Pierre Bastien

The research of Professor Bastien deals mostly with star and planetary system formation. This is one of the priority research areas of identified by the Canadian astronomical community in its Long range plan. Polarization of light is the main tool used by Professor Bastien for getting information. Here are two examples of his ongoing research projects.

Natural light vibrates in a plane that varies continuously and randomly. When it vibrates in a preferential plane, we say that it is polarized. For measuring polarization from celestial objects, Professor Bastien is the principal investigator of a new polarimeter for the Mont-Mégantic Observatory, POMM, that will be 100 times more precise than the previous one, la Belle et la Bête (Beauty and the Beast). Light from a young star is scattered and polarized by microscopic dust grains located mainly in its protoplanetary disk. By measuring this polarization, one can find out about grain properties and the general circumstellar environment. Combining with other observations and with modelling, we learn about conditions in protoplanetary disks where planets are formed. Professor Bastien will also observe stars with close-in exoplanets to learn about the properties of their atmospheres and determine the inclination of their orbit, which is an important parameter to determine their mass.

Finally, Professor Bastien is also the principal investigator of a polarimeter, POL-2, for the James-Clerk-Maxwell radiotelescope on Mauna Kea in Hawaii. It will give information about magnetic fields in dense molecular clouds and star formation processes. The goal is to find out if magnetic fields are more important than turbulence for slowing down the star formation processes because they are slower than what our models predict.

Former Students

• Taylor Bell (PhD, 2021, en co-supervision avec Nicolas Cowan)
• Simon Coudé (PhD, 2018, PhD)