We present basic observational data and association membership analysis for 45 young and active low-mass stellar systems from the ongoing RECONS photometry and astrometry program at the Cerro Tololo Inter-American Observatory .
Most of these systems have saturated X-ray emission ( \log { \frac { L _ { X } } { 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 0.9m telescope .
To this we add low-resolution optical spectroscopy and line measurements from the CTIO 1.5m telescope , and interferometric binary measurements from the Hubble Space Telescope Fine Guidance Sensors .
We also incorporate data from published sources : JHK _ { S } photometry from the 2MASS 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 \beta Pictoris , TW Hydrae , Argus , AB Doradus , two ambiguous \approx 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 parsecs of the Sun .