Olivia Lim

Olivia started her doctoral studies in 2019 at the University of Montreal under the supervision of Professor René Doyon. She focuses on TRAPPIST-1, an exoplanetary system which consists of a red dwarf star and seven orbiting exoplanets. These seven companions are very peculiar because they transit their host star, that is, they pass in front of the star as seen from Earth. These seven planets have sizes similar to that of Earth and three of them are in the habitable zone, which is the region around the star where it is neither too cold or too hot for liquid water to exist at the surface of a planet. TRAPPIST-1 is therefore an ideal target to search for signatures of life outside the solar system, namely with the James Webb Space Telescope.

One of the properties of TRAPPIST-1 that Olivia studies is the atmosphere of the exoplanets in the system. When a planet transits its host star, a fraction of the starlight gets filtered through the atmosphere of the planet before reaching our eyes (or rather before reaching the telescope!). We can then disperse this filtered light into its different colours, or different wavelengths, to get a spectrum of the planetary atmosphere. Dispersion is a common phenomenon that we can witness in our everyday life: when a beam of sunlight goes through a prism, we can see a rainbow on the other side, the spectrum. We then study this spectrum of the planetary atmosphere to determine its chemical composition and physical properties. This is called transit spectroscopy. Olivia uses instruments such as NIRISS and NIRSpec, aboard the Webb telescope, to do transit spectroscopy of the planets of the TRAPPIST-1 system.

In parallel to her research projects, between 2021 and 2023, Olivia was coordinator of the CRAQ calendar, a calendar filled with images and information that aims at sharing the research done by CRAQ members and more generally the passion for astronomy with the population. She regularly participates in outreach activities for the general public. You can watch an ExoBites video in which Olivia participated, a presentation given at the Royal Astronomical Society of Canada (Montreal Centre) as well as an interview presented at Radio-Canada’s Téléjournal 18h.

Supervisor

René Doyon