The GTC provides new data from the Sigma Orionis cluster

The GTC observations have discovered earlier unknown characteristics of stars and brown dwarfs in the Sigma Orionis star cluster. The data are of high quality although some records were taken in non-optimal weather conditions.

 Members of the collaboration Consolider-Gran Telescopio Canarias (GTC) have failed to confirm data regarding the characteristics of ten low-mass stars and brown dwarfs through observations made with the OSIRIS instrument of GTC.

The instrument obtained low-resolution spectra of these objects in the young open cluster of Sigma Orionis, near the famous Nebula Horsehead. The data were obtained in different observing nights during the month of March 2012.

Specifically, the paper takes seven detailed information objects, such as its intensity or spectral classification of the absorption lines of lithium and calcium and hydrogen emission. The spectral type is an indicator of temperature and mass, while the spectral lines are markers of extreme youth and accretion (violent fall of material onto the surface of the star from a surrounding disk).

The objective of this program was to use the nights when conditions are not optimal for viewing other programs (such as the "seeing" high or presence of dense clouds). We obtained high-quality spectra of variable sources unrated known to be relatively bright for a telescope-like 10 meters. Some of the spectra obtained during one of the nights of observation were captured while the rest of telescopes on La Palma were not operating.

Interest in the brown dwarf Mayrit

All the stars and brown dwarfs meet one requirement: they were known variable objects in the optical or X-ray Some objects have been characterized to be of great interest to astrophysicists as the brown dwarf Mayrit 1196092, which has features that until recently were believed certain exclusive and active young stars called T Tauri.

This study is part of two projects: one is the spectroscopic study with OSIRIS / GTC variables obscure sources, and the other is the Mayrit project, whose goal is to catalog in detail all bodies belonging to Sigma Orionis cluster, a real laboratory star formation.

All the stars and brown dwarfs in this catalog are named Mayrit and a number indicating its position in the cluster. Mayrit is the word then evolved to give name to the city of Madrid.

Despite numerous studies carried out previously, many of them Spanish-made by astronomers, there are still dozens of low-mass stars and brown dwarfs in the Sigma Orionis without a detailed spectroscopic characterization. Some of them may even be accreting material or have not yet detected disks, disks where planets may be forming.