To unlock the universe’s many mysteries, astronomers are searching for elusive space objects called rogue worlds — potentially trillions of them. These stellar objects blur the boundary between planets and stars, with the goal of better understanding the cosmic processes that shape both.
A team of astronomers using the James Webb Space Telescope (JWST) recently discovered six new rogue planets in a young nebula. Details of their discovery can be found here Research published on August 27th Astronomical Journal And it suggests that rogue planets could create objects even larger than Jupiter. These newly discovered planets There may also be gas giants five to ten times larger. It is larger than the largest planet in the solar system.
[Related: Space probably has way more ‘rogue planets’ than we thought.]
“We’re probing the limits of the star formation process,” says study co-author Adam Langeveld, an astrophysicist at Johns Hopkins University. It said in a statement“If you have a young Jupiter-like object, could it become a star under the right conditions? This is important context for understanding the formation of stars and planets.”
What is Rogue World?
alias Wandering PlanetThese free-floating objects have masses similar to planets, but unlike planets, they are not bound by the gravity of a central star the way Earth is bound by the gravity of the Sun. Instead, they drift through space.
However, their formation and size are similar to stars. Most rogue planets form from material ejected during the early stages of planet formation, when collisions are more frequent. Others may have surrounding disks of cosmic dust that are important for the formation of stars and planets. Other planets may form by collapse. Molecular Clouds They lack enough mass to undergo nuclear fusion, the energy source of stars, and despite these similarities, they lie on the border between stars and planets.
on the other hand Approximately 70 to 170 known or suspected planetsSome scientists say There may be trillions of them in a galaxy.
Importantly, the mass of rogue planets overlaps with that of gas giants and brown dwarfs like Saturn and Jupiter, making their classification murky. Although rogue planets are rare in our home Milky Way galaxy, the new JWST data shows that they make up about 10% of objects recently observed in target clusters.NGC1333.
Rogue planet in a young nebula
So studyThe team used data from JWST’s deepest survey of the young nebula NGC 1333, a star-forming cluster located in the About 1,000 light years away from Earth NGC 1333 in the constellation Perseus. Newly released images accompanying the study show the nebula glowing with dramatic interstellar dust and clouds.
[Related: The Ring Nebula is a glowing gas-filled donut in the latest JWST snap.]
“We used Webb’s unprecedented sensitivity at infrared wavelengths to seek out the faintest members of young star clusters and answer a fundamental question in astronomy: how much light does an object need to form like a star?” said study co-author Ray Jayawardene, an astrophysicist and provost at Johns Hopkins University. It said in a statement“The smallest stray objects forming like stars turn out to be comparable in mass to giant exoplanets orbiting nearby stars.”
In the observations, the team No objects less than five times the mass of Jupiter were detected.The results suggest that stars lighter than this threshold are more likely to form like planets rather than stars, even though JWST has the sensitivity needed to detect such objects.
“Our observations confirm that nature can produce planetary-mass objects in at least two different ways: from the collapse of clouds of gas and dust as stars form, and from disks of gas and dust around young stars, such as Jupiter in our own solar system,” Jayawardene said.
Dusty disc
The most intriguing of these starless objects is also the lightest, with an estimated mass of about five Jupiter’s mass, or the mass of Earth and its nearby dusty disk.
The presence of the disk suggests the object may have formed in the same way as a star, as such dust particles typically rotate around a central object during the early stages of star formation, according to the study.
Such disks are also a prerequisite for planet formation, and this disk could also have important implications for the formation of potential “mini” planets.
“These small objects with masses comparable to those of the giant planets could potentially form planets themselves,” said study co-author Alek Scholz, an astrophysicist at the University of St. Andrews in Scotland. It said in a statement“This could be a nursery for small planetary systems, much smaller in scale than our solar system.”
[Related: Astronomers spot an extragalactic star with a disc around it for the first time.]
and The NIRISS instrument installed on the JWSTThe astronomers measured the infrared profiles (spectra) of all objects in the cluster’s visible range and reanalyzed 19 known brown dwarfs. They also discovered a new brown dwarf with a planetary-mass companion, an unusual discovery that the team says calls into question some theories about the formation of binary star systems.
“Such pairs likely formed when a cloud collapsed and split apart, similar to how binary systems do,” Jayawardene said. “The diversity of systems created by nature is astonishing, and it challenges us to refine our models of stellar and planetary formation.”
In future studies, the team plans to continue studying the atmospheres of more faint objects and compare them with those of more massive brown dwarfs and gas giants. They also plan to use the JWST to study similar objects with dusty disks and explore whether these disks may form small planetary systems similar to the many moons of Jupiter and Saturn.
