Beauty in the void
UWG Astronomer Helps Reveal New Secrets of the Butterfly Nebula Share this page
In the silent expanse of space, a celestial butterfly made of stardust unfurls its radiant wings. The Butterfly Nebula – a dying star’s final, dazzling performance – has long captured the imaginations of astronomers and dreamers alike. For the University of West Georgia’s Dr. Nicholas Sterling, seeing it through the eyes of the James Webb Space Telescope (JWST) wasn’t just a scientific milestone. It was a moment of pure wonder.
And as part of a global team using JWST, Sterling analyzed one of the universe’s most spectacular transformations. He said balancing scientific precision with this sense of awe is why he’s in astronomy.
“I majored in chemistry before switching to physics and math,” Sterling, a physics professor in the Dr. James ‘Earl’ Perry College of Mathematics, Computing and Sciences, recalled. “After a gap year doing research, I discovered spectroscopy was my fit. A spectrum – bright emission lines from a nebula or dark absorption lines from a star – is a puzzle, and identifying these lines is like sorting pieces by color. Determining compositions, dust masses and physical conditions is putting pieces together to form a picture. But the result is more than that. It’s a story about an object’s life and its context in cosmic evolution.”
The Butterfly Nebula is a brilliantly glowing cloud of gas and dust. Once a star, a few times more massive than our Sun, it shed its outer layers when it ran out of fuel, ejecting bright lobe-shaped streams into space that take the appearance of a butterfly. At its center, the incredible hot core of the star lights up the material it cast off – a powerful reminder that even in death, a star can create something beautiful.
Sterling’s role was to analyze the approximately 200 atomic emission lines detected in the mid-infrared spectrum of this highly unusual object.
“If you disperse white light through a prism, you get a rainbow,” he explained. “When that light passes through a cooler, less dense gas, certain colors appear darker because of absorption. For hot, low-density gases, like a planetary nebula, you see bright lines at specific colors or wavelengths that arise from different atoms and molecules. In the infrared, where these observations were made, there are no ‘colors,’ just a graph of brightness vs. wavelength.”
Explaining a complex shape like this from a single star’s death is difficult, he admitted. Multiple stars could explain its unusual structure, Sterling said, but none have been found. In fact, the Butterfly Nebula’s central star has not even been detected, because it’s enshrouded in a cloak of dust that blocks its light.
Models suggest the hidden star burns at about 220,000 kelvins – far hotter and over 400,000 times brighter than the Sun. This makes it one of the hottest, if not the hottest, stars known, and the nebula itself ranks among the most extreme planetary nebulae ever observed.
That extremity extends to its chemistry. Massive outflows produced oxygen-rich ejecta, yet JWST detected both oxygen-rich dust and large carbon molecules – an unusual combination in such a hot environment. Among those carbon-based molecules is one never before seen in a planetary nebula, believed to play a key role in forming complex carbon compounds. These findings mark a significant step toward understanding how the building blocks of planets emerge and may even offer clues to the fate of our own Sun – though that transformation is still five billion years away.
Sterling’s students are analyzing observations of other planetary nebulae using JWST and telescopes at ground-based research observatories. Sterling said it’s a testament to the university’s STEM faculty and commitment to undergraduate research.
“One of the things that makes UWG special is that undergraduates get involved in cutting-edge research and collaborations,” Sterling said. “We don’t have physics graduate students, so our undergrads take on roles that are rare even at many R1 institutions.”
Projects like this remind us that science isn’t only about equations and observations. It’s about curiosity and a shared desire to understand where we come from – and where we’re going. Finding complex molecules and dust, the building blocks of planets, in a place as harsh and hostile as the Butterfly Nebula, where radiation and high ionization make chemistry difficult, shows that even in extreme environments, the basic ingredients for life can form.
“This really opens the door to the ‘are we alone?’ question,” Sterling concluded. “We’re seeing chemistry in dying stars and molecular clouds forming new stars and planetary systems. It’s fascinating.”