Harvard Classification

In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Light from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colours interspersed with absorption lines. Each line indicates an ion of a certain chemical element, with the line strength indicating the abundance of that ion. The relative abundance of the different ions varies with the temperature of the photosphere. The spectral class of a star is a short code summarizing the ionization state, giving an objective measure of the photosphere's temperature and density.
Posts about Harvard Classification
  • Through the Google lens: search trends December 6-11

    … Annie Jump Cannon after a Google doodle marked her 151st birthday. Cannon—who was deaf for most of her adult life, and often overshadowed by her colleague Edward C. Pickering—was instrumental in the development of the Harvard Classification system, which categorizes stars by their temperature (whether or not they were nominated for a Golden Globe…

    Emily Wood/ The Official Google Blogin Google- 15 readers -
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