On the nature of BD-10 deg 4662

Attention was first called to BD-10 deg 4662 (now assigned variable-star designation FK Ser) by Stienon (1971), who reported a temporary brightening in the blue on a Case objective-prism plate, accompanied by Balmer emission and a strong ultraviolet continuum. In its normal state the star appeared to be an ordinary late K-type object without emission features. Infrared observations show that BD-10 deg 4662 has excesses in the H - K and K - L colors similar to ordinary T Tauri stars. Emission at Ca II H and K confirms the close relationship to that group of objects.