Approximately 200 light-years from the supermassive black hole located at the center of the Milky Way, there exists an intriguing area known as Sagittarius C. While this cosmic cradle is abundant in gas and dust necessary for star formation, it has surprisingly birthed very few stars—especially when considering the expected outcomes based on its available materials.
To delve into this enigma, astronomers utilized the James Webb Space Telescope (JWST), a sophisticated infrared observatory created by NASA in partnership with the European and Canadian space agencies. With its capability to penetrate thick clouds of cosmic dust, Webb offered an extraordinary perspective on Sagittarius C, uncovering new insights regarding its structure and activities.
The results, detailed in two studies published in The Astrophysical Journal, indicate that powerful magnetic fields might be hindering star formation in this area. “A significant question has been, if there is such dense gas and dust present, and we know stars form in these environments, why are so few stars being born in Sagittarius C?” remarked John Bally, an astrophysicist from the University of Colorado Boulder. “For the first time, we’re discovering that intense magnetic fields may significantly impede star formation.”
The infrared capabilities of the Webb telescope enable it to detect faint thermal signatures that would otherwise be hidden by dust—so precise that it can even sense the warmth of a solitary bumblebee on the Moon. Utilizing this advanced technology, researchers discovered two enormous stars—each over 20 times the mass of our Sun—forming deep within Sagittarius C, along with five smaller stars still encased in dense dust.
Alongside these youthful stars, Webb observed 88 luminous hydrogen structures thought to be shock waves caused by newborn stars expelling material into space. The telescope also revealed an adjacent, previously unknown star-forming zone containing at least two additional stars in development.
Previous examinations of Sagittarius C had shown numerous long, threadlike strands of hot hydrogen gas, with some extending several light-years. These strands are believed to be influenced by the magnetic forces emanating from the Milky Way’s central black hole, Sagittarius A*. Scientists now surmise that these forces may be strong enough to counteract gravity, thus preventing the dense gas clouds from collapsing and forming new stars.
“This finding raises new inquiries regarding the impact of magnetic fields on star birth,” stated Samuel Crowe, a Rhodes Scholar at the University of Virginia and co-leader of the research. “Sagittarius C is becoming an essential laboratory for examining our understanding of star formation—not only within our galaxy but throughout the cosmos.”
As researchers pursue further analysis of data from Webb, they aim to attain a more profound comprehension of the intricate dynamics between gravity, magnetic fields, and the cosmic elements that lead to star formation. Grasping these mechanisms is crucial for unraveling how elements vital for life—such as carbon and oxygen—are generated and disseminated across the universe.