A team of astronomers has identified the first known "black hole triple" system, consisting of a black hole consuming a companion star while being orbited by a more distant star. The discovery, made by researchers from MIT and Caltech, raises questions about the formation processes of black holes, traditionally thought to arise from supernova explosions.
The system, V404 Cygni, located about 8,000 light-years from Earth, was previously known as an X-ray binary comprising a black hole and its victim star. However, recent observations revealed a distant third star, which orbits the black hole every 70,000 years, indicating a more gentle formation method termed "direct collapse" rather than a violent supernova.
Kevin Burdge, lead researcher, noted that the presence of the distant star suggests it was not ejected during a typical supernova, which would have imparted a significant kick. This finding implies that at least some black holes can form without such energetic events.
The research utilized data from the Gaia space telescope to confirm the tandem motion of the stars, with a probability of this occurrence being one in ten million. The outer star is currently transitioning into a red giant, allowing the team to estimate the system's age at approximately 4 billion years.
This groundbreaking discovery not only enhances our understanding of black hole evolution but also opens up new avenues for exploring the existence of other triple systems in the universe.