Alex Laroche

I’m a PhD candidate¹ in the Department of Astronomy & Astrophysics at the University of Toronto, working with Maria Drout and Josh Speagle. I’m interested in binary interaction: how the exchange of mass, energy and angular momentum between two stars changes their evolution and final fates. Right now I’m focused on the intermediate-mass helium stars recently discovered in the Magellanic Clouds, which lost their hydrogen envelopes through binary interaction with a companion.

I’m an observer and a data explorer. I use spectroscopy from instruments such as Magellan/MagE, VLT/X-shooter and Gemini/GHOST, together with binary evolution modeling, to study small samples of post-interaction binaries in detail. If the TACs are merciful, perhaps HST or JWST soon! I also build data-driven models to find new binaries and measure stellar properties in big datasets, such as Gaia XP spectra. These two approaches are complementary: detailed studies provide empirical constraints on the uncertain physics in binary evolution models, while surveys present an opportunity to discover new systems and characterize full(er) populations. More details are on my research page.

I grew up in Montreal, Quebec, and graduated from McGill University in 2022 with an Honours BSc in Physics. As an undergraduate I worked on dark matter and strong lensing with Jo Bovy at UofT, and on 21cm cosmology in Adrian Liu’s and Jonathan Sievers’ groups at McGill.

Outside of astrophysics, I run (5k/10k/HM/M: 16:12/33:21/1:13/2:25). I often run with my dog Pacino, at “Pacino pace”.

You can reach me at alex.laroche@mail.utoronto.ca.