An instrument for taking photographs of the sun in light of one wavelength only.
- ‘He invented the spectroheliograph in 1892, a device that allowed him to view the sun in individual wavelengths of light.’
- ‘The most important advantages of this form of spectroheliograph is the large field photographed.’
- ‘Hale also gained prominence as an astronomer with his invention of the spectroheliograph and the discovery of magnetic fields in sunspots.’
- ‘Basically, the spectroheliograph has two spectrographs mounted back-to-back.’
- ‘The solar telescopes and spectroheliographs of the Mount Wilson Observatory were among the earliest modern facilities for the study of the solar surface.’
We take a look at several popular, though confusing, punctuation marks.