Post-AGB Binaries as Interacting Systems

TL;DR

This paper reviews recent advances in understanding the physical interactions in post-AGB binary systems, highlighting their complex dynamics and the need to consider some as post-RGB systems due to their luminosity.

Contribution

It summarizes recent progress in studying the interaction mechanisms in evolved binary systems with circumbinary discs, including the reclassification of some systems as post-RGB.

Findings

Post-AGB binaries have active interaction mechanisms.

Some systems are reclassified as post-RGB based on luminosity.

Ongoing research aims to further understand these interactions.

Abstract

We present recent progress in our understanding of the physical interaction mechanisms at work in evolved binaries of low-to-intermediate initial mass, which are surrounded by a stable disc of gas and dust. These systems are known as post-asymptotic giant-branch (post-AGB) binaries, but recently, it has been shown that some systems are too low in luminosity and should be considered as post-red-giant branch (post-RGB) instead. While the systems are currently well within their Roche lobe, they still show signs of active ongoing interaction between the different building blocks. We end this contribution with some future research plans.