Astronomy Picture of the Day

Explanation: Inside the Cocoon Nebula is a newly developing cluster of stars. Catalogued as IC 5146, the beautiful nebula is nearly 15 light-years wide, located some 4,000 light years away toward the northern constellation Cygnus. Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by young, hot stars and blue, dust-reflected starlight at the edge of an otherwise invisible molecular cloud. In fact, the bright star near the centre of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it clears out a cavity in the molecular cloud's star forming dust and gas. This colour view of the Cocoon Nebula traces remarkably subtle features within and surrounding the dusty stellar nursery.