Binary interaction along the Red Giant Branch: The Barium Star perspective

TL;DR

This paper investigates the binary evolution of Barium stars along the Red Giant Branch, highlighting the need for additional interaction mechanisms to explain observed orbital characteristics.

Contribution

It introduces evolutionary models based on observations of main-sequence Ba systems to better understand binary interactions during the RGB phase.

Findings

Short and eccentric orbits require additional interaction mechanisms.

Models successfully reproduce some orbital features of Ba giants.

Highlights gaps in current understanding of binary interactions along the RGB.

Abstract

Barium (Ba) stars form via mass-transfer in binary systems, and can subsequently interact with their white dwarf companion in a second stage of binary interaction. We used observations of main-sequence Ba systems as input for our evolutionary models, and try to reproduce the orbits of the Ba giants. We show that to explain short and sometimes eccentric orbits, additional interaction mechanisms are needed along the RGB.