Infrared detection of XTE J1727-476=IGR J17269-4737
ATel #629; D. Steeghs, M. A.P. Torres (CfA), K. Koviak, P. McCarthy (OCIW), P. G.Jonker (SRON/CfA)
on 13 Oct 2005; 15:38 UT
Credential Certification: Danny Steeghs (dsteeghs@cfa.harvard.edu)
Subjects: Infra-Red, Optical, X-ray, Binary, Black Hole, Neutron Star, Transient
We report near-infrared imaging of the field containing the X-ray
transient XTE J1727-476=IGR J17269-4737 (ATel #623, #624) obtained using the
wide-field infrared camera on the 100" du Pont telescope at Las
Campanas Observatory.
A series of Ks-band exposures were obtained between Oct 12 23:57UT and
Oct 13 00:09UT, totaling 675s on source. Seeing conditions were 0.6" sampled at 0.2"/pixel.
An astrometric and photometric scale were defined using a large
number of 2MASS sources in the field of view achieving an positional RMS of
0.1" and a zero-point error of less than 0.1 mag.
A Ks=16.2 point source was detected coincident with the I-band
counterpart reported in ATel #628. This is one of the brightest sources consistent with the
SWIFT localisation (ATel #626), yet not present in archival 2MASS
images.
This further solidifies its identification as the counterpart
to the X-ray transient XTE J1727-476=IGR J17269-4737. The position of
this K-band source in the 2MASS reference frame (J2000) is
R.A.=17:26:49.30, Dec=-47:38:25.5.
A finding chart including the 90% SWIFT error circle is available at http://hea-www.cfa.harvard.edu/~dsteeghs/XTEJ1727-476_Ks.jpg
IR finding chart
