Concept
Luminosity Class
Where a star sits on the H–R diagram.
Roman numerals (Ia through VII) appended to a spectral type to indicate giants, supergiants, main-sequence dwarfs, etc.
Overview
Roman numerals (Ia through VII) appended to a spectral type to indicate giants, supergiants, main-sequence dwarfs, etc.
See also
Black Holes
Regions where gravity stops light itself.
The Habitable Zone
Where liquid water can exist on a planet's surface.
Termination Shock
Where the solar wind slows from supersonic to subsonic.
Lagrange Points
Five spots where gravity and orbital motion balance.
Photon Sphere
Where light itself can orbit a black hole.
Big Rip
An end-of-universe scenario where everything is torn apart.