High-resolution Spectroscopic Study of Dwarf Stars in the Northern Sky: Lithium, Carbon, and Oxygen Abundances
| Autor: | Hans Kjeldsen, Gražina Tautvaišienė, Šarūnas Mikolaitis, C. von Essen, E. Stonkutė, Y. Chorniy, R. Minkevičiūtė, Arnas Drazdauskas, V. Bagdonas, E. Pakštienė |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Physics
media_common.quotation_subject Metallicity FOS: Physical sciences chemistry.chemical_element Astronomy and Astrophysics Astrophysics Abundance of the chemical elements Stars chemistry Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Sky Planet Abundance (ecology) Lithium Carbon Solar and Stellar Astrophysics (astro-ph.SR) media_common |
| Zdroj: | Stonkute, E, Chorniy, Y, Tautvaišiene, G, Drazdauskas, A, Minkevičiute, R, Mikolaitis,, Kjeldsen, H, Essen, C V, Pakštiene, E & Bagdonas, V 2020, ' High-resolution Spectroscopic Study of Dwarf Stars in the Northern Sky : Lithium, Carbon, and Oxygen Abundances ', Astronomical Journal, vol. 159, no. 3, 90 . https://doi.org/10.3847/1538-3881/ab6a19 |
| DOI: | 10.3847/1538-3881/ab6a19 |
| Popis: | Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Moletai Astronomical Observatory of Vilnius University. The sample stars have metallicities, effective temperatures, and ages between -0.7 and 0.4 dex; 5000 and 6900 K; 1 and 12 Gyr, accordingly. We confirm a so far unexplained lithium abundance decrease at supersolar metallicities - $A$(Li) in our sample stars, which drop by 0.7 dex in the [Fe/H] range from +0.10 to +0.55 dex. Furthermore, we identified stars with similar ages, atmospheric parameters, and rotational velocities, but with significantly different lithium abundances, which suggests that additional specific evolutionary factors should be taken into account while interpreting the stellar lithium content. Nine stars with predominantly supersolar metallicities, i.e. about 12 % among 78 stars with C and O abundances determined, have the C/O number ratios larger than 0.65, thus may form carbon-rich rocky planets. Ten planet-hosting stars, available in our sample, do not show a discernible difference from the stars with no planets detected regarding their lithium content. 17 pages, 15 figures. Published 2020 February 6, 2020. The Astronomical Journal |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|