galactic disk

galactic disk

Our own Milky Way Galaxy, viewed edge-on, showing the central bulge and disk (within which the Sun lies).
Image source: ESO, GigaGalaxyZoom project.

The galactic disk is the flattened component of a spiral galaxy in which, together with many ordinary stars such as the Sun (see disk star), lie the biggest and brightest of stars – the O stars and B stars. The disk is also home to large tracts of interstellar material from which new stars are continually being made.