Metallicity of M dwarfs. I. A photometric calibration and the impact on the mass-luminosity relation at the bottom of the main sequence
Abstract
We obtained high resolution ELODIE and CORALIE spectra for both components of 20 wide visual binaries composed of an F-, G- or K-dwarf primary and an M-dwarf secondary. We analyse the well-understood spectra of the primaries to determine metallicities ([Fe/H]) for these 20 systems, and hence for their M dwarf components. We pool these metallicities with determinations from the literature to obtain a precise (±0.2 dex) photometric calibration of M dwarf metallicities. This calibration represents a breakthrough in a field where discussions have had to remain largely qualitative, and it helps us demonstrate that metallicity explains most of the large dispersion in the empirical V-band mass-luminosity relation. We examine the metallicity of the two known M-dwarf planet-host stars,
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 2005
- DOI:
- 10.1051/0004-6361:20053046
- arXiv:
- arXiv:astro-ph/0503260
- Bibcode:
- 2005A&A...442..635B
- Keywords:
-
- techniques: spectroscopic;
- stars: abundances;
- stars:;
- late-type;
- binaries: visual;
- planetary systems;
- stars: individual: Gl 876;
- Gl 436;
- Astrophysics
- E-Print:
- final version, accepted for publication (A&