April – May – June

If a single theme defined this quarter, it was community. At the end of May, we proudly celebrated CITA’s 40th anniversary, bringing together over 160 participants in person and hundreds more online from across the globe. The three-day conference presented forward-looking astrophysics research but, just as much, it felt like a family homecoming. We reflected on our founding ethos of collaboration and mutual support and celebrated the fact that many of the world’s leading tenured astrophysicists are CITA alumni. It is incredibly rewarding to see how our collaborative, theoretical approach continues to shape the astrophysics field worldwide.

We are immensely grateful to everyone who has made CITA the remarkable institution it is today. Here’s to the mysteries we’ve solved, the community we’ve built, and the next 40 years of theoretical astrophysics.

CITA@40: Celebrating 40 Years of Theoretical Astrophysics

05/27/2026: The Canadian Institute for Theoretical Astrophysics (CITA) marked its 40th anniversary at the University of Toronto at the end of May, bringing together astrophysicists from around the world for a three-day conference celebrating four decades of research, training and collaboration. More than 160 participants attended in person, with hundreds more joining online. The conference featured 87 speakers from 15 countries — including many former CITA postdoctoral fellows and graduate students who returned to share new research and reconnect with colleagues. A recurring theme throughout the celebratory event was the importance of academic community — with many attendees describing CITA as both a research hub and a formative “home” during their early academic careers. Words like “family” and “homecoming” were scattered through narratives of youthful times, full of enthusiasm for science and fun with friends. CITA Director Shantanu Basu opened the conference by welcoming participants and reflecting on the institute’s history. He noted that this meeting “brings together the three pillars of CITA: members of the CITA flagship in Toronto, the national network of affiliate faculty, and the global network of CITA alumni.”

U of T President Melanie Woodin highlighted CITA’s global reputation and paid tribute to the leadership of its founders, Professors Richard Henriksen and Peter Martin, as well as its first directors, Scott Tremaine and Dick Bond.

Today, a significant percentage of the world’s leading tenured astrophysicists (more than 130) are CITA alumni, who have passed through the institute during their formative postdoctoral years. They carry CITA’s highly collaborative, theoretical approach to universities across the globe.

Back in Toronto for the CITA@40 conference, former postdoctoral fellows were happy to reunite with old friends and reminisce about the good times they had together. Testimonies were shared by CITA alumni both in person and through individual video recordings:

Bernard Carr, Emeritus Professor of Mathematics and Astronomy at Queen Mary University of London, reflected in his video message on the first Kingston meeting he attended in 1986. His reminiscences of CITA highlighted both the lasting friendships he formed and his proud scientific collaboration with Dick Bond. He reflected on both the happy and the sad times he experienced at CITA, and reminded us to “remember those who played such an important role in CITA’s scientific achievements.” 

Doug Johnstone, current President’s Science Advisor and PREAC Secretary at the National Research Council of Canada, (CITA postdoc in 1995) also shared in a video greeting: “The support of the CITA family was crucial for my decision to stay in the field. CITA was a fantastic place for us, and I hope it still is for the current CITA postdocs. While at CITA, I got to know Shantanu Basu very well. We built our own research niche that began with a star formation conference. We did a second version of it last year. It has been a joy to work with Shantanu ever since the 90s.”

John Lattanzio and Mike Fitchett – the first two CITA postdoctoral fellows who joined in 1985– also sent a very long video greeting with highlights from the dawn of times, when “everyone did extra jobs”, “everyone dressed very formally”, and Peter Martin was an Acting Director, but “he did more acting than directing, and we all loved him!”. “We did a lot of science and had great fun together”, said John and Mike, and recommended the same approach to postdocs for years to come – “Have fun and do good science!”

Andrew Jaffe, professor at Imperial College, shared in his video message that “CITA was, and still is, a great place for postdocs to become independent researchers.” Reflecting on his scientific career, he spoke about his work analyzing CMB data and added “understanding Dick’s work over the years has been an honor and a pleasure of my scientific career”.

Zhiqi Huang, Professor in Sun Yat-sen University expressed his gratitude to all CITAzens, with special thanks to his mentors Dick Bond and Lev Kofman, “Their passion and curiosity have kept me on a life-long journey of discovery”.

Henk Hoekstra, professor in Leiden University, and his wife Melanie, a former CITA staff member, visited CITA shortly before the event. In their video message, they shared that “so many memories came back”, reflecting “great time at CITA back 25 years ago”.

Margaret Fukunaga, CITA’s founding staff member, reflected in her letter to CITAzens that her role was to “assure the faculty members who were serving as director that the administrative machine was strong and could keep on carrying CITA.” She expressed her gratitude to the faculty members for their trust in the business officers and in her successors. Along with recalling many memorable and enjoyable moments at CITA, Margaret highlighted what she considered her greatest accomplishment: “to see a postdoc return to CITA as the Interim Director”.

A heartfelt thank you to all the alumni who traveled from near and far to join us for CITA@40! Hearing your stories from the institute’s early days and watching old friends and former colleagues reunite was a moving testament to the community we have built together over the last four decades. We are incredibly grateful for your warm notes of congratulations and for remaining such an integral part of the CITA family.

For those who were unable to attend the conference and/or banquet, we invite you to revisit the celebration through the photos captured during the event. You can also enjoy a video from CITAzens around the world who were unable to join us in person.

Research and Publication Highlights

4/1/2026: New Study Finds Evidence of Cosmic Explosions with Missing Black Holes

In a paper just published in Nature, CITA researchers Professor Maya Fishbach and postdoctoral fellows Aditya Vijaykumar and Amanda Farah, confirm that black holes with masses larger than 45 times the mass of the sun are the result of previous black hole mergers, rather than the collapse of enormous dying stars.

