The Infrared Counterpart of the X-ray Burster KS 1731--260

Abstract

We present JK' infrared images of the X-ray transient KS 1731--260, obtained in 1997 and in 1998 with IRAC2b at the ESO/MPI 2.2-m telescope at La Silla. Using as a reference the recent Chandra position, we confirm the identification of the X-ray source with the previously proposed counterpart (Wijnands et al. 2001b), for which we measure J=17.32 +/- 0.2 and K' = 16.36 +/- 0.18. The source was entering a low X-ray state at the epoch of our observations, and the accretion disk was still dominating the infrared flux. Indeed, when compared with the only published magnitudes in the J-band (Orosz et al. 2001), obtained with the source in quiescence, our photometry confirms the fading of the counterpart during the decay of the RXTE/ASM lightcurve.

4 pages, LaTex, 5 Postscript figures. Astronomy & Astrophysics Letter, accepted

References in corpus (2)

• A Chandra observation of the long-duration X-ray transient KS 1731-260 in quiescence: too cold a neutron star?
• Far-infrared and molecular line observations of Lynds 183 - studies of cold gas and dust

Cited by in corpus (5)

• Thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer
• Detecting gravitational wave emission from the known accreting neutron stars
• Analysing the atolls: X-ray spectral transitions of accreting neutron stars
• Broad-band X-ray measurements of the black hole candidate XTE J1908+094
• Optical/infrared observations of the X-ray burster KS1731-260 in quiescence