Coronagraph facts for kids

Kids Encyclopedia Facts
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Seeing sun with 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 of the Sun, but a new class of conceptually similar instruments (called stellar coronagraphs to distinguish them from solar coronagraphs) are being used to find extrasolar planets around nearby stars.

Invention

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Direct image of exoplanets around the star HR8799 using a vector vortex coronagraph

The coronagraph was introduced in 1930 by the French astronomer Bernard Lyot; since then, coronagraphs have been used at many solar observatories.

As an example, imaging instruments on the Hubble Space Telescope offer coronagraphic capability.

Satellite-based coronagraphs

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Another coronagraph image of the Sun

Coronagraphs in outer space are much more effective than the same instruments would be if located on the ground. This is because the complete absence of atmospheric scattering eliminates the largest source of glare present in a terrestrial coronagraph.

space missions such as NASA-ESA's SOHO, SPARTAN, and Skylab have used coronagraphs to study the outer reaches of the solar corona. The Hubble Space Telescope (HST) is able to perform coronagraphy using the Near Infrared Camera and Multi-Object Spectrometer (NICMOS)


Coronagraph Facts for Kids. Kiddle Encyclopedia.