4/16/2026: How a Cosmic Cloud Becomes a Solar System: Scientists Discover the “EnDTranZ” Missing Link

An international team of researchers—including CITA’s Interim Director, Shantanu Basu—has just published groundbreaking findings in the Astrophysical Journal that solve a decades-old mystery in star formation. We’ve long known that planets form in flat, spinning disks of gas and dust around young stars. But exactly how the material falling from the massive outer cloud “hits the brakes” and organizes into a stable, spinning disk has been a major puzzle. Led by Dr. Indrani Das at the Academia Sinica Institute of Astronomy and Astrophysics, the team discovered the missing link: EnDTranZ  (Envelope Disk Transition Zone).

6/3/2026: Supercomputer Reveals How Exploding Stars “Stir” the Galaxy from the Bottom Up

New research performed on the Trillium/SciNet Supercomputer at the University of Toronto reveals a fundamentally different mechanism by which exploding stars shape the turbulent structure of our galaxy. The study, authored by Dr. James Beattie, postdoctoral fellow at CITA, was accepted for publication in The Astrophysical Journal Letters. It challenges long-standing assumptions about how turbulence is generated and sustained in the interstellar medium.

6/26/2026: Detached but Not Alone

Microlensing surveys have discovered plenty of regular exoplanets, but more surprisingly, they’ve also turned up many solo Neptunes with no star nearby. That there are more free-ranging Neptunes than stars is unsettling, and astronomers aren’t sure how so many planets ended up isolated. New research by Sam Hadden (CITA) and Yanqin Wu (University of Toronto) presents an alternative idea: what if at least some of these free-floating planets aren’t fully on their own, but remain weakly bound to their parent stars? The paper “Free Floating or Merely Detached?,” by Sam Hadden and Yanqin Wu was recently featured by AAS Nova: 2026 ApJ . doi:10.3847/1538-4357/ae6508.

Events and Workshops

4/17/2026: In mid-April CITA welcomed Voyager – a group of 32 undergraduate students, all majoring in astronomy at the University of Groningen in the Netherlands. The visitors travelled across the ocean to meet with CITA researchers and learn about current projects at the institute. Designated hosts were CITA Graduate student Alicia Savelli and Postdoctoral Fellows Vera Delfavero, Sebastiano D. von Fellenberg and Biprateep Dey.

5/4/2026: Welcoming the new cohort of SURFers (Summer Undergraduate Student Fellows) at the Canadian Institute for Theoretical Astrophysics today. Supervisors and students are excited to meet and start planning their research collaborations. Summer is starting!
Supervisors this year are Shantanu Basu, Pratika Dayal, Rohan Dahale, Radhika Achikanath Chirakkara, Haowen Zhang, Sebastiano D. von Fellenberg, Yanlong Shi.

Director Shantanu Basu greeting the 2026 SURF cohort.

Aditya Vijaykumar and Amanda Farah, CITA Postdoctoral Fellows and organisers of GWTC-6.

4/20/2026: 35 of the world’s leading experts in gravitational astronomy gathered at the CITA Flagship in Toronto for the GWTC-6: The Bleeding Edge of Gravitational-Wave Populations – a three-day workshop that took place between April 20 and 22. Researchers from Europe, Australia, UK, US, and Canada have been diving deep into recently released data sets, providing real-time feedback on preliminary results, and charting out new pathways to align theoretical models with observations. A huge thank you to the driving forces behind this event, our organizers: Amanda Farah and Aditya Vijaykumar are the main organizers of the ‘GWTC-6: The Bleeding Edge of Gravitational-wave Populations’, along with faculty members Maya Fishbach and Reed Essick.

Other CITA Supported Conferences in Q2:

June 4-5, 2026: Statstro 2026: Sampling, Simulation, and Scientific Discovery, University of Toronto. Organizers: Reed Essick, Maya Fishbach, Josh Speagle.

June 19-20, 2026: Theory Canada 18, McGill University. Organizers: Simon Caron-Huot, Robert Brandenberger, Manu Paranjape.

June 29 – July 3, 2026: Supermassive Black Holes and Blue Notes 2026, Université de Montréal. Organizers: Julie Hlavacek-Larrondo, Martin Bureau, Daryl Haggard.

Distinctions and Awards

4/28/2026: Congratulations to CITA Inc member Professor Arif Babul, University of Victoria, who was recently recognized by CASCA as the 2026 recipient of the Carlyle S. Beals Award for outstanding scientific achievement. Professor Babul is a world-renowned leader in physical cosmology, known for his work on the assembly, evolution, and physics of galaxy groups and clusters. Throughout his career, Professor Babul has contributed to several ground-breaking discoveries which have reshaped the field of cosmology, including being one of the first to recognize that radiation from early stars and quasars could significantly influence the evolution of cosmic structures.

4/28/2026: Congratulations to CITA Inc member Professor Michel (Mike) Fich, who was announced by CASCA as the recipient of the 2026 Dunlap Award for Innovation in Astronomical Research Tools. This award recognizes his sustained and visionary leadership in developing and ensuring Canadian participation in groundbreaking infrared and mm-scale astronomical instrumentation.

6/26/2026: Congratulations to CITA graduate student Utkarsh Mali and a Junior Fellow at Massey College for receiving this year’s Van Kranendonk Teaching Assistant Award from the Department of Physics at the University of Toronto. The award reflects not only strong subject expertise, but also the ability to inspire, support, and elevate the student learning experience, an impact that often extends far beyond the classroom.