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
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
Stellar abundances and presolar grains trace the nucleosynthetic origin of molybdenum and ruthenium [PDF]
, 2014 This work presents a large consistent study of molybdenum (Mo) and ruthenium (Ru) abundances in the Milky Way. These two elements are important nucleosynthetic diagnostics. In our sample of 71 Galactic metal-poor field stars, we detect Ru and/or Mo in 52
C. Hansen, A. Andersen, N. Christlieb
semanticscholar +1 more source
Stellar Oxygen Abundances [PDF]
Publications of the Astronomical Society of the Pacific, 1994 This dissertation addresses several issues concerning stellar oxygen abundances. The 7774 {A} O I triplet equivalent widths of Abia & Rebolo [1989, AJ, 347, 186] for metal-poor dwarfs are found to be systematically too high. I also argue that current effective temperatures used in halo star abundance studies may be ~150 K too low.
openaire +1 more source
Abundances in Stellar Populations [PDF]
Symposium - International Astronomical Union, 1976 Stellar abundances are reviewed with emphasis on large-scale effects which may yield clues to galactic structure and evolution. Spectroscopic and indirect photoelectric abundance criteria are discussed, and utilized.The abundance statistics of nearby galactic disk stars, dominated by M dwarfs, but observed at spectral types F and GV and K III, suggest ...
openaire +1 more source
Prospects for Measuring Abundances of >20 Elements with Low-resolution Stellar Spectra [PDF]
, 2017 Understanding the evolution of the Milky Way calls for the precise abundance determination of many elements in many stars. A common perception is that deriving more than a few elemental abundances ([Fe/H], [α/Fe], perhaps [C/H], [N/H]) requires medium-to-
Yuan-Sen Ting +3 more
semanticscholar +1 more source
The Stellar Abundances for Galactic Archaeology (SAGA) Database – III. Analysis of enrichment histories for elements and two modes of star formation during the early evolution of the Milky Way [PDF]
, 2013 We study the enrichment histories for nine elements, C, four alpha-elements of Mg, Si, Ca, and Ti, Sc, and three iron-peak elements of Co, Ni, and Zn, by using a large number of stellar data, collected by the Stellar Abundances for Galactic Archaeology ...
S. Yamada +4 more
semanticscholar +1 more source
TRACING THE EVOLUTION OF HIGH-REDSHIFT GALAXIES USING STELLAR ABUNDANCES [PDF]
, 2013 This paper presents the first results from a model for chemical evolution that can be applied to N-body cosmological simulations and quantitatively compared to measured stellar abundances from large astronomical surveys. This model convolves the chemical
Brian Crosby +3 more
semanticscholar +1 more source
Two distinct halo populations in the solar neighborhood. II. Evidence from stellar abundances of Mn, Cu, Zn, Y, and Ba [PDF]
, 2011 A previous study (Nissen & Schuster 2010) of 94 dwarf stars with -1.6 < [Fe/H] < -0.4 has revealed the existence of two distinct halo populations with a systematic difference in [alpha/Fe] at a given metallicity.
P. Nissen, W. Schuster
semanticscholar +1 more source
High-precision abundances of Sc, Mn, Cu, and Ba in solar twins. Trends of element ratios with stellar age [PDF]
, 2016 A previous study of correlations between element abundance ratios, [X/Fe], and ages of solar twin stars is extended to include Sc, Mn, Cu, and Ba. HARPS spectra with S/N > 600 are used to derive very precise (+/- 0.01 dex) differential abundances, and ...
P. Nissen
semanticscholar +1 more source