from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun An instrument used to make spectroheliograms.
from The Century Dictionary.
- noun A specialized spectrograph, invented independently by Hale in the United States and by Deslandres in Paris about 1892, for the purpose of photographing the sun by monochromatic light.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Astrophysics) An apparatus for making spectroheliograms, consisting of a spectroscopic camera used in combination with a telescope, and provided with clockwork for moving the sun's image across the slit.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun astronomy an
instrumentthat produced monochromatic photographsof the sunusing light at a selected wavelength
from Wiktionary, Creative Commons Attribution/Share-Alike License
A "spectroheliograph," consisting of a spectroscopic and a photographic apparatus of special type, attached to the eye-end of an equatoreal twelve inches in aperture, was erected at Kenwood in March, 1891; and with its aid, Professor Hale entered upon original researches of high promise for the advancement of solar physics.
"spectroheliograph" enables him, moreover, to delineate the sun's disc in any selected of its light, with the result of disclosing vast masses of calcium and hydrogen flocculi, piled up at various heights above the solar surface.
Made with the spectroheliograph, showing the immense vortices, or whirling storms like tornadoes, that centre in sun-spots.
Solar prominences, photographed with the spectroheliograph without an eclipse (Ellerman).
Photographed with the spectroheliograph, using the light emitted by glowing calcium vapor.
Solar prominences, photographed with the spectroheliograph without an eclipse (Ellerman) 31.