Results 21 to 30 of about 114,517 (388)

Evidence of Stellar Oscillations in the Post-common-envelope Binary Candidate ASASSN-V J205543.90+240033.5

The Astrophysical Journal Letters, 2023
ASASSN-V J205543.90+240033.5 (ASJ2055) is a possible post-common-envelope binary system. Its optical photometric data show an orbital variation of about 0.52 days and a fast period modulation of P _0 ∼ 9.77 minutes, whose origin is unknown.
J. Takata, A. K. H. Kong, X. F. Wang, F. F. Song, J. Mao, X. Hou, C.-P. Hu, L. C.-C. Lin, K. L. Li, C. Y. Hui   +9 more
doaj   +1 more source

Pulsation properties of ultra-massive DA white dwarf stars with ONe cores [PDF]

Astronomy & Astrophysics, 2018
Context. Ultra-massive hydrogen-rich white dwarf stars are expected to harbor oxygen/neon cores resulting from the progenitor evolution through the super-asymptotic giant branch phase.
F. D. Ger'onimo, A. C'orsico, L. Althaus, F. C. Wachlin, M. Camisassa   +4 more
semanticscholar   +1 more source

Diffusion of neon in white dwarf stars [PDF]

Physical Review E, 2010
Sedimentation of the neutron rich isotope $^{22}$Ne may be an important source of gravitational energy during the cooling of white dwarf stars. This depends on the diffusion constant for $^{22}$Ne in strongly coupled plasma mixtures. We calculate self-diffusion constants $D_i$ from molecular dynamics simulations of carbon, oxygen, and neon mixtures. We
J. Hughto, Don Berry, Charles Horowitz, A. S. Schneider   +3 more
openaire   +4 more sources

White dwarf stars with carbon atmospheres [PDF]

Nature, 2007
White dwarfs represent the endpoint of stellar evolution for stars with initial masses between approximately 0.07 and 8-10, where is the mass of the Sun (more massive stars end their life as either black holes or neutron stars). The theory of stellar evolution predicts that the majority of white dwarfs have a core made of carbon and oxygen, which ...
Dufour, Patrick, Liebert, James W., Fontaine, Guy Hugues, Behara, Natalie Thérèse   +3 more
openaire   +5 more sources

Population Synthesis of Helium White Dwarf–Red Giant Star Mergers and the Formation of Lithium-rich Giants and Carbon Stars [PDF]

Astrophysical Journal, 2020
The formation histories of lithium-rich and carbon-rich red giants are not yet understood. It has been proposed that the merger of a helium-core white dwarf with a red giant branch (RGB) star might provide a solution. We have computed an extended grid of
Xianfei Zhang, C. Jeffery, Yaguang Li, S. Bi   +3 more
semanticscholar   +1 more source

Maximum mass ratio of AM CVn-type binary systems and maximum white dwarf mass in ultra-compact X-ray binaries [PDF]

Serbian Astronomical Journal, 2011
AM CVn-type stars and ultra-compact X-ray binaries are extremely interesting semi-detached close binary systems in which the Roche lobe filling component is a white dwarf transferring mass to another white dwarf, neutron star or a black hole ...
Arbutina Bojan
doaj   +1 more source

Asteroseismological study of massive ZZ Ceti stars with fully evolutionary models [PDF]

, 2013
We present the first asteroseismological study for 42 massive ZZ Ceti stars based on a large set of fully evolutionary carbon$-$oxygen core DA white dwarf models characterized by a detailed and consistent chemical inner profile for the core and the ...
Althaus, L. G., Córsico, A. H., Fraga, L., Kepler, S. O., Romero, A. D.   +4 more
core   +4 more sources

Axions and the Cooling of White Dwarf Stars [PDF]

The Astrophysical Journal, 2008
White dwarfs are the end-product of the lifes of intermediate- and low-mass stars and their evolution is described as a simple cooling process. Recently, it has been possible to determine with an unprecedented precision their luminosity function, that is, the number of stars per unit volume and luminosity interval.
Silvia Catalan, Jordi Isern, Enrique García-Berro, Santiago Torres   +3 more
openaire   +3 more sources

JWST Directly Images Giant Planet Candidates Around Two Metal-polluted White Dwarf Stars [PDF]

Astrophysical Journal Letters
We report the discovery of two directly imaged, giant planet candidates orbiting the metal-rich, hydrogen atmosphere white dwarfs WD 1202−232 and WD 2105−82. JWST’s Mid-Infrared Instrument (MIRI) data on these two stars show a nearby resolved source at a
S. Mullally, J. Debes, M. Cracraft, F. Mullally, Sabrina Poulsen, Loic Albert, Katherine Thibault, W. Reach, J. J. Hermes, T. Barclay, M. Kilic, E. Quintana   +11 more
semanticscholar   +1 more source

Upper limit on the axion-photon coupling from magnetic white dwarf polarization [PDF]

Physical Review D, 2022
Polarization measurements of thermal radiation from magnetic white dwarf (MWD) stars have been proposed as a probe of axion-photon mixing. The radiation leaving the surface of the MWD is unpolarized, but if low-mass axions exist then photons polarized ...
Christopher Dessert, D. Dunsky, B. Safdi
semanticscholar   +1 more source