The Orion Nebula is one of the most observed objects in the sky. All you have to do is look up on a clear night in the northern hemisphere, and it's visible as a small blob in the constellation Orion. Even a modest telescope can reveal intricate details in this star-forming region, but the James Webb Space Telescope sees much more. The latest round of Webb observations has revealed some anomalous objects in this corner of space that have previously escaped notice. They're about the size of Jupiter, occur in pairs, and no one is quite sure how they came to be. For now, they're known as JuMBOs—Jupiter Mass Binary Objects.
The nebula is very close to Earth (in astronomical terms), at a distance of less than 1,400 light years. Despite years of astronomers peering into the nebula with the best optics in the world, no one has spotted a JuMBO before. Probing objects like this is exactly what Webb was designed to do, though. With high sensitivity in the near and mi-infrared, it can capture details of cloud structures and zoom beyond them to see stars that would be invisible to telescopes like Hubble, which operates mostly in the visual spectrum.
This research was led by Mark McCaughrean, a senior scientist at the ESA. The image above shows the wider nebula produced by the team, but it's not a single frame. It's actually a mosaic of 700 smaller frames, each one with more detail than Hubble could ever hope to see. The data shows myriad young solar systems, identified by the protoplanetary disk encircling infant stars. Scientists are beginning to better understand the mechanisms at work in these systems, but JuMBOs don't fit anywhere in those models. They're not rare, either. Webb spotted 42 of them in the new observations.
JuMBOs can approach the mass of Jupiter, but they're mostly about half the size of that world. Meanwhile, an M dwarf (or red dwarf) can be up to 13 times the mass of Jupiter. They have a surface temperature of about 1,000 degrees Fahrenheit (537 degrees Celsius). The binary pairs orbit each other at a distance 200 times greater than the distance between Earth and the sun, and it takes thousands of years to complete a single orbit.
So how did these odd binaries come to be? The European Space Agency tells the BBC that gas physics should prevent JuMBOs from forming in isolation. They would be large for a planet, but they're much smaller than any star. The other possible explanation is that these planets formed around a star and were then ejected. The latter option is currently favored by the researchers, but evidence is sparse. However, neither explanation satisfactorily explains why they seem to occur in pairs. Webb is uniquely capable of scouring the heavens for more JuMBOs. Perhaps, more examples will help explain how they form. Whatever happens, they should keep the acronym.
