Dunlap Institute for Astronomy &amp; Astrophysics

Indigenous Initiatives

Truth and Reconciliation

Subheadline

The groundwork is currently being laid for a coding club and mentoring programs, among other initiatives

A group of astronomers from the ��߲ݴ�ý and students, teachers and caregivers from Toronto’s Kâpapâmahchakwêw – Wandering Spirit School recently shared a once-in-a-lifetime experience: witnessing a total solar eclipse.

The April 8 gathering, which took place in Chiefswood Park on Six Nations of the Grand River, saw the astronomers bring telescopes with solar filters that allowed viewers to observe sunspots and watch as the moon slowly eclipsed the sun. The event also served as a forum for young learners and community members to share traditional knowledge and ask plenty of questions.

It was one of many engagements planned as part of a partnership between U of T’s Dunlap Institute for Astronomy & Astrophysics and the Kâpapâmahchakwêw – Wandering Spirit School, which was founded in 1977 and gives students from kindergarten to Grade 12 the opportunity to learn about Anishinaabe cultural traditions.

Totality at Chiefswood Park (photo by Kara Manovich)

In the future, there are also plans for a coding club, mentoring and tutoring programs, and training for teachers.

“Kâpapâmahchakwêw – Wandering Spirit School is grateful for the growing partnership with Dunlap because it provides an opportunity to practise reciprocity in knowledge sharing,” said Elise Twyford, the school’s principal. “The students and community learned about – and experienced – astrophysics and astronomy, and also had the opportunity to build their skills in sharing traditional knowledge and world views.

“I appreciate the care and thoughtfulness of the Dunlap and ��߲ݴ�ý team in collaborating with Kâpapâmahchakwêw students as partners in learning.”

The roots of the partnership stretch back to 2022 when Emma Stromberg, Indigenous partnership adviser at the Faculty of Arts & Science, and Associate Professor Susan Hill, director of the Centre for Indigenous Studies, approached Dunlap with an opportunity to work with teachers and students from Kâpapâmahchakwêw.

A close-up photo of the moon totally eclipsing the sun on April 8 above Chiefswood Park (photo by Suresh Sivanandam)

“We wanted to see if we could match up the needs and interests of the school to resources at U of T, to build something that can be sustained,” Stromberg says. “Consistent with U of T’s commitments to reconciliation, it is incumbent on all of us to think of ways to redress, in small and big ways, the impacts of settler colonialism and push resources into the community wherever possible.”

Some 20 members of the Dunlap community have since volunteered to help, with many of them recently participating in a workshop with John Croutch from the Office of Indigenous Initiatives to learn about the continued impacts of settler colonialism and what it means to be an ally to Indigenous Peoples.

The U of T astronomers said the opportunity to share a total solar eclipse was a memorable moment for everyone involved.

“You could hear lots of kids screaming in excitement and people gasping in awe at seeing totality,” said Associate Professor Suresh Sivanandam, interim director of the Dunlap Institute for Astronomy & Astrophysics in the Faculty of Arts & Science. “When I walked out of there, I thought, ‘These are the moments in my job where I feel completely fulfilled because I helped other people experience the joy of astronomy.’”

Students recreate the total solar eclipse with paint and pastels on black paper (photo by Emma Stromberg)

Professor Roberto Abraham, chair of the faculty’s David A. Dunlap department of astronomy and astrophysics, said he was the same age as some of the students when he first saw a total solar eclipse.

“It was magic,” he said. “Once you see a total solar eclipse, you won’t be the same person afterwards.”

Earlier this year, Sivanandam and Abraham visited the school to meet students, teachers and staff and hear about how astronomers at U of T can best support them.

For Twyford, the relationship with U of T immerses Kâpapâmahchakwêw students in the fields of astronomy and astrophysics in ways that wouldn’t be possible in the classroom.

“I know that many students now see the wonder and possibility of these sciences and are even more motivated to continue their learning,” Twyford said. “It also helps to complement the traditional and cultural.”

