The Chemical Composition of HD47536: A Planetary Host Halo Giant with Possible λ Bootis Features and Signs of Interstellar Matter Accretion

Abstract

We investigated the chemical composition of the planetary host halo star HD47536 via high-resolution spectral observations recorded using a 1.5 meter Cerro Tololo Inter-American Observatory (CTIO) telescope (Chile). Furthermore, we determined the abundances of 38 chemical elements. Both light and heavy elements were overabundant compared to the iron group elements. The abundance pattern of HD47536 was similar to that of halo-type stars, with an enrichment of heavy elements. We analyzed the relationships between the relative abundances of chemical elements and their second ionization potentials and condensation temperatures. We demonstrated that the interplay of charge-exchange reactions owing to the accretion of interstellar matter and the gas-dust separation mechanism can influence the initial abundances and can be used to qualitatively explain the abundance patterns in the atmosphere of HD47536.

Keywords

• stars: individual (hd47536)
• stars: abundances
• stars: circumstellar matter
• stars: atmospheres
• stars: population ii
• physical data and processes: accretion