Past Colloquia
Probing Dark Matter with X-ray Telescopes and the International Axion Observatory (IAXO)
Cody Hall, 50 St. George Street
Prof. Kerstin M. Perez
September 30, 2026
2:00pm - 3:00pm
Axions are among the best motivated candidates for dark matter. Their existence would subtly alter the processes within stellar interiors, imprinting characteristic signals in astrophysical observations. Observations with existing X-ray telescopes have already begun to exploit this connection, placing leading constraints on axion dark matter…
The Beautiful Confusion. The Earliest Galaxies after JWST
Cody Hall, 50 St. George Street
Prof. Andrea Ferrara
September 23, 2026
2:00pm - 3:00pm
One of the major surprises provided by the first months of early Universe observations by JWST has been the detection of a stunning overabundance of luminous, and likely massive, galaxies at redshift z>10. As the first spectroscopic confirmations are accumulating, it is crucial and timely to…
The Afterlife of Gas Giants: Tidal Disruption and Subsequent Fate of Stripped Cores on Close-in Orbits
Cody Hall, 50 St. George Street
Prof. Heather Knutson
September 16, 2026
2:00pm - 3:00pm
For decades, models have predicted that gas giant planets that come too close to their host stars will be destroyed, with most of their mass accreted onto the host star. However, recent work modeling Roche lobe overflow from close-in gas giants now indicates that angular momentum exchange…
The Seasons of Helium
Cody Hall, 50 St. George Street
Prof. S. R. Kulkarni
September 09, 2026
2:00pm - 3:00pm
SPHEREx, a recently launched astronomy mission, detected a bright 1.083 micron emission feature in the commissioning data. The PI group attributed this feature to the He I 1.0833 micron triplet line. In this seminar I review the physics and aeronomy of this well-known line of…
“Asteroseismology: from slow to fast rotators and from individual stars to populations”
AB107
Prof. Conny Aerts, KU Leuven, Belgium
May 20, 2026
11:00am - 12:00pm
Abstract: After a brief general introduction into the basic principles of asteroseismology, we consider the various restoring forces and the approximations adopted in the theory of stellar oscillations. We discuss the corresponding waves and frequency regimes encountered in modern space photometric light curves of various…
“Unravelling the Symphonies of the Stars with Asteroseismology”
Location: Isabel Bader Theatre, University of Toronto, 93 Charles St. W., Toronto, ON
Prof. Conny Aerts, KU Leuven, Belgium
May 19, 2026
7:00 - 8:30pm
Speaker: Professor Conny Aerts, KU Leuven, Belgium As Part of the Helen Sawyer Hogg Distinguished Visitorship Public Lecture Series Abstract: The life of the stars is determined by the physical processes happening deep inside these hot gaseous balls of fire. In this Helen Sawyer…
From Accretion to Architecture: Giant Planets Across Space and Time
Cody Hall, 50 St. George Street
April 29, 2026
2:00pm - 3:00pm
Planets exhibit extraordinary diversity in physical properties and orbital architectures, spanning more than four orders of magnitude in mass, separation, and age. Interpreting this landscape is challenging as observational biases and orbital migration obscure the pathways of planet formation and evolution across both space and…
What did ancient astronomers know? When and how did they acquire this knowledge? How did they understand the universe?
Cody Hall, 50 St. George Street
Laurie Rousseau-Nepton, University of Toronto
April 22, 2026
2:00pm - 3:00pm
Recently, I have studied the astronomical design of two medicine wheels (MW) stone circles, one in Alberta, known as the Majorville/Iniskim Umaapi site and the other in Wyoming, the Bighorn MW. Although their Astronomical purpose is still debated, I hope to shed some light into…
The First Billion Years, According to JWST
Cody Hall, 50 St. George Street, Room AB107
Prof. Seiji Fujimoto and Prof. Pratika Dayal, University of Toronto
April 08, 2026
2:00pm - 3:00pm
Abstract: The James Webb Space Telescope (JWST) has rapidly transformed our view of galaxy and black hole formation within the first billion years of cosmic history, revealing a population of surprisingly luminous, chemically evolved galaxies and abundant accreting black holes at very early times. These…
Lessons from the JWST for Star and Galaxy Formation in the Early Universe
Cody Hall, 50 St. George Street
Volker Bromm, Department of Astronomy, UT Austi
April 01, 2026
2:00pm - 3:00pm
The JWST has revolutionized our understanding of star and galaxy formation during the first billion years of cosmic history. Among the main surprises is the abundance of UV-bright, massive galaxies already at these early times. An even bigger puzzle is the presence of supermassive black…