Astronomers have uncovered surprising new details about a galaxy that looks like a jellyfish—and even sports a pair of strange “bunny ears.”
This galaxy, named NGC 4858, is racing through a distant cluster of galaxies, and the extreme conditions it’s facing are giving scientists a rare peek into how galaxies behave in harsh environments.
NGC 4858 is located over 300 million light-years away in the Coma Cluster, one of the largest structures in the universe.
Galaxy clusters like this are packed with hot gas and dark matter, creating an environment so intense that galaxies passing through it can lose much of their internal gas.
When that happens, the galaxy stretches out and forms long trails of gas and stars, giving it the nickname “jellyfish galaxy.”
Led by Yale University’s Harrison Souchereau and Professor Jeffrey Kenney, a team of astronomers used powerful radio and space telescopes to get a closer look at NGC 4858.
Using the ALMA radio telescope and data from the Hubble Space Telescope, the team discovered not only the classic jellyfish shape, but also some odd new features that hadn’t been seen clearly before.
Most notably, they found that the galaxy’s spiral arms have been distorted by the powerful pressure around it, creating shapes that resemble bunny ears.
This pressure, known as ram pressure, acts like a wind tunnel, pushing the galaxy’s gas backward as it races forward. Combined with the galaxy’s natural spinning motion, the gas is twisted into unusual forms.
Even more interesting, the team observed something called “fallback.” This happens when gas is pushed out of the galaxy by ram pressure but doesn’t escape completely.
Instead, it falls back toward the galaxy, forming a kind of galactic fountain. As it falls back in, the gas clumps into twisted spiral arms in the galaxy’s inner “tail.”
While fallback has been suggested in the past, this is the clearest evidence yet. It shows that galaxy stripping isn’t always a one-way process—some of the gas can return, possibly helping to form new stars.
“This galaxy gives us a chance to see these rare processes in action,” said Souchereau, who presented the findings at the American Astronomical Society’s summer meeting.
The study involved an international team of scientists from over 10 countries and drew on data from telescopes around the world.
Their discovery helps deepen our understanding of how galaxies evolve and survive in the most extreme corners of the universe—and it proves that even in deep space, surprises can come with floppy “ears.”
Source: Yale.