In photos: Under cloudy skies, U of T community gathers to experience near-total solar eclipse

Christopher.Sorensen — Tue, 09 Apr 2024 14:22:01 +0000

In photos: Under cloudy skies, U of T community gathers to experience near-total solar eclipse

Christopher.Sorensen Tue, 04/09/2024 - 10:22

Cutline

The April 8 solar eclipse in the skies over U of T Mississauga, where the clouds parted just in time to give watch party attendees a thrilling spectacle (photo by Nick Iwanyshyn)

Topic

Skies darkened and temperatures dropped as the solar eclipse swept across the ��߲ݴ�ý’s three campuses Monday, bringing community members together to marvel at the celestial spectacle.

Hundreds of community members gathered outside and donned safety glasses to gaze skyward in hopes of witnessing the eclipse from the three campuses, which were adjacent to the path of totality. Others tuned into a livestream hosted by U of T’s Dunlap Institute for Astronomy & Astrophysics.

While gathering clouds obscured the sun around Greater Toronto, the skies cleared just in time to give a lucky few a clear view of the rare astronomical alignment – including those who gathered for a free viewing party at U of T Mississauga.

Here’s how the day unfolded through the lenses of photographers at the university:

(photo by Matthew Volpe)

On U of T’s St. George campus, hundreds pulled out their phones to capture the CN Tower as the city lights pierced through a blackened mid-day sky.

(photo by Nick Iwanyshyn)

Clouds gave way to clear skies at just the right moment for hundreds of people gathered at U of T Mississauga to witness the solar eclipse.

(photo by Nick Iwanyshyn)

While Mississauga was not in the path of totality, the near-total eclipse turned the sky slate grey and deep blue, while a chill in the air cooled the warm spring day.

(photo by Dan Weaver)

At U of T Scarborough, community members convened outside the Science Wing as overcast skies loomed over the Ma Moosh Ka Win Trail.

(photo by Nick Iwanyshyn)

A station set up by Vera Velasco, a U of T Mississauga plant physiologist at Growth Facilities research greenhouse and growth chambers, walked attendees at the viewing party through an experiment tracking how the eclipse impacts photosynthesis. As the eclipse occurred, Velasco and fellow researchers also showed its colours using a spectrometer.

(photo by Nick Iwanyshyn)

Astronomer Marta Bryan, an assistant professor in U of T Mississauga’s department of chemical and physical sciences, spoke to the crowd about the science behind the solar eclipse, complete with a demonstration from some of the younger audience members playing sun, moon and Earth.

(photo by Nick Iwanyshyn)

While it's possible to see a total solar eclipse from somewhere on Earth every few years, it will be another 120 years before viewers in southern Ontario are treated to an eclipse as total as the one on April 8. "It's truly a once-in-a-lifetime event for all of us," Bryan says.

Read a Q&A with astrophysicist Laurie Rousseau-Nepton about Indigenous perspectives on the eclipse

Total solar eclipse is a cosmic marvel to be shared with loved ones – in keeping with Indigenous teachings

Christopher.Sorensen — Fri, 05 Apr 2024 20:27:49 +0000

Total solar eclipse is a cosmic marvel to be shared with loved ones – in keeping with Indigenous teachings

Christopher.Sorensen Fri, 04/05/2024 - 16:27

Cutline

Laurie Rousseau-Nepton, an assistant professor in U of T’s David A. Dunlap department of astronomy and astrophysics and the Dunlap Institute for Astronomy & Astrophysics, says she’s planning to experience the eclipse alongside a sea of spectators at Montreal’s Parc Jean-Drapeau (supplied image)

Adina Bresge

Topic

Eclipse

Subheadline

"It will probably take 100 years before we get to see another one,” says astrophysicist Laurie Rousseau-Nepton of U of T’s Dunlap Institute"

��߲ݴ�ý astrophysicist Laurie Rousseau-Nepton is brimming with anticipation for her first total solar eclipse.

As eager as she is to witness the celestial spectacle on Monday, Rousseau-Nepton says she’s equally as excited to share in the communal awe of people coming together to marvel at the cosmos.

An assistant professor in the Faculty of Arts & Science’s David A. Dunlap department of astronomy and astrophysics and Dunlap Institute for Astronomy & Astrophysics, Rousseau-Nepton says she’s planning to experience the eclipse alongside a sea of spectators at Montreal’s Parc Jean-Drapeau.

