Astronomers have tasked NASA’s James Webb Space Telescope to investigate the far reaches of our Milky Way galaxy. This area, referred to as the Extreme Outer Galaxy, is situated over 58,000 light-years from the Galactic Center. (In contrast, Earth lies about 26,000 light-years away from this center.)
Astronomers have tasked NASA’s James Webb Space Telescope to investigate the far reaches of our Milky Way galaxy. This area, referred to as the Extreme Outer Galaxy, is situated over 58,000 light-years from the Galactic Center. (In contrast, Earth lies about 26,000 light-years away from this center.)
A group of researchers utilized Webb’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) to capture images of specific areas within two molecular clouds known as Digel Clouds 1 and 2. Thanks to its exceptional sensitivity and clarity, the Webb data provided unprecedented visuals of these regions, which are home to star clusters experiencing rapid bursts of star formation. These details include elements such as very young (Class 0) protostars, outflows, jets, and unique nebular structures.
The observations from Webb, which were conducted under Mike Ressler’s direction at NASA’s Jet Propulsion Laboratory in Southern California, are allowing researchers to explore star formation in the outer Milky Way with the same depth of analysis as seen in our solar neighborhood.
“Previously, we were aware of these star-forming areas but could not deeply investigate their characteristics,” said Natsuko Izumi from Gifu University and the National Astronomical Observatory of Japan, the primary author of the study. “The Webb data enhances our long-term knowledge gathered from various telescopes and observatories. With Webb, we can produce stunning images of these clouds. In the case of Digel Cloud 2, I was surprised to observe such dynamic star formation and amazing jets.”
Stars in Formation
Even though the Digel Clouds are part of our galaxy, they contain fewer heavier elements compared to hydrogen and helium. This quality makes them analogous to dwarf galaxies and resembles the early state of our Milky Way. Consequently, the team took the chance to use Webb to capture activity in four clusters of young stars found within Digel Clouds 1 and 2: 1A, 1B, 2N, and 2S.
For Cloud 2S, Webb revealed the main cluster filled with young, newly formed stars. This vibrant area is highly active, with several stars projecting long jets of material from their poles. Furthermore, while scientists previously speculated about the presence of a sub-cluster within the cloud, Webb’s imaging capabilities verified its existence for the first time.
“From studying other nearby star-forming regions, we know that as stars develop in their early stages, they begin to emit jets of material from their poles,” remarked Ressler, the second author of the study and principal investigator of the observing program. “What astonished me in the Webb data was the multiple jets shooting out in various directions from this star cluster. It resembles a firecracker, with material scattering in all directions.”
The Tale of Stars
The Webb images offer a glimpse into the Extreme Outer Galaxy and the Digel Clouds, serving as an initial step for the research team. They plan to return to this remote section of the Milky Way to uncover answers to various enigmas, such as the distribution of star masses within the extreme Outer Galaxy’s star clusters. Understanding this can aid astronomers in grasping how different environments affect star formation.
“I’m keen to further explore how star formation occurs in these areas. By integrating data from various observatories and telescopes, we can scrutinize each phase of the evolution process,” Izumi stated. “We also aim to study circumstellar disks in the Extreme Outer Galaxy. We still lack insight into why their lifetimes are shorter compared to star-forming regions nearer to us. And, naturally, I would like to understand the movement of the jets we observed in Cloud 2S.”
Despite the intricacies surrounding star formation, and with several aspects still enigmatic, Webb is collecting vital information to assist astronomers in unlocking this detailed narrative.
The observations were conducted as part of the Guaranteed Time Observation program 1237.
