The Solar Neighborhood. XXXIII. Parallax Results from the CTIOPI 0.9 m Program: Trigonometric Parallaxes of Nearby Low-mass Active and Young Systems
Gies, Douglas R.; Nelan, Edmund P.; Blunt, Sarah C.; Henry, Todd J.; Winters, Jennifer G.; Jao, Wei-Chun; Subasavage, John P.; Finch, Charlie T.; Cruz, Kelle L.; Rice, Emily L.; White, Russel J.; Ianna, Philip A.; Riedel, Adric R.; Rodriguez, David R.; Dieterich, Sergio B.; Malo, Lison; Davison, Cassy L.
United States, Chile, Canada
Abstract
We present basic observational data and association membership analysis for 45 young and active low-mass stellar systems from the ongoing Research Consortium On Nearby Stars photometry and astrometry program at the Cerro Tololo Inter-American Observatory. Most of these systems have saturated X-ray emission (log (LX /L bol) > -3.5) based on X-ray fluxes from the ROSAT All-Sky Survey, and many are significantly more luminous than main-sequence stars of comparable color. We present parallaxes and proper motions, Johnson-Kron-Cousins VRI photometry, and multiplicity observations from the CTIOPI program on the CTIO 0.9 m telescope. To this we add low-resolution optical spectroscopy and line measurements from the CTIO 1.5 m telescope, and interferometric binary measurements from the Hubble Space Telescope Fine Guidance Sensors. We also incorporate data from published sources: JHKS photometry from the Two Micron All Sky Survey point source catalog, X-ray data from the ROSAT All-Sky Survey, and radial velocities from literature sources. Within the sample of 45 systems, we identify 21 candidate low-mass pre-main-sequence members of nearby associations, including members of β Pictoris, TW Hydrae, Argus, AB Doradus, two ambiguous ≈30 Myr old systems, and one object that may be a member of the Ursa Major moving group. Of the 21 candidate young systems, 14 are newly identified as a result of this work, and six of those are within 25 pc of the Sun.