“We’re all going to be there experiencing this – most of us for the first time, and maybe for the only time in our lives,” she says. “It will be so special not only for me, but for everybody that will be there.”

Rousseau-Nepton recently spoke to U of T News about this rare astronomical alignment, the scientific opportunities it presents and Indigenous knowledge about eclipses.

What makes this eclipse special?

The upcoming eclipse on April 8th is a total solar eclipse that will be visible in the south part of the country close to major city centres. That means a lot of people will be able to see a total solar eclipse, which is extremely rare. It will probably take 100 years before we get to see another one.

We are very lucky on Earth. Our moon is just about the right size and distance to create this beautiful little display. When the moon is positioned between us and the sun, it will block out the light – and for a few minutes, it will be completely dark. We’ll see things that we never see normally: stars during the day, some planets as well, and the sun’s corona.

This eclipse is also happening close to the maximum of the sun cycle. The sun has a magnetic cycle that lasts about 11 years, and the maximum is expected to be in 2025. That means there’s going to be more sunspots, more solar eruption and people who are able to see auroras in the North will get to see some beautiful displays.

If we’re really lucky and there’s a solar eruption at the same time, we’ll be able to see features of the sun beyond the corona. It’s a little bit like winning the lottery. It might not happen, but it is possible.

What are some of the scientific opportunities this eclipse presents?

During totality, the moon will block the sunlight completely – you’ll still be able to see the moon, but it’ll look slightly different.

The light that will be visible on the surface of the moon is actually the light that first bounces on the Earth’s atmosphere, then goes back onto the moon and back to us. So that light is ultimately light from the Earth’s atmosphere glow. That’s something we can study by pointing instruments at the moon in that moment to get a glimpse of the Earth’s glow and measure it.

What does Indigenous Knowledge tell us about eclipses?

In the Innu community, we have this hero called Tshakapesh – he is known as the man on the moon. After a long life full of adventures, he ended up on the moon and that’s where he is now, looking at us. In one story, Tshakapesh was hunting and trapping when he felt like something was following him. He wanted to trap it, so he put a snare where the snow had melted on a very defined path. And the next morning, the sun got trapped into it. That story is closely related to a lunar eclipse of the sun, when the moon is slightly farther away from us, so we see a line of light around the sun during totality. That line of light represents the snare that Tshakapesh used to capture the sun. The story also involves animals that release the sun – and during the eclipse, we can see some constellations and stars that represent the spirits of those animals.

Across Canada, in many Indigenous stories the eclipse is often a sign of peace. For the Haudenosaunee, the Great Law of Peace was signed by the Six Nations during a total solar eclipse nearly 1,000 years ago. The eclipse is also related to Grandmother Moon, the Skywoman that came down to Turtle Island. During the eclipse, Grandmother Moon meets with someone from her family, so it’s a special moment that they get to see each other for a few hours before leaving again for a long time. It’s seen as a great time for reunion, peace and spending time with your family.

What are your tips for viewing the eclipse?

First, we want to protect our eyes and the best way to do that is with solar eclipse glasses – and you want to be careful with which ones you buy to make sure they’re certified.

If you want to take photos of eclipse, you might be able to get good images during the moment of totality because the lack of sunlight will create a lot of contrast. But during the partial eclipse, the intense sunlight can cause significant glare that will make it hard to see all the details. A good trick is to put those solar eclipse glasses in front of the lens of your camera, which will dampen the amount of sunlight coming in so you can better capture the eclipse.

As for location, it might be nice to have some elevation because the eclipse generates a shadow that you can see from up high. If you really want to see the total eclipse, I would suggest to be mobile in a car, or any way you can move to another place if a cloud comes by. But ultimately, I would say the most important thing is to experience the eclipse with people you love. So, wherever you are, it’s fine.

