scholarly journals Population Synthesis Studies of White Dwarf Binaries

2004 ◽  
Vol 194 ◽  
pp. 101-103
Author(s):  
U. Kolb ◽  
B. Willems
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Cataclysmic Variables ◽  
Eclipsing Binaries ◽  
Main Sequence Star ◽  
Population Synthesis

AbstractWe present population synthesis studies of white dwarf - main-sequence star binaries, of cataclysmic variables that are driven by circumbinary discs, and of eclipsing binaries in the exoplanet transit search SuperWASP.

scholarly journals Evolution Models of Helium White Dwarf–Main-sequence Star Merger Remnants

2017 ◽  
Vol 835 (2) ◽  
pp. 242 ◽  
Author(s):  
Xianfei Zhang ◽  
Philip D. Hall ◽  
C. Simon Jeffery ◽  
Shaolan Bi
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Main Sequence Star

scholarly journals White dwarf-main sequence star collisions

1977 ◽  
Vol 179 (4) ◽  
pp. 705-718 ◽  
Author(s):  
M. M. Shara ◽  
G. Shaviv
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Main Sequence Star

scholarly journals Origin and Radial Distribution of Faint Blue Horizontal-Branch Stars

1988 ◽  
Vol 126 ◽  
pp. 679-680
Author(s):  
Charles D. Bailyn ◽  
Jonathan E. Grindlay ◽  
Haldan Cohn ◽  
Phyllis M. Lugger
Keyword(s):  
Radial Distribution ◽  
White Dwarf ◽  
Main Sequence ◽  
Main Sequence Star ◽  
Horizontal Branch ◽  
Horizontal Branch Stars

We report the identification of 23 faint blue horizontal branch stars in Omega Centauri similar to those discussed by Buonanno et al. (1985) in M15. We find that these stars are significantly concentrated towards the center of the cluster with respect to other giants. We suggest that they may have formed from the collision of a main sequence star and a white dwarf.

scholarly journals Problems in Common Envelope Evolution as a Pre-Stage of Cataclysmic Variables

1979 ◽  
Vol 53 ◽  
pp. 520-520
Author(s):  
F. Meyer ◽  
E. Meyer-Hofmeister
Keyword(s):  
Angular Momentum ◽  
Thermal Instability ◽  
Main Sequence ◽  
Cataclysmic Variables ◽  
Main Sequence Star ◽  
Common Envelope ◽  
Angular Momentum Transport ◽  
Binary Separation ◽  
Low Mass ◽  
Red Giant

We follow the evolution of an originally widely separated red-giant in orbit with a low mass main sequence star to a cataclysmic binary system. Angular momentum transport via differential rotation leads to a common envelope around the red giant core and the main sequence star. The internal binary separation shrinks by frictional transfer of angular momentum to the extended red giant envelope. This shrinkage continues at nearly constant luminosity until after several hundred years the binary “Roche lobe” cuts into the dense layers of the main sequence star. The envelope will then be lost by a thermal instability. Method and computations for a 5 M⊙ + 1 M⊙ binary are presented elsewhere (Astron. Astrophys. 1979, in press).

scholarly journals Detached white dwarf main-sequence star binaries

2004 ◽  
Vol 419 (3) ◽  
pp. 1057-1076 ◽  
Author(s):  
B. Willems ◽  
U. Kolb
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Main Sequence Star

scholarly journals Revised Stellar Parameters for V471 Tau, A Post-common Envelope Binary in the Hyades

2021 ◽  
Vol 163 (1) ◽  
pp. 34
Author(s):  
Philip S. Muirhead ◽  
Jason Nordhaus ◽  
Maria R. Drout
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Hubble Space Telescope ◽  
Main Sequence Star ◽  
Velocity Measurements ◽  
Single Star ◽  
Orbital Parameters ◽  
Common Envelope ◽  
Star Evolution ◽  
First Time

Abstract V471 Tau is a post-common-envelope binary consisting of an eclipsing DA white dwarf and a K-type main-sequence star in the Hyades star cluster. We analyzed publicly available photometry and spectroscopy of V471 Tau to revise the stellar and orbital parameters of the system. We used archival K2 photometry, archival Hubble Space Telescope spectroscopy, and published radial-velocity measurements of the K-type star. Employing Gaussian processes to fit for rotational modulation of the system flux by the main-sequence star, we recovered the transits of the white dwarf in front of the main-sequence star for the first time. The transits are shallower than would be expected from purely geometric occultations owing to gravitational microlensing during transit, which places an additional constraint on the white-dwarf mass. Our revised mass and radius for the main-sequence star is consistent with single-star evolutionary models given the age and metallicity of the Hyades. However, as noted previously in the literature, the white dwarf is too massive and too hot to be the result of single-star evolution given the age of the Hyades, and may be the product of a merger scenario. We independently estimate the conditions of the system at the time of common envelope that would result in the measured orbital parameters today.

scholarly journals Hot subdwarfs from the surviving companions of the white dwarf + main-sequence channel of Type Ia supernovae

2021 ◽  
Vol 507 (3) ◽  
pp. 4603-4617
Author(s):  
Xiang-Cun Meng ◽  
Yang-Ping Luo
Keyword(s):  
White Dwarf ◽  
Birth Rate ◽  
Main Sequence ◽  
Space Velocity ◽  
Type Ia Supernovae ◽  
Population Synthesis ◽  
Parameter Spaces ◽  
Type Ia ◽  
Hot Subdwarfs ◽  
Ia Supernovae

ABSTRACT Some surviving companions of Type Ia supernovae (SNe Ia) from the white dwarf + main-sequence (WD+MS) channel may evolve to hot subdwarfs. In this paper, we perform stellar evolution calculations for the surviving companions of close WD+MS systems in the spin-up/spin-down model and the canonical non-rotating model. This enables us to map out the initial parameter spaces in the orbital period–secondary-mass plane in which the surviving companions can evolve to hot subdwarfs. Based on these results, we carry out a series of binary population synthesis calculations to obtain the Galactic birth rate of hot subdwarfs from the WD+MS channel, which is $2.3{-}6\times 10^{\rm -4}\, {\rm yr}^{\rm -1}$ for the spin-up/spin-down model and $0.7{-}3\times 10^{\rm -4}\, {\rm yr}^{\rm -1}$ for the canonical non-rotating model. We also show the distributions of some integral properties of the hot subdwarfs, for example the mass and space velocity, for different models. In addition, by comparing our results with observations of intermediate helium-rich (iHe-rich) hot subdwarfs, we find that the hot subdwarfs from the WD+MS channel may explain some observational features of the iHe-rich hot subdwarfs, especially those from the spin-up/spin-down model. Although we expect that the SN Ia channel will contribute only a small fraction of the iHe-rich hot subdwarf population, some of these may help to explain cases with unusual kinematics.

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