What does «centelleo» mean in Spanish?
- The action and effect of scintillation.
- In astronomy, the flickering or twinkling observed in celestial bodies, particularly stars, especially when they appear close to the horizon. Starlight, as it passes obliquely through the Earth's atmosphere, changes its trajectory by bending downward, i.e., toward the center of the Earth. Since the refractive index of the air varies with its density and the effect of other factors, such as humidity, it follows that the starlight, passing through air masses of varying and unequal composition, will be more or less deflected at successive times. These changes in the direction of the light cause the stars to appear with their characteristic twinkling in the firmament and also vary in color and brightness. A strong wind prevents the isolation of air masses of different density and therefore reduces the scintillation effect. Even when the stars are very large, their enormous distance from the Earth makes them appear as simple luminous points in the sky. Seen from the same place, our eye captures their image by different luminous paths and on this path it is possible that light waves of a certain frequency (color) are destroyed and those of other frequencies are reinforced instead (v. Interference). The planets, which are much smaller than the visible stars, are, however, much closer to the Earth and therefore we see them with appreciable diameters. Consequently, the light rays coming from the different points on the surface of the planets do not undergo, as a whole, modification as those of the stars and for this reason the scintillation they produce is scarcely noticed on the planets, except when they are very close to the horizon. The scintillation of Mercury is especially observable because of the small apparent angular diameter of this planet. See Reflection and refraction of light.
- (contador de centelleo) Rays from radioactive substances produce luminescence when they strike certain materials such as zinc sulfide or diamond. Observed under the microscope, this luminescence appears to be composed of isolated flashes that together produce a scintillation.