Metallicity and photospheric abundances in field GKM giants and dwarfs
Abstract
This paper deals with standard elemental abundances in late-type stars. By analysing high signal-to-noise ratio and high-resolution data we have found that dwarf stars have generally solar and below-solar abundances, and that all giants in our sample are indicated to be overabundant at the present stage of the study. The dwarf stars match the evolutionary diagram for the age interval ~0.3-10 Gyr. The star EQ Vir from the sample is found to have several signatures of activity: namely, a higher value of v sini (12 km s-1), and emission in spectral lines such as Hα and CaII. Furthermore, its pronounced TiO 7055-Å band head indicates a slight inconsistency with its spectral type. The TiO band head signature has been estimated in the coolest stars in the sample. Also the measured radial velocities indicate possible binarity for some of the stars in the sample. Importantly, emergent radiation from stars is a present topic for debate with respect to the habitable zones of planetary systems.
Based on observations obtained using the Anglo-Australian Telescope, Australia, and the William Herschel Telescope, Canary Islands. E-mail: zboril@astro.sk- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2009
- DOI:
- 10.1111/j.1365-2966.2009.14917.x
- Bibcode:
- 2009MNRAS.397..335Z
- Keywords:
-
- stars: abundances;
- stars: activity;
- stars: individual: EQ Vir;
- stars: late-type