Fr.: tache de diffraction, ~ d'Airy
The bright disk-like image of a point source of light, such as a star, as seen in an optical system with a circular → aperture.
Named after Sir George Biddell Airy (1801-1892), Astronomer Royal, great administrator, who much improved the equipment at Greenwich Observatory. → disk.
Gerdé, → disk; Airy, see above.