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相关论文: $^7$Li Abundances in Halo Stars: Testing Stellar E…

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In this review, I will discuss a few problems which point to the need for improved stellar evolution models of halo stars. Current stellar evolution models do not match the observed $^7$Li abundance patterns, suggesting that the input…

天体物理学 · 物理学 2007-05-23 Brian Chaboyer

The depletion of lithium during the pre-main sequence and main sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. In the…

天体物理学 · 物理学 2011-05-05 M. H. Pinsonneault , T. P. Walker , G. Steigman , V. K. Narayanan

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…

星系天体物理 · 物理学 2022-04-08 Brian D. Fields , Keith A. Olive

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

We have determined Li abundances in 55 metal-poor (3.6 < [Fe/H] < -0.7) stars with extreme orbital kinematics. We find the Li abundance in the Li-plateau stars and examine its decrease in low-temperature, low-mass stars. The Li observations…

天体物理学 · 物理学 2009-11-13 Ann Merchant Boesgaard , Alex Stephens , Constantine P. Deliyannis

Lithium abundances have been determined in more than 100 metal-poor halo stars both in the field and in clusters. From these data we find trends of Li with both temperature and metallicity and a real dispersion in Li abundances in the Spite…

天体物理学 · 物理学 2009-11-11 Ann Merchant Boesgaard , Megan C. Novicki , Alex Stephens

We compare the properties of recent samples of the lithium abundances in halo stars to one another and to the predictions of theoretical models including rotational mixing, and we examine the data for trends with metal abundance. We find…

天体物理学 · 物理学 2008-11-26 M. H. Pinsonneault , G. Steigman , T. P. Walker , V. K. Narayanan

We have computed a grid of up-to-date stellar evolutionary models including atomic diffusion, in order to study the evolution with time of the surface Li abundance in low-mass metal-poor stars. We discuss in detail the dependence of the…

天体物理学 · 物理学 2009-11-06 Maurizio Salaris , Achim Weiss

The observed lithum (Li) abundance of Galactic halo stars mainly fall within the range of 2.0--2.4 dex. This nearly constant value, known as the Spite plateau, is approximately a factor of three lower than the value predicted from cosmic…

太阳与恒星天体物理 · 物理学 2026-02-27 Wuming Yang , Shuya Dou , Xiangcun Meng , Yaqian Wu , Shaolan Bi

We present Li abundances for 73 stars in the metallicity range -3.5 < [Fe/H] < -1.0 using improved IRFM temperatures (Casagrande et al. 2010) with precise E(B-V) values obtained mostly from interstellar NaI D lines, and high-quality…

太阳与恒星天体物理 · 物理学 2015-05-14 J. Melendez , L. Casagrande , I. Ramirez , M. Asplund , W. J. Schuster

Light element ($^6$Li, $^7$Li and $^9$Be) depletion isochrones for halo stars have been calculated with standard stellar evolution models. These models include the latest available opacities and are computed through the sub-giant branch. If…

天体物理学 · 物理学 2009-10-22 Brian Chaboyer

We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. Li…

星系天体物理 · 物理学 2015-06-05 P. E. Nissen , W. J. Schuster

The discovery of the Spite plateau in the abundances of 7Li for metal-poor stars led to the determination of an observationally deduced primordial lithium abundance. However, after the success of the Wilkinson Microwave Anisotropy Probe…

天体物理学 · 物理学 2009-11-13 A. Hosford , S. G. Ryan , A. E. Garcia Perez , J. E. Norris , K. A. Olive

There has been recent progress in the study of the angular momentum evolution of low mass stars (Krishnamurthi et al 1997a). Theoretical models can now be constructed which reproduce the angular momentum evolution of low mass open cluster…

天体物理学 · 物理学 2007-05-23 M. H. Pinsonneault , V. K. Narayanan , G. Steigman , T. P. Walker

We find that hot jupiter host stars within the T$_\mathrm{eff}$ range 5900-6300K show lower Li abundances, by 0.14 dex, than stars without detected planets. This offset has a significance at the level 7$\sigma$, pointing to a stronger…

Lithium abundances in a selected sample of halo stars have been revised by using the new accurate IRFM effective temperatures by Alonso, Arribas & Martinez-Roger (1996a). From 41 plateau stars (Teff > 5700 and [Fe/H] <= -1.5) we found no…

天体物理学 · 物理学 2015-06-24 Piercarlo Bonifacio , Paolo Molaro

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…

天体物理学 · 物理学 2007-05-23 Sean G. Ryan

We have measured the Li abundance of 18 stars with -2 <~ [Fe/H] ~< -1 and 6000 K <~ Teff <~ 6400 K, a parameter range that was poorly represented in previous studies. We examine the Galactic chemical evolution (GCE) of this element,…

Of all the light elements, lithium is the most sensitive indicator of stellar evolution. This review discusses current data on the abundance of lithium in the atmospheres of A-, F-, G-, and K-stars of different types, as well as the…

太阳与恒星天体物理 · 物理学 2017-01-23 L. S. Lyubimkov

Very high-quality spectra of 24 metal-poor halo dwarfs and subgiants have been acquired with ESO's VLT/UVES for the purpose of determining Li isotopic abundances. The derived 1D, non-LTE 7Li abundances from the LiI 670.8nm line reveal a…

天体物理学 · 物理学 2008-11-26 Martin Asplund , David L. Lambert , Poul Erik Nissen , Francesca Primas , Verne V. Smith
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