Research story
Behind every star, there is more than one story: not only the story of its birth, but also the story of how astronomers have observed it. Thanks to high-performance instruments, astronomers can now study stars ever more closely and thus expand our knowledge of the universe.
Astrophysicist Laurie Rousseau-Nepton has begun to build a picture of the universe using the SITELLE imaging spectrometer mounted on the Canada-France-Hawaii telescope. Since 2023, she has been conducting research as an assistant professor at the University of Toronto’s
Dr. Rousseau-Nepton, how did you become interested in astronomy?
When I was young, I didn’t know that I could be an astronomer; it’s not a profession that you hear much about. But I think the first sign I had that I was going to be a researcher was that I was so curious. I asked the people around me a thousand and one questions about the environment and the sky.
The first branch of science that I got interested in was physics, which helps us to understand things that are infinitely small and things that are infinitely large. Then my curiosity made me want to understand the universe and all the mysteries it still holds, which led me to astronomy.
NSERC is proud to support you in exploring space and in particular in developing a new astronomical instrument. How is this new instrument different from SITELLE and what will it let you observe?
The instrument that we’re planning to build in my laboratory at the University of Toronto is a Fourier transform imaging spectrometer, like SITELLE and SpIOMM, another instrument used at the Mont-Mégantic observatory. Imaging spectrometers are used to analyze the composition of objects in detail.
This new instrument will incorporate highly advanced technologies: very specialized cameras and microwave kinetic inductance detectors (MKIDs), which are a kind of quantum detector. MKIDs have the unique ability to detect every particle of light one by one over time in a very precise way. When MKIDs are incorporated into an imaging spectrometer, they multiply its capabilities by a factor of 10, thus letting us make very precise observations across a broad spectrum of light, from the ultraviolet to the near infrared.
This new instrument will let us make more precise observations of objects and structures in the universe that are hard to detect and do so at very high resolution, which opens opportunities for myriad scientific studies that require very high precision.
You’re the director of the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey (SIGNALS), an ambitious international program whose objective is to observe the formation of stars in 40 different galaxies. What are your hopes for the data that you’re collecting in this program?
The mission of SIGNALS is to provide future generations with a unique database for studying the formation of stars. We’re collecting data on over 50,000 star-forming regions in the near universe, where the objects are close enough for us to observe them in detail.
When you use an imaging spectrometer, you get a continuous spectrum across the entire surface of the object that you’re observing, which lets you perform a much more extensive analysis than you otherwise could. The data that we’re collecting in the SIGNALS program are letting us produce a big catalogue of all the star-forming regions and their characteristics, such as the chemical composition of the environment and the local conditions in the galaxy that led to the birth of its stars. SIGNALS will let us push research on star formation even further.
You devote special care to training the next generation of researchers. Why is that so important? Do you have any advice for young people who are interested in careers in astronomy?
Being an astronomer is the best job in the world! Of course, that’s my personal opinion, but I’m convinced that there are lots of young people who share my passion. I think it’s very important to pass my passion along to the younger generation, because I want them to be able to live the same dream as I have: pursuing the career of their choice and studying the things that fascinate them.
I’m not going to discover everything there is to know about how stars form. Many generations of researchers will have to come after me to continue that work. So I find it very motivating to participate in training future astronomers and helping them to do the best job in the world.
In addition to your research activities, you do a lot to communicate about science to general audiences. NSERC is pleased to support your science-promotion activities with a PromoScience grant. What does your PromoScience project involve?
The goal of the Discover the Universe program is to train teachers to teach astronomy and give them the tools they need to do so. This program offers a wealth of educational resources. It also has an Indigenous astronomy component: the Astronomy for a Better World program, in which we work in partnership with Indigenous communities throughout Canada that want support for teaching astronomy in their schools on the basis of their ancestral knowledge. This program also helps astronomers to create varied, interesting content in multiple languages, including Indigenous ones.
We’re also trying to expand the teaching program to include concepts related to astronomy, such as light pollution, climate issues and settings in which astronomy can be helpful.
Do your Indigenous roots influence the way that you communicate about science to non-scientists?
In my community, we use stories to transmit knowledge. There’s an incredible beauty and an incredible esthetic in our oral tradition: our stories are both poetic and very well structured, which makes them easy to remember. This system for passing along knowledge has been built up over many generations and continued for millennia, which proves how effective it is. It also incorporates concepts from a variety of disciplines, so that you can learn about astronomy by drawing connections with the environment, history and long voyages, for example.
I use some elements of the oral tradition when I talk about my research. I think it’s very important to tell these stories, so that people get a complete view of what scientific work is. Research leads to results, but we should remember that there is always a story behind them, and that this story often began several generations before us. I am proud of the legacy that my community has contributed to astronomy, and I want it to be recognized.
I think that when we scientists present our discoveries in the form of stories, people feel much closer to us. Science is done by human beings, for human beings, and telling stories lets us remind people of that.
Do you have a favourite story about your own research?
Well, you feel a certain pride when you collect the first data with an instrument that you’ve been working on for years. I’m thinking about the first time that we mounted SITELLE on the Canada-France-Hawaii telescope and used it to observe a planetary nebula. The whole team was there. We had worked so hard without knowing until the last minute whether it was all going to work. You feel proud when you see an image from the telescope appear on your computer screen and you know that for many years, maybe even for decades, researchers all over the world will be able to use this technology.
It’s the pride of having not only discovered something, but also increased the opportunities to discover more. We have successfully designed a unique instrument that lets us see the universe differently.
This interview has been edited for conciseness and clarity.
About Laurie Rousseau-Nepton
After earning her doctorate in astrophysics at Université Laval, Laurie Rousseau-Nepton spent over six years in Hawaii studying the birth of stars with the Canada-France-Hawaii telescope and the SITELLE imaging spectrometer, which she helped to develop. In 2023, she joined the University of Toronto’s