Ultra low-mass star and substellar formation in sigma Orionis

Abstract

The nearby young sigma Orionis cluster (~360 pc, ~3 Ma) is becoming one of the most important regions for the study of ultra low-mass star formation and its extension down to the mass regimes of the brown dwarfs and planetary-mass objects. Here, I introduce the sigma Orionis cluster and present three studies that the JOVIAN group is developing: a pilot programme of near-infrared adaptive-optics imaging, intermediate-resolution optical spectroscopy of a large sample of stars of the cluster and a study of the mass function down to the planetary-mass domain. This paper is a summary of the content of four posters that I presented in the Ultra low-mass star formation and evolution Workshop, as single author or on behalf of different collaborations.

4 pages, 4 figures. Proceeding at the IAC-TNG Workshop on Ultra low-mass star formation and evolution, 28 June - 1 July 2005, La Palma, Canary Islands, Spain. Accepted for publication in Astron. Nachr

References in corpus (6)

• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• Very Low Mass Stars and Brown Dwarfs in Taurus-Auriga
• Rotation and accretion of very low mass objects in the SigmaOri cluster
• XMM-Newton observations of the sigma Ori cluster. I. The complex RGS spectrum of the hot star sigma Ori AB
• An L'-band survey for circumstellar disks around low-mass stars in the young sigma Orionis cluster
• Discovery of a dust cloud next to sigma Orionis

Cited by in corpus (12)

• Spitzer Space Telescope study of disks in the young $\sigma$ Orionis cluster
• The substellar mass function in sigma Orionis. II. Optical, near-infrared and IRAC/Spitzer photometry of young cluster brown dwarfs and planetary-mass objects
• The brightest stars of the sigma Orionis cluster
• Orbital and physical properties of the $\sigma$ Ori Aa,Ab,B triple system
• Spatial distribution of stars and brown dwarfs in sigma Orionis
• Dynamical parallax of sigma Ori AB: mass, distance and age
• High-Resolution Chandra X-ray Imaging and Spectroscopy of the Sigma Orionis Cluster
• A deep look into the cores of young clusters I. sigma-Orionis
• Circumstellar discs in the young sigma Orionis cluster
• Are isolated planetary-mass objects really isolated? A brown dwarf-exoplanet system candidate in the sigma Orionis cluster
• Stars and brown dwarfs in the sigma Orionis cluster. IV. IDS/INT and OSIRIS/GTC spectroscopy and Gaia DR2 astrometry
• Sigma Orionis IRS1 A and B: A Binary Containing a Proplyd