# Angular+distance+from+the+equator

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**Clairaut's theorem**— For the interpretation of this theorem in terms of symmetry of second derivatives of a mapping , see Symmetry of second derivatives. Figure 1: An ellipsoid …122

**Central angle**— CoordinatesOn a sphere or ellipsoid, the central angle is delineated along a great circle.The usually provided coordinates of a point on a sphere/ellipsoid is its common latitude ( Lat ), phi,!, and longitude ( Long ), lambda,!. The point ,… …123

**Gravity darkening**— Gravity darkening, also referred to as Gravity Brightening, is an astronomical phenomenon where a star rotates so rapidly that it has a detectibly oblate shape, such as in Regulus in the Leo constellation.When a star is oblate, it has a larger… …124

**Flattening**— Ellipticity redirects here. For ellipticity in differential calculus, see elliptic operator. This article is about geometry. For psychopathology, see flattening of affect. The flattening, ellipticity, or oblateness of an oblate spheroid is a… …125

**Nepenthes rajah**— Large lower pitcher of Nepenthes rajah. Mount Kinabalu, Borneo. Conservation status …126

**Non-line-of-sight propagation**— Non line of sight (NLOS) or near line of sight is a term used to describe radio transmission across a path that is partially obstructed, usually by a physical object in the innermost Fresnel zone. Many types of radio transmissions depend, to… …127

**Retrograde motion**— This article is about retrograde motions of celestial bodies relative to a gravitationally central object. For the apparent motion as seen from a particular vantage point, see Apparent retrograde motion. Retrograde orbit: the satellite (red)… …128

**Eclipse**— An eclipse is an astronomical event that occurs when one celestial object moves into the shadow of another. The term is derived from the ancient Greek noun gr. ἔκλειψις ( gr. ékleipsis ), from verb gr. ἐκλείπω ( gr. ekleípō ), I cease to exist, a …