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GCN Circular 16670

GRB 140808A: Swift-XRT observations
2014-08-08T18:47:37Z (10 years ago)
Kim Page at U.of Leicester <>
K.L. Page, P.A. Evans (U. Leicester) and S.B. Cenko (GSFC) report on
behalf of the Swift-XRT team:

We have analysed 3.0 ks of XRT data for the GBM-detected burst: GRB
140808A (Zhang, GCN Circ. 16669), from 41.9 ks to 52.0 ks after the GBM
trigger. The data are entirely in Photon Counting (PC) mode.  An X-ray
source is detected within the XRT field of view. Using 1513 s of PC
mode data and 1 UVOT images, we find an enhanced XRT position (using
the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 221.22196, +49.21463 which is equivalent to:

RA (J2000): 14h 44m 53.27s
Dec(J2000): +49d 12' 52.7"

with an uncertainty of 3.3 arcsec (radius, 90% confidence). This
position is 1.6 arcsec from the iPTF position (Singer et al., GCN CIrc.
16668).  The source has a mean count rate of 1.5e-02 ct/sec; we cannot
determine at the present time whether it is fading. We note that this
count rate is just below the ROSAT All Sky Survey detection limit, so
this source would not have been listed in the RASS. However, given the
transient nature of the iPTF optical candidate, it seems likely this is
a new X-ray source. 

The results of the XRT-team automatic analysis are available at

This circular is an official product of the Swift-XRT team.
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