THE SOLAR NEIGHBORHOOD. XXIV. PARALLAX RESULTS FROM THE CTIOPI 0.9 m PROGRAM: STARS WITH {mu} {>=} 1.''0 yr{sup -1} (MOTION SAMPLE) AND SUBDWARFS

Journal Article · Fri Apr 15 04:00:00 EDT 2011 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/141/4/117· OSTI ID:21583178

Jao, Wei-Chun; Henry, Todd J; Winters, Jennifer G; Riedel, Adric R ^[1]; Subasavage, John P ^[2]

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1. Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30302 (United States)
2. Cerro Tololo Inter-American Observatory, La Serena (Chile)

We present 41 trigonometric parallaxes of 37 stellar systems, most of which have proper motions greater than 1.''0 yr{sup -1}. These are the first trigonometric parallaxes for 24 systems. Overall, there are 15 red dwarf systems and 22 red subdwarf systems in the sample. Five of the systems are multiples with directly detected companions, and we have discovered perturbations caused by unseen companions in two additional cases, the dwarf LHS 501 and the subdwarf LHS 440. The latter system may eventually provide important dynamical mass points on the subdwarf mass-luminosity relation. Two additional stars of note are LHS 272, the third closest M-type subdwarf at a distance of only 13.6 pc, and LHS 2734 AB, a high-velocity subdwarf binary with V{sub tan}> 700 km s{sup -1}, which likely exceeds the escape velocity of the Milky Way. We also report the first long-term variability study of cool subdwarfs indicating that cool subdwarfs are less photometrically variable than their main-sequence counterparts.

• OSTI ID: 21583178
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 4 Vol. 141; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DISTANCE
GALAXIES
LUMINOSITY
MASS
MILKY WAY
MOTION
OPTICAL PROPERTIES
PERTURBATION THEORY
PHYSICAL PROPERTIES
PROPER MOTION
STARS