The effect of stellar activity on the spectroscopic stellar parameters of the young solar twin HIP 36515

Abstract

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 Åline 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.

5 pages, 3 figures, accepted for publication in MNRAS

References in corpus (12)

• New Grids of ATLAS9 Model Atmospheres
• The Solar Twin Planet Search. I. Fundamental parameters of the stellar sample
• Sun-as-a-Star Spectrum Variations 1974-2006
• Stellar Chemical Abundances: In Pursuit of the Highest Achievable Precision
• 18 Sco: a solar twin rich in refractory and neutron-capture elements. Implications for chemical tagging
• The temporal evolution of neutron-capture elements in the Galactic discs
• HD 98618: A Star Closely Resembling our Sun
• The Li-age correlation: the Sun is unusually Li deficient for its age
• Lithium Abundances in a Sample of Planet Hosting Dwarfs
• Constraining the evolution of stellar rotation using solar twins
• The Gaia-ESO Survey: the first abundance determination of the pre-main-sequence cluster Gamma Velorum
• On the role of magnetic fields in abundance determinations

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