I am an Associate Professor at the University of Toronto. I develop numerical methods to solve problems in astrophysics. I have developed many numerical integrators and the N-body code REBOUND. I am also the developer of several iOS outreach apps such as Exoplanet and Comet Neowise, and most recently Mega Constellations. Learn more about the upcoming Solar Eclipse on Aptil 8th 2024.

I currently work at the University of Toronto at Scarborough where I am a member of the Department for Physical and Environmental Sciences. My graduate appointments are at the Department of Astronomy and Astrophysics and the Department of Physics. If you want to know where Hanno Rein is, check out this handy plot (updated daily)!

I'm very interested in numerical methods, in particular N-body codes and integration methods for planetary systems. Other research interests include planet formation, stochastic processes, planet migration, celestial mechanics, and Saturn's rings. I like to explore the posibility of using novel high performance computing platforms for astrophysics.

Make sure to check out my REBOUND code. It is an open source N-body code which gives you access to the world's fastest and most accurate numerical integrators. You can do almost anything with it from long-term symplectic orbit integrations to collisional shearing-sheet simulations of Saturn's rings. The installation takes literally 30 seconds and it comes with an easy to use python interface. It's really cool and I'm very proud of it.

You also don't want to miss the Exoplanet App. It is a free smartphone application for the iPhone/iPad that I wrote. It let's you explore almost the entire universe, including the cosmic microwave background, galaxy clusters, our Milky Way, the Solar System and all discovered extra-solar planets. Several million people have already downloaded it!

If you like cycling, have you considered cycling to UTSC? It's really fun!

Looking for an old version of this website? Check out these somewhat old, moderately old, and very old backups.

Research Group


Current graduate students

Current undergraduate students

  • Ruth Huang
  • Pranav Mundhra

Past undergraduate and graduate students

Caden Armstrong, Bryce Bolin, Jade Checlair, Alice Chen, Chin Chen, Sunny Chen, Ian Chow, Eric Dapp, Emily Eckels, Taylor Esch, Michael Fairbrother, Patrick Fraser, Samin Bahojb Ghalibafan, Theodora Girgis, Eren Gunes, Prateek Gupta, Ethan Hargrove, Emma Holmes, Fergus Horrobin, Pejvak Javaheri, Vikeeta Jhagru, Hemani Kalucha, Mei Kanda, Michelle Lau, Shang-Fei Liu, Brody McManus, Farasha Meem, Srivathsan Morkonda, Ekin Ozturk, Feiyu Quan (全飞宇), Aleksandar Rachkov, Chandler Ross, Jasmeer Sangha, Vismay Shah, Pengshuai Shi, Ari Silburt, Natasha Urbancic, Trevor Vincent, Quentin Xue, Eric Yeung.


Past and present collaborators in alphabetical order:

Eugene Chiang, Miles Cranmer, Eric Ford, Yuka Fujii, David Hernandez, Willy Kley, Eiichiro Kokubo, Marc Kuchner, Henrik Latter, Zoe Leinhardt, Geoffroy Lesur, Shang-Fei Liu, Wladimir Lyra, Leonidas Moustakas, Gordon Ogilvie, Margaret Pan, John Papaloizou, David Spiegel, Dan Tamayo, Scott Tremaine, Dimitri Veras.

Interested in working with me?

Graduate students

I am currently looking for one or two new graduate students. If you are interested in working with me, please get in touch. I'm afraid, I don't have a list of ten amazing thesis projects which you can pick and choose from. I've found that item on such a list are often either really boring, or so interesting that I've already done them myself. So instead, I'd like you to have a rough idea of the topic that interests you most (Supernovas, Earth-like planets, FPGAs, etc). Then we can meet and come up with a well defined thesis project that combines your interests with my expertise and an open scientific question in astrophysics. At the end of the day, it's your PhD and you can do whatever you want! I'm just your advisor, sharing my own knowledge, directing you towards interesting problems, helping you avoid common mistakes, and making sure you get the most out of your PhD.

Undergraduate students

If you're an undergraduate student looking for a project in astrophysics, I might be able to supervise you. Since everything I do is computational, it would be great if you have some basic python knowledge to help get you started. I do not have a list of projects for you to choose from. Think about what interests you most. Then find some recent news articles or scientific papers in that area. We can then sit together and brainstorm about a project for you.

Reference letters

If you need a reference letter for a graduate school application or some other purpose, get in touch early, at least 4 weeks before the deadline. Writing letters takes a lot of time and I simply won't be able to write you one on short notice. When contacting me, please include your CV, a transcript, and what you are applying to.

UTSC Observatory

For several years, I have been in charge of the Astronomical Observatory at the University of Toronto Scarborough. Unfortunately, the observatory is currently not operational due to ongoing construction work related to a new animal testing lab.

Curriculum vitae

Associate Professor
2018 - now, University of Toronto, Canada
2017 - 2020, Centre for Planetary Sciences, University of Toronto
Assistant Professor
2013 - 2018, University of Toronto, Canada
Member at the Institute for Advanced Study
2010 - 2013, Institute for Advanced Study, Princeton, US
PhD, Doctor of Philosophy
2007 - 2010, University of Cambridge, DAMTP, England
Thesis: The effects of stochastic forces on the evolution of planetary systems and Saturn's rings
Supervisor: Professor John C. B. Papaloizou
MASt, Master of Advanced Study, Part III of the Mathemtical Tripos
2006 - 2007, University of Cambridge, DAMTP, England
With distinction
Exams: General Relativity, String Theory, Quantum Field Theory, Advanced Quantum Field Theory, Black Holes
Essay: Finite time singularities (with Stephen J. Cowley)
Undegratuate studies in both Mathematics and Physics
2003 - 2006, University of Tuebingen, Germany

Click here to download my full CV in pdf format


NSERC Discovery Grant (2020-2026)
Funded by: The Natural Sciences and Engineering Research Council of Canada
The Solar Walk at UTSC (2017)
Funded by: The UTSC Canada 150th Fund
UTSC Observatory grant (2015)
Funded by: The UTSC 50th Anniversary Fund
Connaught New Researcher Award (2014)
Funded by: The Connaught Fund
NSERC Discovery Grant (2014-2020)
Funded by: The Natural Sciences and Engineering Research Council of Canada
Exoplanet Smartphone App (2012)
Funded by: The Royal Astronomical Society, London
Principal investigator: Hanno Rein
Propellers, Frogs, and Random Walks (2012)
Funded by: NASA, ROSES-11, Outer Planets Research Program
Principal investigator: Eugene Chiang
Collaborators: Hanno Rein, Matthew Tiscareno, Margaret Pan