Source: wikibot/cygnus-ob9
= Cygnus OB9
{wiki=Cygnus_OB9}
Cygnus OB9 is a region in the constellation Cygnus that is notable for its association with a group of bright, massive stars known as an OB association. OB associations are collections of stars that are primarily composed of spectral types O and B, which are the hottest and most luminous classes of stars. These stars are typically short-lived, burning through their nuclear fuel relatively quickly compared to cooler stars like the Sun.