A new survey of cool supergiants in the Magellanic Clouds

TL;DR

This paper presents a pilot survey of red supergiants in the Magellanic Clouds, expanding the known sample, analyzing their properties, and developing improved classification methods using infrared data.

Contribution

It introduces a new infrared-based candidate selection and classification approach, significantly enlarging the known population of red supergiants in the Magellanic Clouds.

Findings

Detected around two hundred new RSGs.

Identified the onset of mass-loss and dust effects.

Developed improved infrared classification criteria.

Abstract

In this study, we conduct a pilot program aimed at the red supergiant population of the Magellanic Clouds. We intend to extend the current known sample to the unexplored low end of the brightness distribution of these stars, building a more representative dataset with which to extrapolate their behaviour to other Galactic and extra-galactic environments. We select candidates using only near infrared photometry, and with medium resolution multi-object spectroscopy, we perform spectral classification and derive their line-of-sight velocities, confirming the nature of the candidates and their membership to the clouds. Around two hundred new RSGs have been detected, hinting at a yet to be observed large population. Using near and mid infrared photometry we study the brightness distribution of these stars, the onset of mass-loss and the effect of dust in their atmospheres. Based on this sample, new a priori classification criteria are investigated, combining mid and near infrared photometry to improve the observational efficiency of similar programs as this.