Results 11 to 20 of about 374,493 (293)

Deficiency of Metals in Population II Stars [PDF]

Nature, 1963
I PROPOSE the following as an explanation for the deficiency of heavy elements in Population II stars.
GEORGE WALLERSTEIN, E. MARGARET BURBIDGE
exaly   +5 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

Surface convection in Population II stars [PDF]

Proceedings of the International Astronomical Union, 2008
AbstractThe initial surface abundances of Population II stars have been altered by the interplay between convection, rotational mixing and diffusion. In particular the shallower the outer convection zone the stronger the diffusion impact. We present preliminary results on constraining the extension of the convection zones of Population II stars thanks ...
Laurent Piau, Robert F. Stein
openaire   +1 more source

Unique Chemical Composition of the Very Metal-poor Star LAMOST J1645+4357

The Astrophysical Journal, 2023
We report on the chemical composition of the very metal-poor (VMP; [Fe/H] = −2.9) star LAMOST J1645+4357, which was identified as a red giant having peculiar abundance ratios by Li et al. The standard abundance analysis is carried out for this object and
Wako Aoki, Haining Li, Nozomu Tominaga, Tadafumi Matsuno, Satoshi Honda, Gang Zhao   +5 more
doaj   +1 more source

The stochastic enrichment of Population II stars [PDF]

Monthly Notices of the Royal Astronomical Society, 2020
ABSTRACT We investigate the intrinsic scatter in the chemical abundances of a sample of metal-poor ([Fe/H] < −2.5) Milky Way halo stars. We draw our sample from four historic surveys and focus our attention on the stellar Mg, Ca, Ni, and Fe abundances.
Louise Welsh, Ryan Cooke, Michele Fumagalli   +2 more
openaire   +4 more sources

An empirical mass-loss law for Population II giants from the Spitzer-IRAC survey of Galactic globular clusters [PDF]

, 2014
The main aim of the present work is to derive an empirical mass-loss (ML) law for Population II stars in first and second ascent red giant branches.
Dalessandro, E., Fabbri, S., Ferraro, F. R., Origlia, L., Pecci, F. Fusi, Rich, R. M., Valenti, E.   +6 more
core   +1 more source

Distances and ages of globular clusters using Hipparcos parallaxes of local subdwarfs [PDF]

, 1998
We discuss the impact of Population II and Globular Cluster (GCs) stars on the derivation of the age of the Universe, and on the study of the formation and early evolution of galaxies, our own in particular.
A Gould, A Renzini, A Renzini, A Sandage, A Sandage, A Sandage, A Udalsky, A Udalsky, AA Cole, AC Layden, AK Pandey, AR Walker, AU Landolt, B Chaboyer, B Chaboyer, B Madore, B Paczynski, BW Carney, BW Carney, BW Carney, BW Carney, C Cacciari, C Pryor, DA VandenBerg, DH McNamara, EL Sandquist, EP Rubestein, F Arenou, F D’Antona, F Ferraro, F Leeuwen van, F Pont, G Clementini, G Lynga, GS Costa Da, H Scheffler, HB Richer, HE Bond, I Skillen, IN Reid, IN Reid, J Fernley, J Fernley, J Fernley, J Kaluzny, J Kaluzny, J Kaluzny, J Storm, JC Wheeler, JR King, L Spitzer, M Salaris, MG Lee, MS Bessel, MW Feast, MW Feast, O Straniero, P Cote, P Fischer, PB Stetson, PM Salomon, R Zinn, RB Hanson, RG Gratton, RG Gratton, RL Kurucz, RM Rich, RP Kraft, RV Jones, S Cassisi, S Holland, SG Ryan, T Liu, T Liu, T Tsujimoto, TE Lutz, V Caloi, WB Burton, WJ Schuster   +78 more
core   +2 more sources

Machine Learning Detects Multiplicity of the First Stars in Stellar Archaeology Data

The Astrophysical Journal, 2023
In unveiling the nature of the first stars, the main astronomical clue is the elemental compositions of the second generation of stars, observed as extremely metal-poor (EMP) stars, in the Milky Way.
Tilman Hartwig, Miho N. Ishigaki, Chiaki Kobayashi, Nozomu Tominaga, Ken’ichi Nomoto   +4 more
doaj   +1 more source

Binary Statistics Among Population II Stars [PDF]

International Astronomical Union Colloquium, 2004
AbstractPopulation II stars are old, metal-poor, Galactic halo stars with high proper motion. We have carried out a visual binary survey of 164 halo stars in the solar neighborhood (median distance 100 pc), using infrared speckle interferometry, adaptive optics, and wide field direct imaging.
H. Zinnecker, R. Köhler, H. Jahreiß
openaire   +1 more source

Following the Cosmic Evolution of Pristine Gas III: The Observational Consequences of the Unknown Properties of Population III Stars [PDF]

, 2019
We study the observational consequences of several unknown properties of Population III (Pop III) stars using large-scale cosmological simulations that include a subgrid model to track the unresolved mixing of pollutants.
Côté, Benoit, Sarmento, Richard, Scannapieco, Evan   +2 more
core   +2 more sources