2023-10-04 10:35:00
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At the heart of the Orion Nebula, the James Webb Space Telescope (JWST) has uncovered the existence of the JuMBOs (Jupiter Mass Binary Objects, or Jovian Mass Binary Objects), a series of celestial entities that blur the lines that separate the planets from the stars.
Video: images from the James Webb Space Telescope
The difference between a planet and a star, in principle, seems clear. However, the distinction becomes blurred when we look at gas giants like Jupiter and stellar objects like brown dwarfs. Both, although with different masses, share a similar composition, which is not a mostly solid rock like the Earth.
Neither stars nor planets: this is what brown dwarfs are like
The key to unraveling this distinction lies in how these celestial objects reach the critical mass necessary to trigger nuclear reactions in their core. Stars are born when gas clouds collapse under their own gravity, reaching masses sufficient to fuse hydrogen into helium. On the other hand, brown dwarfs, with masses between 13 and 80 times that of Jupiter, do not reach this critical threshold and fall short on the path to nuclear fusion. Now, JuMBOs add another layer of complexity to this scenario.
JuMBOs, gaseous entities
These entities are gaseous in nature, exhibiting traces of methane and steam in their atmosphere, with a surface temperature that reaches 1,000 °C. Not being linked to any star, JuMBOs are expected to experience progressive cooling over the next few million years.
The emblematic photograph, the work of the James Webb telescope, It is the result of the fusion of 700 images captured over the course of a week using the near-infrared instrument (NIRcam). In the composite image, tiny duos of objects are seen glowing and hovering in a section of the nebula.
Extremely small objects
Located in the Trapezium cluster in the Orion Nebula, a stellar nursery just 300,000 years old, JWST has revealed extremely small objects, with masses even lower than that of Jupiter.
The new data show that, under the right conditions, collisions and interactions in the nebula can lead to the formation of objects with masses as low as 0.6 times that of Jupiteror what is the same, twice the mass of Saturn.
This has been the first year of exploration of the James Webb
These JuMBOs could be planets freed from the gravity of the stars with which they formed after some relevant interaction. However, the alternative, which still has no theoretical explanation, is that they could have formed as stars. Most intriguingly, about 40% of these objects are found in binary pairs, suggesting a completely different formation than planets of similar masses.
This discovery raises a fascinating question:How small can an object that forms like a star be?
As follow-up observations with JWST are planned, scientists seek to unravel the mysteries of these JuMBOs and their role in the vast cosmic scene. Are these objects a substantial part of the planets that roam freely in the galaxy, untethered to a star? Although there are still no definitive answers, the truth is that the Orion Nebula and its JuMBOs have opened a window to the exploration of the boundaries between planets and stars, promising to redefine theories of star and planetary formation.
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