Results 51 to 60 of about 2,016,206 (398)
A Chondritic Solar Neighborhood
The Planetary Science Journal, 2023 A persistent question in exoplanet demographics is whether exoplanetary systems form from similar compositional building blocks to our own. Polluted white dwarf stars offer a unique way to address this question, as they provide measurements of the bulk ...
Isabella L. Trierweiler +2 more
doaj +1 more source
ON THE EVOLUTION OF MAGNETIC WHITE DWARFS [PDF]
The Astrophysical Journal, 2015 We present the first radiation magnetohydrodynamics simulations of the atmosphere of white dwarf stars. We demonstrate that convective energy transfer is seriously impeded by magnetic fields when the plasma-beta parameter, the thermal to magnetic pressure ratio, becomes smaller than unity.
P.-E. Tremblay +7 more
openaire +4 more sources
A white dwarf catalogue from Gaia-DR2 and the Virtual Observatory [PDF]
Monthly notices of the Royal Astronomical Society, 2018 We present a catalogue of 73,221 white dwarf candidates extracted from the astrometric and photometric data of the recently published Gaia DR2 catalogue.
F. Jiménez-Esteban +7 more
semanticscholar +1 more source
The WFCAM transit survey and cool white dwarfs
EPJ Web of Conferences, 2013 We present results from our search for cool white dwarfs in the WTS (WFCAM Transit Survey). Repeat observations starting in 2007 allowed to produce deep stacked images in J and measure proper motions.
Pinfield D. +4 more
doaj +1 more source
The Post-Common Envelope and Pre-Cataclysmic Binary PG 1224+309 [PDF]
, 1998 We have made extensive spectroscopic and photometric observations of PG 1224+309, a close binary containing a DA white dwarf primary and an M4+ secondary. The H alpha line is in emission due to irradiation of the M-star by the hot white dwarf and is seen
Chavira E. +13 more
core +3 more sources
, 2022 48 pages, 6 figures, Invited (and accepted) chapter for the Handbook of X-ray and Gamma-ray Astrophysics, Editors: Cosimo Bambi, Andrea ...
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
White dwarfs in the WTS: Eclipsing binaries
EPJ Web of Conferences, 2013 We have identified photometric white dwarf candidates in the WFCAM transit survey through a reduced proper motion versus colour approach. Box-fitting with parameters adjusted to detect the unique signature of a white dwarf + planet/brown dwarf transit ...
Burleigh M.R. +4 more
doaj +1 more source
Evidence from K2 for rapid rotation in the descendant of an intermediate-mass star [PDF]
, 2017 Using patterns in the oscillation frequencies of a white dwarf observed by K2, we have measured the fastest rotation rate, 1.13(02) hr, of any isolated pulsating white dwarf known to date.
Bell, Keaton J. +11 more
core +3 more sources
Symposium - International Astronomical Union, 1974 The effects of core crystallization and of convection in the envelope on the cooling of white dwarfs are reviewed. The case of a 0.6 M⊙ white dwarf composed of an oxygen core and a helium envelope is taken as example. Also the amount of hydrogen that a white dwarf can accrete before nuclear burning occurs is estimated and possible evolutionary ...
openaire +1 more source