Results 11 to 20 of about 1,884 (262)
Intriguing Revelations from Lithium, Beryllium, and Boron
The Astrophysical Journal, 2023 This is a report on some highlights of research on the rare light elements, lithium (Li), beryllium (Be), and boron (B), that were presented at my Henry Norris Russell Lecture in 2020 January.
Ann Merchant Boesgaard
doaj +1 more source
The Astrophysical Journal, 2023 We present the first isotopic abundances of both ^13 CO and C ^18 O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions.
David R. Coria +5 more
doaj +1 more source
ACTINIUM ABUNDANCES IN STELLAR ATMOSPHERES
Odessa Astronomical Publications, 2021 This paper presents a study of radioactive actinium in the atmospheres of stars located in galaxies with different chemical evolution history – namely, Przybylski's Star (HD 101065) in the Milky Way and the red supergiant PMMR27 in the Small Magellanic Cloud; it also reports the findings of the previous research of the red supergiant RM 1-667 in the ...
V. Yushchenko +5 more
openaire +4 more sources
Stellar Abundances in Local Group Galaxies [PDF]
Highlights of Astronomy, 2005 AbstractHere we describe some of our latest results from measuring detailed abundances in Local Group dwarf galaxies with the VLT. Combining spectroscopic abundances with Color-Magnitude diagrams allows the effective measurement of detailed chemical evolution with time in these galaxies.
Tolstoy, Eline, Venn, Kim
openaire +2 more sources
Forming super-Mercuries: Role of stellar abundances
Astronomy & Astrophysics, 2023 Rocky exoplanets with bulk iron mass fraction of more than 60%, known as super-Mercuries, appear to be preferentially hosted by stars with higher iron mass fraction than that of the Sun. It is unclear whether these iron-rich planets can form in the disc or whether giant impacts are necessary for their formation.
Mah, Jingyi, Bitsch, Bertram
openaire +3 more sources
The Abundance of S-Process Elements: Temporal and Spatial Trends from Open Cluster Observations
Universe, 2022 Spectroscopic observations of stars belonging to open clusters, with well-determined ages and distances, are a unique tool for constraining stellar evolution, nucleosynthesis, mixing processes, and, ultimately, Galactic chemical evolution.
Laura Magrini +8 more
doaj +1 more source
Uncertainties in Stellar Abundance Analyses [PDF]
Highlights of Astronomy, 2005 AbstractOver the last half-century quantitative stellar spectroscopy has made great progress. However, most stellar abundance analyses today still employ rather simplified models, which can introduce severe systematic errors swamping the observational errors.
openaire +2 more sources
Stellar and Gaseous Abundances in M82
The Astrophysical Journal, 2004 The near infrared (IR) absorption spectra of starburst galaxies show several atomic and molecular lines from red supergiants which can be used to infer reliable stellar abundances. The metals locked in stars give a picture of the galaxy metallicity prior to the last burst of star formation. The enrichment of the new generation of stars born in the last
Origlia, L. +3 more
openaire +2 more sources
Stellar evolution with SMC chemical abundances [PDF]
International Astronomical Union Colloquium, 1981 Evolutionary computations are presented for massive stars between 20 Mo and 100 Mo with chemical abundances holding for the Small Magellanic Cloud, i.e. X = .76 and Z = .003. Mass loss by stellar wind is taken into account during core hydrogen burning.
P. Hellings, D. Vanbeveren
openaire +1 more source
Lithium in Turnoff Stars in the Globular Cluster M5: A Quest for Primordial Lithium
The Astrophysical Journal, 2023 The light element lithium is formed by nucleosynthesis during the Big Bang. Its abundance can help to define the parameters of the early Universe. To find this primordial value, it is necessary to determine Li abundances in the oldest stars because it is
Ann Merchant Boesgaard +1 more
doaj +1 more source