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相关论文: The Lithium Plateau Enigma

200 篇论文

The cosmic dispersion in the abundances of the heavy elements strontium and barium in halo stars is well known. Strontium and barium are detected in most cool, metal-poor giants, but are these elements always detectable? To identify stars…

太阳与恒星天体物理 · 物理学 2015-06-12 Ian U. Roederer

The dependence of lithium abundance on modified gravity in low-mass stellar objects is demonstrated. This may introduce an additional uncertainty to age determination techniques of young stars and globular clusters if they rely on the light…

广义相对论与量子宇宙学 · 物理学 2021-02-24 Aneta Wojnar

Lithium abundances are presented and discussed for 70 members of the 50 Myr old open cluster alpha Per. More than half of the abundances are from new high-resolution spectra. The Li abundance in the F-type stars is equal to its presumed…

太阳与恒星天体物理 · 物理学 2015-05-19 Suchitra C. Balachandran , Sushma V. Mallik , David L. Lambert

We have refined the estimate of the primordial level of $^7$Li abundance to an accuracy better than 10%, based on high-precision Li abundances for metal-poor halo stars, and a recent model of post-BBN (Big Bang Nucleosynthesis) chemical…

天体物理学 · 物理学 2009-10-31 Takeru Ken Suzuki , Yuzuru Yoshii , Timothy C. Beers

The measurement of the cosmic microwave background has strongly constrained the cosmological parameters of the Universe. When the measured density of baryons (ordinary matter) is combined with standard Big Bang nucleosynthesis calculations,…

天体物理学 · 物理学 2009-11-11 A. J. Korn , F. Grundahl , O. Richard , P. S. Barklem , L. Mashonkina , R. Collet , N. Piskunov , B. Gustafsson

For the purpose of deriving the helium abundances in chemically peculiar stars, the importance of assuming a correct helium abundance has been investigated for determining the effective temperature and gravity of main sequence B-type stars,…

天体物理学 · 物理学 2007-05-23 F. Leone

The existence of one percent of lithium-rich giant stars among normal, lithium-poor giant stars continues to be poorly explained. By merging two catalogues, one containing 10,535 lithium-rich giant stars with lithium abundances ranging from…

太阳与恒星天体物理 · 物理学 2024-12-09 R. de la Reza

Mapping lithium evolution for evolved stars will provide restrictions and constraints on the fundamental stellar interior physical processes, which further shed light on our understanding of the theory of stellar structure and evolution.…

太阳与恒星天体物理 · 物理学 2021-09-29 Jinghua Zhang , Jian-Rong Shi , Hong-Liang Yan , Yaguang Li , Qi Gao , Chun-Qian Li , Xianfei Zhang , Shuai Liu , Shaolan Bi , Gang Zhao , Yan Li

We address the existence and origin of the lithium (Li) desert, a region in the Li - T_eff plane sparsely populated by stars. Here we analyze some of the explanations that have been suggested for this region, including mixing in the late…

太阳与恒星天体物理 · 物理学 2018-06-13 Claudia Aguilera-Gómez , Iván Ramírez , Julio Chanamé

The discrepancy between the predictions of primordial nucleosynthesis and the observed lithium abundance in Spite plateau stars has been attributed either to a challenge to the standard model of nucleosynthesis or to stellar processes…

宇宙学与河外天体物理 · 物理学 2025-10-17 Oswaldo D. Miranda

We present a comparison of the lithium abundances of stars with and without planetary-mass companions. New lithium abundances are reported in 79 planet hosts and 38 stars from a comparison sample. When the Li abundances of planet host stars…

天体物理学 · 物理学 2009-11-10 Garik Israelian , Nuno Santos , Michel Mayor , Rafael Rebolo

The prediction of the PLANCK-constrained primordial lithium abundance in the Universe is in discordance with the observed Li abundances in warm Population II dwarf and subgiant stars. Among the physically best motivated ideas, it has been…

Lithium plays a unique role in astrophysics, as it is a powerful diagnostic for the physics and evolution of low-mass stars, Galactic archaeology, and cosmology. We review the Li observations in stars at different phases of their evolution,…

太阳与恒星天体物理 · 物理学 2026-02-20 C. Charbonnel , N. Prantzos

In 1982, Monique and Francois Spite discovered that the 7Li abundance in the atmosphere of old metal-poor dwarf stars in the galactic halo was independent of metallicity and temperature. Since then, 7Li abundance in the Universe has become…

高能天体物理现象 · 物理学 2014-02-24 Rachid Ouyed

Recent observational work by Israelian et al. has shown that sun-like planet host stars in the temperature range 5700K < Teff < 5850K have lithium abundances that are significantly lower than those observed for "single" field stars. In this…

太阳与恒星天体物理 · 物理学 2015-05-18 S. G. Sousa , J. Fernandes , G. Israelian , N. C. Santos

Lithium is one of the few elements produced during the Big Bang Nucleosynthesis in the early universe. Moreover, its fragility makes it useful as a proxy for stellar environmental conditions. As such, the lithium abundance in old systems is…

The dispersion in lithium abundance at fixed effective temperature in young cool stars like the Pleiades has proved a difficult challenge for stellar evolution theory. We propose that Li abundances relative to a mean temperature trend,…

天体物理学 · 物理学 2009-10-31 Jeremy King , Anita Krishnamurthi , Marc H. Pinsonneault

It has been known for a long time (Mestel~1953) that the meridional circulation velocity in stars, in the presence of mu-gradients, is the sum of two terms, one due to the classical thermal imbalance (Omega-currents) and the other one due…

天体物理学 · 物理学 2009-09-25 Sylvie Theado , Sylvie Vauclair

Spectroscopically determined Li abundances of metal-poor turn-off dwarfs are known to be nearly constant (Spite plateau), but lower than the primordial value expected from the standard cosmological model. However, abundance determination by…

太阳与恒星天体物理 · 物理学 2019-02-06 Yoichi Takeda

In this work we show that the cosmological lithium problem and the $H_0$ tension could be eased at the same time by allowing variations in the fundamental constants. We compute the primordial abundances of light elements resulting from Big…

宇宙学与河外天体物理 · 物理学 2021-07-07 S. A. Franchino-Viñas , M. E. Mosquera