Stars and brown dwarfs in the sigma Orionis cluster: the Mayrit catalogue

TL;DR

This paper introduces the Mayrit catalogue, a comprehensive list of stars and brown dwarfs in the sigma Orionis cluster, based on optical-near infrared data and multi-wavelength confirmation, to aid in studying its stellar population.

Contribution

The Mayrit catalogue is the first extensive compilation of sigma Orionis members, combining optical, infrared, X-ray, and astrometric data to identify and characterize the cluster's stellar population.

Findings

Lists 241 confirmed cluster members and brown dwarfs.

Identifies 97 candidate members, including 40 new discoveries.

Provides a complete sample for future studies of the cluster's properties.

Abstract

The young sigma Orionis cluster is an indispensable basis for understanding the formation and evolution of stars, brown dwarfs and planetary-mass objects. Our knowledge of its stellar population is, however, incomplete. I present the Mayrit catalogue, that comprises most of the stars and high-mass brown dwarfs of the cluster. The basis of this work is an optical-near infrared correlation between the 2MASS and DENIS catalogues in a circular area of radius 30 arcmin centred on the OB-type binary sigma Ori AB. The analysis is supported on a bibliographic search of confirmed cluster members with features of youth and on additional X-ray, mid-infrared and astrometric data. I list 241 sigma Orionis stars and brown dwarfs with known features of youth, 97 candidate cluster members (40 are new) and 115 back- and foreground sources in the survey area. The 338 cluster members and member candidates constitute the Mayrit catalogue. This catalogue is a suitable input for studying the spatial ditribution, multiplicity, properties and frequency of discs and the complete mass function of sigma Orionis.