Astrophysics (index)


(occurring slowly over a long period of time)

Secular, as used in Astronomy, indicates occurrence over a long period of time and not periodic. It is especially used to discuss the long-term trends in a motion that is periodic over the shorter term, such as stating that an orbit changes over time.

It is commonly used in describing dynamics and orbits. Some uses:

  • "secular variation"
  • "secular phenomena"
  • "secular perturbation"
  • "secular chaos"
  • "secular acceleration"
  • "secular drift"

It is also used in Time Series Analysis, with an analogous meaning.


Referenced by:
Laplace-Lagrange Secular Theory
Perturbation Theory