What are Some Different Types of Stars?
Most stars fall into a categorization class called the main sequence, also known as dwarf stars. In a standard chart plotting star color against magnitude, known as the Hertzsprung-Russell diagram, the main sequence stars form a coherent curve, unlike the other categories — white dwarfs, subgiants, giants, bright giants, and supergiants. Although not usually included on the chart, black holes, which are gravitationally collapsed stars, might be considered points on the chart with zero luminosity and a spectral signature of 0° K. The reason why the main sequence stars fall on a predictable curve is because their luminosity and spectral signatures are dictated solely by their mass, which ranges from 0.08 to about 158 solar masses. White dwarfs, stars that have exhausted their nuclear fuel, have similar spectral signatures to main sequence stars, but much less luminosity. This is because they do not fuse elements or have an ongoing source of energy — their luminosity and heat is all left-
