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The process that leads to the formation and early evolution of low-mass stars is in a broad sense well understood theoretically and carefully traced observationally. The largest uncertainties in this framework reside in the poorly known…

Astrophysics · Physics 2007-05-23 Francesco Palla , Sofia Randich

The primordial Lithium Problem is intimately connected to the assumption that ${}^{7}{\rm Li}$ observed in metal-poor halo stars retains its primordial abundance, which lies significantly below the predictions of standard big-bang…

Astrophysics of Galaxies · Physics 2022-04-08 Brian D. Fields , Keith A. Olive

The primordial abundances of light elements produced in the standard theory of Big Bang nucleosynthesis (BBN) depend only on the cosmic ratio of baryons to photons, a quantity inferred from observations of the microwave background. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-20 J. Christopher Howk , Nicolas Lehner , Brian D. Fields , Grant J. Mathews

It is argued that apart from the well known dependence of the Am phenomenon on the mass, age (effective temperature, gravity) and rotation there is also a complex dependence on the orbital parameters in binary systems. This is why the…

Astrophysics · Physics 2007-11-29 I. Iliev , J. Budaj

We show by detailed model computation how much the Pre-Main Sequence (PMS) Lithium depletion depends on the treatment of over-adiabaticity, by taking advantage of the results of new models by Montalb\'an et al., which apply different…

Astrophysics · Physics 2009-11-10 F. D'Antona , J. Montalban

Planet engulfment has been identified as one of the mechanisms for enhancing lithium abundance in stars. However, comprehensive investigations into lithium signatures following such events remain limited. Stars born together, sharing a…

The lithium plateau observed in halo stars has long appeared as a paradox in the general context of the lithium abundance behavior in stellar outer layers. First, the plateau is flat, second, the lithium abundance dispersion is extremely…

Astrophysics · Physics 2009-11-06 Sylvie Theado , Sylvie Vauclair

The cosmological lithium problem, i.e. the discrepancy between the lithium abundance predicted by the Big Bang Nucleosynthesis and the one observed for the stars of the "Spite plateau", is one of the long standing problems of modern…

Solar and Stellar Astrophysics · Physics 2020-04-17 S. Cassisi , M. Salaris , S. Degl'Innocenti , P. G. Prada Moroni , E. Tognelli

Lithium abundance derived in metal-poor main sequence stars is about three times lower than the value of primordial Li predicted by the standard Big Bang nucleosynthesis when the baryon density is taken from the CMB or the deuterium…

Solar and Stellar Astrophysics · Physics 2015-06-22 Xiaoting Fu , Alessandro Bressan , Paolo Molaro , Paola Marigo

The success of primordial nucleosynthesis has been limited by the long-standing Lithium problem. We use a self-consistent perturbative analysis of the effects of relevant theoretical parameters on primordial nucleosynthesis, including…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 M. Deal , C. J. A. P. Martins

The aim of the present paper is to quantify the dependence of the estimates of luminosities and stellar mass of early-type galaxies on the different models and model parameters which can be used to analyze the observational data. The paper…

Astrophysics · Physics 2009-11-13 Marcella Longhetti , Paolo Saracco

The disagreement between theoretical predictions and observations for surface lithium abundance in stars is a long-standing problem, which indicates that the adopted physical treatment is still lacking in some points. However, thanks to the…

Solar and Stellar Astrophysics · Physics 2015-06-11 E. Tognelli , S. Degl'Innocenti , P. G. Prada Moroni

We present the initial results of a study of the surface lithium abundance in a sample of low-mass members (M~0.4-1.0 Msun) of the Orion Nebula Cluster (ONC) that provide an independent clock to estimate stellar ages. We report discovery of…

Astrophysics · Physics 2009-11-11 F. Palla , S. Randich , E. Flaccomio , R. Pallavicini

The chemical evolution of lithium in the Milky Way represents a major problem in modern astrophysics. Indeed, lithium is, on the one hand, easily destroyed in stellar interiors, and, on the other hand, produced at some specific stellar…

Astrophysics of Galaxies · Physics 2016-10-26 G. Guiglion , P. de Laverny , A. Recio-Blanco , C. C. Worley , M. De Pascale , T. Masseron , N. Prantzos , S. Mikolaitis

Abundance ratios of radioactive to stable neutron-capture elements in very metal-poor stars may be used to estimate the age of our Galaxy. But extracting accurate ages from these data requires continuing work on many fronts: a)…

Astrophysics · Physics 2007-05-23 C. Sneden

Star-to-star variations in abundances of the light elements carbon, nitrogen, oxygen, and sodium have been observed in stars of all evolutionary phases in all Galactic globular clusters that have been thoroughly studied. The data available…

Astrophysics of Galaxies · Physics 2011-05-26 Sarah L. Martell

We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the structure and evolution of the associated…

(Abridged) Estimates of the interstellar deuterium abundance span a wide range of values. Here we study the evolution of deuterium in the framework of successful models for the chemical evolution of the Milky Way able to reproduce the…

Astrophysics · Physics 2009-11-11 Donatella Romano , Monica Tosi , Cristina Chiappini , Francesca Matteucci

Lithium abundances and rotation, determined for 120 subgiant stars in Lebre et al. (1999) are analyzed. To this purpose, the evolutionary status of the sample as well as the individual masses have been determined using the HIPPARCOS…

Astrophysics · Physics 2007-05-23 J. D. do Nascimento , C. Charbonnel , A. Lebre , P. de Laverny , J. R. De Medeiros

The mass of an astrophysical object can be estimated by the amount of gravitational lensing of another object that it causes. To arrive at the estimation however, one assumes the validity of the inverse square law of gravity, or…

General Relativity and Quantum Cosmology · Physics 2023-03-07 Saurya Das , Sourav Sur
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