Watch a video about Indigenous perspectives on the eclipse

Register for the Dunlap Institute’s eclipse livestream

'A black box in astronomy knowledge': PhD researcher probes the earliest stars in the universe

Christopher.Sorensen — Tue, 26 Mar 2024 18:20:25 +0000

'A black box in astronomy knowledge': PhD researcher probes the earliest stars in the universe

Christopher.Sorensen Tue, 03/26/2024 - 14:20

Cutline

PhD researcher Margaret Ikape presents at the Astronomy on Tap T.O. event (photo by Alicia Richardson)

Michael Pereira

Topic

Graduate Students

Subheadline

Margaret Ikape is working to determine the properties of the first stars and how they influenced everything that followed

As a child, Margaret Ikape had a prime view of the stars from her hometown of Lagos, Nigeria.

“When I was really young, I saw a shooting star. And that got me looking up at the night sky a lot more,” Ikape says. She recalls thinking: “Can I count all the stars? Can I really go to a star? What would it be like if I could really go to a star? How long would it take?”

Today, Ikape is still looking at stars with the same curiosity, albeit ones that are much farther away. A PhD researcher at the ��߲ݴ�ý’s Dunlap Institute for Astronomy & Astrophysics and David A. Dunlap Department of Astronomy & Astrophysics, she’s working to tell the story of the first stars in the universe, and how they influenced everything that followed.

Theory predicts that ultraviolet light from the first stars was so powerful that it ionized — or split — some of the first hydrogen atoms back into protons and electrons. This period of cosmic history is known as the Epoch of Reionization (EoR). During this time, the first stars and galaxies began to form, and with them, the universe as we know it today.

Ikape is working to determine the properties of these first stars, like how big they were and how long the reionization took. “That period is like a black box in astronomy knowledge. We know it happened, because the universe is ionized today, but we don’t know many details about it,” Ikape says.

A representation of the evolution of the universe over 13.77 billion years (image by NASA / WMAP Science Team)

Current optical telescopes cannot see back far enough to capture the EoR, so Ikape uses thousands of computer simulations to reimagine it and test theories in a kind of virtual sandbox shaped by what we know of the universe. Some of these simulations require significant processing power and must be run through the “Helen” computing cluster, named after renowned Canadian astronomer Helen Sawyer Hogg.

Ikape also learns about the EoR by studying the first light emitted in the universe, the Cosmic Microwave Background (CMB). As light from the CMB travels to Earth, it passes through all that is between us and the point in cosmic history at which the CMB was emitted, approximately 380,000 years after the Big Bang. Ikape can isolate how light from the CMB was impacted by the EoR and analyze it to tell us more about this time.

“Margaret’s work connects models and simulations of how the first stars in the universe lit up and ionized the surrounding gas with our observations of the cosmic microwave light—so she is the detective piecing the story together,” says Associate Professor Renée Hložek, Ikape’s PhD supervisor.

Ikape has forecasted that a new generation of telescopes will unlock more details about this mysterious period and the universe’s first stars, including the Simons Observatory and the fourth-generation ground-based cosmic microwave background experiment, or CMB-S4. She co-authored research that predicts that the CMB-S4 will help scientists close in on when the EoR began and how long it lasted.

A nine-year Wilkinson Microwave Anisotropy Probe (WMAP) heat map of temperature fluctuations in the CMB (photo by NASA/WMAP)

When she isn’t unpacking the mysteries of distant stars, Ikape is involved in outreach initiatives on the ground.

She’s an instructor with the Pan-African School for Emerging Astronomers, a bi-annual school for emerging astronomers in Africa that aims to introduce astronomy undergraduate students to research practices and career avenues in the field, and participated in its inaugural program in Zambia in 2022.

In Toronto, Ikape was recently a speaker at Astronomy on Tap and has given presentations on astronomy at libraries, high schools and even a long-term care home.

“We are lucky to have students like Margaret at the Dunlap Institute; she combines her scientific curiosity with a passion for sharing what she learns with the broader community and training the next generation of bright minds,” Hložek says.

“The universe fascinates me a lot and I’m super excited every time I think about it," Ikape says. "So I think that everybody should know about it.”

