Results 1 to 10 of about 498,367 (290)

Horizontal Branch evolution, metallicity and sdB stars [PDF]

Astronomy & Astrophysics, 2011
Context. Abundance anomalies have been observed in field sdB stars and in nearly all Horizontal Branch (HB) stars of globular clusters with Teff > 11 000K whatever be the cluster metallicity. Aims.
Behr, Behr, Behr, Bergeron, Blanchette, Carretta, Charpinet, Charpinet, Charpinet, Charpinet, Charpinet, Cortés, Fabbian, Fontaine, Fontaine, G. Michaud, Geier, Geier, Heber, Hu, Hu, Iglesias, J. Richer, Jeffery, Khalack, Khalack, Kilkenny, Kinman, Kraft, Kupka, LeBlanc, LeBlanc, Marino, Michaud, Michaud, Michaud, Michaud, Michaud, Michaud, Moehler, Morrison, O. Richard, O’Toole, Pace, Quievy, Randall, Richard, Richard, Richard, Richer, Richer, Sargent, Talon, Théado, VandenBerg, Vick   +55 more
core   +6 more sources

Rotation of Horizontal Branch Stars in Globular Clusters [PDF]

The Astrophysical Journal, 1999
The rotation of horizontal branch stars places important constraints on angular momentum evolution in evolved stars and therefore rotational mixing on the giant branch.
Pinsonneault, M., Sills, A.
core   +6 more sources

The peculiar Horizontal Branch of NGC 2808

, 2010
We present an accurate analysis of the peculiar Horizontal Branch (HB) of the massive Galactic globular cluster NGC 2808, based on high-resolution far-UV and optical images of the central region of the cluster obtained with HST. We confirm the multimodal
B. Lanzoni, Bailyn, Bedin, Bedin, Bekki, Bertin, Brown, Brown, Buonanno, Buonanno, Busso, Calamida, Cardelli, Carretta, Carretta, Cassisi, Castellani, Castellani, Castellani, Cohen, Corwin, D'Antona, D'Antona, D'Antona, D'Cruz, D'Ercole, Da Costa, Dalessandro, Dalessandro, Decressin, Decressin, Dieball, Dorman, Dotter, Dotter, E. Dalessandro, E. Sabbi, F. Fusi Pecci, F. R. Ferraro, Ferraro, Ferraro, Ferraro, Ferraro, Ferraro, Ferraro, Ferraro, Girardi, Gratton, Gratton, Harris, Harris, Holtzman, Hui-Bon-Hoa, Iannicola, Lanzoni, Lee, M. Salaris, Mackey, Marino, Michaud, Miller Bertolami, Moehler, Moni Bidin, Montegriffo, Pace, Pancino, Pietrinferni, Piotto, Piotto, Quievy, R. T. Rood, Recio-Blanco, Rich, Rood, Rood, Rood, Rutledge, S. Cassisi, Samus, Sollima, Sosin, Ventura, Villanova, Zinn   +83 more
core   +2 more sources

Horizontal Branch Evolution and Atomic Diffusion [PDF]

The Astrophysical Journal, 2007
Stellar evolution models of a 0.8 Msolar star (Y=0.2352, Z=0.0001, ?=0.3) have been calculated in detail from the zero-age main sequence to the horizontal branch, both with and without atomic diffusion. We analyze the effects of atomic diffusion on the horizontal branch models themselves, as well as on the properties of giant-branch tip stars that ...
G. Michaud, J. Richer, O. Richard
openalex   +3 more sources

The binary fraction of blue horizontal branch stars

Astronomy & Astrophysics
Context. Blue horizontal branch (BHB) stars are old, low-mass, metal-poor stars that serve as important tracers of the Galactic halo structure, kinematics, and evolution. Understanding their binary properties provides key insights into their formation channels and the role of binary interactions in the evolution of horizontal branch stars. Aims.
Yanjun Guo, Kun Chen, Zhenwei Li, Jie Ju, Chao Liu, Xiang-Xiang Xue, M. Dorsch, Zhanwen Han, Xuefei Chen   +8 more
openalex   +3 more sources

Horizontal Branch Stars [PDF]

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
openaire   +2 more sources

Possible Models of Horizontal Branch Stars.

The Astronomical Journal, 1966
Jr. Iben Icko, J. S. Faulkner
openalex   +3 more sources

Horizontal Branch Evolution [PDF]

International Astronomical Union Colloquium, 1989
AbstractIn 1973 the outstanding problems confronting the theory of horizontal branch evolution were the “second parameter” problem and the Oosterhoff Effect. Despite significant progress, particularly in the observations and in the observation/theory interface, they remain as the outstanding problems of 1988.
R.T. Rood, D.A. Crocker
openaire   +1 more source

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, Noam Soker, Sonja Schuh, Horst Drechsel, Ulrich Heber   +4 more
openaire   +4 more sources

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, Josefina Montalbán, Andrea Miglio, Mathieu Vrard, Giada Casali, Amalie Stokholm, Marco Tailo, Warrick H. Ball, Walter E. van Rossem, Marica Valentini   +9 more
openaire   +3 more sources