James Webb and Very Large telescopes discover bizarre ‘runaway’ planet that’s acting like a star, eating 6 billion tons per second
Astronomers have spotted a “rogue” planet gobbling up gas and dust at a record rate, and they can’t explain its puzzling behavior.
Although many rogue planets, which float freely in space without orbiting a star, have already been discovered, this one – known as Cha 1107-7626 – appears to be the fastest-growing free-floating planet ever discovered, gorging itself at a peak rate of 6.6 billion tons (6 billion metric tons) of material per second, according to observations with the European Southern Observatory’s Very Large Telescope (VLT). in Chile and Chile. James Webb Space Telescope (JWST).
“Our main motivation for studying this type of object is to understand whether these objects are ancient planets that were ejected from their planetary systems, or whether they formed ‘isolated’ from the gravitational collapse of molecular cloud matter, like stars,” said the study’s lead author. Victor Almendros-Abadan astronomer at the Palermo Astronomical Observatory in Italy, told Live Science in an email.
The team spotted an “accretion explosion,” which occurs when a planet suddenly attracts a large amount of material from its surrounding disk of gas and dust. Cha 1107-7626 still accumulates from this source material, but the study shows that the accretion rate is not stable. In fact, by August 2025, the planet was accumulating eight times faster than it was just months before.
Accretionary bursts suggest that rogue worlds might resemble young stars, since these sudden bursts of nourishment have been observed in stars. But because rogue planets are much smaller than stars, it’s unclear where their formation pathways diverge.
“Accretion bursts have been known for some time; the first was discovered in the late 1930s, well before it was clear what we were seeing,” co-author of the study. Alexander Scholzprofessor of astrophysics at the University of St. Andrews in Scotland, told Live Science in an email. “We now know that such events play an important role in the assembly of stars. They also shape the environment in which planetary systems form, by heating the nebula of gas and dust surrounding young stars.
“The remnants of such explosions can be seen in the chemistry of meteorites from our own solar system,” Scholz continued. “It is not clear whether the bursts occur in all young stars, or what triggers them. The discovery of a similar event in a planetary-mass object could be a clue to the existence of a universal mechanism behind accretionary bursts. In this sense, our discovery will have a much broader impact.”
Scientists have spotted more rogue planets in recent years, including a notable capture by JWST that discovered more than 500 of these worlds in a trapezoid-shaped location within the Orion Nebula, a vast cloud of gas known for star birth.
Rogue planets remain difficult to find, however, because they glow in infrared light (radiant energy) better visible in large telescopes such as the JWST and VLT, Almendros-Abad said. Scientists hope the VLT and JWST can examine more of these rogue planets, to find out whether they form like stars or planets. Almendros-Abad noted that accretion parallels between stars and planets are not fully understood.
“One of the next steps is to understand how common these types of events are on ‘rogue planets,'” he said. “This will tell us how important it is [accretion events] are in their evolution.”
