Pierre Bastien

Working at the Université de Montréal, Professor Pierre Bastien’s research focuses mainly on the formation of stars and planetary systems. This is one of the priority research areas in the Canadian astronomical community’s Long Range Plan. For this work, he mainly uses the polarization of light as a means of obtaining information. Here are two examples of current projects:

Natural light has a plane of vibration that varies randomly. Light can also vibrate according to a preferential plane, in which case it is said to be polarized. Professor Bastien is the principal investigator of the polarimeter, POMM, which is 100 times more accurate than the Mont-Mégantic Observatory’s previous polarimeter, “Beauty and the Beast”. Microscopic dust grains in the protoplanetary disk of young stars scatter and polarize the light emitted by these stars. By measuring this polarization, it is possible to characterize the properties of the grains and the general environment of the stars. Together with other types of observations and models, it is thus possible to study the conditions in protoplanetary disks where planets form. Professor Bastien will also be observing stars with closely-spaced exoplanets to learn about the properties of these planets’ atmospheres and determine the inclination of their orbits, an important parameter in determining their mass.

As principal investigator, Professor Bastien also built a polarimeter, POL-2, for the James-Clerk-Maxwell radio telescope on Mauna Kea in Hawaii. This will soon provide information on the effects of magnetic fields in dense molecular clouds and on star formation processes. The aim is to find out whether magnetic fields are more important than turbulence in slowing down star formation, which is slower than our models predict.