Astronomers have made a groundbreaking discovery, witnessing a young sun-like star emitting high-energy gamma radiation for the first time. This observation provides important evidence that low-mass stars, known as T. Tauri stars, which are surrounded by planet-forming disks, can emit gamma radiation. Gamma radiation is the most energetic form of light and this discovery could have significant implications for our understanding of stars and planetary systems during their early stages of formation.
The discovery was made by a team of astronomers led by Agostina Filócomo from the Universidad Nacional de La Plata. The team captured their observations using the Fermi satellite telescope, which has the unique ability to collect high-energy radiation data that is difficult to gather from Earth’s surface. Since its launch in 2008, Fermi has observed the sky and identified many gamma rays, but approximately 30% of these gamma rays were unattributed to a source. Filócomo and her team set out to identify some of these mysterious sources.
Their research led them to focus on the star-forming region NGC 2071, located around 1,350 light-years from Earth in the northern part of the molecular cloud Orion B. In particular, they looked for T. Tauri stars in NGC 2071, as these stars are often found near star-forming regions and exhibit fluctuating levels of brightness. They ultimately identified three unidentified gamma-ray sources that seemed to be coming from the direction of NGC 2071, where at least 58 T. Tauri stars are known to be currently forming. The researchers ruled out other objects in the region as potential sources of gamma-ray emissions.
The team theorizes that T. Tauri stars may emit gamma rays sporadically during powerful flare events called “megaflares.” These megaflares occur when magnetic energy stored in the atmospheres of young stars is released as powerful electromagnetic bursts. While similar to solar flares launched by the sun, megaflares are on a much larger scale and can stretch for distances several times greater than the stars themselves. Megaflares are so powerful that if the sun were to produce such an eruption, life on Earth would be threatened. However, some scientists suggest that megaflares in the early history of the solar system may have actually been beneficial for planet formation by driving gas and triggering the formation of rocky materials.
This discovery not only helps explain previously unattributed gamma-ray detections but also has implications for our understanding of the solar system’s formation. Filócomo emphasized that the phenomenon could provide insights into how not only the sun but also our home planet, Earth, was formed and evolved.
The team’s findings were published in the journal Monthly Notices of the Royal Astronomical Society and mark a significant step forward in our knowledge of stars and planetary systems. The discovery of gamma radiation emission from T. Tauri stars opens up new avenues for research and could shed light on the processes and conditions that occur during the early phases of star formation, potentially revolutionizing our understanding of the universe.