Results 1 to 10 of about 2,846 (98)
Symposium - International Astronomical Union, 1974 The properties of horizontal branch stars depend on the amount of carbon, nitrogen and oxygen that they contain but all theoretical models have difficulty in explaining those stars right at the blue end of the horizontal branch. The length of the theoretical evolutionary tracks always appears to be less than what is observed.
R. J. Tayler, J. E. Hesser
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Red horizontal branch stars: An asteroseismic perspective
Astronomy & Astrophysics, 2023 Robust age estimates of red giant stars are now possible thanks to the precise inference of their mass based on asteroseismic constraints. However, there are cases where such age estimates can be highly precise yet very inaccurate. An example is giants that have undergone mass loss or mass transfer events that have significantly altered their mass.
Massimiliano Matteuzzi +9 more
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Planets around Extreme Horizontal Branch Stars [PDF]
AIP Conference Proceedings, 2011 We review three main results of our recent study: We show that a proper treatment of the tidal interaction prior to the onset of the common envelope (CE) leads to an enhance mass loss. This might increase the survivability of planets and brown dwarfs that enter a CE phase.
Ealeal Bear +4 more
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The horizontal-branch A stars [PDF]
Publications of the Astronomical Society of the Pacific, 1979 The observational determination of astrophysical parameters of horizontal-branch A stars is discussed. Effective temperatures, surface gravities, and bolometric magnitudes are determined for seven field horizontal-branch A stars, and their masses are calculated. The mean mass for these seven stars is 0.6 + or - 0.4 solar mass.
D. S. Hayes, A. G. D. Philip
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Horizontal branch evolution, metallicity, and sdB stars [PDF]
Astronomy & Astrophysics, 2011 Accepted for publication by A& ...
Michaud, Georges +2 more
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Blue Horizontal Branch Stars in M92 [PDF]
The Astronomical Journal, 1997 14 pages with 2 figures, LateX, to be published in the Astronomical ...
Cohen, J. G., McCarthy, J. K.
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Non-variable horizontal-branch stars [PDF]
Symposium - International Astronomical Union, 1997 For 25 years our ignorance of the physical basis of this mass loss process has been the barrier to progress in understanding horizontal branch morphology. I review some recent observational and theoretical results which may be giving us clues about the nature of the mass loss process.
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Rotation of Horizontal‐Branch Stars in Globular Clusters [PDF]
The Astrophysical Journal, 2000 The rotation of horizontal branch stars places important constraints on angular momentum evolution in evolved stars and therefore rotational mixing on the giant branch. Prompted by new observations of rotation rates of horizontal branch stars, we calculate simple models for the angular momentum evolution of a globular cluster giant star from the base ...
Sills, Alison, Pinsonneault, M. H.
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Hot Horizontal‐Branch Stars in the Galactic Bulge. I. [PDF]
The Astrophysical Journal, 1999 We report the discovery of hot horizontal branch stars in the nuclear bulge of the Milky Way. Spectra from the 2dF instrument of the Anglo-Australian Telescope allow us to confirm their membership in the bulge through radial velocities. We also review the current observational information on hot horizontal branch stars in Milky Way clusters and the ...
Peterson, Ruth C. +3 more
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The ages of stars: The horizontal branch [PDF]
Proceedings of the International Astronomical Union, 2008 AbstractHorizontal branch (HB) stars play a particularly important role in the “age debate,” since they are at the very center of the long-standing “second parameter” problem. In this review, I discuss some recent progress in our understanding of the nature and origin of HB stars.
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