EDP Sciences
Free access
Volume 442, Number 2, November I 2005
Page(s) 635 - 642
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20053046

A&A 442, 635-642 (2005)
DOI: 10.1051/0004-6361:20053046

Metallicity of M dwarfs

I. A photometric calibration and the impact on the mass-luminosity relation at the bottom of the main sequence
X. Bonfils1, 2, X. Delfosse1, S. Udry2, N. C. Santos2, 3, T. Forveille1, 4 and D. Ségransan2

1  Laboratoire d'Astrophysique, Observatoire de Grenoble, BP 53, 38041 Grenoble Cedex 9, France
    e-mail: Xavier.Bonfils@obs.ujf-grenoble.fr
2  Observatoire de Genève, 51 ch. des Maillettes, 1290 Sauverny, Switzerland
3  Centro de Astronomia e Astrofisica da Universidade de Lisboa, Observatório Astrónomico de Lisboa, Tapada de Ajuda, 1349-018 Lisboa, Portugal
4  Canada-France-Hawaii Telescope Corporation, 65-1238 Mamalahoa Highway, Kamuela, HI 96743, Hawaii, USA

(Received 11 March 2005 / Accepted 19 May 2005 )

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 ($\pm$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, Gl 876 (+0.02 dex) and Gl 436 (-0.03 dex), in the context of preferential planet formation around metal-rich stars. We finally determine the metallicity of the 47 brightest single M dwarfs in a volume-limited sample, and compare the metallicity distributions of solar-type and M-dwarf stars in the solar neighbourhood.

Key words: techniques: spectroscopic -- stars: abundances -- stars: late-type -- binaries: visual -- planetary systems -- stars: individual: Gl 876, Gl 436

SIMBAD Objects

© ESO 2005

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.