The Solar Neighborhood. XXXX. Parallax Results from the CTIOPI 0.9 m Program: New Young Stars Near the Sun

Journal Article · Sun Oct 01 04:00:00 EDT 2017 · Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/AA8457· OSTI ID:22663147

Bartlett, Jennifer L.; Finch, Charlie T. ^[1]; Lurie, John C. ^[2]; Riedel, Adric ^[3]; Ianna, Philip A.; Henry, Todd J. ^[4]; Jao, Wei-Chun ^[5]; Winters, Jennifer G. ^[6]

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1. U.S. Naval Observatory, Washington, DC 20392 (United States)
2. Department of Astronomy, University of Washington, Seattle, WA 98195 (United States)
3. California Institute of Technology, Pasadena, CA 91125 (United States)
4. RECONS Institute, Chambersburg, PA 17201 (United States)
5. Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30302 (United States)
6. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

As a step toward completing and characterizing the census of the solar neighborhood, we present astrometric, photometric, and spectroscopic observations of 32 systems observed with the Cerro Tololo Inter-American Observatory 0.9 m and 1.5 m telescopes. Astrometry from the 0.9 m indicates that among the 17 systems that had no previous published trigonometric parallaxes, 14 are within 25 pc. In the full sample, nine systems have proper motions larger than 0.″5 yr{sup −1}, including 2MASS J02511490-0352459, which exceeds 2.″0 yr{sup −1}. VRI photometry from the 0.9 m and optical spectra from the 1.5 m indicate that the targets have V  = 11–22 mag and spectral types M3.0V–L3.0V. For 2MASS J23062928-0502285 (TRAPPIST-1), we present updated astrometry and photometric variability based on over 12 years of observations. Of the nine binaries in the sample, two promise mass determinations in the next decade: LHS 6167AB, an M4.5V system for which we present an accurate parallax placing the binary at 9.7 pc, and 2MASS J23515048-2537367AB, an M8.5V system at 21.1 pc for which we present the first evidence of an unseen, low-mass companion. Most importantly, Na i and K i gravity indicators, H α measurements, long-term photometric variability, locations on the H-R diagram, and kinematic assessments indicate that as many as 13 of the systems are young, including candidate members of young moving groups, with ages less than ∼120 Myr.

• OSTI ID: 22663147
• Journal Information: Astronomical Journal (Online), Journal Name: Astronomical Journal (Online) Journal Issue: 4 Vol. 154; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION SPECTRA
BINARY STARS
GRAVITATION
HERTZSPRUNG-RUSSELL DIAGRAM
INDICATORS
MASS
PHOTOMETRY
PROPER MOTION
SUN
TELESCOPES