Occultation

[ok-uhl-tey-shuh n] /ˌɒk ʌlˈteɪ ʃən/

noun
1.
Astronomy. the passage of one celestial body in front of another, thus hiding the other from view: applied especially to the moon’s coming between an observer and a star or planet.
2.
disappearance from view or notice.
3.
the act of blocking or hiding from view.
4.
the resulting hidden or concealed state.
/ˌɒkʌlˈteɪʃən/
noun
1.
the temporary disappearance of one celestial body as it moves out of sight behind another body
2.
the act of occulting or the state of being occulted
n.

early 15c., “disguise or concealment of identity,” from Latin occultationem (nominative occultatio), noun of action from past participle stem of occultare “to hide, conceal,” frequentative of occulere (see occult).
occultation
(ŏk’ŭl-tā’shən)
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.