The B[e] Phenomenon in Supergiants. A Result of Mass Transfer in Binaries, Mergers, or What?

TL;DR

This paper reviews the B[e] phenomenon in supergiants, exploring its possible origins from binary interactions, mergers, or other evolutionary processes, and discusses observational evidence and theoretical implications.

Contribution

It synthesizes current knowledge on the B[e] phenomenon in supergiants, proposing potential mechanisms like binary mergers and interactions as underlying causes.

Findings

B[e] phenomenon observed in various stellar objects including supergiants.

Evidence suggests some B[e] supergiants are binary systems or merger products.

The origin of the B[e] phenomenon may involve binary interactions or mergers.

Abstract

The B[e] phenomenon discovered nearly 50 years ago features the presence of forbidden emission lines due to extended and dense circumstellar gas and large IR excesses due to the radiation from circumstellar dust in a wide variety of objects from pre-main-sequence stars to Planetary Nebulae. It also shows up in a small group of supergiants that includes Luminous Blue Variables, such as {\eta} Carinae. Over the years, some of them were proven to be binary systems, but the presence of a secondary component in other is still elusive. At the same time, there is growing evidence that the B[e] phenomenon can be due to binary mergers or interactions in triple systems.