Describe the key features of stellar spectra and describe how these are used to classify stars

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Describe the key features of stellar spectra and describe how these are used to classify stars

  • Stars are divided into seven spectral classes based on their surface temperatures: O, B, A, F, G, K and M (Oh Be A Fine Girl Kiss Me).
  • O is the hottest class.
  • M is the coolest class.
  • Each class is divided into ten further subdivisions using the numbers from 0 to 9.
  • Our sun is a G2 star.
  • The hotter a star is, the shorter its dominant wavelength is.
  • Thus, by observing wavelengths through spectroscopy, temperature can be determined and stars can be classified.