Astronomical Scintillation

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Astronomical Scintillation

Any scintillation phenomena, such as irregular oscillatory motion, variation of intensity, and color fluctuation observed in the light emanating from am extraterrestrial source; to be distinguished from terrestrial scintillation primarily in that the light source for the latter lies somewhere within the earth's atmosphere. Also called stellar scintillation . See

Astronomical scintillation is typically strongest for celestial objects lying at large zenith distances and is not easily observed by eye for objects whose zenith distances are under 30°. Nonperiodic vibratory motions of stellar images with frequencies of the order of 1 to 10 cycles per second create a troublesome problem of seeing in astronomical work. The size of the schlieren producing vibratory scintillations has been estimated to be of the order of centimeters, and chromatic scintillations of celestial objects appear to be produced by parcels whose dimensions are of the order of decimeters or, perhaps, meters. Hence, astronomical scintillation is primarily a consequence of the high-frequency, short-wavelength type of atmospheric turbulence.


This article is based on NASA's Dictionary of Technical Terms for Aerospace Use