Researchers from the University of Sheffield and Imperial College London has observed a fascinating celestial event that challenges previous assumptions about star interactions. Using the Gaia satellite, a mission aimed at mapping billions of stars in our galaxy, the scientists spotted a “retired” asymptotic giant branch (AGB) star passing through a young star-forming region – a phenomenon previously believed to be impossible.
This remarkable finding was made possible by Gaia’s latest data release, Data Release 3, which allows for precise identification of interloping stars. These interlopers are stars that were not born in the region but have wandered into it. The researchers had previously come across young interloping stars, but this time, they were astonished to find an older, evolved AGB star making its way through the young star-forming area.
AGB stars in their retired state produce substantial amounts of radioactively unstable chemical elements, specifically Aluminum-26 and Iron-60. These elements were delivered to our young solar system during the planet formation phase and are believed to have played a major role in early internal heating of Earth. They might have even indirectly contributed to crucial geological processes like plate tectonics, which sustain a habitable atmosphere on our planet. Understanding the role of Aluminum-26 and Iron-60 in planetary formation is essential for comprehending the origins of these vital chemical elements in our solar system.
Dr. Richard Parker, the lead author of the study published in The Astrophysical Journal Letters and a lecturer in Astrophysics at the University of Sheffield, expressed excitement over the discovery. He stated that until now, researchers had doubts about the possibility of interactions between old AGB stars and young stars in the process of forming planets. This finding opens up new insights into the dynamics, relationships, and journeys of stars. Additionally, it challenges the notion that other massive sources like winds and supernovae of massive stars are solely responsible for producing Aluminum-26 and Iron-60 in our solar system.
Dr. Christina Schoettler, an Astrophysics research associate at Imperial College London, played a crucial role in identifying the AGB star in the Gaia DR3 data. She described Gaia as a game-changer, revolutionizing our understanding of star formation and movement in the galaxy. The discovery of an old, evolved star in close proximity to young planet-forming stars exemplifies the unexpected power of serendipity in scientific research.
The researchers’ next step involves exploring other young star-forming regions for similar evolved stars to determine how common these retired interlopers are. The findings could provide further insights into the fascinating and complex interactions between stars, shedding light on the origins of our own solar system and the conditions that make life on Earth possible.
Source: University of Sheffield