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:
Pierre Bergeron is interested in the study of white dwarf stars and more particularly in the calculation of model atmospheres. White dwarf stars represent the final evolutionary stage of more than 97% of stars in our galaxy, including our Sun. Having exhausted the nuclear energy sources in their center, a white dwarf slowly cools down over several billions of years. They have a mass comparable to that of the Sun but in a volume equal to that of the Earth, which makes them extremely compact objects whose density is a million times that of the Sun. The study of these stellar remnants and the determination of their fundamental parameters such as temperature, mass and chemical composition tell us not only about the nature of these stars, but also on the evolutionary link with the stars that spawned them. The most accurate method used to measure the basic parameters of white dwarf stars is to compare in detail the spectroscopic data, i.e. the flux distribution as a function of wavelength, with theoretical predictions obtained from state-of-the-art model atmospheres, a method refined for years at the Université de Montréal. Pierre Bergeron is also interested in the study of pulsating white dwarf stars, called ZZ Ceti stars, and in particular the determination of the empirical boundaries of their instability strip. All his theoretical projects rely heavily on photometric and spectroscopic data obtained at various telescopes at Kitt Peak observatories in Arizona (2.3 m Steward, 2.1 m and 4 m Kitt Peak) and the Observatoire du Mont-Mégantic.
Prix et distinctions: