Abundance analysis of a nitrogen-rich extreme-helium hot subdwarf from the SALT survey [PDF]
, 2023 L. J. A. Scott. +4 more
openalex +1 more source
Spectral energy distribution of M-subdwarfs: A study of their atmospheric properties [PDF]
, 2016 Context. M-type subdwarfs are metal-poor low-mass stars and probe for the old populations in our Galaxy. Accurate knowledge of their atmospheric parameters and especially the composition is essential for understanding the chemical history of our Galaxy ...
A. Rajpurohit +8 more
semanticscholar +1 more source
Pulsations driven by the ɛ-mechanism in post-merger remnants: First results
EPJ Web of Conferences, 2013 Helium-rich subdwarfs are a rare subclass of hot subdwarf stars which constitute a small and inhomogeneous group showing varying degrees of helium enrichment. Only one star, LS IV °14 116 has been found to show multiperiodic luminosity variations.
Zhang X. +4 more
doaj +1 more source
COOL SUBDWARF INVESTIGATIONS. I. NEW THOUGHTS ON THE SPECTRAL TYPES OF K AND M SUBDWARFS [PDF]
The Astronomical Journal, 2008 Using new spectra of 88 K and M-type subdwarfs, we consider novel methods for assigning their spectral types and take steps toward developing a comprehensive spectral sequence for subdwarf types K3.0 to M6.0. The types are assigned based on the overall morphology of spectra covering 6000 to 9000 .
Jao, Wei-Chun +3 more
openaire +2 more sources
Hydrogen in hot subdwarfs formed by double helium white dwarf mergers [PDF]
, 2016 Isolated hot subdwarfs might be formed by the merging of two helium-core white dwarfs. Before merging, helium-core white dwarfs have hydrogen-rich envelopes and some of this hydrogen may survive the merger.
Philip D. Hall, C. Jeffery
semanticscholar +1 more source
PRELIMINARY ABUNDANCE ANALYSIS OF 9 SUBDWARFS
Odessa Astronomical Publications, 2017 We provide parameter and abundance determination of 9 subwarfs including two SMR stars (HD 161797 and HD 182572). These stars show metallicity overabundance in agreement with previous results.
T. V. Mishenina +2 more
doaj +1 more source
COOL SUBDWARF INVESTIGATIONS. II. MULTIPLICITY [PDF]
The Astronomical Journal, 2009 accepted by ...
Jao, Wei-Chun +4 more
openaire +2 more sources
The Solar Neighborhood. XLII. Parallax Results from the CTIOPI 0.9 m Program—Identifying New Nearby Subdwarfs Using Tangential Velocities and Locations on the H–R Diagram [PDF]
, 2017 Parallaxes, proper motions, and optical photometry are presented for 51 systems consisting of 37 cool subdwarf and 14 additional high proper motion systems. Thirty-seven systems have parallaxes reported for the first time, 15 of which have proper motions
Wei-Chun 君 Jao 饒惟 +6 more
semanticscholar +1 more source
ON THE OBSERVED PHYSICAL PROPERTIES AND EVOLUTIONARY TRENDS OF HOT SUBDWARFS IN BINARY SYSTEMS
Odessa Astronomical Publications, 2017 In our brief review we summarize the latest advances in studies of white dwarfs both as single objects and the components of binary systems. We discuss the observed properties of the hot subdwarfs (sdws), the various techniques of their discovery and ...
I. Pustylnik
doaj +1 more source
The Formation of Blue Large-amplitude Pulsators from White-dwarf Main-sequence Star Mergers
The Astrophysical Journal, 2023 Blue large-amplitude pulsators (BLAPs) are hot low-mass stars that show large-amplitude light variations likely due to radial oscillations driven by iron group opacities. Period changes provide evidence of both secular contraction and expansion among the
Xianfei Zhang +3 more
doaj +1 more source