The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-Rich Stars in the Solar Neighborhood
Autor: | 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, Riddle, Reed |
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Rok vydání: | 2019 |
Předmět: | |
Druh dokumentu: | Working Paper |
DOI: | 10.3847/1538-4357/ab1018 |
Popis: | 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 ($\approx$K7$-$M5) stars within 100 pc selected primarily on the basis of activity indicators from $GALEX$ and $ROSAT$. Approximately two thousand active and potentially young stars are identified, over 600 of which we have followed up 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 $\approx$10$-$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. Comment: Accepted to ApJ |
Databáze: | arXiv |
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