Epoch (astronomy) Guide, Meaning , Facts, Information and Description
In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. In the case of celestial coordinates, the position at other times can be computed by taking into account precession and proper motion. In the case of orbital elements, it is necessary to take account of perturbation by other bodies in order to calculate the orbital elements for a different time.The currently used standard epoch is J2000.0, which is very close to January 1, 2000 at 12:00 UTC. The prefix "J" indicates that it is a Julian epoch. The previous standard epoch was B1950.0, with the prefix "B" indicating it was a Besselian epoch.
Besselian epochs were used before 1984, however Julian epochs are now used.
This is an Article on Epoch (astronomy). Page Contains Information, Facts Details or Explanation Guide About Epoch (astronomy)