U of T researcher seeks out new insights on the universe's oldest galaxies

Christopher.Sorensen — Thu, 08 Feb 2024 19:27:46 +0000

U of T researcher seeks out new insights on the universe's oldest galaxies

Christopher.Sorensen Thu, 02/08/2024 - 14:27

Cutline

Jacqueline Antwi-Danso, a postdoctoral researcher with the David A. Dunlap department of astronomy and astrophysics, is studying massive galaxies that formed “when the universe was still just a baby” (supplied image)

Chris Sasaki

Topic

Black

Statistical Sciences

Subheadline

"We're trying to understand why these galaxies formed the way they did and how they became so big so quickly"

Jacqueline Antwi-Danso remembers a book from her junior high school library describing how stars are born and how the most massive stars die in gigantic explosions called supernovae.

“The book explained that there were objects out in space that gave off so much energy we could see and study them and make precise observations of their physical properties,” says Antwi-Danso, who credits her parents for nurturing her interest in education and reading while growing up in Ghana. “That just blew my mind.”

Today, Antwi-Danso is an NSERC Banting postdoctoral fellow at the ��߲ݴ�ý’s David A. Dunlap department of astronomy and astrophysics in the Faculty of Arts & Science. Her work focuses on studying massive galaxies that formed “when the universe was still just a baby.”

She is also active in supporting Black, Latinx and Indigenous women who are interested in a career in science.

She recently spoke to U of T’s Chris Sasaki about her career, research and goals.

Was there an important milestone in your journey to becoming an astronomer?

After high school, my plan was to take a gap year to figure out if I wanted to stay in Ghana and do something in the sciences at the university level or go elsewhere.

That’s when an opportunity came my way. There was a program run by the American Embassy in Accra for Ghanaian high school students interested in studying in the U.S. It provided mentorship for things like how to apply to schools in the U.S., how to write a good college application and how to select courses. They also helped you think about what you wanted to do in your career.

It was a big turning point in my life when I was selected to join the program. That’s how I learned about opportunities outside of Ghana and realized that if I was going to study astronomy, I would have to leave because we don't have astronomy at the collegiate level. And so, I made my decision to study astronomy at Texas Christian University.

Large, relatively nearby galaxies like this one took billions of years to form. Antwi-Danso is trying to determine how large galaxies in the very distant universe formed in a small fraction of that time (photo by ESA/Hubble & NASA, D. Jones Acknowledgement: G. Anand, L. Shatz.)

As an astronomer, what questions are you trying to answer?

I study massive galaxies in the very distant universe – some of the very first structures that formed after the Big Bang nearly 14 billion years ago. We're trying to understand why these galaxies formed the way they did and how they became so big so quickly. We’re finding them at increasingly earlier times, as far back as when the universe was just four per cent of its current age.

This goes against our understanding of the hierarchical formation of large structures – where massive galaxies like our Milky Way galaxy were formed from the merger of galaxies that were formed from stars, which, in turn, formed from clouds of gas and dust.

For our galaxy, it took billions of years to attain its current stellar mass. These distant, massive galaxies had only a fraction of the time to go through this process, so we have no idea how they formed so quickly. So, one of two things is happening: either there's something wrong with our observations or we need to revise our current models. That's the big problem I'm working on and I’m actually looking for a summer undergraduate student to work on this project.

Jacqueline Antwi-Danso speaks to students at a meeting of the American Astronomical Society (supplied image)

You’re working to support Black, Indigenous and Latinx women in science. Can you tell me more about that?

The League of Underrepresented Minoritized Astronomers (LUMA) is a peer mentoring organization for women in astronomy, physics and the planetary sciences that was formed in 2015 by Catherine Espaillat, who is the director of the Institute for Astrophysical Sciences at Boston University. She started LUMA because, as a Dominican American grad student, she felt isolated.

There weren’t many people in her field who looked like her, with whom she shared backgrounds. So, she created LUMA to be a community of people with similar experiences who could provide each other with support. I joined because I also realized there weren't many people in my field who looked like me. There were even fewer African astronomers. And, like Catherine, I wanted a place where we could come together as a community and support each other.

Do have you have plans to do the same type of work here in Canada?

I would like to continue this work, so I've been learning about and trying to understand what the Canadian science landscape looks like. I think the challenge in Canada is similar to the challenge that LUMA faces in the U.S. – there are very few Black, Indigenous or Latinx women in science in either country. So, yes, I would like to do similar work here. I just don't know what that looks like yet.

What about in Ghana?

One thing that I had in mind was trying to create some sort of pipeline for students in Ghana who might be interested in astronomy and might want to study in the U.S. or Canada. There are challenges, of course, but I’m talking to people who have been involved in similar projects and have found solutions to these challenges. For example, it might mean helping by providing mentorship to students who are already interested in physics and to students who are a little further along in their studies. I'm hopeful there are a number of ways to make this work.

How do you feel about receiving the NSERC Banting fellowship?

I’m very grateful and humbled to receive it. For me, it represents an exciting opportunity to work independently on my research, especially at U of T with all the people in the Dunlap Institute (for Astronomy & Astrophysics), the department of astronomy and astrophysics, CITA (Canadian Institute for Theoretical Astrophysics) and the department of statistical sciences. I feel like U of T is the perfect place for me because I’m combining astronomy with statistics and cosmological simulations to understand these really massive, distant galaxies. I’m having the time of my life, and I’m looking forward to seeing what the next few months will bring.

U of T astronomers discover first population of binary stripped stars

rahul.kalvapalle — Wed, 20 Dec 2023 15:22:31 +0000

U of T astronomers discover first population of binary stripped stars

rahul.kalvapalle Wed, 12/20/2023 - 10:22

Cutline

Artist's impression of a massive star stripping the hydrogen envelope of its companion star in a binary system (illustration by Navid Marvi, courtesy of the Carnegie Institution for Science)

Michael Pereira

Topic

Breaking Research

Research and Innovation

Subheadline

New findings confirm the existence of hot helium stars long thought to be at the heart of hydrogen-poor supernovae and neutron star mergers

Astronomers at the ��߲ݴ�ý have discovered a population of massive stars that have been stripped of their outer hydrogen layer by companion stars.

For over a decade, scientists have theorized that approximately one in three massive stars are stripped of their hydrogen envelope in binary systems (systems where two stars are gravitationally bound to one another). Yet, until now, only one possible candidate had been identified.

The findings, published in Science, shed light on the hot helium stars that are believed to be the origins of hydrogen-poor core-collapse supernovae and neutron star mergers.

“If it turned out that these stars are rare, then our whole theoretical framework for all these different phenomena is wrong, with implications for supernovae, gravitational waves and the light from distant galaxies,” said Maria Drout, assistant professor in the David A. Dunlap department of Astronomy & Astrophysics at the ��߲ݴ�ý and an associate at the Dunlap Institute for Astronomy & Astrophysics.

“This finding shows these stars really do exist.”

It also opens up possibilities for more detailed research going forward. “For example, predictions for how many neutron star mergers we should see are dependent on the properties of these stars, such as how much material comes off of them in stellar winds," Drout says. "Now, for the first time, we’ll be able to measure that, whereas people have been extrapolating it before."

Assistant Professor Maria Drout with the Magellan Telescope at Las Campanas Observatory (photo by Tom Holoien/Maria Drout)

Drout and her colleagues propose that these newly discovered stars will eventually explode as hydrogen-poor supernovae. These star systems are also thought to be necessary to form neutron star mergers.

In fact, the researchers believe that a few objects in their current sample are stripped stars with neutron star or blackhole companions. These objects are at the stage immediately before they become double-neutron-star or neutron-star-plus-blackhole systems that could eventually merge.

“Many stars are part of a cosmic dance with a partner, orbiting each other in a binary system. They’re not solitary giants but part of dynamic duos, interacting and influencing each other throughout their lifetimes,” says Bethany Ludwig, a PhD student in the David A. Dunlap department of Astronomy & Astrophysics and third author on the paper. “Our work sheds light on these fascinating relationships, revealing a universe that is far more interconnected and active than we previously imagined.

“Just as humans are social beings, stars too, especially the massive ones, are rarely alone.”

(Left to right): Bethany Ludwig, Anna O’Grady, Maria Drout and Ylva Götberg (all authors on the paper) at the Magellan Telescopes at Las Campanas Observatory in Chile (photo by Ylva Götberg)

As stars evolve and expand to become red giants, the hydrogen at the outer edges of one can be stripped by the gravitational pull of its companion star – leaving a very hot helium core exposed. The process can take tens of thousands or even hundreds of thousands of years.

Stripped stars are difficult to find because much of the light they emit is outside of the visible light spectrum and can be obstructed by dust in the universe or outshone by their companion stars.

Drout and her collaborators began their search in 2016. Having studied hydrogen-poor supernovae during her PhD, Drout set out to find the stripped stars thought to be at the heart of these supernovae during a NASA Hubble postdoctoral fellowship at the Observatories of the Carnegie Institution for Science.

The researchers, who include co-author Ylva Götberg, assistant professor at the Institute of Science and Technology Austria, later designed a survey to look in the ultraviolet part of the spectrum where extremely hot stars emit most of their light. Using data from the Swift Ultra-Violet/Optical Telescope, they collected brightness data for millions of stars in the Large and Small Magellanic Clouds, two of the closest galaxies to Earth.

Ludwig, who developed the first wide-field UV catalogue of the Magellanic Clouds, used UV photometry to detect systems with unusual UV emissions – signaling the possible presence of a stripped star.

The researchers used this ultraviolet dataset of the Large and Small Magellanic Clouds, the two closest major galaxies to our own, to identify the candidate systems (image by NASA/Swift/S. Immler (Goddard) and M. Siegel (Penn State)

The team carried out a pilot study of 25 objects, obtaining optical spectroscopy with the Magellan Telescopes at Las Campanas Observatory between 2018 and 2022, and demonstrated that the stars were hot, small, hydrogen-poor, and in binary systems – all consistent with their model predictions.

Currently, the researchers are continuing to study the stars identified in the paper and expanding their search to find more. They will be looking both within our own Milky Way and nearby galaxies with approved programs on the Hubble Space Telescope, the Chandra X-ray Telescope, the Magellan Telescopes and the Anglo-Australian Telescope.

As part of this publication, all theoretical models and data used to identify these stars have been made public and available to other scientists.

Collaborating institutions include the ��߲ݴ�ý, the Observatories of the Carnegie Institution for Science, Max-Planck-Institut für Astrophysik, Anton Pannekoek Institute for Astronomy, Dunlap Institute for Astronomy & Astrophysics and Steward Observatory.

Astrophysicist Laurie Rousseau-Nepton discusses Indigenous contributions to her field on CTV's The Social

Christopher.Sorensen — Thu, 02 Nov 2023 16:01:42 +0000

Astrophysicist Laurie Rousseau-Nepton discusses Indigenous contributions to her field on CTV's The Social

Christopher.Sorensen Thu, 11/02/2023 - 12:01

Cutline

(supplied image)

Topic

Subheadline

"In the Innu culture and many cultures in Canada, we come from the stars and we also return to the stars"

Astrophysicist Laurie Rousseau-Nepton says her research on how stars form and influence each other over generations is an extension of the knowledge passed down to her by her Innu ancestors.

"In the Innu culture and many cultures in Canada, we come from the stars and we also return to the stars – and it's a cycle,” Rousseau-Nepton, an assistant professor at the Dunlap Institute for Astronomy & Astrophysics, told CTV’s The Social.

"For me, it makes sense that I'm doing this. It's something that I've actually learned all of my life: to study where we come from.”

The first Indigenous woman in Canada to earn a PhD in astrophysics, Rousseau-Nepton says the academic community is playing catchup to Indigenous knowledge that has been around for centuries.

“I like to think that if scientists maybe 400 years ago would have followed that path right away – 'Where are we coming from? are we linked to the stars?' – maybe we would have made those discoveries that are very real that we now know," she said.

Rousseau-Nepton appeared on the talk show to discuss the five-part documentary series North Star, which chronicles her journey as a resident astronomer at the Canada-France-Hawaii Telescope. The series can be streamed on the National Film Board of Canada website at no cost.

Watch the full clip on CTV’s The Social

Watch North Star

'I love blowing people’s minds': Alum helps communicate space discoveries to the world

Christopher.Sorensen — Thu, 17 Aug 2023 16:38:28 +0000

'I love blowing people’s minds': Alum helps communicate space discoveries to the world

Christopher.Sorensen Thu, 08/17/2023 - 12:38

Cutline

Kelly Lepo stands in front of a radio dish at the Very Large Array (VLA) at the National Radio Astronomy Observatory in New Mexico (photo courtesy of Kelly Lepo)

David Goldberg

Topic

Alumni

Subheadline

Kelly Lepo is an education and outreach scientist at the Space Telescope Science Institute in Baltimore

Kelly Lepo likes to joke that she’s a real-life Lisa Simpson. Like the famous cartoon character known for her intellect and activism, the alumna of the ��߲ݴ�ý’s Faculty of Arts & Science is a self-proclaimed “nerd” who will share her love of science with anyone who will listen.

“I love blowing people’s minds,” says Lepo, who earned her PhD from the David A. Dunlap department of astronomy and astrophysics in 2015 and is now an education and outreach scientist at the Space Telescope Science Institute in Baltimore, Md.

Lepo supports the James Webb Space Telescope by communicating the observatory’s discoveries to the world. She works at the same institute that oversees the famous spacecraft’s systems, schedules telescope time for scientists and records data.

Lepo says U of T was the perfect place to hone her public outreach skills as a TA and receive media exposure as a trusted expert in Canada’s largest astronomy department. She also learned how to educate large audiences and communicate complex theories about the universe.

“It’s an extraordinary experience learning from some of the top astronomers in a prestigious, yet nurturing environment,” says Lepo. “I remember the first time I landed in Toronto and it all sunk in that I was at one of the top universities in the world.”

During her PhD research, Lepo investigated stars that will explode as one type of supernovae to determine whether they were caused by two white dwarf stars colliding, or one star transferring its mass to another. She directed telescope operators in Chile and Australia to gather data from thousands of stars in the Small Megellanic Cloud, a tiny galaxy orbiting the Milky Way. In the end, she couldn’t find proof of supernovae caused by mass transfer, but her work was an important contribution to research in the field.

“In other studies, astronomers have used these supernovae to figure out the expansion history of the universe. They discovered our universe is not only expanding, but also accelerating in this expansion,” Lepo says. “Eventually, all galaxies are going to be so far away from each other that we're all going to be living in island universes.”

Her PhD adviser, Professor Marten van Kerkwijk, says Lepo was an efficient and driven astronomer.

“She has ample reason to be proud of her research,” says van Kerkwijk. “And I always appreciated the work she did while completing her PhD.”

In 2013, Lepo was a key organizer of the first ever West African International Summer School for Young Astronomers, a program partly sponsored by the Canadian Institute for Theoretical Astrophysics (CITA).

Lepo also cultivated her reputation as a trusted astronomy voice amid media coverage of the ancient Mayans' doomsday prophecy of 2012. Lepo debunked myths about killer solar flares and mysterious runaway planets on a collision course with Earth.

The experience complemented her TA duties in an Arts & Science class on the apocalypse, which took an interdisciplinary approach.

“We had someone from astronomy, someone from English and someone from sociology collaboratively teaching the course,” says Lepo. “That was really interesting to see how you could approach the same topic across several subjects.”

For her achievements inside and outside the classroom, Lepo won the Fieldus Award in 2014, given to one graduate student each year for excellence in leadership, teaching and research.

After graduation, Lepo taught physics at Gonzaga University before becoming the first co-ordinator of the McGill Space Institute at McGill University.

But she always ties her passion for public outreach back to U of T.

“One of my favourite memories is being in the middle of the St. George campus with a big inflatable sun and trying to get people to look at the sun safely through some solar telescopes; we must have come off as some kind of sun cult,” Lepo recalls.

“We explained to one person that the sun was much larger than the moon and they honestly had no idea, and this completely blew their mind. Those were the moments I really loved.”

U of T alum helps prepare Canadarm3 for lunar orbit

siddiq22 — Mon, 14 Aug 2023 14:59:08 +0000

U of T alum helps prepare Canadarm3 for lunar orbit

siddiq22 Mon, 08/14/2023 - 10:59

Cutline

An artist's rendering of Canadarm3 on the Lunar Gateway (photo by CSA, NASA)

David Goldberg

Topic

Canadian Institute for Theoretical Astrophysics

Alumni