occultation

oc·cul·ta·tion  (kl-tshn)

n.

1. The act of occulting or the state of being occulted.

2. Astronomy

a. The passage of a celestial body across a line between an observer and another celestial object, as when the moon moves between Earth and the sun in a solar eclipse.

b. The progressive blocking of light, radio waves, or other radiation from a celestial source during such a passage.

c. An observational technique for determining the position or radiant structure of a celestial source so occulted: a lunar occultation of a quasar.

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[Middle English occultacion, from Latin occultti, occulttin-, from occulttus, past participle of occultre, frequentative of occulere, to conceal; see occult.]

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occultation  (kl-tshn)

The passage of one celestial object in front of another, temporarily blocking the more distant object from view. Occultations can provide information about the existence and measurements of the obscuring object. For example, when an asteroid passes in front of a star, the star is temporarily obscured to an observer on Earth, thus revealing the presence and approximate size of the asteroid. In 1977, astronomers were able to identify the rings around the planet Uranus when the otherwise invisible rings were observed to occult a background star. Occultations have also led to the discovery of more distant objects in space, such as binary stars and extrasolar planets. Compare transit.

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occultation

the process of one heavenly body disappearing behind another as viewed by an observer.

See also: Astronomy, Planets

Thesaurus

Noun

1.

occultation - one celestial body obscures another eclipse egress, emersion - (astronomy) the reappearance of a celestial body after an eclipse ingress, immersion - (astronomy) the disappearance of a celestial body prior to an eclipse break, interruption - some abrupt occurrence that interrupts an ongoing activity; "the telephone is an annoying interruption"; "there was a break in the action when a player was hurt" solar eclipse - the moon interrupts light from the sun lunar eclipse - the earth interrupts light shining on the moon total eclipse - an eclipse as seen from a place where the eclipsed body is completely obscured partial eclipse - an eclipse in which the eclipsed body is only partially obscured