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Lithium evolution in the low-mass evolved stars with asteroseismology and LAMOST spectroscopy [PDF]
Fundamental ResearchLithium 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 +9 more
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Searching for Barium Stars from the LAMOST Spectra Using the Machine-learning Method: I
The Astronomical Journal, 2023 Barium stars are chemically peculiar stars that exhibit enhancement of s -process elements. Chemical abundance analysis of barium stars can provide crucial clues for the study of the chemical evolution of the Galaxy. The Large Sky Area Multi-Object Fiber
Fengyue Guo +7 more
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The Astrophysical Journal, 2023 In previous work, we identified a population of 38 cool and luminous variable stars in the Magellanic Clouds and examined 11 in detail in order to classify them as either Thorne–Żytkow objects (TŻOs; red supergiants with a neutron star cores) or super ...
Anna J. G. O‘Grady +11 more
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The Astrophysical Journal, 2023 Carbon-deficient red giants (CDGs) are a peculiar class of stars that have eluded explanation for decades. We aim to better characterize CDGs by using asteroseismology (Kepler, TESS) combined with spectroscopy (APOGEE, LAMOST), and astrometry (Gaia).
Sunayana Maben +4 more
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Mixing and Magnetic Fields in Asymptotic Giant Branch Stars in the Framework of FRUITY Models
Universe, 2021 In the last few years, the modeling of asymptotic giant branch (AGB) stars has been much investigated, both focusing on nucleosynthesis and stellar evolution aspects. Recent advances in the input physics required for stellar computations made it possible
Diego Vescovi
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s-Processing in Asymptotic Giant Branch Stars in the Light of Revised Neutron-Capture Cross Sections
Universe, 2021 Current AGB stellar models provide an adequate description of the s-process nucleosynthesis that occurs. Nonetheless, they still suffer from many uncertainties related to the modeling of the 13C pocket formation and the adopted nuclear reaction rates ...
Diego Vescovi, René Reifarth
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Chemical Compositions Of Red Giant Stars in the Old Open Cluster NGC 7789
The Astronomical Journal, 2023 We have gathered optical-region spectra, derived model atmosphere parameters, and computed elemental abundances for 15 red giant stars in the open cluster NGC 7789.
Neel Nagarajan +3 more
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Li-rich Giants Identified from LAMOST DR8 Low-resolution Survey
The Astronomical Journal, 2023 A small fraction of giants possess photospheric lithium (Li) abundance higher than the value predicted by the standard stellar evolution models, and the detailed mechanisms of Li enhancement are complicated and lack a definite conclusion.
Beichen Cai +5 more
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Chromospheres of Chemically Peculiar Giant Stars [PDF]
International Astronomical Union Colloquium, 1989 AbstractA review is given of the chromospheres of evolved stars with peculiar chemical abundances, emphasizing the observed dependence of chromospheric properties upon the evolutionary status of the stars. Some old and new physical processes which are potentially important in determining the observed chromospheric features are discussed.
openaire +1 more source
Could the Ultra Metal-poor Stars be Chemically Peculiar and Not Related to the First Stars? [PDF]
, 2008 Chemically peculiar stars define a class of stars that show unusual elemental abundances due to stellar photospheric effects and not due to natal variations.
Asplund M. +12 more
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