Noun

Singular occultation

Plural occultations

occultation (plural occultations)

1. (astronomy) An astronomical event that occurs when one celestial object is hidden by another celestial object that passes between it and the observer when the nearer object appears larger and completely hides the more distant object
2. (religion) Describes the state of an Imam that has been hidden by Allah. (see Muhammad al-Mahdi)

   "The example of the Imam in occultation is like the sun behind the clouds. You may not see it, but it continues to sustain and aid you."

An occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The word is used in astronomy (see below) and can also be used in a general (non-astronomical) sense to describe when an object in the foreground occults (covers up) objects in the background. In the general sense, occultation applies to the visual scene from low-flying aircraft and in Computer-Generated Imagery (CGI) technology, where foreground objects obscure distant ones in a dynamic way as the scene changes.

Astronomical events which cause occultation include transits and eclipses. The word transit refers to cases where the nearer object appears smaller in apparent size than the more distant object, such as transit of Mercury or Venus across the Sun's disk. The word eclipse generally refers to those instances in which one object moves into the shadow of another. Each of these three events is the visible effect of a syzygy.