THE SOLAR NEIGHBORHOOD. XXXII. THE HYDROGEN BURNING LIMIT

• Published in: The Astronomical journal Vol. 147; no. 5; pp. 1 - 25
• Main Authors: Dieterich, Sergio B, Henry, Todd J, Jao, Wei-Chun, Winters, Jennifer G, HOSEY, ALTONIO D, RIEDEL, ADRIC R, Subasavage, John P
• Format: Journal Article
• Language: English
• Published: United States 01.05.2014
• Subjects: ABUNDANCE; ALGORITHMS; Astronomical instruments; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BOLOMETERS; Boundaries; COLOR; Combustion; COMPARATIVE EVALUATIONS; DISTANCE; ENERGY SPECTRA; HEAT EXCHANGERS; HERTZSPRUNG-RUSSELL DIAGRAM; HYDROGEN BURNING; Infrared; INTERFEROMETRY; LUMINOSITY; MASS; Mathematical analysis; PHOTOMETRY; Solar neighborhood; Spectra; STARS
• ISSN: 0004-6256; 1538-3881; 1538-3881
• DOI: 10.1088/0004-6256/147/5/94

We construct a Hertzsprung-Russell diagram for the stellar/substellar boundary based on a sample of 63 objects ranging in spectral type from M6V to L4. We report newly observed VRI photometry for all 63 objects and new trigonometric parallaxes for 37 objects. We check our methodology by comparing our calculated radii to radii directly measured via long baseline optical interferometry. We find evidence for the local minimum in the radius-temperature and radius-luminosity trends that signals the end of the stellar main sequence and the start of the brown dwarf sequence at T sub(eff) ~ 2075 K, log(L/L[odot]) ~ -3.9, and (R/R[odot]) ~ 0.086. We also report new color-absolute magnitude relations for optical and infrared colors which are useful for estimating photometric distances. We study the optical variability of all 63 targets and find an overall variability fraction of 36 super(+9) sub(-7)% at a threshold of 15 mmag in the I band, which is in agreement with previous studies.