Our Sun is a type G star, which means it is in the middle of the range when it comes to stellar colors and surface temperatures. To add more detailed information, astronomers often add an Arabic numeral and a Roman numeral after the spectral type letter for stars. In that case, the Sun’s spectral type is written G2V. The 2 means that the Sun is closer to a type F star than a type K star, and the V means that the Sun is not a giant star but rather a main-sequence star.