With its recognizable belt of three stars, Orion is one of the best known constellations in the night sky. Observers have imagined these stars as a hunter, holding aloft a club in one hand and a shield or a bow in the other. Three dimmer stars under Orion's belt represent his sword, and in the middle of these lies the Orion Nebula, an interstellar cloud.
To the naked eye, it appears as a hazy dot, but to the James Webb Space Telescope’s NIRCam instrument, the Orion Nebula’s plumes of multi-colored gas and dust appear as never seen before.
Previous telescopes, such as Hubble and Spitzer, have struggled to peer through the dense dust of space to identify structures within the nebula. But Webb can look past the dust with its unparalleled sensitivity to infrared light. The telescope is so good, in fact, that it could detect a bumblebee’s infrared body heat from as far away as the moon, according to a “Tweet Chat” with Webb project scientist John Mather.
Still, capturing this nebula was a challenge for the telescope, “because it is very bright for Webb’s unprecedented sensitive instruments,” says Olivier Berné, a scientist with the French National Centre for Scientific Research who co-led the observations, in a statement. “But Webb is incredible. Webb can observe distant and faint galaxies, as well as Jupiter and Orion, which are some of the brightest sources in the infrared sky.”
This new look into the heart of the Orion Nebula is illuminated by a group of young, massive stars placed just outside the upper-right corner of the composite image. Located in the middle of the nebula, these hot stars, known as the Trapezium cluster, emit harsh ultraviolet radiation that shapes the region. The area close to these high-energy stars gets eroded away, in a sense, by the extreme radiation, leaving a cavity visible at the top right of the picture.
At the image's center, the diagonal Orion Bar—a dense ridge of gas and dust—acts as a shield from the Trapezium stars' intensity. This structure is key to learning more about how stars are born, says Els Peeters, an astronomer at Western University in Canada who co-led the observations, to CBC News’s Nicole Mortillaro.
"If you want to understand the star formation in the universe, and your planet formation, you need to understand the basics," Peeters tells CBC News. "The Orion Bar is kind of a laboratory: You go there, find out what's going on, and then you apply it to other areas."
Within the Orion Bar, thread-like filaments deliver gasses and other materials to fuel stars, writes Insider’s Paola Rosa-Aquino. Some of these can be made out in the lower right of Webb’s new image. “These filamentary structures may promote a new generation of stars in the deeper regions of the cloud of dust and gas," Berné says in the statement.
The image also reveals young protostars, including one that’s “forming inside a cocoon of gas,” per Insider, which does not appear in the Hubble telescope’s view of the nebula.
“These new observations allow us to better understand how massive stars transform the gas and dust cloud in which they are born,” Peeters says in the statement.
At 1,350 light-years away, the Orion Nebula is the nearest stellar nursery to Earth. Conditions there mirror what our solar system looked like as it first formed, so it acts as a template for understanding our local history, per a press release from the University of Michigan.
The Orion Nebula images will be examined by an international team of researchers that spans more than 18 countries. The team is currently waiting on spectroscopic data, which will reveal the specific elements that make up this region, CBC News reports.
“Seeing these first images of the Orion Nebula is just the beginning,” Emilie Habart of the Institut d’Astrophysique Spatiale, who co-led the observations, says in the statement. “We expect new discoveries about these early phases of the formation of stellar systems.”