Results 11 to 20 of about 25,571 (294)

Subgiants in NGC 188 reveal that rotationally induced mixing creates the main sequence Li-Dip [PDF]

Nature Communications
The Lithium-Dip is a severe lithium depletion observed in mid-F (6200-6650 K) dwarfs, which has puzzled astronomers since it was discovered in 1986. Proposed mechanisms include effects related to rotation, magnetic fields, diffusion, gravity waves, and ...
Qinghui Sun, Constantine P. Deliyannis, Barbara J. Anthony-Twarog, Bruce A. Twarog, Xiao-Tian Xu, Aaron Steinhauer, Jeremy R. King   +6 more
doaj   +2 more sources

Using a neural network approach and starspots dependent models to predict effective temperatures and ages of young stars. [PDF]

PLoS ONE
This study presents a statistical approach to accurately predict the effective temperatures of pre-main sequence stars, which are necessary for determining stellar ages using the isochrone methodology and cutting-age starspots-dependent models.
Marco Tarantino, Loredana Prisinzano, Nicoletta D'Angelo, Francesco Damiani, Giada Adelfio   +4 more
doaj   +2 more sources

Lithium evolution in the low-mass evolved stars with asteroseismology and LAMOST spectroscopy [PDF]

Fundamental Research
Lithium is an ancient element that was first produced by the Big Bang Nucleosynthesis (BBN) a few minutes after the birth of the Universe. Lithium is a sensitive tracer for a number of processes in a variety of astrophysical environments due to its multi-
Hong-Liang Yan, Jing-Hua Zhang, Yu-Tao Zhou, Qi Gao, Jian-Rong Shi, Yerra Bharat Kumar, Wako Aoki, Haining Li, Chunqian Li, Gang Zhao   +9 more
doaj   +2 more sources

Lithium In Population II Stars [PDF]

Highlights of Astronomy, 1995
AbstractSince the work of Spite & Spite (1982), halo main sequence turn-off stars have usually been considered a site where Li synthesized in the Big-Bang is wholly preserved and uncontaminated by other Li sources. However, the interpretation of halo dwarf Li abundances has become more complex as new samples of halo star Li I observations have ...
openaire   +1 more source

On the possible existence of a self-regulating hydrodynamical process in slowly rotating stars II. Lithium Plateau in Halo Stars and Primordial Abundance [PDF]

, 2001
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 small.
Alonso, Blackwell, Boesgaard, Bonifacio, Burles, Chaboyer, Chaboyer, Charbonneau, Deliyannis, Deliyannis, Deliyannis, Deliyannis, Hobbs, Hobbs, Hobbs, Maeder, Mestel, Mestel, Michaud, Michaud, Michaud, Molaro, Norris, Norris, Paquette, Pinsonneault, Pinsonneault, Proffitt, Richard, Ryan, Ryan, S. Théado, S. Vauclair, Smith, Smith, Spiegel, Spite, Spite, Thorburn, Turcotte, Vauclair, Vauclair, Vauclair, Vauclair, Vauclair, Vauclair, Vauclair, Zahn   +47 more
core   +2 more sources

THE NATURE OF MAGNETIC CHEMICALLY PECULIAR STARS PHENOMENON AND THE ORIGIN OF LITHIUM

Odessa Astronomical Publications, 2012
According to the modern theory of the evolution of chemical elements their origin seems understandable for most of the elements, from the lightest up to the heavy ones.
V. F. Gopka, A. V. Shavrina, A. V. Yushchenko, V. A. Yushchenko   +3 more
doaj   +1 more source

Lithium in Giant Stars [PDF]

Symposium - International Astronomical Union, 2000
Lithium continues to be a surprising element and more than ever the study of its creation, destruction and distribution is giving us tools to understand, not only the chemical evolution of this element, but also the nature of mass loss of evolved giants and nucleosynthesis of other elements in cases of very low-metal giants.
openaire   +1 more source

Weak G-band stars on the H-R Diagram: Clues to the origin of Li anomaly [PDF]

, 2011
Weak G-band (WGB) stars are a rare class of cool luminous stars that present a strong depletion in carbon, but also lithium abundance anomalies that have been little explored in the literature since the first discovery of these peculiar objects in the ...
A. Palacios, Alonso, Bidelman, Brown, Brun, Böhm-Vitense, Cameron, Cantiello, Chandrasekhar, Charbonnel, Charbonnel, Charbonnel, Charbonnel, Cottrell, Decressin, Douglass, Drake, Forestini, G. Jasniewicz, Gratton, Griffin, Hartoog, Hartoog, Hekker, Hobbs, Houdashelt, Huang, Jasniewicz, Karakas, Kumar, Lambert, Lebzelter, Lind, Lu, M. Parthasarathy, Monaco, Palacios, Palacios, Palmerini, Parthasarathy, Parthasarathy, Parthasarathy, Rao, Reddy, Reimers, Siess, Sneden, Sneden, Takeda, Tomkin, Turcotte, Ulrich, Wu, Y. Bharat Kumar   +53 more
core   +3 more sources

The ups and downs of inferred cosmological lithium [PDF]

EPJ Web of Conferences
I summarize the stellar side of the cosmological lithium problem(s). Evidence from independent studies is accumulating and indicates that stars may very well be fully responsible for lowering their surface lithium from the predicted primordial value to ...
Korn Andreas
doaj   +1 more source

Discovery of "isolated" comoving T Tauri stars in Cepheus [PDF]

, 2010
During the course of a large spectroscopic survey of X-ray active late-type stars in the solar neighbourhood, we discovered four lithium-rich stars packed within just a few degrees on the sky.
A. Frasca, A. Klutsch, Appenzeller, Cardelli, Chugainov, Chugainov, D. Montes, Dobashi, Droege, E. Marilli, Feigelson, Frasca, Frasca, Grenier, Guillout, Guillout, Hauschildt, Hillenbrand, Hubble, Høg, Kun, Kun, Kurosawa, López-Santiago, Magazzu, Makarov, Meyer, Mizuno, Monet, Montes, Montes, Moon, Muzerolle, Nations, Olano, P. Guillout, Siess, Sterzik, Sterzik, Tachihara, Tachihara, Zacharias, Zuckerman   +42 more
core   +3 more sources