Astrophysics (Index)About


(one celestial body hiding another from an observer)

An occultation occurs when one celestial body hides another, i.e., it enters an observer's line of sight and is large enough that the further body is not visible. In contrast, a transit is one body hiding part of another by passing in front of it, and an eclipse is one body throwing a shadow on another, e.g., when two planets are in a line with their star, and in astronomy occlusion refers to an obstruction, and is sometimes used as something of a measure, e.g., partial occlusion, and could be used to describe the effects of a partially transparent object such as a cloud. The terms are not mutually exclusive: often they describe different aspects of the same scenario.

Atmospheres of both extra-solar planets and solar system bodies are studied using occultation, by studying the spectra absorbed by the body's atmosphere when that atmosphere is in front of another body producing EMR (transmission spectroscopy).

(astronomy,event type,transient type)
Further reading:

Referenced by pages:
amateur astronomy
Arecibo Occultation Survey (AO)
celestial event
exoplanet eclipse light curve
high-resolution imaging
occultation observations
secondary eclipse
Trace Gas Orbiter (TGO)
transit spectroscopy
Upper Atmosphere Research Satellite (UARS)