Results 81 to 90 of about 210,874 (237)

Chemical abundance analysis of 19 barium stars

open access: yes, 2016
We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at
Chen, Y. Q.   +12 more
core   +2 more sources

Determination of Abundances of Chemical Elements in Open Star Clusters of the Galaxy

open access: yesOpen Astronomy, 2016
Spectroscopic determinations of the relative abundances of chemical elements produced in different nuclear-synthesis processes, [el/Fe], are collected for 90 open star clusters of the Galaxy using data from 109 papers published between 1991 and 2015 ...
Gozha M. L.   +2 more
doaj   +1 more source

The effect of rotation on the abundances of the chemical elements of the A-type stars in the Praesepe cluster

open access: yes, 2008
We study how chemical abundances of late B-, A- and early F-type stars evolve with time, and we search for correlations between the abundance of chemical elements and other stellar parameters, such as effective temperature and Vsini.
Abt   +56 more
core   +2 more sources

The Impact of Initial Composition on Massive Star Evolution and Nucleosynthesis

open access: yesThe Astrophysical Journal
We study the sensitivity of presupernova evolution and supernova nucleosynthesis yields of massive stars to variations of the initial composition. We use the solar abundances from Lodders, and compute two different sets of initial stellar compositions ...
Christopher West   +4 more
doaj   +1 more source

CHEMICAL IMPRINTS IN ATMOSPHERIC ABUNDANCES IN PLANET- HOSTING STARS

open access: yesOdessa Astronomical Publications, 2019
We examined 12 planet-hosting stars based on homogeneous spectral data (obtained with the SOPHIE echelle spectrograph with R = 75,000 at the OHP, France) and using uniform techniques for determination of parameters and abundances of a series of elements (
T. Mishenina, N. Basak, V. Kovtyukh
doaj   +1 more source

Noble Gas Planetology and the Xenon Clouds of Uranus

open access: yesThe Planetary Science Journal
Noble gases provide tracers of cosmic provenance that are accessible to a future Uranus atmospheric probe. Argon and krypton are expected to be well mixed on Uranus with respect to H _2 and He, although condensation at the winter pole may be possible ...
Kevin Zahnle
doaj   +1 more source

Chemical Doppelgangers in GALAH DR3: The Distinguishing Power of Neutron-capture Elements among Milky Way Disk Stars

open access: yesThe Astrophysical Journal
The observed chemical diversity of Milky Way stars places important constraints on Galactic chemical evolution and the mixing processes that operate within the interstellar medium. Recent works have found that the chemical diversity of disk stars is low.
Catherine Manea   +5 more
doaj   +1 more source

The First Chemical Census of the Milky Way’s Nuclear Star Cluster

open access: yesThe Astrophysical Journal Letters
An important step in understanding the formation and evolution of the nuclear star cluster (NSC) is to investigate its chemistry and chemical evolution. Additionally, exploring the NSC’s relationship to the other structures in the Galactic center and the
Govind Nandakumar   +6 more
doaj   +1 more source

What Can We Learn from the Nitrogen Abundance of High-z Galaxies?

open access: yesThe Astrophysical Journal
We present measurements of the gas-phase oxygen and nitrogen abundances obtained by applying the direct method to JWST NIRspec R  ∼ 1000 spectroscopy for six galaxies at redshift greater than 3.
Massimo Stiavelli   +11 more
doaj   +1 more source

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