The activities of comets related to their aging and origin

  title={The activities of comets related to their aging and origin},
  author={Fred Lawrence Whipple},
  journal={Celestial Mechanics and Dynamical Astronomy},
  • F. Whipple
  • Published 1992
  • Physics, Geology
  • Celestial Mechanics and Dynamical Astronomy
Two indices have been developed for the purpose of comparing the natures of various classes of comets. The first is the Activity Index (AI), measuring the inherent magnitude increase in brightness from great solar distances to maximum near perihelion. The second, or Volatility Index (VI), measures the variation in magnitude near perihelion. Tentative determinations of these two indices are derived from observations by Max Beyer over more than 30 years for long-period (L-P) and short-period (S-P… 

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