Dictionary.net

• A photograph of the sun made by monochromatic light, usually of the calcium line (k), and showing the sun's faculae and prominences.

2010 - New Age Dictionary Database
By Oddity Software

• A photograph of the sun made by monochromatic light, usually of the calcium line (k), and showing the sun's faculae and prominences.

1913 - Webster's Revised Unabridged Dictionary
By Noah Webster.