A reddish gaseous layer immediately above the photosphere of the sun or another star. Together with the corona, it constitutes the star's outer atmosphere.
- ‘Prominences, flares, plages, and other features of the solar chromosphere can be observed in hydrogen light.’
- ‘For decades astronomers labored to get good photographs of the chromosphere, and in particular its spectrum.’
- ‘The chromosphere is the first layer of atmosphere above the sun's surface layer.’
- ‘Solar flares appear as sudden, intense flashes in the chromosphere of the Sun.’
- ‘But the hotter hydrogen in the chromosphere and corona above it is madly emitting at the same wavelength.’
Mid 19th century: from chromo- color + sphere.
We take a look at several popular, though confusing, punctuation marks.