spectroheliograph

American  

[spek-troh-hee-lee-uh-graf, -grahf] / ˌspɛk troʊˈhi li əˌgræf, -ˌgrɑf /

noun

1. an apparatus for making photographs of the sun with a monochromatic light to show the details of the sun's surface and surroundings as they would appear if the sun emitted only that light.

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spectroheliograph British  

/ -ˌɡræf, ˌspɛktrəʊˈhiːlɪəˌɡrɑːf /

noun

1. an instrument used to obtain an image of the sun in light of a particular wavelength, such as calcium or hydrogen, to show the distribution of the element over the surface and in the solar atmosphere. The image obtained is a spectroheliogram

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Other Word Forms

• spectroheliographic adjective

Etymology

Origin of spectroheliograph

First recorded in 1890–95; spectro- + heliograph

Example Sentences

They anatomize sunspots by way of US astronomer George Ellery Hale, who pioneered their observation with his 1889 invention of the spectroheliograph.

From Nature

Hale's first spectroheliograph at Kenwood in 1890 was attached to a 12-inch refractor, and the solar image was but two inches in diameter.

From Project Gutenberg

Although devised for quite another purpose, that of photographing the hydrogen prominences on the limb of the sun, the spectroheliograph has contributed very effectively to many departments of solar research.

From Project Gutenberg

The spectroheliograph reveals vast zones of facul� otherwise invisible, related to the sun-spot zones proper on both sides of the equator.

From Project Gutenberg

Then it was taken up by Deslandres of Paris and Hale of Chicago independently, both of whom succeeded in devising a complex type of apparatus known as the spectroheliograph, by which all the prominences surrounding the entire limb of the sun can be photographed at any time by light of a single wave-length, together with the disk of the sun on the same negative.

From Project Gutenberg