Free Astronomy Magazine November-December 2024

19 NOVEMBER-DECEMBER 2024 ASTRO PUBLISHING solar neighborhood. “In the past, we knew about these star forming regions but were not able to delve into their properties,” said Natsuko Izumi of Gifu University and the Na- tional Astronomical Observatory of Japan, lead author of the study. “The Webb data builds upon what we have incrementally gathered over the years from prior observa- tions with different telescopes and N ASA’s James Webb Space Telescope observed the outskirts of our Milky Way galaxy. Known as the Extreme Outer Galaxy, this region is located more than 58,000 light-years from the Galactic Center. To learn more about how a local environment affects the star formation process within it, a team of scien- tists directed the telescope’s NIRCam (Near-Infrared Camera) and MIRI (Mid- Infrared Instrument) toward a total of four star-forming areas within Digel Clouds 1 and 2: 1A, 1B, 2N, and 2S. In the case of Cloud 2S, shown here, Webb revealed a luminous main cluster that contains newly formed stars. Several of these young stars are emitting extended jets of material from their poles. To the main cluster’s top right is a sub-cluster of stars, a feature that scientists previously suspected to exist but has now been confirmed with Webb. Addi- tionally, the telescope revealed a deep sea of background galaxies and red nebulous structures that are being carved away by winds and radiation from nearby stars. [NASA, ESA, CSA, STScI, Michael Ressler (NASA-JPL)] observatories. We can get very pow- erful and impressive images of these clouds with Webb. In the case of Digel Cloud 2, I did not expect to see such active star formation and spec- tacular jets.” Although the Digel Clouds are within our galaxy, they are relatively poor in elements heav- ier than hydrogen and helium. This composition makes them similar to dwarf galaxies and our own Milky Way in its early history. Therefore, the team took the opportunity to use Webb to capture the activity oc- curring in four clusters of young stars within Digel Clouds 1 and 2: 1A, 1B, 2N, and 2S. For Cloud 2S, Webb captured the main cluster containing young, newly formed stars. This dense area is quite active as several stars are emitting extended jets of material along their poles. Additionally, while scientists previously suspected a sub-cluster might be present within the cloud, Webb’s imaging capabilities confirmed its existence for the first time. “We know from studying other nearby star-forming regions that as stars form during their early life phase, they start emitting jets of material at their poles,” said Ressler, second author of the study and principal investigator of the observ- ing program. “What was fascinating and astounding to me from the Webb data is that there are multiple jets shooting out in all different di- rections from this cluster of stars. It’s a little bit like a firecracker, where you see things shooting this way and that.” The Webb imagery skims the surface of the Extreme Outer Galaxy and the Digel Clouds, and is just a start- ing point for the team. They intend to revisit this outpost in the Milky Way to find answers to a variety of current mysteries, including the rel- ative abundance of stars of various masses within Extreme Outer Galaxy star clusters. This measurement can help astronomers understand how a particular environment can influ- ence different types of stars during their formation. “I’m interested in continuing to study how star forma- tion is occurring in these regions. By combining data from different ob- servatories and telescopes, we can examine each stage in the evolution process,” said Izumi. “We also plan to investigate circumstellar disks within the Extreme Outer Galaxy. We still don’t know why their life- times are shorter than in star-form- ing regions much closer to us. And of course, I’d like to understand the kinematics of the jets we detected in Cloud 2S.” Though the story of star formation is complex and some chapters are still shrouded in mystery, Webb is gath- ering clues and helping astronomers unravel this intricate tale. !