Jolly Yellow Giant

One of the largest stars in the galaxy blazes brightly in this recent image from the Very Large Telescope in Chile. HR 5171A is a yellow hypergiant, a rare type of star that is evolving quickly as it nears the end of its life. It produces a fierce "wind" that surrounds the star in a cocoon of gas (the cloud around the star). It is about 1,300 times the Sun's diameter, or more than 1.1 billion miles (1.8 billion km). If it took the Sun's place in our own solar system, the star would extend beyond the orbit of Jupiter, the fifth planet out. Additional observations suggest HR 5171A has a smaller companion star, which orbits so closely that the two stars actually touch. The system is about 12,000 light-years away, in the southern constellation Centaurus. [ESO/Digitized Sky Survey 2]