galactic

Galactic is an adjective used to describe things related to a galaxy or to galaxies in general. Etymologically, it derives from the Greek galaktikos ("milky"), related to galakt- for milk; the noun galaxy comes from Greek galaxias via Latin galaxia.

In astronomy, galactic terms describe structures and phenomena within or between galaxies. For the Milky Way, notable examples include the galactic center, home to the supermassive black hole Sagittarius A*, and the galactic plane, a disk where most of the galaxy’s mass lies. The galactic halo surrounds the disk with older stars and dark matter. Astronomers also use the term galactic year to denote the Sun’s orbital period around the center, about 225 to 250 million years.

Galactic is often contrasted with extragalactic, which refers to objects outside the Milky Way. The term appears in measurements, mappings of the sky, and descriptions of galaxies as a whole.

In popular culture, Galactic is used as a proper noun. Notably, Galactic is the name of an American funk band formed in New Orleans in 1994. The term also appears in titles and branding related to science fiction and space-themed media.