English
Related papers

Related papers: Can Li-rich giants eject shells? Assembling the li…

200 papers

A small fraction of low-mass stars have been found to have anomalously high Li abundances. Although it has been suggested that mixing during the red giant branch phase can lead to Li production, this method of intrinsic Li production cannot…

A sample of AGB/RGB stars with an excess of Li abundances is considered in order to estimate their mass loss rates. Our method is based on a correlation between the Li abundances and the stellar luminosity, using a modified version of…

Solar and Stellar Astrophysics · Physics 2018-06-13 W. J. Maciel , R. D. D. Costa

We present FLAMES/GIRAFFE spectroscopy obtained at the Very Large Telescope (VLT). Using these observations we have been able for the first time to observe the Li I doublet in the Main Sequence stars of a Globular Cluster. We also observed…

Astrophysics of Galaxies · Physics 2015-05-14 J. I. González Hernández , P. Bonifacio , E. Caffau , M. Steffen , H. -G. Ludwig , N. Behara , L. Sbordone , R. Cayrel , S. Zaggia

We adopt up-to-date 7Li yields from asymptotic giant branch stars in order to study the temporal evolution of 7Li in the solar neighbourhood in the context of a revised version of the two-infall model for the chemical evolution of our…

Astrophysics · Physics 2016-08-30 Donatella Romano , Francesca Matteucci , Paolo Ventura , Francesca D'Antona

Using a sample of 116 wide binary systems as coeval and chemically homogeneous stellar pairs, we investigate the factors governing lithium depletion in main-sequence stars. We recover the well-established morphology of the…

Solar and Stellar Astrophysics · Physics 2026-03-20 Cheng-Cheng Xie , Hai-Jun Tian , Jian-Rong Shi , Ze-Ming Zhou

The cosmological Li problem is the observed discrepancy between Li abundance, A(Li), measured in Galactic dwarf, old and metal-poor stars (traditionally assumed to be equal to the initial value A(Li)_0), and that predicted by standard Big…

Solar and Stellar Astrophysics · Physics 2015-06-22 A. Mucciarelli , M. Salaris , P. Bonifacio , L. Monaco , S. Villanova

Lithium (Li) is a powerful tracer of stellar mixing, gradually depleted in solar twins by non-standard transport below the convective zone. Here, we identify six new solar twins with exceptionally low Li levels that are not explained by…

The evolution of the 7Li abundance in the Galaxy has been computed by taking into account several 7Li sources: novae, massive AGB stars, C-stars, Type II SNe and GCRs. The theoretical predictions for the evolution of the 7Li abundance in…

Astrophysics · Physics 2011-05-23 D. Romano , F. Matteucci , P. Molaro , P. Bonifacio

Convergent lines of evidence suggest that globular clusters host multiple stellar populations. It appears that they experience at least two episodes of star formation whereby a fraction of first-generation stars contribute astrated ejecta…

The massive First Stars (the first ones to contribute to the chemical enrichment of the Universe due to their short lifetimes) are long dead, and even though efforts to directly observe them in high redshift galaxies are underway, a step…

Astrophysics of Galaxies · Physics 2013-01-10 Gabriele Cescutti , Cristina Chiappini

Motivated by the recent report of a high Li6 ``plateau'' extending to low metallicities in Galactic halo stars, we study the energetics of an early production of Li6 through the interaction of energetic particles with the interstellar…

Astrophysics · Physics 2009-11-11 Nikos Prantzos

Explaining the well established observation that the expansion rate of the universe is apparently accelerating is one of the defining scientific problems of our age. Within the standard model of cosmology, the repulsive 'dark energy'…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-20 Marco Regis , Chris Clarkson

Recent detection of the isotope $^7$Be (that decays into $^7$Li) in the outburst of classical novae confirms the suggestion made in the 70s that novae could make $^7$Li. We reconsidered the role of novae as producers of Li by means of a…

Solar and Stellar Astrophysics · Physics 2019-01-16 Gabriele Cescutti , Paolo Molaro

We want to determine the lithium abundances of solar twin stars as a function of stellar age to provide constraints for stellar evolutions models and to investigate whether there is a connection between low Li abundance and the occurrence…

Solar and Stellar Astrophysics · Physics 2016-02-24 Marilia Carlos , Poul E. Nissen , Jorge Melendez

A highly homogeneous study of 23 halo field dwarf stars has achieved a Li abundance accuracy of 0.033 dex per star. The work shows that the intrinsic spread of the Li abundances of these stars at a given metallicity is <0.02 dex, and…

Astrophysics · Physics 2007-05-23 Sean G. Ryan

We propose the Wind of Fast Rotating Massive Stars scenario to explain the origin of the abundance anomalies observed in globular clusters. We compute and present models of fast rotating stars with initial masses between 20 and 120 Msun for…

Astrophysics · Physics 2009-10-12 T. Decressin , G. Meynet , C. Charbonnel , N. Prantzos , S. Ekström

The surface abundance of lithium on the Sun is 140 times less than protosolar, yet the temperature at the base of the surface convective zone is not hot enough to burn Li. A large range of Li abundances in solar type stars of the same age,…

We report on photometry and high-resolution spectroscopy for IRAS 19285+0517. The spectral energy distribution based on visible and near-IR photometry and far-IR fluxes shows that the star is surrounded by dust at a temperature of $T_{\rm…

Astrophysics · Physics 2009-11-07 Bacham E. Reddy , David L. Lambert , Bruce J. Hrivnak , Eric J. Bakker

We present a scenario to explain the lithium-rich phase which occurs on the red giant branch at the so-called bump in the luminosity function. The high transport coefficients required to enhance the surface lithium abundance are obtained in…

Astrophysics · Physics 2009-11-06 A. Palacios , C. Charbonnel , M. Forestini

Thanks to their usefulness in various fields of astrophysics (e.g. mixing processes in stars, chemical evolution of galaxies), the last few years have witnessed a large increase in the amount of abundance data for early-type stars. Two…

Astrophysics · Physics 2008-11-26 T. Morel