Characterization of the Most Luminous Star in M33: A Super Symbiotic Binary

TL;DR

This paper reports the discovery and spectral analysis of the most luminous infrared star in M33, revealing it as the most luminous symbiotic binary, composed of a massive O star and a dust-enshrouded Red Hypergiant, likely a very young, massive system.

Contribution

It provides the first spectrum of this luminous star, identifying it as the most luminous symbiotic binary and characterizing its binary nature and composition.

Findings

The star is a binary with a massive O star and a Red Hypergiant.

It is the most luminous symbiotic binary discovered.

Its radial velocity matches the hydrogen gas in M33's disk.

Abstract

We present the first spectrum of the most luminous infrared star in M33, and use it to demonstrate that the object is almost certainly a binary composed of a massive O star and a dust-enshrouded Red Hypergiant. This is the most luminous symbiotic binary ever discovered. Its radial velocity is an excellent match to that of the hydrogen gas in the disk of M33, supporting our interpretation that it is a very young and massive binary star.