These celestial bodies are slightly larger than Jupiter
Astronomers using the James Webb Space Telescope have detected six rogue worlds—cosmic bodies that do not orbit stars. These celestial bodies are slightly larger than Jupiter and offer new insights into the formation of stars and planets in the universe.
The Webb telescope observed the star-forming nebula NGC 1333, located 960 light-years away within the Perseus molecular cloud. This nebula's turbulence causes knots to form that collapse under gravity, leading to the formation of stars. Unlike the Hubble Space Telescope, which was hampered by dust, Webb's ability to observe in infrared light allowed it to see through the dust and capture detailed images.
Within the nebula, Webb identified objects with masses similar to newborn stars, brown dwarfs, and planets about five to ten times heavier than Jupiter. These findings highlight the existence of low-mass objects that formed through processes typically associated with star formation, rather than planets or brown dwarfs.
The study has been accepted for publication. Astronomical JournalThis study explores the fundamental question of how an object can form in such a light that it can become a star. “The smallest free-floating objects that form like stars are comparable in mass to giant exoplanets,” said senior study author Ray Jayawardhana, an astrophysicist at Johns Hopkins University.
Study lead author Adam Langeveld, also an astrophysicist at Johns Hopkins, emphasized that these observations push the boundaries of understanding stellar and planetary formation, and raised the question of whether objects resembling young Jupiters could become stars under certain conditions.
The study confirms that planetary-mass objects can form in two different ways: from the contraction of clouds of gas and dust that resemble stars, or from disks of gas and dust around young stars, as is the case with Jupiter in our solar system.
A recently discovered object has a mass equivalent to five Jupiters, or about 1,600 Earths, and the dusty disk surrounding it suggests it formed like a star. This raises the possibility that such planet-like bodies could form their own small planetary systems.
Alex Scholz, an astrophysicist at the University of St. Andrews and co-author of the study, suggested that bodies with similar masses to planets could potentially form their own planets, leading to the creation of small planetary systems.
The Webb telescope also discovered a rare pair: a brown dwarf with a planetary-mass companion body that likely formed from a fragmented cloud.
Researchers continue to study these rogue planets, aiming to understand their formation and evolution. NASA's Nancy Grace Roman Space Telescope, launching in May 2027, could further clarify the nature of these wandering planets and help unravel the mysteries of their existence.