Faculty of Science

Fifteen years after Western astronomers first discovered ‘buckyballs’ in space (soccer ball-shaped molecules that resemble a hollow sphere), they’re back with stunning images and rich data generated using the James Webb Space Telescope (JWST) – the most powerful space telescope ever built. The team led by Jan Cami, a physics and astronomy professor, first detected buckyballs using NASA’s Spitzer Space Telescope in 2010. The fantastic find came from the planetary nebula Tc 1, formed from a dying star more than 10,000 light-years away in the constellation Ara. These molecules, which contain 60 perfectly arranged carbon atoms, were first synthesized in 1985 at the University of Sussex by Sir Harry Kroto and his colleagues – a breakthrough that earned the 1996 Nobel Prize in chemistry. Kroto named the molecule “buckminsterfullerene” after famed architect Buckminster Fuller, who designed and developed geodesic domes, which share the same structural principles. While Kroto immediately predicted that buckyballs would be widespread and abundant throughout the cosmos, it took Cami, his collaborators and another 25 years to prove them right with a study, published in the high impact journal Science in 2010. And now the Western team has returned their attention to Tc 1, this time armed with more data from the JWST’s Mid-Infrared Instrument (MIRI), to capture the first-ever detailed view of the planetary nebula and the result is spectacular. The new image reveals delicate rays, wispy filaments and shimmering shells of gas across the frame (hotter gas glowing blue, cooler material traced in red) and at the heart of the nebula, an ethereal feature resembling an upside-down question mark hints at the complexity still waiting to be understood. “Tc 1 was already extraordinary, as it was the object that told us buckyballs exist in space, but this new image shows us we had only scratched the surface,” said Cami, principal investigator of the new JWST General Observer (GO) program. “The structures we’re seeing now are breathtaking, and they raise as many questions as they answer.” According to Cami, the image is the opening act of what promises to be a landmark series of results. The new JWST observations include not just imaging, but rich spectroscopic data – detailed chemical fingerprints of the gas and molecules throughout the nebula – and several scientific papers are currently in preparation. “When we proposed these observations, we knew Tc 1 was special. But what JWST has shown us goes far beyond what we anticipated. We are already gaining new insight into the nature of the buckyballs themselves, and into why they shine so exceptionally bright in this object – questions we have been puzzling over for fifteen years. This is one of those datasets that will keep us busy for years to come,” said Els Peeters, physics and astronomy professor.  

Beauty in the details

Beyond a regular camera, JWST’s MIRI instrument can also record the chemical fingerprint of the gas and dust at every point across the nebula. This technique, known as integral field unit (IFU) spectroscopy, allows scientists to map not just what Tc 1 looks like, but what it is made of: the temperature, density, chemical composition and motions of the gas throughout the nebula. The result is an extraordinarily powerful window into the physics and chemistry of a dying star. “As beautiful as this image is, for me it is first and foremost a dataset. The sharpness and sensitivity of JWST are unlike anything I have worked with before,” said Charmi Bhatt, a physics and astronomy PhD candidate at Western. “Structures that were completely invisible to us are now laid out with stunning clarity: the shells, the rays, the fine details in the outer halo. And crucially, through the integral field unit spectroscopy, we can now connect everything we see morphologically in the image directly to the chemistry and physics happening throughout the nebula. That combination is what makes this dataset so powerful.”  

A molecule inside a molecule’s shape

Among the new dataset’s early revelations is the three-dimensional distribution of the buckyballs themselves. Physics and astronomy PhD candidate Morgan Giese led the analysis of the C60 emission in the new data and found they are not scattered randomly through the nebula but are concentrated in a thin spherical shell surrounding the central star. “We painstakingly measured the properties of the buckyballs throughout our dataset and then put together a map of where they all are. Funnily enough, these microscopic hollow spheres are actually distributed in the shape of a hollow sphere as well. Buckyballs arranged like one giant buckyball. We’re still working on why they’re located here, but it’s really fun to see all these small things pop up in our data,” said Giese.

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A question mark in the cosmos

Among the most striking features in the new image is a delicate, curved structure near the centre of the nebula that bears an uncanny resemblance to an upside-down question mark. Its origin is not yet known, and it is one of several mysterious features – alongside bright rays and tenuous wisps of glowing material – that the team’s forthcoming papers will seek to explain. “We put a lot of effort into the data analysis, because we had so many questions about the buckyballs and their surroundings. After a long time, we finally thought we’d start to see some answers, only for the nebula to show us a giant question mark, right in our face. The universe has a cruel sense of humour,” said physics and astronomy PhD candidate Simon Van Schuylenbergh.  

The life and death of a Sun-like star

Tc 1 is what remains after a star similar to our own sun exhausted its nuclear fuel and shed outer layers in expanding shells of gas and dust. The hot stellar core left behind – a white dwarf – floods its surroundings with ultraviolet radiation, causing the expelled gas to glow. This process, unfolding over tens of thousands of years, sculpts the intricate structures now visible with JWST. The carbon-rich chemistry of Tc 1, including its buckyballs, reflects the composition of the star that made it: a window into stellar evolution written in molecules. “Discovering buckyballs in space is important because it helps scientists, like us, track carbon chemistry, explain mysterious signals and understand how organic materials change in extreme environments. Their discovery has also challenged traditional views about space chemistry and offered clues about how life may have begun,” said postdoctoral researcher Dries Van De Putte, who is working on another source that shows fullerene emission. “I am focused on discovering whether these buckyballs formed the same way as they did on Earth or by a completely different process.” https://www.youtube.com/watch?v=CgXL12Tr8PA

A teacher brings the cosmos to life

The striking image released today was processed by Katelyn Beecroft, a secondary school science teacher who is also an avid and gifted amateur astronomer. Beecroft regularly brings her students to Western’s Hume Cronyn Memorial Observatory for field trips and was approached by Cami because of her exceptional skill in drawing subtle structures out of raw telescope data. “Typically, when I work on an image, I have an idea of what the object looks like and what to expect when processing the data. In the case of Tc 1, there are almost no images for the nebula, and those that are available are nowhere near the resolution that JWST captured. There is something wonderful about seeing and bringing out all of the fine detail in a nebula, especially when it is one that you are seeing for the very first time,” said Beecroft. The observations were conducted as part of JWST program GO-4706. The support of the Canadian Space Agency, the Natural Sciences and Engineering Research Council of Canada (NSERC) and a Western University Accelerator Award has been instrumental in building and sustaining this research program. Together, these investments have enabled Western to assemble a diverse team of experienced researchers and internationally recruited graduate students that has established itself as the world leader in the study of cosmic fullerenes. Multiple papers describing the scientific results are in preparation. Learn more about how Western is turning curiosity into solutions.