Discovery of close companions to the nearby young stars HD 199143 and HD 358623

Abstract

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.

9 pages, 1 PostScript figure, to appear in The Astrophysical Journal Letters

References in corpus (1)

• Discovery of close companions to the nearby young stars HD 199143 and HD 358623

Cited by in corpus (13)

• The Palomar/Keck Adaptive Optics Survey of Young Solar Analogs: Evidence for a Universal Companion Mass Function
• A Spectroscopic Survey of Subarcsecond Binaries in the Taurus-Auriga Dark Cloud with the Hubble Space Telescope
• Reaching the boundary between stellar kinematic groups and very wide binaries. III. Sixteen new stars and eight new wide systems in the beta Pictoris moving group
• The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-Rich Stars in the Solar Neighborhood
• Magneto-Convection and Lithium Age Estimates of the βPictoris Moving Group
• Resolved Imaging of the HD191089 Debris Disc
• Binaries among low-mass stars in nearby young moving groups
• Infrared imaging and spectroscopy of companion candidates near the young stars HD 199143 and HD 358623 in Capricornius
• Discovery of close companions to the nearby young stars HD 199143 and HD 358623
• HD 199143 and HD 358623: Two Recently Identified Members of the Beta Pictoris Moving Group
• Imaging survey of subsystems in secondary components to nearby southern dwarfs
• VIBES: VIsual Binary Exoplanet survey with SPHERE Upper limits on wide S-planet and S-BD frequencies, triple system discovery, and astrometric confirmation of 20 stellar binaries and three triple systems
• No disk needed around HD 199143 B