Black Hole Rips Star
Tidal forces shred a star apart if it wanders too close to a black hole. Such events are called tidal disruptions, where stellar debris is thrown outward at high speeds while the rest fall towards the black hole. The result is a unique X-ray flare that can last for years. Astronomers recently observed these tidal disruptions near a supermassive black hole at the center of a galaxy 290 million light years away, the closest observed yet.
As a star is destroyed, the strong gravitational forces from the black hole attract most of the star’s remains. X-ray radiation is released as friction heats these incoming debris. As the X-ray radiates, the amount of light decreases as the star’s materials fall beyond the event horizon, the point from which no light or other information can escape. Gas often spirals into the black hole and forms what are called accretion disks. This process has been unclear to scientists, but this recent observation allowed them to witness the formation as it happened by looking at the X-rays at different wavelengths and tracking how those emissions changed over time. The X-ray data also imply that there is wind moving away from the black hole with stellar gas. However, its speed is insufficient to escape the black hole's gravitational grasp.
Astronomers hope to study more events like this as it allows them to test theoretical models about how black holes affect nearby environments. It also allows them to learn more about what black holes do to any stars or other bodies that wander too close.