Jets may have sculpted rings of Cat’s Eye nebula

One high school student’s curiosity unraveled this nebula’s structure

A 3-D model of the Cat’s Eye nebula (left) reveals partial gas rings (yellow) as well as knots and whorls on either side of the central gas bubble (blue). All of these features were probably sculpted by jets erupting from the nebula's core. The visualization is based in part on an image from the Hubble Space Telescope (right).

Visualization: R. Clairmont; Image: NASA, ESA, HEIC and The Hubble Heritage Team/STScI/AURA (CC BY-NC-SA 4.0)

The Cat’s Eye nebula sits roughly 3,000 light-years from Earth. Left in the wake of a star’s death, this whirling cloud of gas and dust is one of the most complex, mysterious nebulae out there. A new computer model has now revealed its 3-D structure. It hints that not one, but two dying stars sculpted its elegant twist.

The research was led by Ryan Clairmont. He’s a college student at Stanford University in California. Last year, while a high school student in San Diego, Calif., he reached out to a couple of astrophysicists. They work at a scientific imaging company called Ilumbra. They had written software to build 3-D models of objects in space. Clairmont wanted to make a 3-D model of the Cat’s Eye.

“I realized there hasn’t been a comprehensive study of the structure of the nebula since the early ’90s,” says Clairmont.

He and his teammates made their model using observations from several telescopes. One was the Hubble Space Telescope. Others were telescopes on the ground. The observations were taken in several different wavelengths of light. Together, they revealed motions in the nebula’s gas. Learning which parts were moving toward and away from Earth helped unveil its 3-D structure.

The team spotted two partial rings on either side of the nebula’s center. The rings are symmetrical, but not complete circles. Those details offer clues to their origins.

Two stars in the nebula’s center could have teamed up to launch two jets of plasma. These gas jets would have blasted out in opposite directions, pointing away from the poles of one of the stars. The jets may have formed the rings on either side of the nebula. But the jets were probably snuffed out before completing a full circle. That’s why the rings appear unfinished. 

The new results appeared in the October Monthly Notices of the Royal Astronomical Society. The work also won Clairmont a prize at the 2021 International Science and Engineering Fair. That competition is run by the Society for Science, which publishes Science News Explores.

Wolfgang Steffen is a partner at Ilumbra who worked on the study. He’s based in Kaiserslautern, Germany. At first, Steffen was doubtful that Clairmont could meet his tight deadline. When the high schooler reached out, he had just two months to complete the project.

“I said that’s impossible!” Steffen says. But Clairmont “did it brilliantly. He pulled it all off and more than we expected.”

Lisa Grossman is the astronomy writer at Science News. She has a degree in astronomy from Cornell University and a graduate certificate in science writing from University of California, Santa Cruz. She lives near Boston.

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