The effect of stellar activity on the spectroscopic stellar parameters of the young solar twin HIP 36515
| Autor: | Adriana Valio, Henrique Reggiani, Jorge Melendez, Jhon Yana Galarza, Diego Lorenzo-Oliveira, Lorenzo Spina, Raphaëlle D. Haywood, Marilia Carlos, Geisa Ponte, Davide Gandolfi |
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| Rok vydání: | 2019 |
| Předmět: |
stars: abundances
Metallicity FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics stars: activity stars: atmospheres stars: fundamental parameters stars: solar-type techniques: spectroscopic 01 natural sciences Spectral line Abundance (ecology) 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Line (formation) Physics 010308 nuclear & particles physics Astronomy and Astrophysics Effective temperature Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science ATMOSFERAS ESTELARES Microturbulence Astrophysics::Earth and Planetary Astrophysics Excitation |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1745-3933 1745-3925 |
| DOI: | 10.1093/mnrasl/slz153 |
| Popis: | Spectroscopic equilibrium allows us to obtain precise stellar parameters in Sun-like stars. It relies on the assumption of the iron excitation and ionization equilibrium. However, several works suggest that magnetic activity may affect chemical abundances of young active stars, calling into question the validity of this widely-used method. We have tested for the first time variations in stellar parameters and chemical abundances for the young solar twin HIP 36515 ($\sim$0.4 Gyr), along its activity cycle. This star has stellar parameters very well established in the literature and we estimated its activity cycle in $\sim$6 years. Using HARPS spectra with high resolving power (115 000) and signal-to-noise ratio ($\sim$270), the stellar parameters of six different epochs in the cycle were estimated. We found that the stellar activity is strongly correlated with the effective temperature, metallicity, and microturbulence velocity. The possibility of changes in the Li I 6707.8 \AA line due to flares and star spots was also investigated. Although the core of the line profile shows some variations with the stellar cycle, it is compensated by changes in the effective temperature, resulting in a non variation of the Li abundance. Comment: 5 pages, 3 figures, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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