Astronomers have discovered a free-floating planet, untethered to any star, that is consuming surrounding gas and dust at a rate never before seen. The object is undergoing a colossal growth spurt, packing on mass at a furious pace that provides new insights into the turbulent environments of the galaxy’s youngest, most isolated worlds. This finding challenges long-held assumptions about the boundaries between the formation of planets and stars.
The cosmic wanderer, identified as Cha 1107-7626, is pulling in material at a peak rate of six billion tons per second, the most powerful accretion episode ever documented for a planetary-mass object. Located about 620 light-years from Earth, this young rogue planet offers a rare, real-time glimpse into a formation process that appears to mimic that of a star. The observations, detailed in The Astrophysical Journal Letters, suggest the infancy of these lonely planets is far more chaotic and dynamic than previously understood.
A Celestial Wanderer’s Violent Growth
Cha 1107-7626 is a massive object, estimated to be five to 10 times the mass of Jupiter, located in the Chamaeleon constellation. Unlike planets in our solar system, it drifts through space alone, without a parent star. Researchers found that the planet is still actively forming, fed by a large disk of gas and dust that surrounds it. Material from this disk continuously falls onto the object in a process known as accretion.
What startled the international research team was the sheer intensity of this process. An analysis of observations revealed that the planet’s growth rate is highly unstable. By August 2025, Cha 1107-7626 was accreting matter about eight times faster than it had been just a few months earlier, reaching the record-setting speed of six billion tons per second. “We’ve caught this newborn rogue planet in the act of gobbling up stuff at a furious pace,” said Ray Jayawardhana, a senior co-author from Johns Hopkins University. Víctor Almendros-Abad, the study’s lead author, confirmed this is “the strongest accretion episode ever recorded for a planetary-mass object.”
The Engine of Planetary Accretion
How Rogue Planets Grow
Planets are built through accretion, where gravity slowly pulls dust, gas, and other small bodies together into larger and larger clumps. For a rogue planet like Cha 1107-7626, this process is fueled by a personal protoplanetary disk, much like those that form planets around young stars. As this material spirals inward, it crashes onto the central body, causing it to gain mass over millions of years.
A Star-Like Magnetic Field
The extreme rate of accretion observed in Cha 1107-7626 suggests a mechanism more powerful than gravity alone may be at work. Researchers believe the planet’s magnetic field played a significant role in its rapid growth spurt. This field can channel infalling material from the disk directly onto the planet, accelerating the accretion rate in a way that has previously been observed in young, developing stars but not in planets.
Blurring the Lines of Formation
The discovery forces a re-evaluation of how rogue planets come to be. “The origin of rogue planets remains an open question,” explained co-author Aleks Scholz of the University of St Andrews. “Are they the lowest-mass objects formed like stars, or giant planets ejected from their birth systems?” Most theories have centered on the idea that they are gas giants violently kicked out of their home solar systems during periods of instability.
However, the behavior of Cha 1107-7626 provides strong evidence for an alternative path. The intense, variable accretion bursts it displays are remarkably similar to the feeding frenzies of infant stars. This suggests that at least some rogue planets may form in isolation from clouds of interstellar gas and dust, just as stars do, representing the smallest possible objects to emerge from that process. “This discovery blurs the line between stars and planets and gives us a sneak peek into the earliest formation periods of rogue planets,” said astronomer Belinda Damian, also at St Andrews.
Telescopes Pinpoint the Discovery
Ground and Space-Based Observations
The breakthrough was made possible by combining data from some of the world’s most powerful observatories. The core findings came from the X-shooter spectrograph on the European Southern Observatory’s Very Large Telescope (VLT), located in Chile’s Atacama Desert. This sensitive instrument allowed the team to measure the glow from the accreting material and calculate its velocity and mass. The team also utilized data from the James Webb Space Telescope and reviewed archival observations made by the VLT’s SINFONI spectrograph to build a comprehensive picture of the planet’s behavior over time.
Tracking Chemical Changes
The observations also revealed a surprising chemical transformation during the growth spurt. According to one report, water vapor was not detected around the planet prior to the accretion burst but became present during the high-rate episode. This suggests the intense infall of new material from the disk altered the chemistry in the planet’s immediate vicinity, providing another layer of data on the complex interactions involved in its formation.
A New Understanding of Planetary Infancy
The case of Cha 1107-7626 marks a significant step forward in understanding the diversity of planetary evolution. It shows that the lives of cosmic wanderers can be unexpectedly active and violent, reshaping the narrative that planets are quiet and stable worlds. The discovery demonstrates that starless planets can grow through dramatic, episodic bursts that profoundly influence their development, mirroring the behavior of their stellar cousins.
By capturing such a rare and intense event, astronomers have opened a new window into the physical processes governing the galaxy’s smallest and most mysterious objects. The findings provide a crucial anchor point for theories of planet and star formation, showing that the universe has more than one way to build a world. The research highlights that the earliest phases of these rogue objects are more tumultuous and star-like than anyone had realized.
