Key Words

• absolute magnitude

• apparent brightness

• apparent magnitude

• binary star (binary)

• brown dwarf

• center of mass

• color ratio

• distance modulus

• double star

• eclipsing binary

• giant

• Hertzsprung-Russell diagram

• H-R diagram

• inverse-square law

• light curve

• luminosity

• luminosity class

• luminosity function

• magnitude scale

• main sequence

• main-sequence star

• mass-luminosity relation