An Etymological Dictionary of Astronomy and Astrophysics

A general term for a relatively bright or dark feature seen in monochromatic images taken in the red Hα → Balmer line of the solar → chromosphere. Mottles constitute the fine structure of the quiet solar chromosphere and are found near bright points at → supergranulation boundaries.

Etymology (EN): Probably back formation from motley, from M.E., O.E. mot “speck,” of unknown origin; maybe related to Du. mot “sawdust, grit;” Norw. mutt “speck.”

Etymology (PE): Capârak noun from capâr “spotted, speckled, mottled” + -ak diminutive/similarity suffix.