Cygnus X, a star-forming region located about 4,500 light years away, is thought to contain enough material to make two million stars similar to our sun. In the above image, a stellar grouping called Cygnus OB2 appears near the center. Within Cygnus OB2 are 65 stars of the hottest, brightest variety, called O stars, and about 500 B stars. This grouping, called an OB association, is alone thought to have a mass more than 30,000 times that of our sun's.

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Image: NASA.