9 articles for "Perihelion"
Perihelion [Astro*Index]From the Greek "near the Sun." The point in the orbit of a body that is nearest the center of the Sun. Opposite of Aphelion. Because of the mutual perturbation in the planets' orbits, the direction of each planet's perihelion/aphelion axis precesses. The rates are as follows (in arc seconds per century): Mercury, 574; Venus,???; Earth, 1165; [the rest of the planets???]. There has been close agreement between observation and prediction of this shift according to Einstein's theory of general relativity. William Lilly mentioned "the apsis of Mars . . . when it shall appear in Virgo" in his famous prediction of the great 1666 London fire: "Who shall expect less than a strange catastrophe of human affairs in commonwealth, monarchy and the Kingdom of England." [double check this; how much does Mars precess per century? is this what Lilly was referring to; how accurate and well-known were Kepler's (laws) measurements at that time?]
1990.0 Perihelia | |||
---|---|---|---|
ME | 17 | GE | 42 |
VE | 10 | LE | 48 |
EA | 12 | CA | 46 |
MA | 05 | PI | 51 |
JU | 15 | AR | 32 |
SA | 02 | CA | 37 |
UR | 18 | VI | 36 |
NE | 24 | TA | 55 |
PL | 13 | SC | 38 |
[ Neptune's p/a axis varies widely from the norm . . . ]
See also:Perihelion [Prima]
♦ Periapsis ♦ Apoapsis ♦ Aphelion ♦ Einstein ♦ Perturbation ♦ Kepler's Laws
The word is of Greek origin and means "near the Sun." A planet's perihelion is the point in its orbit that is nearest the center of the Sun. It is opposite in meaning and position to aphelion.
Each planet's perihelion/aphelion axis precesses due to the mutual perturbation in the orbits of the planets.
See also:Perihelion [Munkasey M.]
♦ Periapsis ