Non-rotating early galaxy a surprise to astronomers who say this work helps give clues to origins of the universe

An international group of astronomers, including from 91亚色鈥檚 department of Physics and Astronomy, using the world鈥檚 most powerful space telescope, have made a surprising discovery about a galaxy long, long ago and far, far away: It isn鈥檛 rotating.

That鈥檚 something typically seen in more mature galaxies that are closer to us in space and time, says Ben Forrest, a research scientist at the Department of Physics and Astronomy at the University of California, Davis, and first author on the paper published May 4 in Nature Astronomy. 

鈥淭his one in particular did not show any evidence of rotation, which was surprising and very interesting,鈥� Forrest said.

According to current theories, as the first galaxies formed, irregularities in gas flows and the influence of gravity set them spinning.

Over many billions of years, some galaxies, especially those within galaxy clusters, merged with each other multiple times and their combined rotations added to or partly canceled each other. That鈥檚 why some galaxies that are closest to Earth (and therefore also relatively recent) can show little overall rotation but a lot of random movement of stars within them.

This process should take an enormously long time, so it鈥檚 surprising that galaxy XMM-VID1-2075 had achieved this state when the universe was less than two billion years old.

Forrest and colleagues, including second author and 91亚色 Physics and Astronomy Professor Adam Muzzin, who worked closely on the research with Forrest, had previously observed this galaxy with another observatory in Hawaii.

鈥淲e were especially keen to do this observation as it is one the most massive galaxies from the early universe,鈥� says Muzzin. 鈥淒etecting these types of galaxies is challenging and the observations can be subtle, but that keeps the work interesting.鈥�

The team used the James Webb Space Telescope (JWST) to take a closer look at XMM-VID1-2075 and two other objects of similar age. With instruments on the Webb telescope, they were able to measure the relative movement of material inside them.

Of the three galaxies they sampled, one is clearly rotating, one is 鈥渒ind of messy,鈥� and one has no rotation but a lot of random motion. 鈥淭hat鈥檚 consistent with some of the most massive galaxies in the local universe, but it was a bit surprising to find it so early on,鈥� says Forrest.

How did this galaxy become a 鈥渟low rotator鈥� in less than two billion years? One possibility is that it is the result not of multiple mergers, but a single collision between two galaxies rotating pretty much in opposite directions. That idea is supported by the team鈥檚 observations.

鈥淔or this particular galaxy, we see a large excess of light off to the side. And so that's suggestive of some other object which has come in and is interacting with the system and potentially changing its dynamics,鈥� Forrest said.

The astronomers are continuing to look for other, similar objects in the early universe. By comparing their observations with simulations, they can test theories about galaxy formation.

Last year, Muzzin was granted the largest ever allotment for a single researcher on the JWST and says that this research is not just about understanding this particular galaxy, but gives us clues as to the origin story of the universe, and through that humanity.

鈥淭his is literally where it all started, where we all came from,鈥� says Muzzin. 鈥淭his research is one important step in understanding that story more fully.鈥�

The work was supported by grants from NASA, the Space Telescope Science Institute and National Science Foundation.

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91亚色 is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change, and prepare our students for meaningful life and career paths. 91亚色's Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. 91亚色鈥檚 campus in Costa Rica offers students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contact: Emina Gamulin, 91亚色 Media Relations, 437-217-6362, egamulin@yorku.ca

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Commenting on the TD Bank money-laundering scandal following two shareholder groups calling for an outside review of board governance, Professor Richard Leblanc tells Bloomberg that while shareholder resolutions are valuable, they fall short compared to the robust regulatory measures seen in the U.S., which he says Canada lacks. and criticizes outdated and vague guidelines from Canadian regulators for allowing excessive company discretion.

Canada Post has been laying off striking employees as labour action approaches the two-week mark. Canada Post spokeswoman Lisa Liu confirmed the layoffs, saying they are temporary. On its face, Canada Post appears to be violating that section of the labour code, Professor David J. Doorey tells The Canadian Press. "Therefore, if CUPW challenges the layoffs, Canada Post will need strong evidence to persuade the labour board that the layoffs are entirely unrelated to the fact that the workers went on strike. It would be interesting to hear that argument," he says, adding that "unless those jobs no longer exist." Doorey also spoke to The Globe and Mail earlier this week about the strike as negotiations between the postal service and its workers鈥� union broke down. "The Liberals' recent interventionist role in ending labour disputes is unusual even by Canadian standards, and the minister has been heavily criticized by the labour movement and their allies for siding with employers to quash the right to strike in airlines, railways and ports," says Doorey. "The minister no doubt wants to avoid intervening again, but ."

Artificial intelligence can improve productivity and efficiency but project management software at a company-wide level can present problems. Professor Valerio de Stefano says there need to be strict boundaries for the types of decisions AI is allowed to make in a workplace. "Tech could help us be more productive, help us manage our tasks more efficiently. and assess whether what we are doing is productive or not," de Stefano tells the Financial Post.

Tech could help us be more productive, help us manage our tasks more efficiently. What it cannot do is to replace the judgment of the human supervisor and assess whether what we are doing is productive or not.

de Stefano speaking to the Financial Post

Professor Giuseppina D'Agostino talks to CBC Radio about publishers increasingly turning to fan fiction for their next hit, warning that creators could encounter legal challenges if they try to profit from characters they don't own. D'Agostino says there hasn't been an appetite to go after fanfic authors in Canada, yet. "There are exceptions in the Copyright Act also to enable a vibrant culture to create and use work," says D'Agostino. "They're not really doing any damage to the initial original work. If anything, they're paying homage to it and ."

In April, two NASA scientists surveying the Greenland Ice Sheet found Camp Century, a Cold War U.S. military base abandoned in 1967, while attempting to map the ice sheet. It's not the first time the base has been seen on radar flights. The base housed 85 to 200 soldiers and was powered by a nuclear reactor. Professor William Colgan, who co-authored a study on the Camp Century released in August, tells USA Today that . "When we looked at the climate simulations, they suggested that rather than perpetual snowfall, it seems that as early as 2090, the site could transition from net snowfall to net melt," Colgan said at the time of the study's publishing. "Once the site transitions from net snowfall to net melt, it's only a matter of time before the wastes melt out; it becomes irreversible."

A team led by Professor Cora Young has been measuring for gaseous fluorine to better understand the extent of previously unaccounted-for PFAS in the atmosphere. The team found 65 to 99 per cent of the fluorine in the air inside the lab was not normally unaccounted for, while outside that number was about 50 per cent. 鈥淚t's important as missing gaseous fluorine accounts for a huge part of airborne PFAS compared to what we actually measure at the moment, ,鈥� Young tells Environmental Science and Engineering Magazine.

Now reports on Reddit users discussing tourist destinations outside the downtown core, mentioning the on Keele Campus as a spot worth visiting.

Do you have a new research study or an academic achievement to share? Contact media@yorku.ca with details. For daily 91亚色 in the News highlights, follow on X.

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91亚色-led findings show astronauts can safely assess distances in weightless environment

TORONTO, March 25 2024 鈥� New research led by 91亚色 finds .

The findings of the study, done in collaboration with the Canadian Space Agency and NASA, have implications for crew safety in space and could potentially give clues to how aging affects people鈥檚 balance systems here on Earth, says the study鈥檚 lead Faculty of Health Professor .

鈥淚t has been repeatedly shown that the perception of gravity influences perceptual skill. The most profound way of looking at the influence of gravity is to take it away, which is why we took our research into space,鈥� says Harris, an expert on vision and the perception of motion who also heads up the Multisensory Integration Lab and is the former director of the at 91亚色.

鈥淲e鈥檝e had a steady presence for close to a quarter century in space and with space efforts only increasing as we plan to go back to the moon and beyond, answering health-and-safety questions only becomes more important. Based on our findings it seems as though humans are surprisingly able to compensate adequately for the lack of an Earth-normal environment using vision.鈥�

Harris and collaborators 鈥� who include Lassonde School of Engineering professors Robert Allison and Michael Jenkin, and two generations of 91亚色 post docs and graduate students Bj枚rn J枚rges, Nils Bury, Meaghan McManus and Ambika Bansal 鈥� studied a dozen astronauts aboard the International Space Station, which orbits about 400 kilometres from the Earth鈥檚 surface. Here, Earth's gravity is approximately cancelled out by centrifugal force generated by the orbiting of the station. In the resulting microgravity, the way people move is more like flying, says Harris.

鈥淧eople have previously anecdotally reported that they felt they were moving faster or further than they really were in space, so this provided some motivation to actually record this,鈥� he explains.

The researchers compared the performance of a dozen astronauts 鈥� six men and six women 鈥� before, during, and after their year-long missions to the space station and found that their sense of how far they travelled remained largely intact.

Space missions are busy endeavours and it took the researchers several days to connect with the astronauts once they arrived at the space station. Harris says that it鈥檚 possible their research was unable to capture early adaptation that may have occurred in those first few days, 鈥渋t's still a good news message because it says that whatever adaptation happens, happens very quickly.鈥�

Space missions are not without risk. As the ISS orbits the Earth it is sometimes hit with small objects that could penetrate the vessel requiring astronauts to move to safety.

鈥淥n a number of occasions during our experiment, the ISS had to perform evasive maneuvers,鈥� recalls Harris. 鈥淎stronauts need to be able to go to safe places or escape hatches on the ISS quickly and efficiently in an emergency. So, it was very reassuring to find that they were actually able to do this quite precisely.鈥�

The study, published recently in npj Microgravity, has been a decade in the making, and represents the first of three papers that will emerge from the research investigating the effects of microgravity exposure on different perceptual skills including the estimation of body tilt, travelled distance, and object size.

Harris says research shows exposure to microgravity mimics the aging process on a largely physiological level  鈥� wasting of bones and muscles, changes in hormonal functioning and increased susceptibility to infection  鈥� but this paper finds that self-motion is largely unaffected, suggesting the balance issues that frequently come from old age may not be related to the vestibular system.

鈥淚t suggests that the mechanism for the perception of movement in older people should be relatively unaffected, and that the issues involved in falling may not be so much in terms of the perception of how far they've moved, but perhaps more to do with how they're able to convert that into a balance reflex.鈥�

About 91亚色

91亚色 is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change, and prepare our students for success. 91亚色鈥檚 fully bilingual Glendon Campus is home to Southern Ontario鈥檚 Centre of Excellence for French Language and Bilingual Postsecondary Education. 91亚色鈥檚 campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.

Media Contacts: Emina Gamulin, 91亚色 Media Relations and External Communications, 437-217-6362, egamulin@yorku.ca

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Associate Professor Adam Muzzin leads working group studying young galaxies

TORONTO, Dec. 15, 2021 鈥� The new (JWST) 鈥� a collaboration between NASA, the European Space Agency and the Canadian Space Agency 鈥� is expected to launch this month with the Canadian-built (NIRISS). It will take images and spectra of fainter objects than the Hubble Telescope ever could, and it鈥檚 creating an astronomical amount of excitement.

What will the telescope do for astronomy? 鈥淓verything. It鈥檚 the most powerful telescope of all time, blowing away what the Hubble Space telescope can do. It will completely revolutionize all aspects of astronomy,鈥� says 91亚色 Associate Professor Adam Muzzin of the Faculty of Science.

One of the things this new telescope will be able to do is see infrared light. This will be important for Muzzin, a member of the Canadian instrument team that built the NIRISS, as he leads one of the working groups on the large Canadian NIRISS Unbiased Cluster Survey (CANUCS) project. The NIRISS instrument can take higher resolution images than Hubble and will allow Muzzin and other astronomers to better study objects in space, including the formation of planets, as well as distant galaxies. It鈥檚 a project 91亚色 grad student Ghassan Sarrouh, a next generation astrophysicist, is currently working on for his MSc thesis.

Video of Profs Adam Muzzin and Cemile Marsan by freelance science journalist Dan Falk when he was a Science Communicator in Residence at 91亚色

The CANUCS project will look at how some of the first galaxies, some 13 billion light years away, were formed and how they grew. But as Muzzin says: 鈥淭he universe is expanding, with everything moving away from us, and so the light coming from distant galaxies is stretching and shifting towards the red part of the electromagnetic spectrum. If we want to see far-away galaxies from the early days of our universe, we need to able to see infrared.鈥�

Muzzin is one of the lucky few to have guaranteed observing time on the telescope for his work on the instrument, along with 91亚色 Visiting Professor Cemile Marsan in the 91亚色 Department of Physics and Astronomy, one of only 10 Canadians to receive their own observing time on the telescope in open competition.

Marsan鈥檚 project will look at massive, extreme galaxies in the distant Universe that were fully formed when the Universe was less than 10 per cent of its current age. According to physics theories, these聽galaxies should not exist.

"Over the last decade, astronomers have compiled a myriad of lines of observational evidence hinting that these extreme structures 鈥� being 10 times more massive than today鈥檚 Milky Way 鈥� must exist in the young Universe, but we can鈥檛 say much more about them due to current instrumental limitations," says Marsan. "With JWST, we will be able to 'see' for the first time how such rare and exceptionally massive galaxies were able to assemble during an epoch when the Universe is expected to be busy building smaller structures."

Are these galaxies experiencing a rapid build-up of stars in conjunction with the growth of their supermassive black holes at their centers? Is there something unique about the environment they reside in? These are just two of the questions Marsan hopes the new telescope will help answer.

The experts:

Muzzin, Marsan and Sarrouh are available to discuss their celestial projects.

Assistant Professor , an expert in astronomy and space exploration in the Faculty of Science, can discuss the mission, what Canada contributed, what the JWST will allow astronomers to study over the next decade, what it will do for astronomy and the excitement in the astronomy community.

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91亚色 is a modern, multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change and prepare our students for success. 91亚色's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education. 91亚色鈥檚 campuses in Costa Rica and India offer students exceptional transnational learning opportunities and innovative programs. Together, we can make things right for our communities, our planet, and our future.聽

Media Contact:
Sandra McLean, 91亚色 Media Relations, 416-272-6317, sandramc@yorku.ca

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Interdisciplinary investigation of the planet鈥檚 south pole points to clays being the likely culprit

TORONTO, July 29, 2021聽鈥�聽For years scientists have been debating what might lay under the Martian planet鈥檚 south polar cap after bright radar reflections were discovered and initially attributed to water. But now, a聽new聽study published in聽,聽led by planetary scientists from Lassonde School of Engineering at 91亚色, puts that theory to rest and demonstrates for the first time that another material is most likely the answer.

Research led by Isaac Smith, Canada Research Chair and聽assistant professor of聽Earth聽and Space Science at Lassonde聽School of Engineering and research scientist at the Planetary Science Institute, uses聽multiple lines of evidence to show that聽smectites, a common type of clay, can explain all of the observations,聽putting the Mars lake theory on ice.

"Since being first reported as bodies of water, the scientific community has shown skepticism about the lake hypothesis and recent publications questioned if it was even possible to have liquid water," said Smith. Papers in 2018 and 2021 demonstrated that the amount of salt and heat聽required聽to thaw ice at the bottom of the polar cap was much more than Mars provides, and recent evidence showing these radar detections are much more widespread 鈥� to places even harder to thaw ice 鈥� put the idea further into question.

Mars South Polar Layered Deposits on top of Martian Smectites: The multi-kilometer thick south polar ice cap has a base that is composed, at least partially, of a common type of clays. These clays are found over nearly half of the planet's surface and now at the edges of the ice cap. Radar measurements of the clays from a lab led by Smith show that they can explain the bright reflections observed by MARSIS, a simpler explanation than bodies of liquid water.聽Credits: ESA/DRL/FU Berlin (top), NASA (bottom).

The research team, which includes researchers from the University of Arizona, Cornell, Purdue and Tulane universities, used聽experimental and聽modelling聽work to demonstrate that聽smectites聽can better explain the radar observations made聽by the聽MARSIS聽instrument聽aboard the European Space Agency鈥檚 Mars Express orbiter. Further, they found spectral evidence that聽smectites聽are present at the edges of the south polar cap.

鈥淪mectites聽are very abundant on Mars, covering about half the planet, especially in the聽Southern Hemisphere," said Smith. 鈥淭hat knowledge, along with the radar properties of聽smectites聽at cryogenic temperatures, points to them being the most likely explanation to the riddle."

Experiments done at 91亚色 measured the radar characteristics of hydrated聽smectites聽at room temperature and cryogenic temperatures. The radar characteristics in question are two numbers that represent the real and imaginary parts of the dielectric constant. Both numbers are important for fully characterizing a material, but the 2018 study used聽modelling聽that included only the real part of the dielectric value, leaving out certain classes of materials from being considered 鈥� namely clays.

Spectral color map from the CRISM instrument on Mars Reconnaissance Orbiter draped over HiRISE imagery at the edge of the south polar ice cap. Specific colors from this map indicate the presence of smectite clays, an important discovery that helps to explain the MARSIS radar observations. Credit: NASA/JPL/UA.

Once the experimental measurements were completed, data was evaluated using code. It was in these simulations researchers聽found that frozen clays have numbers big enough to make the reflections.

Smectites聽are a class of clay that is formed when basalt (the volcanic rock that comprises most of Mars' surface) breaks down chemically in the presence of liquid water.

"Detecting possible clay minerals in and below the south polar ice cap is important because it tells us that the ice includes sediments that have interacted with water sometime in the past, either in the ice cap or before the ice was there,鈥� said Briony Horgan, co-author and associate professor in Earth, Atmospheric, and Planetary Sciences at Purdue University. 鈥淪o, while our work shows that there may not be liquid聽water and an associated habitable environment for life under the cap today, it does tell us about water that existed in this area in the past."

To support this new hypothesis,聽Smith聽conducted聽experiments in his聽lab聽with equipment designed for measuring dielectric values. To simulate the conditions beneath Mars's south polar cap as best as possible, his team froze the clays to -50 C and measured them again, something that had never been done before.聽Smith adds that the infrared absorptions attributable to these minerals are present in south polar orbital聽visible-near聽infrared reflectance spectra. Because these minerals are both present at the聽south pole聽and can cause the reflections, the team believes this to be a more viable scenario than the presence of liquid water. No salt or heat is聽required.

鈥淲e used our聽lab聽measurements of clay minerals as the input for a radar reflection model and found that the results of the model matched very well with the real, observed data,鈥� said Dan聽Lalich,聽post-doctoral聽researcher at the聽Cornell Center for Astrophysics and Planetary Science聽at Cornell University and second author on the study. 鈥淲hile it's disappointing that liquid water might not actually be present below the ice today, this is still a cool observation that might help us learn more about conditions on ancient Mars.鈥�

"We analyzed the聽MARSIS聽radar data and identified observations with high-power values at the base of the south polar layered deposits, both in the proposed lake region and elsewhere," said聽Jenny Whitten, co-author and planetary scientist in the聽Department of聽Earth聽and Environmental Sciences at Tulane University.

"The first reason the bright reflectors cannot be water is because some of them continue from underground onto the surface. If that is the case, then we should see springs, which we don't," said Stefano聽Nerozzi,聽post-doctoral聽fellow in the聽Lunar and Planetary Laboratory and Department of Geosciences at the University of Arizona and co-author.聽"Not only that, but multiple reflectors are stacked on top of each other, and some are even found right in the middle of the polar cap. If this were water, this would be physically impossible."

Putting the results in perspective Smith says the answer is clear.

鈥淣ow, we have the trifecta. One, we measured dielectric properties of materials that are known to exist on over 50 per cent of Mars' surface and found them to have very high values. Two, we聽modelled聽how those numbers would respond in Mars' south-polar conditions and found them to match the radar observations well. Three, we demonstrated that these minerals are at the聽south pole. Because the liquid water theory聽required聽incredible amounts of heat which is six-to-eight times more than Mars provides, and more salt than Mars has, it was聽already聽implausible. Now, the clays can explain the observations with absolutely no qualifiers or asterisks.鈥�

About 91亚色

91亚色聽is a modern,聽multi-campus, urban university located in Toronto, Ontario. Backed by a diverse group of students, faculty, staff, alumni and partners, we bring a uniquely global perspective to help solve societal challenges, drive positive change and prepare our students for success. 91亚色's fully bilingual Glendon Campus is home to聽Southern Ontario's Centre of Excellence for French Language and Bilingual聽Postsecondary聽Education. 91亚色鈥檚 campuses in Costa Rica and India offer students exceptional transnational learning聽opportunities聽and innovative programs. Together, we can make things right for our communities, our planet, and our future.

About Lassonde School of Engineering

Located in the heart of the multicultural Greater Toronto Area, the聽听补迟听91亚色聽ishome to engineers, scientists and entrepreneurs, representing a diverse community of students, faculty, staff, alumni and partners. With 11 undergraduate programs, seven graduate programs and a host of certificates and accessible study options, Lassonde is shaping the next generation of creators who will tackle the world鈥檚 biggest challenges and devise creative solutions through interdisciplinary learning opportunities. Lassonde鈥檚 creators think in big systems rather than small silos, design with people in mind and embrace ambiguity.

Media contact:聽Kayla Lewis, 91亚色 Media Relations, cell 416-455-4710,聽lewiskay@yorku.ca

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Enhanced image of super blue blood moon. Credit: NASA

TORONTO, Friday, Jan. 26, 2018 鈥� It鈥檚 rare to see a super blue blood moon and a lunar eclipse all at the same time, says 91亚色 Professor Paul Delaney. The last one was in 1866. But that鈥檚 what Jan. 31 will bring eager celestial watchers.

The 鈥渂lue鈥� in the super blue blood moon is because it鈥檚 the second full moon of the month, and as it will be relatively close to the Earth, it鈥檚 also called a 鈥渟uper鈥� moon. In addition, this particular phase of the moon will see the moon, Earth and Sun all line up, causing a lunar eclipse as the Earth blocks the sun鈥檚 light from falling onto the lunar surface. If you鈥檙e where the totality phase of the lunar eclipse is visible, this particular super blue moon will not have a bluish cast, but a reddish glow, which makes it a blood moon.

It will depend where you are just how much of the lunar eclipse you鈥檒l be able to see. From British Columbia, residents will see totality, but from Toronto and further east, the Sun will rise before the totality phase is reached.

If you miss this one, the opportunity won鈥檛 come again until next year.

WHAT: Super blue blood moon and lunar eclipse

WHEN: Wednesday, Jan. 31

WHO: Paul Delaney of the Faculty of Science will be available to talk about the celestial event.

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聽champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. 91亚色 students and graduates push limits, achieve goals and find solutions to the world鈥檚 most pressing social challenges, empowered by a strong community that opens minds. 91亚色 U is an internationally recognized research university 鈥� our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, 91亚色 is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni.聽91亚色 U's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education.

Media contact:

Sandra McLean, 91亚色 Media Relations, 416-736-2100 ext. 22097, sandramc@yorku.ca

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TORONTO, October 12, 2016 鈥�聽Planets that revolve around two suns may surprisingly survive the violent late stages of the stars鈥� lives, according to new research out of the NASA Goddard Space Flight Centre and 91亚色. The finding is surprising because planets orbiting close to a single sun, like Mercury and Venus in our solar system, would be destroyed when the aging star swells into a red giant.

Led by Veselin Kostov at the NASA Goddard Space Flight Centre, in collaboration with 91亚色 master鈥檚 student Keavin Moore and Professor Ray Jayawardhana, the study found that planets orbiting two (binary) stars 鈥� also referred to as circumbinary planets or 鈥淭atooine worlds鈥� after the iconic planetary home of Luke Skywalker in Star Wars 鈥� often escape death and destruction by moving out to wider orbits.

Artist view of a planet orbiting two aging stars that exchange material and spiral closer together. Image by Jon Lomberg

The paper, 鈥�,鈥� has been accepted for publication in聽.

鈥淭his is very different from what will happen in our own solar system a few billion years from now, when our Sun starts to evolve and expand to such a tremendous size that it will engulf the inner planets, like Mercury and Venus and possibly Earth too, faster than they can migrate out to larger orbits鈥� says Kostov. 鈥淚t seems that if we had a second star in the center of our solar system, things might go differently.鈥�

Binary star systems are ubiquitous in the Universe and consist of two stars that orbit around a common center of gravity. If the two stars are close enough to each other, when one starts evolving and expanding into a giant, they exchange material and spiral towards each other resulting in their sharing a common atmosphere (also called a common envelope). The binary star system ends up losing a large amount of mass, or might be destroyed in a supernova explosion.

鈥淕iven the exciting recent discoveries of planets circling binary stars, some with orbits similar in size to that of Mercury around the Sun, we were curious to explore the ultimate fate of these Tatooine worlds,鈥� says Jayawardhana. 鈥淲e found that many such planets are likely to survive the messy and violent late stages of their stars鈥� lives by moving farther out.鈥�

Reconfiguration of the orbit of planet (green) initially orbiting the binary at Mercury鈥檚 distance (black dotted). If the binary was instead a single, Solar-type star, it would expand to the yellow dashed circle during the Red Giant Stage, engulfing Mercury, Venus, and even potentially Earth itself.

The team, which also included Daniel Tamayo of the Canadian Institute for Theoretical Astrophysics and Stephen Rinehart of NASA Goddard, simulated the fate of nine circumbinary planets recently discovered by NASA鈥檚 Kepler mission. They found that the planets will predominantly survive the common envelope phase 鈥� even those orbiting very close to their stars. In addition, the planets can migrate to farther orbits similar to what it would be like if Venus moved out to where Uranus orbits our Sun. In some cases, planets can even reach more than twice the distance to Pluto.

Interestingly, when there are multiple planets orbiting a binary star, some can be ejected from the system, while others can switch places or even collide with their stars.

鈥淭he reconfiguration can be quite dramatic when there are several planets,鈥� says Moore. 鈥淎lthough all of the known circumbinary planets are gas giants, it is possible that somewhere out there is a terrestrial circumbinary planet that migrates to an orbit that now makes the planet potentially habitable for a little while.鈥�

Images:

Caption: Artist view of a planet orbiting two aging stars that exchange material and spiral closer together. Image by Jon Lomberg.

Caption: Reconfiguration of the orbit of planet (green) initially orbiting the binary at Mercury鈥檚 distance (black dotted). If the binary was instead a single, Solar-type star, it would expand to the yellow dashed circle during the Red Giant Stage, engulfing Mercury, Venus, and even potentially Earth itself.

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