Search results
Results From The WOW.Com Content Network
The main visible effect (in longitude) of the variation of the Moon is that during the course of every month, at the octants of the Moon's phase that follow the syzygies (i.e. halfway between the new or the full moon and the next-following quarter), the Moon is about two thirds of a degree farther ahead than would be expected on the basis of its mean motion (as modified by the equation of the ...
The semi-analytic planetary theory VSOP (French: Variations Séculaires des Orbites Planétaires) is a mathematical model describing long-term changes (secular variation) in the orbits of the planets Mercury to Neptune.
Variation (astronomy), any perturbation of the mean motion or orbit of a planet or satellite, particularly of the moon; Genetic variation, the difference in DNA among individuals or the differences between populations Human genetic variation, genetic differences in and among populations of humans
This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: [1] Intrinsic variables , whose luminosity actually changes periodically; for example, because the star swells and shrinks.
In the Hipparchian, Ptolemaic, and Copernican systems of astronomy, the epicycle (from Ancient Greek ἐπίκυκλος (epíkuklos) 'upon the circle', meaning "circle moving on another circle") [1] was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets.
Transit-timing variation is a method for detecting exoplanets by observing variations in the timing of a transit. This provides an extremely sensitive method capable of detecting additional planets in the system with masses potentially as small as that of Earth. In tightly packed planetary systems, the gravitational pull of the planets among ...
Of Babylonian astronomy, practically nothing was known to historians of science before the 1880s. [3] Surviving ancient writings of Pliny had made bare mention of three astronomical schools in Mesopotamia – at Babylon, Uruk, and 'Hipparenum' (possibly 'Sippar'). [4]
Time-domain astronomy is the study of how astronomical objects change with time. Said to have begun with Galileo's Letters on Sunspots, the field has now naturally expanded to encompass variable objects beyond the Solar System. Temporal variation may originate from movement of the source, or changes in the object itself.