Spectral class is the group of which stars are classified in, based on their spectrum and especially using the Harvard classification.
Created and Edited by Ariel
Harvard Classification
The Harvard Classification is a system of classifying stars based on their spectral types. The chief classes consists of O,B,A,F,G, K, and M, which forms a series of hot blueish-white stars all the way to cool red stars. This will also be referenced as spectral type.
What does the Chief Classes Mean?
The chief classes is what separates the luminosity of the stars to their spectral type. The class 'O' describes a star whose temperature is anywhere from 30,000K, to 60,000K and is the color blue. The class 'B' describes a star whose temperature is anywhere from 10,000K to 30,000K and is the color blue. The class 'A' describes a star whose temperature is anywhere from 7,500K to 10,000K and is a white color. The class 'F' describes a star whose temperature is 6,000K to 7,500K and whose color is white or yellowish. The class 'G' describes a star whose temperature is 5,000K to 6,000K and the color is yellow, like our Sun. The class 'K' describes a star whose temperature is anywhere from 3,500K to 5,000K and the color is orange. Finally, the class 'M', describes a star whose temperature is anywhere from 2,000K to 3,500K and is the color red.