coronagraph

coronagraph
—coronagraphic /keuh roh'neuh graf"ik/, adj.
/keuh roh"neuh graf', -grahf'/, n. Astron.
an instrument for observing and photographing the sun's corona, consisting of a telescope fitted with lenses, filters, and diaphragms that simulate an eclipse.
[1885-90; earlier coronograph. See CORONA, -GRAPH]

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  telescope that blocks the light of a star inside the instrument so that objects close to the star can be observed. It was invented in 1930 by the French astronomer Bernard Lyot (Lyot, Bernard) and was used to observe the Sun's (Sun) corona and prominences (solar prominence).

      When a coronagraph is used to observe the Sun, a round metal screen blocks the overwhelming brightness of the Sun's central disk, or photosphere. Other screens and diaphragms block reflections of the photospheric image. The coronagraph must be used at high altitudes and on very clear days, when the atmospheric diffusion of light is at a minimum; imperfect lenses or dust inside the instrument will scatter enough photospheric light to obscure the dim solar corona.

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Universalium. 2010.

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Look at other dictionaries:

  • coronagraph — [kə rō′nə graf΄] n. [earlier coronograph < CORON(A) + o + GRAPH] a telescope designed for observing the corona of the sun by means of devices that obstruct the light of the sun s disk …   English World dictionary

  • Coronagraph — A coronagraph is a telescopic attachment designed to block out the direct light from a star so that nearby objects – which otherwise would be hidden in the star s bright glare – can be resolved. Most coronagraphs are intended to view the corona… …   Wikipedia

  • coronagraph — also coronograph noun Date: 1885 a telescope for observation of the sun s corona …   New Collegiate Dictionary

  • coronagraph — noun A telescope that has an attachment which blocks out the direct light from the sun or other star, allowing examination of the corona and the detection of exoplanets …   Wiktionary

  • coronagraph — instrument for viewing the corona of the sun Scientific Instruments …   Phrontistery dictionary

  • coronagraph — noun an instrument that blocks out light emitted by the sun s actual surface so that the corona can be observed …   English new terms dictionary

  • coronagraph — co·ro·na·graph …   English syllables

  • coronagraph — /kəˈroʊnəgræf/ (say kuh rohnuhgraf), / graf/ (say grahf) noun an instrument for measuring the sun s corona …  

  • coronagraph —   n. astronomical instrument by which the solar corona can be observed in full sunlight …   Dictionary of difficult words

  • coronagraph — n. an instrument for observing the sun s corona, esp. other than during a solar eclipse …   Useful english dictionary

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