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Related papers: Brown Dwarfs as Ejected Stellar Embryos: Observati…

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We suggest that a high proportion of brown dwarfs are formed by gravitational fragmentation of massive, extended discs around Sun-like stars. We argue that such discs should arise frequently, but should be observed infrequently, precisely…

Astrophysics · Physics 2009-11-13 Dimitris Stamatellos , Anthony P. Whitworth

The formation mechanism of Brown Dwarfs (BDs), whether akin to stars or ejected planetary-mass objects, remains debated. We present the first 3D radiation-MHD simulations of magnetized, turbulent, gravitationally unstable low-mass cores…

Solar and Stellar Astrophysics · Physics 2025-09-17 Adnan Ali Ahmad , Benoît Commerçon , Gilles Chabrier , Antonin Borderies

We review recent theoretical progress aimed at understanding the formation and the early stages of evolution of giant planets, low-mass stars and brown dwarfs. Calculations coupling giant planet formation, within a modern version of the…

Astrophysics · Physics 2007-05-23 G. Chabrier , I. Baraffe , F. Selsis , T. Barman , P. Hennebelle , Y. Alibert

The formation of brown dwarfs via encounters between proto-stars has been confirmed with high-resolution numerical simulations with a restricted treatment of the thermal conditions. The new results indicate that young brown dwarfs (BDs)…

Astrophysics · Physics 2010-11-11 Sijing Shen , James Wadsley

Isolated low-mass stars are formed, in the standard picture, from the collapse of dense cores condensed out of strongly magnetized molecular clouds. The dynamically collapsing inflow traps nearly half of the critical magnetic flux needed…

Astrophysics · Physics 2009-11-07 Zhi-Yun Li

Observations from optical to centimeter wavelengths have demonstrated that multiple systems of two or more bodies is the norm at all stellar evolutionary stages. Multiple systems are widely agreed to result from the collapse and…

The formation of low-mass protostars and especially of brown dwarfs currently are ``hot topics'' in cool star research. The talks contributed to this splinter session discussed how low in mass and how low in luminosity objects might exist,…

Astrophysics · Physics 2007-05-23 Jochen Eislöffel , Jürgen Steinacker

The dominant formation mechanism of brown dwarfs and planetary mass objects in star-forming regions is presently uncertain. Do they form like stars, via the collapse and fragmentation of cores in Giant Molecular clouds, or do they form like…

Solar and Stellar Astrophysics · Physics 2023-08-16 Richard J. Parker , Catarina Alves de Oliveira

We have carried out 200,000 N-body simulations of three identical stellar embryos with masses from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions, while accreting using…

Solar and Stellar Astrophysics · Physics 2015-06-23 Bo Reipurth , Seppo Mikkola

One of the fundamental questions in star formation is whether or not brown dwarfs form in the same way as stars, or more like giant planets. If their formation scenarios are different, we might expect brown dwarfs to have a different…

Astrophysics of Galaxies · Physics 2014-05-29 Richard J. Parker

We present the results of multiple simulations of open clusters, modelling the dynamics of a population of brown dwarf members. We consider the effects of a large range of primordial binary populations, including the possibilities of having…

Astrophysics · Physics 2009-11-07 Tim Adams , Melvyn B. Davies , Richard F. Jameson , Aylwyn Scally

We have undertaken a series of hydrodynamic + N-body simulations in order to explore the properties of young stars. Our results suggest that the IMF may be sensitive to environment in its substellar region, with more brown dwarfs being…

Astrophysics · Physics 2007-05-23 Eduardo Delgado-Donate , Cathie Clarke

The protostellar outflow mechanism operates for a significant fraction of the pre-main sequence phase of a solar mass star and is thought to have a key role in star and perhaps even planet formation. This energetic mechanism manifests…

Solar and Stellar Astrophysics · Physics 2014-07-01 E. T. Whelan

These lectures attempt to expose the most important ideas, which have been proposed to explain the formation of stars with particular emphasis on the formation of brown dwarfs and low-mass stars. We first describe the important physical…

Astrophysics of Galaxies · Physics 2015-06-04 Patrick Hennebelle

Brown dwarfs, which straddle the mass range between stars and planets, appear to be common both in the solar neighborhood and in star-forming regions. Their ubiquity makes the question of their origin an important one both for our…

Astrophysics · Physics 2007-05-23 Ray Jayawardhana

The formation and evolution of brown dwarfs are currently "hot topics" in cool star research. Latest observations and modeling efforts on disks, accretion, outflows, spatial distribution, and binarity in the context of the formation by…

Astrophysics · Physics 2007-05-23 Jochen Eisloeffel , Subhanjoy Mohanty , Alexander Scholz

Abridged/ We present numerical results on the properties of young binary and multiple stellar systems. Our analysis is based on a series of SPH + Nbody simulations of the fragmentation of small molecular clouds, that fully resolve the…

Astrophysics · Physics 2009-11-10 E. J. Delgado-Donate , C. J. Clarke , M. R. Bate , S. T. Hodgkin

The formation mechanism of brown dwarfs (BDs) is one of the long-standing problems in star formation because the typical Jeans mass in molecular clouds is too large to form these substellar objects. To answer this question, it is crucial to…

Astrophysics of Galaxies · Physics 2016-07-27 Tien-Hao Hsieh , Shih-Ping Lai , Arnaud Belloche , Friedrich Wyrowski

The final expulsion of gas by a star as it forms a planetary nebula --- the ionized shell of gas often observed surrounding a young white dwarf --- is one of the most poorly understood stages of stellar evolution. Such nebulae form…

Astrophysics · Physics 2009-10-30 M. Bobrowsky , K. C. Sahu , M. Parthasarathy , P. Garcia-Lario

We investigate the formation of brown dwarfs and very low-mass stars through the gravitational fragmentation of infalling gas into stellar clusters. The gravitational potential of a forming stellar cluster provides the focus that attracts…

Astrophysics · Physics 2009-11-13 Ian A. Bonnell , Paul C. Clark , Matthew R. Bate