Results 41 to 50 of about 116,162 (381)

Searching for benchmark systems containing ultra-cool dwarfs and white dwarfs

EPJ Web of Conferences, 2013
We have used the 2MASS all-sky survey and WISE to look for ultracool dwarfs that are part of multiple systems containing main sequence stars. We cross-matched L dwarf candidates from the surveys with Hipparcos and Gliese stars, finding two new systems ...
Pinfield D.J., Gomes J.I.
doaj   +1 more source

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   +4 more sources

The potential of asteroseismology for probing the core chemical stratification in white dwarf stars [PDF]

, 2016
Context. The details of the C/O core structure in white dwarf stars has mostly remained inaccessible to the technique of asteroseismology, despite several attempts carried out in the past. Aims.
N. Giammichele, S. Charpinet, P. Brassard, G., Fontaine   +4 more
semanticscholar   +1 more source

A highly magnetized and rapidly rotating white dwarf as small as the Moon [PDF]

Nature, 2021
White dwarfs represent the last stage of evolution of stars with mass less than about eight times that of the Sun and, like other stars, are often found in binaries1,2. If the orbital period of the binary is short enough, energy losses from gravitational-
I. Caiazzo, K. Burdge, J. Fuller, J. Heyl, S. Kulkarni, T. Prince, H. Richer, J. Schwab, I. Andreoni, E. Bellm, A. Drake, D. Duev, M. Graham, G. Helou, A. Mahabal, F. Masci, Roger M. Smith, M. Soumagnac   +17 more
semanticscholar   +1 more source

Constraining planet formation around 6M⊙-8M⊙ stars [PDF]

, 2020
Identifying planets around O-type and B-type stars is inherently difficult; the most massive known planet host has a mass of only about 3M⊙. However, planetary systems which survive the transformation of their host stars into white dwarfs can be detected
Gaensicke, Boris T., Hermes, J. J., Kennedy, Grant M., McDonald, Catriona H., Meru, Farzana, Tremblay, Pier-Emmanuel, Veras, Dimitri   +6 more
core   +2 more sources

Magnetic white dwarf stars [PDF]

Publications of the Astronomical Society of the Pacific, 1996
NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Three aspects of magnetic white dwarf stars are studied to aid in the understanding of stellar evolution. A survey of ~ 50 DC white dwarf stars was conducted in circular spectropolarimetry to search for magnetic fields [...] 30 kG. Four
openaire   +2 more sources

A New Generation of Cool White Dwarf Atmosphere Models. I. Theoretical Framework and Applications to DZ Stars [PDF]

Astrophysical Journal, 2018
The photospheres of the coolest helium-atmosphere white dwarfs are characterized by fluidlike densities. Under those conditions, standard approximations used in model atmosphere codes are no longer appropriate. Unfortunately, the majority of cool He-rich
S. Blouin, P. Dufour, N. Allard
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
Horowitz, C. J., Hughto, J., Schneider, A. S., Berry, D. K.   +3 more
openaire   +3 more sources

Pulsations of massive ZZ Ceti stars with carbon/oxygen and oxygen/neon cores [PDF]

, 2004
We explore the adiabatic pulsational properties of massive white dwarf stars with hydrogen-rich envelopes and oxygen/neon and carbon/oxygen cores. To this end, we compute the cooling of massive white dwarf models for both core compositions taking into ...
A. H. Córsico, Alexander, Althaus, Althaus, Althaus, Althaus, Arnould, Barstow, Bradley, Bradley, Brassard, Brassard, Caughlan, Córsico, Córsico, D'Antona, Dahn, Dupuis, E. García-Berro, Ferrario, García-Berro, García-Berro, García-Berro, Gil-Pons, Grossman, Guerrero, Herwig, Iben, J. Isern, Kanaan, Kawaler, L. G. Althaus, Magni, Montgomery, Montgomery, Osaki, Pfeiffer, Ritossa, Salaris, Schmidt, Segretain, Segretain, Segretain, Segretain, Straniero, Tassoul, Winget   +46 more
core   +3 more sources

A radio-pulsing white dwarf binary star [PDF]

Nature, 2016
White dwarfs are compact stars, similar in size to Earth but ~200,000 times more massive. Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions, and the resulting mass transfer can generate atomic line and X-ray ...
Marsh, T. R., Gänsicke, B. T., Hümmerich, S., Hambsch, F.-J., Bernhard, K., Lloyd, C., Breedt, E., Stanway, E. R., Steeghs, D. T., Parsons, S. G., Toloza, O., Schreiber, M. R., Jonker, P. G., van Roestel, J., Kupfer, T., Pala, A. F., Dhillon, V. S., Hardy, L. K., Littlefair, S. P., Aungwerojwit, A., Arjyotha, S., Koester, D., Bochinski, J. J., Haswell, C. A., Frank, P., Wheatley, P. J.   +25 more
openaire   +10 more sources