James Webb has done it again. A spectacular new image has just been added, indeed, to the growing collection of impressive cosmic photographs made by the most powerful space telescope of all time.
It is, this time, the Orion Nebula, one of the best known and studied regions of space by astronomers. The telescope, this time, has obtained the sharpest and most detailed images that exist of the inner region of the nebula, a bustling ‘star nursery’ located 1,350 light years from Earth.
“We are impressed by the impressive images of the Orion Nebula,” says astrophysicist Els Peeters of Western University in Canada and co-leader of the team. We started this project in 2017, so we have been waiting more than five years to get this data.”
“These new observations – continues Peeters – allow us to better understand how massive stars transform the cloud of gas and dust in which they are born. Massive young stars emit large amounts of ultraviolet radiation directly into the native cloud that still surrounds them, and this changes the physical shape of the cloud as well as its chemical composition. It is not yet known precisely how this works and how it affects star and planet formation.”
Surrounded by dust and gas
Stars are born inside dense clouds of dust and gas. Gravity causes these materials to accumulate around the densest points, heating them up more and more in the process. In the end, the amount of mass and temperature of each of these points is enough to ‘ignite’ the nuclear furnace of new stars, which are born inside the cloud.
However, the very nature of the process makes it extremely difficult to observe, as all that dust and gas prevents light from escaping and showing us what’s going on inside. But James Webb’s instruments, which operate in the infrared, don’t have that problem, as they can cut through dense dust clouds and show us what’s on the other side. Something impossible to achieve with telescopes that work with other wavelengths of light, such as Hubble, which works in the visible spectrum.
In the words of Olivier Berné, who together with Peeters has directed the work, “observing the Orion Nebula has been quite a challenge because it is very bright for Webb’s sensitive instruments. But Webb is amazing, and he can easily see both faint, distant galaxies like Jupiter and Orion, which are some of the brightest sources in the infrared sky.”
The new Webb images do indeed reveal many spectacular structures within the nebula, on scales comparable to the size of the Solar System.
“We clearly see several dense filaments,” Berné continues. These filamentary structures can promote a new generation of stars in the deepest regions of the cloud of dust and gas. Stars that are in full formation also appear. Inside their ‘cocoons’ are young stars with a disk of dust and gas in which planets are forming. Also clearly visible are the small cavities carved out by the new stars within the cloud after being blown out by the intense radiation and stellar winds from the other newborn stars.”
Other objects in the image include globules (dense clumps of material with baby stars inside) and a growing young star surrounded by a disk of material. That disk is evaporating from the outside due to radiation from nearby stars. About 180 of these objects, called ‘proplyds’, have already been found in the Orion Nebula. Never before have these environments and the way in which planetary systems are formed been observed in such great detail.
a similar environment
Astronomers have long studied the Orion Nebula because our own Solar System is believed to have formed, more than 4.5 billion years ago, in a very similar environment. The new images from the Jamen Webb Space Telescope could therefore shed light on what happened during the first million years of our own planetary evolution.
However, the study of these new images of the Orion Nebula has only just begun. Further analysis will undoubtedly reveal much more detail about what can be seen in the photographs.
“Seeing these first images of the Orion Nebula – concludes Emilie Habart, the third team leader – is just the beginning. We are working hard to analyze the Orion data and look forward to new discoveries about these early stages of star system formation. We are excited to be a part of Webb’s journey of discovery.”