The enigmatic “rogue” duo of Jupiter-sized objects identified by the James Webb Space Telescope (JWST) may represent only a fraction of what was initially formed, according to new research. This discovery implies that these intriguing entities, referred to as “Jumbos,” are more uncommon than previously believed and prompts deeper inquiries into their existence.
Jumbo, an abbreviation for “Jupiter-Mass binary object,” refers to the pair of Jupiter-sized celestial bodies found by JWST in the trapezoidal region of the Orion Nebula cluster in 2023. Each jumbo comprises two gas giants, with masses ranging from 0.7 to 30 times that of Jupiter. Notably, Jumbo pairs do not orbit around stars; rather, they revolve around each other at distances of approximately 25 to 400 astronomical units, existing freely or in a state described as “injustice.” (One astronomical unit is about 93 million miles, or 150 million kilometers—the average distance between the Earth and the Sun.)
The existence of these pairs and their apparent detachment from any stellar anchor challenges prevailing theories regarding planetary formation. Nevertheless, scientists have proposed several hypotheses regarding the emergence of jumbos. One suggestion is that they originated from another star. Another theory posits that Jumbos represent the cores of eroded embryonic stars, indicating their formation process resembles that of stars.
However, some researchers express skepticism about the very existence of Jumbos. For instance, in 2024, Kevin Luman, a professor in the Department of Astronomy and Astrophysics at Pennsylvania State University, suggested through a reanalysis of JWST’s observations that the objects in question were not actually planets. Instead, he theorized that they could be distant background entities inadvertently captured in the imagery of the Orion Nebula Cluster by JWST.
In fact, Richard Parker, a senior lecturer in astrophysics at the University of Sheffield and the lead author of this new study, informed Live Science via email that Luhman’s research discussions were the catalyst for these new investigations. During a collaborative meeting, Simon Goodwin, a professor of Theoretical Astrophysics at the University of Sheffield and co-author of the current study, suggested that simulations could assist in illuminating how prone Jumbos are to destruction. Notably, prior studies had not examined the longevity of these planetary pairs in the interstellar medium, which is filled with stars capable of fracturing the duo through intense gravitational pulls.
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To investigate how well Jumbos can withstand turbulence in their birth environments, Parker, Goodwin, and Jessica Diamond, an Integrated Masters student at the University of Sheffield, created a computer simulation of the nebula containing a mixture of stars and jumbos.
The researchers produced five variations of this model, adjusting internal parameters such as the distance between members of a binary system and the overall density of the nebula. Each model underwent a 10-round N-body simulation.
“These computer simulations compute the gravitational forces acting on each object from all others,” Parker noted, emphasizing that these calculations can be iterated to reveal how various components of the modeled nebula interact over time.
Findings indicated that the simulated jumbos have a notably short lifespan. In densely populated nebulae, nearly 90% of the planetary pairs were erased by neighboring stars within a million years. Even under the best circumstances—where fewer stars exist and Jumbos gracefully circulate—the survival rate for the pairs was only about 50%. The analysis showed that a greater separation between planet pairs increased their odds of becoming confused.
Parker remarked that he and his colleagues had previously discovered that planetary systems are exceedingly fragile in star-dense environments, and he was not especially surprised by these results. “This is because the planets and planet binaries are relatively small, possess low energy, and are highly susceptible to destruction.”
The results were published in the journal on May 2nd Monthly Notices of the Royal Astronomical Society: Letters, indicating that the observed Jumbos are exceptionally rare. However, Parker stated that this could imply the same troubling possibility proposed by Luman: The planetary pairs must have originated in much larger numbers than currently considered to account for the number of Jumbos detected by JWST. According to Parker, this underscores the idea of Jumbo origins as mere background artifacts.
“I think the next step is for someone else to reanalyze the original JWST data,” he concluded.
Source: www.livescience.com