The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-rich Stars in the Solar Neighborhood

Bowler, Brendan P.; Hinkley, Sasha; Ziegler, Carl; Baranec, Christoph; Gizis, John E.; Law, Nicholas M.; Liu, Michael C.; Shah, Viyang S.; Shkolnik, Evgenya L.; Riaz, Basmah und Riddle, Reed (2019): The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-rich Stars in the Solar Neighborhood. In: Astrophysical Journal, Vol. 877, No. 1, 60

Abstract

Young stars in the solar neighborhood serve as nearby probes of stellar evolution and represent promising targets to directly image self-luminous giant planets. We have carried out an all-sky search for late-type (approximate to K7-M5) stars within 100 pc selected primarily on the basis of activity indicators from the Galaxy Evolution Explorer and ROSAT. Approximately 2000 active and potentially young stars are identified, of which we have followed up over 600 with low-resolution optical spectroscopy and over 1000 with diffraction-limited imaging using Robo-AO at the Palomar 1.5 m telescope. Strong lithium is present in 58 stars, implying ages spanning approximate to 10-200 Myr. Most of these lithium-rich stars are new or previously known members of young moving groups including TWA, beta Pic, Tuc-Hor, Carina, Columba, Argus, AB Dor, Upper Centaurus Lupus, and Lower Centaurus Crux;the rest appear to be young low-mass stars without connections to established kinematic groups. Over 200 close binaries are identified down to 0 ''.2-the vast majority of which are new-and will be valuable for dynamical mass measurements of young stars with continued orbit monitoring in the future.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 0004-637X
• Language: English