Fans of outer space, rejoice! The James Webb Space Telescope has just snapped an incredible image of the Orion Nebula for us to enjoy.
Since going online, the James Webb Space Telescope has been producing some breathtaking images of the universe around us. And now, it strikes again. Over the weekend, the telescope captured the inner region of the Orion Nebula in all its stunning glory.
Those of us who love to gaze up at the night sky will undoubtedly be familiar with the constellation Orion — the Hunter — and its distinctive three-star belt. The constellation is made complete with the red dot Betelgeuse at its shoulder and the spear in Orion’s hand.
What’s less apparent from Earth is that the bright spot at the tip of the spear isn’t actually a star, but a whole nebula, a cloud of gas and dust, thick with newborn stars. At roughly 24 light-years wide and sitting some 1,300 light years away from Earth, this nebula is the closest star-forming hotspot to Earth, and, understandably, draws quite a lot of interest from astronomers.
So the James Webb Space Telescope took a closer look.
Pretty gas
The newly-released image is a composite of several pictures taken through 11 different filters on the telescope’s NIRCam (Near InfraRed Camera). These images focused on the Orion Bar, a region drenched in radiation at the heart of the nebula. The high levels of radiation here come from the clusters of young stars which accreted here, each of them releasing its stellar wind and ultraviolet (UV) rays into the space around them.
The Bar can be seen in the images as a dense ‘wall’ of gas and dust, cutting across from the upper left to the lower right. It forms a physical barrier that absorbs much of the UV radiation blowing out from the star cluster in the upper right corner of the image — known as the Trapezium Cluster. However, the Bar is being slowly eroded by the waves of radiation battering it down, which produces the cavities seen in the wall.
Structures like the Orion Bar are known as “photo-dissociation regions” because they absorb radiation. The energy in radiation incoming into the Bar is consumed to strip away electrons from atoms (it ‘ionizes’ them), which breaks apart the matter inside the Bar.
The edge of the Bar that is directly facing the Trapezium Cluster is facing the brunt of its radiation output. Here, incoming UV light is so full of energy to ionize hydrogen atoms, leaving behind a cloud of what are, essentially, free protons — which we see as the glow around the Cluster.
Each of the filters used to capture these images allowed a different wavelength of light to be recorded by the telescope. What this means is that each filter allowed the device to see just light emitted by ionized gas, molecular gas, dust, or hydrocarbons (from dust grains).
The James Webb telescope can see a much larger palette of wavelengths than the human eye, but it does ‘translate’ what it picks up on. By peering into the infrared, it can look through dense layers of interstellar dust that would block the view of a traditional optical telescope like Hubble, or to pick up on materials that are cooler than their surroundings, like the molecular hydrogen at the core of the nebula.
