scholarly journals Pre-Main Sequence Models for Low-Mass Stars and Brown Dwarfs

2001 ◽  
Vol 200 ◽  
pp. 483-491
Author(s):  
Isabelle Baraffe ◽  
Gilles Chabrier ◽  
France Allard ◽  
Peter Hauschildt
Keyword(s):  
Equation Of State ◽  
Main Sequence ◽  
Brown Dwarfs ◽  
Evolutionary Models ◽  
Recent Improvement ◽  
Low Mass Stars ◽  
Theory Equation ◽  
Low Mass

We present evolutionary models for young low mass stars (m ≤ 1M⊙) based on recent improvement of the theory: equation of state, atmosphere models, etc. We concentrate on early evolutionary phases from the initial deuterium burning phase to the zero-age Main Sequence. Evolutionary models for young brown dwarfs are also presented. We discuss the uncertainties of the present models. We analyse the difficulties arising when comparing models with observations for very young objects, in particular concerning the problem of reddening.

Theoretical models of low-mass stars and brown dwarfs. I - The lower main sequence

1989 ◽  
Vol 342 ◽  
pp. 1003 ◽  
Author(s):  
Ben Dorman ◽  
Lorne A. Nelson ◽  
W. Y. Chau
Keyword(s):  
Main Sequence ◽  
Brown Dwarfs ◽  
Theoretical Models ◽  
Low Mass Stars ◽  
Low Mass

scholarly journals The early evolution of low mass stars and brown dwarfs

2009 ◽  
Vol 5 (H15) ◽  
pp. 755-755
Author(s):  
Isabelle Baraffe
Keyword(s):  
Magnetic Field ◽  
Star Formation ◽  
Brown Dwarfs ◽  
Early Evolution ◽  
Evolutionary Models ◽  
Low Mass Stars ◽  
Low Mass ◽  
Effects Of Rotation ◽  
Star Formation Regions

My talk will focus on the early evolution of low mass objects. I will discuss the main uncertainties on current evolutionary models and the effects of rotation, magnetic field and early accretion history on young object's structure. I will also present possible solutions to the well known spread in HRD observed in star formation regions for objects of a few Myr old.

scholarly journals A Relative Age Test of Pre-Main Sequence Evolutionary Models Based on the Young Quadruple System GG Tauri

2001 ◽  
Vol 200 ◽  
pp. 464-467
Author(s):  
Russel J. White
Keyword(s):  
Spectral Type ◽  
Temperature Scale ◽  
Main Sequence ◽  
Evolutionary Models ◽  
Low Mass Stars ◽  
Relative Age ◽  
Wide Range ◽  
Quadruple System ◽  
Low Mass

The components of the young hierarchical quadruple GG Tau, which span a wide range in spectral type (K7 – M7.5), are used to test both evolutionary models and the temperature scale for very young, low mass stars under the assumption of coeval formation. Of the evolutionary models tested which extend into the substellar regime, those of Baraffe et al. yield the most consistent ages when combined with a temperature scale intermediate between that of dwarfs and giants. The Palla & Stahler and Siess et al. models are also capable of yielding a coeval age down to their lowest mass (0.1 M⊙). These latter two models, which extend to much higher masses than the Baraffe et al. models, agree reasonably well with the Baraffe et al. models at 1.0 M⊙ and thus could be combined to construct a set evolutionary models that extends from Substellar to several solar masses.

scholarly journals Atmosphere models for very low mass stars, brown dwarfs and exoplanets

1997 ◽  
Vol 189 ◽  
pp. 227-233
Author(s):  
I. Baraffe ◽  
F. Allard
Keyword(s):  
Main Sequence ◽  
Accurate Determination ◽  
Brown Dwarfs ◽  
Considerable Effort ◽  
Low Mass Stars ◽  
The Past ◽  
Substellar Objects ◽  
Cool Stars ◽  
Low Mass

Over the past decade considerable effort, both observational and theoretical, has been directed towards a more accurate determination of the stellar lower main sequence and of the sub-stellar domain covered by Brown Dwarfs and Planets. Astronomers have been looking for brown dwarfs for more than a decade, either with standard astronomical technics or with microlensing experiments. A breakthrough in the search for brown dwarfs was very recently achieved with the discovery of the first cool brown dwarf GL 229B (Nakajima et al. 1995). At the same epoch, the search for planets blossomed with the discovery of a Jupiter - mass companion of the star 51 Pegasi (Mayor and Queloz 199,5). Now, the number of faint, cool stars and substellar objects is rising rapidly.

scholarly journals Evolutionary Models for Low Mass Stars and Brown Dwarfs at Young Ages

2003 ◽  
Vol 211 ◽  
pp. 41-50 ◽  
Author(s):  
Isabelle Baraffe ◽  
Gilles Chabrier ◽  
France Allard ◽  
Peter Hauschildt
Keyword(s):  
Initial Conditions ◽  
Brown Dwarfs ◽  
Evolutionary Models ◽  
Low Mass Stars ◽  
Low Mass

We analyse evolutionary tracks at young ages for low mass stars with masses m ≤ 1.4 M⊙ and brown dwarfs down to one mass of Jupiter. We analyse current theoretical uncertainties due to initial conditions. Simple tests on initial conditions show the high uncertainties of models at ages ≲ 1 Myr.

scholarly journals New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit

2015 ◽  
Vol 577 ◽  
pp. A42 ◽  
Author(s):  
Isabelle Baraffe ◽  
Derek Homeier ◽  
France Allard ◽  
Gilles Chabrier
Keyword(s):  
Main Sequence ◽  
Evolutionary Models ◽  
Low Mass Stars ◽  
Hydrogen Burning ◽  
Low Mass

scholarly journals Evolutionary models for low-mass stars and brown dwarfs: Uncertainties and limits at very young ages

2002 ◽  
Vol 382 (2) ◽  
pp. 563-572 ◽  
Author(s):  
I. Baraffe ◽  
G. Chabrier ◽  
F. Allard ◽  
P. H. Hauschildt
Keyword(s):  
Brown Dwarfs ◽  
Evolutionary Models ◽  
Low Mass Stars ◽  
Low Mass

scholarly journals Evolutionary Models for Very Low‐Mass Stars and Brown Dwarfs with Dusty Atmospheres

2000 ◽  
Vol 542 (1) ◽  
pp. 464-472 ◽  
Author(s):  
G. Chabrier ◽  
I. Baraffe ◽  
F. Allard ◽  
P. Hauschildt
Keyword(s):  
Brown Dwarfs ◽  
Evolutionary Models ◽  
Low Mass Stars ◽  
Low Mass

scholarly journals Effect of accretion on the pre-main-sequence evolution of low-mass stars and brown dwarfs

2017 ◽  
Vol 605 ◽  
pp. A77 ◽  
Author(s):  
Eduard I. Vorobyov ◽  
Vardan Elbakyan ◽  
Takashi Hosokawa ◽  
Yuya Sakurai ◽  
Manuel Guedel ◽  
...  
Keyword(s):  
Main Sequence ◽  
Brown Dwarfs ◽  
Sequence Evolution ◽  
Low Mass Stars ◽  
Low Mass
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