An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Rays of → sunlight that appear to converge at the → antisolar point. Like → crepuscular rays, they are parallel beams of sunlight from holes in the clouds, and their apparently odd directions are a perspective effect.

→ anti-; → crepuscular rays.

Rays of sunlight that appear to diverge from a single point in the sky when parallel columns of light, partially blocked by clouds, pour through gaps in clouds. They result from light scattering and an optical effect called perspective.

Crepuscular "of, pertaining to, or resembling twilight," from L. crepuscul(um), "twilight, dusk," from crepus-, from creper "dusky, dark."

Partowhâ "rays," from partow, → ray; nimtâbi "of, pertaining to, or resembling nimtâb" → twilight.