Département de physique
Université de Montréal
C.P. 6128, Succursale Centre-Ville
Canada H3C 3J7
Research field: White dwarf stars; stellar atmospheres; asterosismology.
Description of the research project:
Patrick Dufour's research is mainly focused on the study of the atmosphere of white dwarf stars, both from a theoretical point of view (detailed calculations of model atmospheres) as well as from observational data (spectroscopy and photometry). White dwarfs are remnants of low-mass stars that have exhausted their nuclear fuel. A typical white dwarf is composed of a core of carbon and oxygen, representing more than 99% of its mass, surrounded by a layer of helium which itself is surrounded, in about 80% of the cases, by a superficial layer of hydrogen. These layers, although physically thin, are optically thick and regulate the energy loss rate of the star (i.e. its cooling rate). In order to fully understand the evolution of white dwarfs, it is therefore essential to understand the physical properties of these superficial layers. Spectroscopic analysis of the light coming from the atmosphere of white dwarf stars is the main technique used to obtain information on the external parts of these stars. Patrick Dufour's main interest is the analysis of the properties of stars with traces of heavy elements (spectral type DZ and DQ) as well as stars with a carbon-rich atmosphere.