Fig8_3 Spectral type and luminosity class in the H-R Diagram

Fig8_3 Spectral type and luminosity class in the H-R Diagram

Fig. 8.3 . When both a starís spectral type (top horizontal axis) and luminosity class (Roman numerals) are known, the starís luminosity (left vertical axis) in units of the Sunís luminosity, denoted L?, and effective disk temperature (bottom horizontal axis) can be obtained. The spectral types are shown at the coolest temperature for each type. A Roman numeral V designates the main sequence stars, subgiants by IV, giants by III, bright giants by II and supergiants by Ia and Ib. VI or SD denotes the subdwarfs, and D or VII designates the white dwarf stars.

Copyright 2010, Professor Kenneth R. Lang, Tufts University