These celestial bodies are slightly larger than Jupiter, and their studies reveal how stars and planets form in the universe.
JWST was aimed at a star-forming nebula, a cloud of gas and dust NGC 1333, 960 light-years away in a larger cloud of gas and dust called the Perseus Molecular Cloud. Turbulence in the hazy nebula creates clumps that collapse (collapse) due to gravity to give birth to a star.
Although the Hubble Space Telescope has captured images of the nebula before, the dust obscured the view of the star formation process. However, JWST, which can observe the universe in the infrared range, was able to penetrate the dust.
The nebula contains newly formed stars, brown dwarfs, and planet-like objects, all about 5 to 10 times more massive than Jupiter. They have been found to be the lowest-mass objects that emerged from the process that normally forms stars (which are much larger than planets) or brown dwarfs (objects in the sky that are neither stars nor planets at all). Brown dwarfs are more massive than planets, but not as massive as stars.
“By searching for the faintest members of the young star cluster with the JWST instrument at infrared wavelengths, we sought to answer a fundamental question in astronomy: at what light can an object form as a star?” – said in a statement one of the authors of the study, Johns Hopkins University vice-chancellor and astrophysicist Ray Jayawardhana. “It turns out that the smallest free-floating objects that form as stars have the same mass as the giant exoplanets orbiting the nearest stars.”
These observations help astronomers better understand the different ways in which stellar objects form.
“We are probing the very limits of the star formation process,” lead study author Adam Langeveld, an astrophysicist at Johns Hopkins University, said in a statement. – If we 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 an important context for understanding both star and planet formation.”
Creating free-floating worlds
Stars usually form from clouds of gas and dust. The material left over from star formation then forms planets. But it’s possible that stellar bodies can also form in a similar way to planets, the study’s authors say.
“Our observations confirm that nature creates planetary-mass objects in at least two different ways: from the collapse of a cloud of gas and dust, the way stars form, and from disks of gas and dust around young stars, the way Jupiter formed in our Solar System.” said R. Jayawardhana.
One of the newly discovered objects has a mass equal to the mass of five Jupiters. The disk of dust surrounding the object suggests that it likely formed in a similar way to a star. And given that disks of gas and dust can drive planet formation, it’s possible that a planet-like object could have formed “mini” planets as well.
“These tiny objects, with masses comparable to giant planets, can form their own planets,” said one of the study’s authors, astrophysicist Alex Scholz of the University of St. Andrews in the United Kingdom. “It could be the cradle of a miniature planetary system much smaller in scale than our own solar system.”
Using JWST, the team examined the nebula in detail in infrared light, which is invisible to the human eye, and observed a rare phenomenon: a brown dwarf with an accompanying object that also has the mass of a planet.
“It is likely that such a pair formed in the same way that binary star systems form, from a cloud that fragmented as it contracted,” Jayawardhana said. “The variety of systems created by nature is extraordinary and forces us to improve our existing models of star and planet formation.”
Astronomers are still trying to figure out how free-floating worlds form and evolve. It is possible that planet-like bodies initially form around stars and orbit them, but are pushed out by gravitational interactions with other bodies.
Free-floating planets make up about 10 percent. celestial bodies in the nebula studied by JWST, but these mysterious objects are still considered rare in the Milky Way. In the future, the team will use JWST to study more such objects and see how they might form their own mini-planet systems.
And when in 2027 NASA’s Nancy Grace Roman Space Telescope will be launched in May and will be able to detect hundreds of free-floating planets and help astronomers unravel the secrets of these worlds, writes CNN.
2024-09-01 05:42:11