Large-scale magnetic fields and anomalies of chemical composition of stellar coronae

TL;DR

This paper investigates how large-scale magnetic field topology influences chemical composition anomalies in stellar coronae, revealing correlations between magnetic field components and FIP effect variations across different star types.

Contribution

It provides new observational evidence linking magnetic field topology with chemical abundance anomalies in stellar coronae, including the inversion of the FIP effect in fully convective stars.

Findings

Correlations between FIP effect and magnetic flux components in the Sun.

Increase of low FIP element abundance with decreasing poloidal magnetic field in solar-type stars.

Inversion of FIP effect observed in fully convective stars.

Abstract

We present evidences that anomalies in abundance of the chemical minor elements with the low first ionization potential (FIP) in the low corona of the late-type stars can be related with topology of the large-scale magnetic field. The solar observations show the increased abundances of the low FIP elements in compare to the abundances of the high FIP elements above the active regions and in the closed magnetic configurations of the low corona. Observational data of Ulysses and the Stanford Solar Observatory show high correlations between FIP effect of the solar wind, amount of the unsigned open magnetic flux, and the ratio between strength of the large-scale toroidal and poloidal magnetic field on the surface. The solar-type stars show the increase abundance of the low FIP elements relative to elements with the high FIP with the decrease of the large-scale poloidal magnetic field (and increase the toroidal component of the magnetic field). The branch of the fully convective stars demonstrates inversion of the FIP-effect. This inversion can be result from strong coronal activity, which is followed to the strong poloidal magnetic on these stars.