Red novae, stellar mergers in binary and triple systems, and bipolar nebulae

TL;DR

This paper explores the connection between red novae, stellar mergers in binary and triple systems, and the formation of bipolar nebulae, suggesting some post-AGB or pre-PN objects may be merger remnants.

Contribution

It investigates the potential link between red novae remnants and bipolar nebulae, proposing that some post-main-sequence objects could be misclassified merger remnants.

Findings

Red novae remnants often display bipolar structures similar to post-AGB systems.

Some post-PN objects may actually be stellar merger remnants.

Stellar mergers could explain certain morphological features of bipolar nebulae.

Abstract

Red novae are transients powered by collisions of non-compact stars. Among their progenitors are systems of evolved subgiants and giants stars. Remnants of such red novae display bipolar structures which have remarkably close characteristics to many post-AGB or pre-PN systems. It is important to ask (and eventually verify) whether some of the less-known post-main-sequence objects (mis-)classified as pre-PNe can be merger remnants similar to the red nova remnants.