Unlike the planets in our Solar System, as well as most of the exoplanets we have discovered so far, "rogue" planets do not orbit a star, but wander through space on their own. New observations, carried out with the European Southern Observatory’s (ESO) VLT telescope (ESO), reveal that one of them is absorbing gas and dust from its surroundings at a rate of six billion metric tons per second. This is the fastest growth rate ever recorded for any planet.
With a mass 5 to 10 times greater than that of Jupiter, this rogue planet, designated Cha 1107-7626, is located approximately 620 light-years away. According to the relevant observations, it is surrounded by a disk of gas and dust, from which it absorbs large quantities of material, constantly increasing its mass. A study of this object by a team of astronomers led by Victor Almendros-Abad of the National Institute of Astrophysics (INAF) in Italy demonstrates that the rate at which the young planet’s mass increases—as it attracts more and more particles of matter through its gravitational pull—is not constant.
Starting in August 2025, that is, the rate at which its mass was increasing had increased eightfold compared to what had been calculated just a few months earlier, now reaching six billion metric tons of matter per second! ““This is the strongest episode of matter accumulation ever recorded for an object with a mass comparable to that of a planet,”Almendros-Abad said. The results of the study were published on October 2 in the scientific journal TheAstrophysicalJournalLetters.
"The origin of 'stray' planets remains an open question: Are these perhaps the objects with the smallest mass, which formed in much the same way as stars, or are they giant planets that were ejected from their parent planetary systems for some reason?” asks co-author Aleks Scholz, an astronomer at the University of St. Andrews in Scotland. It is well known that such “bursts” of matter accumulation are observed primarily in newborn stars, which are surrounded by protoplanetary disks of gas and dust. The new findings show, however, that some rogue planets may indeed form in much the same way as stars.
In fact, according to an analysis of the relevant data, the trigger for this dramatic “spike” in aggregation may well be magnetic activity—something that, until now, had only been observed in stars. This suggests that even objects with low mass—such as planets—may possess strong magnetic fields capable of triggering these phenomena of enhanced matter accumulation.
As Amelia Bayo, one of the study’s authors and an ESO astronomer, stated, “The idea that a planetary object can behave like a star is striking and makes us wonder what other worlds beyond our own, during their early stages of evolution.”.
Photo: Artist's impression of the "rogue" planet Cha 1107-7626 (Credit: ESO/L. Calçada/M. Kornmesser)