The James Webb Space Telescope has captured two stunning wide-field mosaics of the grandiose Orion Nebula, a large region of star formation that’s one of the closest stellar nurseries to the solar system. It sits just 1,344 light-years away.
The huge mosaics, made of over 3,000 individual images, have also been added to the European Space Agency’s ESASky app, which is an interactive all-sky map with a user-friendly interface that enables members of the public to view amazing images of the universe taken by the likes of the James Webb Space Telescope (JWST) and the Hubble Space Telescope.
The Orion Nebula is rife with budding stars located inside its billowing clouds of molecular gas. Some 2,800 young stars are known to exist inside the nebula, with many more stellar embryos cocooned within the area’s dense veil of gas and dust. And the JWST’s Near Infrared Camera, known as NIRCam for short, is able to peer through much of this gas and dust — doing so has revealed proto-stellar disks, outflows from burgeoning stars, and even free-floating planets.
On a winter’s night, the nebula is visible to the unaided eye as a fuzzy object just below the three stars that make up the Belt of the Orion constellation. The nebula is illuminated by the Trapezium Cluster, which is a grouping of young stars so-named after the pattern of their four most prominent members. Each star in this quartet is massive, with between 15 and 30 times the mass of our Sun. Their short lives, spanning just a few millions of years rather than billions, will end in supernova explosions.
Up to a thousand fainter stars lurk in the Trapezium Cluster as well, some with evaporating circumstellar disks — these are disks of gas and dust that sprouted planets. Now, residual gas from such planet formation is being blown away by the newly awoken stars’ stellar winds.
Not all of the planets born in the Trapezium have parent stars, however; the JWST has detected about 40 pairs of free-floating gas-giant planets, or Jupiter Mass Binary Objects (JuMBOs).
Free-floating planets have been found in the Orion Nebula before, but the JuMBOs are surprising because they seem to come as couples. The question astronomers are still unable to answer is, did the JuMBOs (and other free-floating planets) form directly out of the gas of the Orion Nebula as failed stars, or were they snatched from a planetary system, perhaps by the gravity of a close-passing star that wrenched them from their orbits?
The new mosaics are split between longer and shorter wavelengths. NIRCam’s short wavelength channel, which covers an infrared waveband between 0.6 and 2.3 microns, is closest to the visible red end of the spectrum and achieves the greatest angular resolution the JWST can accomplish. The short-wavelength mosaic shows all the fine details of the nebula’s star-forming activity.
Meanwhile, NIRCam’s longer wavelength channel, covering 2.4 to 5.0 microns, has recorded the network of dust and organic compound filaments, known as polycyclic aromatic hydrocarbons, that abound in the Orion Nebula. PAHs are carbon-based molecules that make up a good proportion of dust found everywhere in the universe, and observations such as those of the Orion Nebula are teaching astronomers how these ubiquitous molecules form. Given how interstellar dust is recycled into the next generation of stars, PAH abundance has a role to play that the infrared vision of the JWST can reveal.
In particular, the JWST’s greater spectral resolution can reveal PAHs on smaller spatial scales than ever before, helping to determine how they accumulate depending upon their molecular size, shape and electric charge.
The Orion Nebula is one of those rare objects that is accessible for inspection by everyone, from stargazers with the most basic observing kit to the most advanced space telescopes. As Orion rises this winter, what can you see in the greatest nebula in the sky?