Planetary collision in Fomalhaut star system, illustration. The star Fomalhaut is located 25 light-years away in the constellation Piscis Austrinus. An image obtained in 2008 was thought to show a planet, named Fomalhaut b, orbiting far from the star. However, the object faded and expanded over time. The object is now thought to be an expanding cloud of dust caused by the collision of two icy bodies, each approximately 200 kilometers in diameter. The dust cloud is estimated to be 160 million kilometres across.