A SINGULAR INTERACTING ECLIPSING BINARY IN THE GALACTIC HALO

The IRAS source 00016 - 3056 is identified with a 508-d eclipsing bina ry situated in the halo, approximately 5 kpc above the Galactic plane. Near-infrared photometry, optical photometry and spectroscopy of the system are discussed. The JHK light curves show two eclipses as well a s a pronounced reflection effect exceeding 0.5 mag at J. The primary i s an early-M giant, possibly an AGB star, seen in the infrared through A(V) approximately 5.3 mag of extinction. In contrast, the optical li ght experiences much lower extinction (A(V) approximately 0.8 mag), an d can be understood as the result of a reflection of one of the centra l stars from a circum-binary cloud. The nature of the secondary remain s unclear, although various possibilities are discussed. It is suggest ed that the system may be a unique representative of a short-lived evo lutionary phase and that changes due to evolution may be observable ov er a relatively short time interval.