.0 arcsec (radius, 90% confidence).
This is consistent with the optical ground-based position
(2.7 arcsec away from the PAIRITEL position reported by
Bloom and Starr, GCN Circ. 7542).

This is an official product of the Swift XRT team.