Light-Element Depletion in Contracting Brown Dwarfs and Pre-Main-Sequence Stars

@article{Ushomirsky1998LightElementDI,
  title={Light-Element Depletion in Contracting Brown Dwarfs and Pre-Main-Sequence Stars},
  author={G. Ushomirsky and C. Matzner and E. Brown and L. Bildsten and Vadim G. Hilliard and P. Schroeder},
  journal={The Astrophysical Journal},
  year={1998},
  volume={497},
  pages={253-266}
}
We present an analytic calculation of the thermonuclear depletion of the light elements lithium, beryllium, and boron in fully convective, low-mass stars. Under the presumption that the pre-main-sequence star is always fully mixed during contraction, we find that the burning of these rare light elements can be computed analytically, even when the star is degenerate. Using the effective temperature as a free parameter, we constrain the properties of low-mass stars from observational data… Expand

Figures and Tables from this paper

The effect of star-spots on the ages of low-mass stars determined from the lithium depletion boundary
In a coeval group of low-mass stars, the luminosity of the sharp transition between stars that retain their initial lithium and those at slightly higher ma sses in which Li has been depleted byExpand
3D NLTE spectral line formation of lithium in late-type stars.
TLDR
A grid of synthetic lithium spectra that are computed in non-local thermodynamic equilibrium (NLTE) across the stagger grid of three-dimensional (3D) hydrodynamic stellar atmosphere models, and finds that the abundance corrections are up to 0.15 dex more negative than in previous work, due to a previously overlooked NLTE effect of blocking of UV lithium lines by background opacities. Expand
WHITE DWARF DONORS IN ULTRACOMPACT BINARIES: THE STELLAR STRUCTURE OF FINITE-ENTROPY OBJECTS
We discuss the mass-radius (M-R) relations for low-mass (M < 0.1 M☉) white dwarfs (WDs) of arbitrary degeneracy and evolved (He, C, O) composition. We do so with both a simple analytical model andExpand
An Improved Determination of the Lithium Depletion Boundary Age of Blanco 1 and a First Look on the Effects of Magnetic Activity
The Lithium Depletion Boundary (LDB) is a robust method for accurately determining the ages of young clusters, but most pre-main-sequence models used to derive LDB ages do not include the effects ofExpand
L Dwarfs and the Substellar Mass Function
Analysis of initial observations sky surveys has shown that the resulting photometric catalogs, combined with far-red optical data, provide an extremely effective method of finding isolated, veryExpand
Cumulative theoretical uncertainties in lithium depletion boundary age
We performed a detailed analysis of the main theoretical uncertainties affecting the age at the lithium depletion boundary (LDB). To do that we computed almost 12 000 pre-main- sequence models withExpand
The Lithium depletion boundary in NGC 2547 as a test of pre-main-sequence evolutionary models
Intermediate resolution spectroscopy from the European Southern Observatory Very Large Telescope is analysed for 63 photometrically selected low-mass (0.08-0.30 M ○. ) candidates of the open clusterExpand
A lithium depletion boundary age of 22 Myr for NGC 1960
We present a deep Cousins RI photometric survey of the open cluster NGC 1960, complete to R C ≃ 22, I C ≃ 21, that is used to select a sample of very low mass cluster candidates. Gemini spectroscopyExpand
The lithium depletion boundary and the age of NGC 2547
We present the results of a photometric and spectroscopic survey of cool M dwarf candidates in the young open cluster NGC 2547. Using the 2dF fibre spectrograph, we have searched for the luminosityExpand
Modules for Experiments in Stellar Astrophysics (MESA): Planets, Oscillations, Rotation, and Massive Stars
We substantially update the capabilities of the open source software package Modules for Experiments in Stellar Astrophysics (MESA), and its one-dimensional stellar evolution module, MESA star.Expand
...
1
2
3
4
...

References

SHOWING 1-10 OF 62 REFERENCES
Lithium Depletion in Fully Convective Pre-Main-Sequence Stars
We present an analytic calculation of the thermonuclear depletion of lithium in contracting, fully con- vective, preEmain-sequence stars of mass Previous numerical work relies on still uncertain M (Expand
Implications of a Subthreshold Resonance for Stellar Beryllium Depletion
Abundance measurements of the light elements lithium, beryllium, and boron are playing an increasingly important role in the study of stellar physics. Because these elements are easily destroyed inExpand
Evolution of Stars of Small Masses in the Pre-Main-Sequence Stages
The structure of the outer envelope with an H-ii:mization zone and an H 2-dissociation zone is investigated for Population I stars of small masses (2M02:M>0.05M(!)), which have low luminositiesExpand
The evolution of very low mass stars
The results of numerical evolutionary calculations for stars with masses in the range of 0.01-0.10 solar mass are presented. The stellar models by which these stars are followed from the early stagesExpand
On the Li and Be tests for brown dwarfs
We present the results of stellar evolution calculations which show quantitatively how the measured abundances of Li and Be in low-mass stellar objects can be used to discriminate between brownExpand
Mass-Luminosity Relationship and Lithium Depletion for Very Low Mass Stars
We derive mass-luminosity relationships for very low mass stars (0.06 < m/M☉ < 0.6) for different metallicities. Calculations are conducted with the different nongray atmosphere models presentlyExpand
Is there a classical Hyades lithium problem
The distribution of surface lithium abundances in the Hyades cluster, as a function of effective temperature, has resisted a satisfactory theoretical explanation for more than two decades. Trends inExpand
Deuterium and the stellar birthline
A series of simplified evolutionary calculations are used to show that deuterium burning acts as an effective thermostat in low-mass protostars over a plausible range of initial conditions and massExpand
Hydrodynamical instabilities in the envelopes of main-sequence stars: constraints implied by the lithium, beryllium, and boron observations.
The abundances of lithium, beryllium, and boron in main-sequence stars are studied in view of their implications on the hydrodynamics in stellar interiors. Since they are destroyed by nuclearExpand
Evidence of a Thermonuclear Runaway and Proton-Capture Material on a White Dwarf in a Dwarf Nova*
We present Hubble Space Telescope Goddard High-Resolution Spectrograph G160M spectra of the white dwarf in VW Hydri, exposed during quiescence, 1 month after the end of a normal dwarf nova outburst.Expand
...
1
2
3
4
5
...