We report the first survey of chemical abundances in M and K dwarf stars using atomic absorption lines in high-resolution spectra. We have measured Fe and Ti abundances in 35 M and K dwarf stars using equivalent widths measured from λ/∆λ~ 33000 spectra. Our analysis takes advantage of recent improvements in model atmospheres of low-temperature dwarf stars. The stars have temperatures between 3300 and 4700 K, with most cooler than 4100 K. They cover an iron abundance range of -2.44 < [Fe/H] < +0.16. Our measurements show [Ti/Fe] decreasing with increasing [Fe/H], a trend similar to that measured for warmer stars, where abundance analysis techniques have been tested more thoroughly. This study is a step towards the observational calibration of procedures to estimate the metallicity of low-mass dwarf stars using photometric and low-resolution spectral indices.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2005
- stars: abundances;
- stars: late-type;
- 6 pages, LaTeX. To appear in MNRAS. Full version of Table 2 available at http://www.astro.washington.edu/vmw/mnras/table2.pdf