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GCN Circular 18311

GRB 150907A: Swift-XRT afterglow detection
2015-09-14T16:02:36Z (8 years ago)
Boris Sbarufatti at INAF-OAB/IASFPA <>
J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A. D'ai (INAF-IASFPA), A. Maselli
 (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows (PSU) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
MAXI-detected burst GRB 150907A (Nakagawa et al. GCN Circ. 18246). The
observations now extend from T0+8.8 ks to T0+489.4 ks. The source
previously reported by Kennea et al. (GCN Circ. 18250), "Source 1", is
fading with 3-sigma significance, and is therefore likely the GRB
afterglow.  The position of this source is RA, Dec=225.0528, -47.7080
which is equivalent to:

RA (J2000): 15:00:12.68
Dec(J2000): -47:42:28.8

with an uncertainty of 6.8 arcsec (radius, 90% confidence).  This
position is 10.9 arcmin from the MAXI position.  The source is fading
with alpha >0.5.

The results of the XRT-team automatic analysis of the likely afterglow
are at
The results of the full analysis of the tiled XRT observations are
available at

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