(CN) — Six rogue worlds — planetlike objects not bound to any star — detected by the James Webb Space Telescope suggest to researchers that these free-floating bodies, which are only slightly larger than Jupiter, may form like stars do.
In a recent survey of the NGC1333 nebula, the James Webb Space Telescope identified six rogue worlds, including one with a surrounding dusty disk. The bodies, with masses five to ten times that of Jupiter, are some of the lowest-mass objects discovered that were born in the same process that usually produces stars and brown dwarfs — bodies somewhere between stars and planets that never ignite and eventually fade.
“We are probing the very limits of the star-forming process,” said Adam Langeveld, an astrophysicist at Johns Hopkins University and the lead author of the study, in a news release. “If you have an object that looks like a young Jupiter, is it possible that it could have become a star under the right conditions? This is important context for understanding both star and planet formation.”
A new image from the survey, released Tuesday by the European Space Agency, shows the glowing nebula gleaming with dust and clouds. The survey’s findings will be published in The Astronomical Journal.
Webb’s observations focused on the star-forming region about 1,000 light-years away in the Perseus constellation. The telescope’s infrared sensitivity means the researchers could detect even the faintest members of the star cluster, shedding light on how light an object can be while still forming like a star.
According to the researchers, one notable find is a rogue planet five times the mass of Jupiter, surrounded by a dusty disk. The disk suggests that the planet likely formed as stars do, where gas and dust gather around a central object in the early stages of its development.
“Those tiny objects with masses comparable to giant planets may themselves be able to form their own planets,” said co-author Aleks Scholz, an astrophysicist at the University of St. Andrews, in the news release. “This might be a nursery of a miniature planetary system, on a scale much smaller than our solar system.”
These rogue planets, which have masses similar to gas giants, are thought to originate from collapsing molecular clouds that lack the mass to trigger nuclear fusion, the process that powers stars. They may also form within disks of gas and dust around stars and later be ejected from their star systems by gravity.
Although these free-floating objects are considered rare in the Milky Way galaxy, Webb’s data suggest they account for about 10% of the celestial bodies in the targeted star cluster.
In addition to these rogue worlds, the team also discovered a new brown dwarf paired with an object that has a planetlike mass — a rare duo.
“It’s likely that such a pair formed the way binary star systems do, from a cloud fragmenting as it contracted,” said Ray Jayawardhana, senior author of the study, in the news release.
The team will continue studying these objects’ atmospheres and compare them to larger brown dwarfs and gas giants. The scientists plan to use additional observation time with the Webb Telescope to explore more objects with dusty disks to see whether these rogue worlds might host miniature planetary systems.
“The diversity of systems that nature has produced is remarkable and pushes us to refine our models of star and planet formation,” Jayawardhana said.