The lower main sequence of stars in the solar neighborhood: Model predictions versus observation

Abstract

We have used the Simbad database and VizieR catalogue access tools to construct the observational color-absolute magnitude diagrams of nearby K-M dwarfs with precise Hipparcos parallaxes (σ_π/π< 0.05). Particular attention has been paid to removing unresolved double/multiple and variable stars. In addition to archival data, we have made use of nearly 2000 new radial-velocity measurements of K-M dwarfs to identify spectroscopic binary candidates. The main sequences, cleaned from unresolved binaries, variable stars, and old population stars which can also widen the sequence due to their presumably lower metallicity, were compared to available solar-metallicity models. Significant ofsets of most of the model main-sequence lines are seen with respect to observational data, especially for the lower-mass stars. Only the location and slope of the Victoria-Regina and, partly, BaSTI isochrones match the data quite well.

Submitted to JENAM-2011 SpS3 (Saint Petersburg, July 4-8, 2011) Proceedings

References in corpus (4)

• The Dartmouth Stellar Evolution Database
• The Luminosity and Mass Functions of Low-Mass Stars in the Galactic Disk: II. The Field
• A Large Stellar Evolution Database for Population Synthesis Studies. III. Inclusion of the full Asymptotic Giant Branch phase and Web tools for stellar population analyses
• The main sequence from F to K stars of the solar neighbourhood in SDSS colours