From June 8 to 11, astronomers from across Canada gathered at Université de Montréal’s Campus MIL for the 2026 annual meeting of the Canadian Astronomical Society (CASCA).
Hosted this year by UdeM under the theme “MIL-ion Futures of Astrophysics,” the conference brought together researchers, students and astronomy professionals for four days of scientific presentations, posters, workshops and discussions covering nearly every corner of modern astronomy – from exoplanets and stars to galaxies, black holes, gravitational waves and the next generation of astronomical observatories.
Members of the CASCA 2026 Local Organizing Committee. Top row, left to right: Sacha Perry-Fagant, Anabel Tan, Mathieu Marquis, Julie Hlavacek-Larrondo, Charles-Antoine Parent, Érika Le Bourdais, Neil Cook, Olivia Pereira, Marek Detière-Venkatesh, Emma Pimentel, Benjamin Vigneron. Bottom row, left to right: Rafael Daignault, Nathalie Ouellette, Frédérique Baron, René Doyon, Auriane Thilloy, Darya Daniels, Danika Belzile, Viplav Nafade.
UdeM and the Trottier Institute for Research on Exoplanets (IREx) also played a major role behind the scenes. The local organizing committee was chaired by IREx’s Frédérique Baron, with Julie Hlavacek-Larrondo, IREx Director René Doyon, and IREx Deputy Director Nathalie Ouellette as co-chairs, alongside numerous other members of the UdeM and IREx communities. UdeM researchers were also strongly represented on the scientific organizing committee.
Throughout the meeting, UdeM/IREx researchers shared their work across a wide range of fields, with an especially strong showing from the exoplanet community.
During the first exoplanet session, Thomas Vandal presented new James Webb Space Telescope (JWST) observations investigating how often the coldest brown dwarfs have companions, Amélie Gressier presented a new atmospheric atlas of sub-Neptunes observed with JWST, and Romain Allart looked back at three years of exoplanet atmospheric characterization with NIRPS. Allart’s presentation highlighted results ranging from atmospheric escape to the compositions of warm Neptunes and hot Jupiters, while looking ahead to how NIRPS is helping prepare astronomers for instruments such as ANDES on the Extremely Large Telescope.
CASCA 2026 Attendees peruse lanes of research posters during the poster sessions. Credit: Amélie Philibert.
In the second exoplanet session, IREx Ph.D. student Alexandrine L’Heureux presented her work teasing out the tiny radial-velocity signals of the seven planets in the TRAPPIST-1 system using SPIRou and NIRPS.
UdeM science extended well beyond exoplanets. Leslie Moranta presented work on the rotation rates of newly identified young stellar clusters, while UdeM researchers contributed talks on topics including artificial intelligence and strong gravitational lensing, supermassive black holes and next-generation astronomical instrumentation. For example, Gabriel Missael Barco presented work using computer models to study distant galaxies distorted by gravitational lensing and the distribution of matter creating these effects.
UdeM and IREx researchers were equally visible during the conference’s poster sessions. Their contributions included Samuel Boucher’s JWST observations mapping the atmosphere of the ultra-short-period rocky planet TOI-561 b, Salma Salhi’s work using machine learning to correct noise in JWST/NIRISS exoplanet spectra, and Guillaume Payeur’s application of machine-learning techniques to gravitationally lensed galaxies. Other UdeM posters explored subjects ranging from stellar winds and galaxy evolution to astronomical instrumentation.
The program also provided opportunities for the community to discuss the future of Canadian astronomy, including town halls devoted to JWST, Gemini and CFHT, ALMA and the ngVLA, SKAO and CASTOR, as well as next-gen Very Large Optical Telescopes.
IREx’s Frédérique Baron presents an invited talk at CASCA 2026 on the state of astronomy in Canada and Quebec. Credit: Amélie Philibert
The meeting also highlighted the importance of communicating astronomy beyond the scientific community. IREx’s Frédérique Baron was an invited speaker for the conference’s education and public outreach session.
On Tuesday evening, Nathalie Ouellette, Deputy Director of IREx and the Observatoire du Mont-Mégantic, delivered the conference’s public lecture. Her talk explored how JWST is transforming our understanding of the earliest galaxies and the unexpectedly massive galaxies astronomers are finding in the young Universe. A recording of her talk is available to watch on the IREx Youtube channel here.
CASCA 2026 also welcomed educators to Campus MIL for a French-language professional development day led by Julie Bolduc-Duval, Director of Discover the Universe, dedicated to bringing astronomy and science into the classroom. The program combined presentations on Canadian astronomy, exoplanets, and JWST, and practical educational resources – including an activity led by IREx PhD student Alexandrine L’Heureux in which participants simulated the process of selecting an exoplanet and preparing a JWST observing proposal.
IREx’s Deputy Director, Nathalie Ouellette, presents during the CASCA 2026 Teacher’s Workshop. Credit: Amélie Philibert.
Beyond the talks and posters, CASCA 2026 was an opportunity to bring Canada’s astronomy community together in Montréal. Events included a welcome reception at the Montréal Planetarium, a conference banquet in Vieux Port, poster sessions and discussions on topics ranging from research partnerships with Indigenous communities to the future of Canada’s major astronomical facilities.
The conference also created opportunities for learning and professional development beyond the main scientific program. On June 8, ahead of the official start of CASCA 2026, graduate students gathered at Campus MIL for the Graduate Student Workshop, providing a dedicated space for students to connect with one another and take part in activities geared toward early-career astronomers.
And the great science conversations continued after CASCA wrapped up. On June 12, Campus MIL hosted the Canadian Astronomical Instrumentation Workshop, bringing together astronomers and engineers interested in the technologies behind current and future astronomical facilities. The workshop continued a Canadian initiative designed to showcase the country’s expertise and contributions to astronomical instrumentation and to foster connections among researchers and engineers working on instrumentation projects.
For UdeM and IREx, hosting CASCA 2026 was both an opportunity to welcome colleagues from across the country to Campus MIL and to showcase the breadth of astronomy being carried out in Montréal: from the atmospheres of nearby worlds to stars, galaxies and the largest structures in the Universe.
Researchers from Université de Montréal and the Trottier Institute for Research on Exoplanets contributed talks, posters and discussions across the CASCA 2026 program.
Sponsors of CASCA 2026 include: Université de Montréal Département de physique, Espace pour la vie, Sidrat Research, Fédération des astronomes amateurs du Quebec (FAAQ), University of Toronto’s Dunlap Institute for Astronomy & Astrophysics, Trottier Space Institute at McGill, Canada-France-Hawai’i Telescope (CFHT), The Royal Astronomical Society of Canada (RASC), Club D’astronomie Mont Tremblant, W.M. Keck Observatory, Gemini Observatory, CanDIAPL, Honeywell, Bishop’s University, ABB, and Fonds de recherche Québec.
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