Using the James Webb Space Telescope (JWST), astronomers recently discovered a new type of celestial object in the star birth region closest to Earth that could challenge existing theories about how planets and stars are born.
The object discovered in the Orion Nebula, located about 1,350 light years from Earth and known as Messier 42 (M42), has a mass similar to that of Jupiter—and much more in the form of a binary pair. Scientists who observed around 42 pairs of objects floating freely and not tied to this star named them “Jupiter-mass binary objects” or “JuMBO”.
JuMBO’s mass is too small to be considered a stellar body or even a “failed star” brown dwarf, but one of its discoverers, Mark McCaughrean, senior science advisor at the European Space Agency (ESA), said Popular Mechanics that just because these objects have what astronomers call “planetary mass” does not mean they should also be labeled planets.
Dive Deeper Into the Cosmos ⬇️
What exactly is JuMBO?
JuMBO is hot and gaseous, and is something completely new—and more than a little strange.
This new class of celestial bodies is very strange because they can pair up even though they have a mass smaller than the lightest stars. This is contrary to the current binary model, which states that the smaller the mass of an object, the less likely it is to be accompanied.
Although about 75 percent of massive stars are binaries, only about 50 percent of solar-mass stars are found in binaries, and only 25 percent of low-mass stars are found in pairs. Brown dwarf binary systems – objects with masses 13 to 75 times the mass of Jupiter that are born like stars, but do not have enough mass to trigger the hydrogen nuclear fusion that forms a star – are increasingly rare.
Apep, a triple star system containing a Wolf-Rayet binary and a hot supergiant, in the constellation Norma. This winding vortex was formed by the collision of two strong stellar wind trains, producing a cloud of dust that looked like a reddish pinwheel.
ESO/VLT/ Callingham et al.
This means that objects with masses well below 13 times the mass of Jupiter and just below the theoretical mass of the smallest brown dwarf – about three to seven Jupiter masses – should not be in a partnership, especially in a wide binary separated by up to 300 times the distance of Earth and sun.
“It’s amazing to find this. “What we see are wide binaries separated by the size of our solar system, and the frequency of wide binaries when you get to the bottom of a brown dwarf is effectively zero,” he explained. McCaughrean, who discovered JuMBO with fellow ESA scientist Samuel Pearson. “But, suddenly, for us, when we switched to smaller masses, the number increased to 10 percent. That’s one of the things about JuMBO that really makes people wonder: how do I change the binary frequency back?”
JuMBO 10.
NASA/ESA/CSA JWST NIRCam (McCaughrean dkk.)
Nobody predicted JuMBO
University of Exeter astrophysicist Matthew Bate, who studies star and planet formation and was not involved in the discovery, is one of those metaphorical head-scratchers.
“The fact that there are free-floating planets is not a surprise, but this planetary-mass binary object was a big surprise because no one expected it,” Bate said. Popular Mechanics. “One or two objects, you can explain it by an unusual set of initial conditions, but the fact that there are so many objects found in Orion implies that there is a fairly frequent way of forming these systems, and it is not understood at all.”
McCaughrean argues that there are essentially two possible basic mechanisms for JuMBO formation, but neither of these theories is perfect.
“The first method will look at the shape of JuMBOs like stars and brown dwarfs, from the fragmentation of an initial large cloud of gas and dust into smaller and smaller chunks,” explained the ESA scientists. “The problem is, there’s a boundary that says, ‘Sorry, you can’t get past it,’ and the cloud won’t break up into smaller pieces. We see objects that are, say, ten times smaller than that limit.”
McCaughrean added that another possibility is that JuMBO formed like a planet in a disk of gas and dust called a “protoplanetary disk” around young stars – as planets in the solar system did 4.6 billion years ago – and then somehow removed from this system. as a result of internal or external gravitational effects such as encounters with other star systems.
This is a Hubble Space Telescope image of four protoplanetary disks circling young stars in the Orion Nebula, about 1,300 light years away. The size of the disk ranges from two to eight times the diameter of our solar system.
Mark McCaughrean (Max-Planck Institute for Astronomy), C. Robert O’Dell (Rice University), and NASA
“The problem is that no one knows how to repel these two planetary-mass objects and keep them stuck to each other,” McCaughrean said.
When considering JuMBOs, Bate also considered the possibility that they formed like planets and were then exiled from their native star systems.
“It’s hard to see how you would do that for this JuMBO because you would have to reject two Jovian mass planets almost simultaneously from the same planetary system meaning they would still be weakly bound and orbiting each other,” Bate said. “Again, maybe this could happen very, very rarely, but it doesn’t seem unreasonable that you could do that and produce 42 of them in the Orion Nebula Cluster.”
A wide view of the Orion Nebula, with the four Trapezium stars in the center.
KPNO/NOIRLab/NSF/AURA/Ryan Steinberg and Family/Adam Block, CC BY 4.0, via Wikimedia Commons
Does JuMBO exist somewhere else in the universe?
Bate ran simulations of star and planet formation processes and said he had never seen JuMBO form in those models. This means, according to him, that the discovery of JuMBO shows that there is a missing element in our recipe for how celestial bodies are born. The big question for Bate now is whether JuMBO is unique to Orion or whether we will find it in other star-forming regions.
“There’s clearly something strange going on, and it’s not just happening on Orion; this may happen elsewhere,” McCaughrean said. “Of course, one of the things we want to do now is leave until we find these things somewhere else.”
The search for JuMBO beyond Orion could help determine whether a large bright star called the Trapezium star, which sits at the heart of this nebula, could have played a role in the formation of this strange object. These stars can act as giant “ultraviolet flashlights” in the center of the region, blowing away star-forming gas and dust and also influencing it in a way that allows the creation of objects smaller than typical star formation allows.
“I’ve been watching Orion, as I said, for about 37 years, and I’ve tried to use the best technology to see what’s new, what the last generation of technology couldn’t see,” McCaughrean said. “But to discover something I didn’t expect at all? That’s what we live for, as astronomical observers, pointing a telescope somewhere and seeing something no human has ever seen before. Yes, that’s what the dream is like, isn’t it?”
Robert Lea is a freelance science journalist who focuses on outer space, astronomy, and physics. Rob’s article was published on News Week, Space, Live Science, Astronomy magazines and New Scientist. He lives in the North West of England with too many cats and comic books.
2023-10-25 07:08:58
#Astronomers #scratch #heads #discover #JuMBO #SurabayaPostKota.net
