A sudden growth spurt has led to a ‘rogue’ planet becoming the fastest-growing planet ever seen.
The planet unexpectedly began gorging on the gas surrounding it a few months ago and is now swallowing down six billion tonnes (2.2 trillion pounds) every second, according to a new study. That makes it the hungriest world on record.
The planet, named Cha 1107-7626, is 5 to 10 times the mass of Jupiter and located 620 light-years away. As a rogue planet, it doesn’t orbit a star but instead floats freely through the cosmos on its own.
Where these rogue planets come from is still a mystery, but the discovery seems to suggest this one, at least, is forming more like a star than a planet.
“People may think of planets as quiet and stable worlds, but with this discovery we see that planetary-mass objects freely floating in space can be exciting places,” said Dr Victor Almendros-Abad, an astronomer from the National Institute for Astrophysics, Italy, who led the study.
Cha 1107-7626 is surrounded by a disc of gas and dust that is falling onto the planet’s surface, allowing it to grow through a process known as accretion.
Over the last year, astronomers noticed the planet was growing increasingly ravenous, feasting on more and more gas. By August 2025 it was gathering eight times more gas than it had done just a few months before.
“This is the strongest accretion episode ever recorded for a planetary-mass object,” said Almendros-Abad.
Exactly how these wandering worlds come to be has puzzled astronomers for years. Currently, there are two leading theories: either they started life around a star but were then hurled out into the void, or they grow on their own from a collapsed cloud of gas and dust like a star does.
To find some clue, astronomers picked through the light from the planet before and during its burst. They found signs that a strong magnetic field was guiding how the gas fell onto the planet. There were also signs of water vapour surrounding it during the burst, but not before. Both of these phenomena have been seen around growing stars but never in infant planets.
“The idea that a planetary object can behave like a star is awe-inspiring and invites us to wonder what worlds beyond our own could be like during their nascent stages,” said Dr Amelia Bayo, an astronomer for the European Southern Observatory, who also took part in the study.
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