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| Scientists used NASA’s James Webb Space Telescope to examine star-forming regions in the Extreme Outer Galaxy, including Digel Cloud 2S, revealing young stars, their jets, and a backdrop of galaxies and red nebulous structures. Webb’s MIRI and NIRCam filters assigned red, green, and blue colors to various wavelengths for this image. |
Astronomers have utilized NASA’s James Webb Space Telescope to probe the Extreme Outer Galaxy, a distant region of the Milky Way located over 58,000 light-years from the Galactic Center. This area is more remote compared to Earth’s position, which is about 26,000 light-years from the center.
Employing Webb’s NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument), scientists have imaged the Digel Clouds 1 and 2, two molecular clouds within this far-flung region. Webb’s high sensitivity and resolution have provided unprecedented detail on these star-forming regions, revealing components such as very young (Class 0) protostars, their outflows and jets, and intricate nebular structures.
The observations, directed by Mike Ressler from NASA’s Jet Propulsion Laboratory, have allowed researchers to explore star formation in the outer Milky Way with the same depth as in our local galactic neighborhood. Natsuko Izumi of Gifu University and the National Astronomical Observatory of Japan, lead author of the study, noted, “The Webb data builds upon prior observations, offering powerful images of these clouds. For instance, in Digel Cloud 2, the active star formation and spectacular jets were beyond my expectations.”
Though the Digel Clouds are part of our galaxy, their composition is akin to dwarf galaxies and the early Milky Way, being low in elements heavier than hydrogen and helium. Webb’s data focused on four star clusters within the clouds: 1A, 1B, 2N, and 2S. Notably, for Cloud 2S, Webb’s imaging revealed a dense cluster of newly formed stars and multiple jets of material, confirming the presence of a sub-cluster previously suspected but unverified.
Ressler, the second author of the study, expressed amazement at the Webb data, stating, “The multiple jets from this star cluster are reminiscent of a firework display, with jets shooting in various directions.”
These initial Webb observations serve as a foundation for future studies. Researchers plan to revisit the Extreme Outer Galaxy to address several questions, such as the star mass distribution within these clusters and the lifespan of circumstellar disks compared to those closer to the Milky Way’s core. Izumi aims to combine Webb data with other observatory findings to further investigate star formation processes and the dynamics of jets in Cloud 2S.
The findings, published in the Astronomical Journal, mark the beginning of an exciting chapter in understanding stellar evolution in the far reaches of our galaxy. The observations were part of Guaranteed Time Observation program 1237.
