* Within each star type, individual stars are assigned a number on a nine point scale. For example, B8 would be between a B and O star, but closer to an O star. Luminosity is denoted in a Roman numeral scale from Ia (brightest) to VII (white dwarf). For example, the star Rho Persei is a Type M4 IIIa. This means it is roughly in between a Type M and Type K star and has a luminosity that would classify it as a normal giant (much more luminous than the sun which is G2V).