Scientists discover remains of Jellyfish Nebula's 'sister' supernova

Astronomers may have found the remains of two long-dead stellar siblings

By Sam Macdonald edited by Claire Cameron

A large, irregularly shaped red cloud extends across the upper half of the image. The background is dotted with yellow-white stars, two of which are bright, located in the middle and about 25% of the left and right sides of the image, forming large circles with diffraction spikes. In the center is a short arc of purple gas. To its right, streamers of yellow-white gas form a dome-shaped structure, while at the base of the dome, the streamers appear to be no longer contained, spreading out in curved arcs. An irregular red streamer forms a ring at the base of the dome, about halfway up the complete structure. Shapeless patches of orange and brown clouds evident throughout the scene. — This composite of radio, infrared, optical and ultraviolet data shows the region around IC 443, a famous supernova remnant also known as the Jellyfish Nebula.
NASA Goddard Space Flight Center/Mr. Michailidis et al. 2026; DSS (DSSoptical); MWSIP/ESA/Planck (*radio*); NASA/WISE/JPL-Caltech/UCLA (*infrared*); NASA/Swift (*ultraviolet*); SSR/eROSITA (*x-ray*)

Join our community of science lovers!

Millions of years ago, two massive stars orbited each other in a cosmic dance. Then one of the stars left supernova. The explosion likely threw the exploded star’s companion through space, leaving it adrift in the cosmos for tens of thousands of years before it also succumbed to the same explosive end.

At least that’s what astronomers think happened to a pair of newly identified stellar remnants. Using observations from NASA’s Fermi Gamma-ray Space Telescope, researchers suggest that two clouds of supernova debris were once part of a binary star system: a pair of stars bound together by gravity and orbiting a common center.

“There are so many striking connections between the two remains,” said Miltiadis Michailidis, a postdoctoral researcher in the physics department at Stanford University. in a statement. “They are likely related, giving us the first known example of a binary system in which both stars underwent supernova explosions.”

On supporting science journalism

If you enjoy this article, please consider supporting our award-winning journalism by subscribe. By purchasing a subscription, you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

When a star explodesit expels powerful shock waves that can accelerate charged particles to near-light speeds, creating cosmic rays. As these cosmic rays strike nearby gas cloudsthey produce gamma rays, the most energetic form of light. By detecting these gamma rays, astronomers can trace the lingering remains of ancient supernovae long after the original stars have disappeared.

Against a mottled reddish background dotted with stars, streams of yellow gas at center right outline a dome-shaped structure from which curving tendrils extend toward the lower right. Blue and red filaments trace a ring around the base of the dome. A purple arc extends from right to left, just above the center of the image, and the irregular orange gas clouds become thicker toward the upper left. — This multi-wavelength scene shows the remnant of the Jellyfish Nebula supernova (*RIGHT*), the interstellar cloud it interacts with and a distinctive curved filament at upper left.
NASA Goddard Space Flight Center/Mr. Michailidis et al. 2026; DSS (DSSoptical); NASA/WISE/JPL-Caltech/UCLA (*infrared*); NASA/Swift (*ultraviolet*)

Using 16 years of Fermi observations, researchers examined two remnants of the Gemini constellation: the famous Jellyfish Nebula (IC 443) and a much weaker neighbor called G189.6+3.3. Both remnants appear to interact with the same dense gas clouds. Computer simulations further confirmed the observations. Combined with estimates placing the objects at roughly the same distance from Earth, the data suggests that the two remains share not only a neighborhood but potentially a common origin.

The researchers also calculated that the chances that the observed alignment occurred by chance are less than 1 percent. “We can now connect the bright remnants of two massive stars to a powerful pair that evolved together for thousands of years,” Elizabeth Hays, a Fermi project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in the same release.

If confirmed, the interaction between the Jellyfish Nebula and G189.6+3.3 would provide a rare target for studying how massive binary stars evolve and die. The discovery could also help astronomers better understand the origin of some of the most energetic particles in the universe.

It’s time to defend science

If you enjoyed this article, I would like to ask for your support. Scientific American has been defending science and industry for 180 years, and we are currently experiencing perhaps the most critical moment in these two centuries of history.

I was a Scientific American subscriber since the age of 12, and it helped shape the way I see the world. SciAm always educates and delights me, and inspires a sense of respect for our vast and magnificent universe. I hope this is the case for you too.

If you subscribe to Scientific Americanyou help ensure our coverage centers on meaningful research and discoveries; that we have the resources to account for decisions that threaten laboratories across the United States; and that we support budding and working scientists at a time when the value of science itself too often goes unrecognized.

In exchange, you receive essential information, captivating podcastsbrilliant infographics, newsletters not to be missedunmissable videos, stimulating gamesand the best writings and reports from the scientific world. You can even give someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you will support us in this mission.