[vsnet-grb-info 2060] GRB 050827: XRT possible afterglow detection

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3899
SUBJECT: GRB 050827: XRT possible afterglow detection
DATE:    05/08/28 18:04:29 GMT
FROM:    Milvia Capalbi at ISAC/ASDC  <capalbi at asdc.asi.it>

M. Capalbi (ASDC), V. Mangano (INAF-IASF), G. Tagliaferri (INAF-OAB),
J. Kennea (PSU), N. Gehrels (GSFC), D. Hinshaw (GSFC-SPSYS),
F. Marshall (GSFC) report on behalf of the Swift XRT team:

We have analyzed the Swift XRT data from the first
observation (2 orbits) of GRB 050827 (Capalbi, et al., GCN 3893).

The spacecraft slewed to this burst after 17.8 hrs due to the Moon
constraint.

An uncatalogued, X-ray source was detected at the following position:

RA(J2000) = 04h 17m 09.4s
Dec(J2000) = +18 11 57.9

with an uncertainty of 8 arcseconds radius (90% containment).
No other source is detected within the BAT error circle.

This position is 69 arcsec from the refined BAT position given
in GCN 3894 (Sakamoto et al.).

This source has a count rate of (2.0+/-0.3)E-02  cts s^-1
that approximately corresponds to a flux of 1.0E-12 erg cm^-2 s^-1
(there are not enough counts for a spectral fit).

The light curve however does not seem to decay, thus we need
more data to confirm this source as the afterglow of GRB 050827.