Figure 17-17: R I V U X G
How a Star’s Size Affects Its Spectrum These are the spectra of two stars of the same spectral type (B8) and surface temperature (13,400 K) but different radii and luminosities: (a) the B8 supergiant Rigel (luminosity 58,000 L⊙) in Orion, and (b) the B8 main-sequence star Algol (luminosity 100 L⊙) in Perseus.
How a Star’s Size Affects Its Spectrum These are the spectra of two stars of the same spectral type (B8) and surface temperature (13,400 K) but different radii and luminosities: (a) the B8 supergiant Rigel (luminosity 58,000 L⊙) in Orion, and (b) the B8 main-sequence star Algol (luminosity 100 L⊙) in Perseus.
(From An Atlas of Stellar Spectra, W. W. Morgan, P. C. Keenan, and E. Kellman, University of Chicago Press, © 1943)