Results 1 to 10 of about 1,072 (156)

Stellar Properties of Observed Stars Stripped in Binaries in the Magellanic Clouds

open access: yesThe Astrophysical Journal, 2023
Massive stars (∼8–25 M _⊙ ) stripped of their hydrogen-rich envelopes via binary interaction are thought to be the main progenitors for merging neutron stars and stripped-envelope supernovae.
Y. Götberg   +8 more
doaj   +1 more source

Lithium in Kepler Red Giants: Defining Normal and Anomalous

open access: yesThe Astronomical Journal, 2023
The orders-of-magnitude variations in the lithium abundances of evolved stars have long been a puzzle. Diluted signals, ambiguous evolutionary states, and unknown masses have made it challenging to both map the expected lithium signals and explain the ...
Jamie Tayar   +3 more
doaj   +1 more source

Mass Distribution for Single-lined Hot Subdwarf Stars in LAMOST

open access: yesThe Astrophysical Journal, 2023
Masses for 664 single-lined hot subdwarf stars identified in LAMOST were calculated by comparing synthetic fluxes from spectral energy distribution with observed fluxes from a Virtual Observatory service.
Zhenxin Lei   +6 more
doaj   +1 more source

HST spectroscopy of chemically peculiar hot subdwarfs: PG 0909+276 and UVO0512–08

open access: yesOpen Astronomy, 2017
High-resolution ultraviolet spectroscopy of two chemically peculiar hot subdwarfs, PG 0909+276 and UVO0512-08, has been obtained using the Hubble Space Telescope.
Wild James, Jeffery Christopher Simon
doaj   +1 more source

Hot subdwarf stars from the Hamburg Quasar Survey

open access: yesAstronomy & Astrophysics
Hot subluminous stars (subdwarf B&O; sdB, sdO) are evolved low mass stars originating from red giants that lost their envelope almost entirely. The multitude of observed phenomena imply that several pathways may form hot subdwarfs, most involving close ...
Heber U.   +6 more
doaj   +1 more source

The Arizona-Montréal Spectroscopic Survey of hot subluminous stars★

open access: yesAstronomy & Astrophysics
Context. Hot subdwarf B (sdB) and O (sdO) type stars are evolved helium-burning objects that lost their hydrogen envelope before the helium flash when their progenitors were close to the tip of the red giant branch (RGB).
Latour M.   +8 more
doaj   +1 more source

Chemical fingerprints of He-sdO stars

open access: yesOpen Astronomy, 2018
The chemical composition of helium-rich hot subluminous O stars plays an important role to understand and model their formation history. We present a spectroscopic analysis of four He-sdO stars,CD-31° 4800, [CW83] 0904- 02, LSS 1274 and LS IV +10° 9. The
Schindewolf Markus   +5 more
doaj   +1 more source

Envelope loss of RGB/AGB stars and the formation of hot subdwarfs

open access: yesEPJ Web of Conferences, 2013
Low mass stars may lose their envelopes in the first giant branch (RGB) or the asymptotic giant branch (AGB) via envelope ejection (i.e. superwind). The envelope loss of AGB stars leads to the formation of carbon-oxygen (CO) white dwarfs (WDs), while the
Chen X., Han Z.
doaj   +1 more source

A constant upper luminosity limit of cool supergiant stars down to the extremely low metallicity of I Zw 18

open access: yesAstronomy & Astrophysics
Stellar wind mass loss of massive stars is often assumed to depend on their metallicity Z. Therefore, evolutionary models predict that massive stars in lower-Z environments are able to retain more of their hydrogen-rich layers and evolve into brighter ...
Schootemeijer Abel   +5 more
doaj   +1 more source

A Spectroscopic Catalog of Single-lined and Composite Spectra Hot Subdwarfs from LAMOST DR13 and Gaia DR3: Helium Abundance Classification, Atmospheric Properties, and FGK Companion Characteristics

open access: yesThe Astrophysical Journal Supplement Series
We present a homogeneous spectroscopic analysis of 2817 single-lined hot subdwarf candidates and 178 composite spectra hot subdwarf binary candidates observed by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and selected from two
Luo Yangping, Jiajun Hu
doaj   +1 more source

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