• The mass of dust and gas surrounding the nucleus of a comet. Coma plus nucleus make up the head of a comet.
  • In a CRT, a form of distortion in which a spot moving away from the center of the screen forms a comet shape. May be due, for instance, to a misalignment of the focusing of the electron beams.
  • In an optical system, a form of aberration in which a point source of light forms a comet shape. Also known as coma aberration.

Not what you were looking for?