  Young stellar systems in the solar neighborhood provide valuable laboratories
for detailed studies of star and planet formation. The bright F8V star HD
199143 and the Li-rich late-type emission line star HD 358623 are among the
nearest young stars identified to date, and may be members of a young
association in Capricornus. We present high-resolution near-infrared images of
these two sources, obtained using the adaptive optics system on the 3.6-meter
telescope at the European Southern Observatory in La Silla, Chile. Our
observations reveal that both are in fact close binary systems. The newly
discovered companion at a separation of $\sim$1'' may account for the unusual
characteristics of HD 199143 --rapid rotation, emission lines, ultraviolet
variability, and excess infrared emission-- recently discussed by van den
Ancker and co-workers. HD 199143 may be a rare example of a close binary with
only a circum{\it secondary} disk. With the detection of a $\sim$2'' companion,
HD 358623 is now possibly one of the closest known T Tauri binaries. Both
binary systems are prime targets for follow-up spectroscopic and astrometric
observations.

Astrophysics