The formation of low-mass stars and brown dwarfs

Abstract

It is estimated that ~60% of all stars (including brown dwarfs) have masses below 0.2Msun. Currently, there is no consensus on how these objects form. I will briefly review the four main theories for the formation of low-mass objects: turbulent fragmentation, ejection of protostellar embryos, disc fragmentation, and photo-erosion of prestellar cores. I will focus on the disc fragmentation theory and discuss how it addresses critical observational constraints, i.e. the low-mass initial mass function, the brown dwarf desert, and the binary statistics of low-mass stars and brown dwarfs. I will examine whether observations may be used to distinguish between different formation mechanisms, and give a few examples of systems that strongly favour a specific formation scenario. Finally, I will argue that it is likely that all mechanisms may play a role in low-mass star and brown dwarf formation.

6 pages, a short review, to appear in the proceedings of the conference "The labyrinth of star formation", edited by Stamatellos, Goodwin & Ward-Thompson

References in corpus (17)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Analytical theory for the initial mass function: CO clumps and prestellar cores
• The properties of brown dwarfs and low-mass hydrogen-burning stars formed by disc fragmentation
• The Effects of Radiative Transfer on Low-Mass Star Formation
• Magnetic processes in a collapsing dense core. I Accretion and Ejection
• The Importance of Radiative Feedback for the Stellar Initial Mass Function
• The Two Modes of Gas Giant Planet Formation
• The AstraLux Large M-dwarf Multiplicity Survey
• Brown dwarf formation by gravitational fragmentation of massive, extended protostellar discs
• The minimum mass for star formation, and the origin of binary brown dwarfs
• Tidally induced brown dwarf and planet formation in circumstellar discs
• Disk Formation Enabled by Enhanced Resistivity
• Interferometric Identification of a Pre-Brown Dwarf
• Episodic accretion, protostellar radiative feedback, and their role in low-mass star formation
• Enhanced Dust Emission in the HL Tau Disc: A Low-Mass Companion in Formation?
• Simulating star formation in molecular cloud cores IV. The role of turbulence and thermodynamics
• Interactions between brown-dwarf binaries and Sun-like stars

Cited by in corpus (4)

• The slow spin of the young sub-stellar companion GQ Lupi b and its orbital configuration
• The properties of discs around planets and brown dwarfs as evidence for disc fragmentation
• Deep near-IR observations of the Globular Cluster M4: Hunting for Brown Dwarfs
• Search for Brown Dwarfs in IC 1396 with Subaru HSC: Interpreting the Impact of Environmental Factors on Sub-stellar Population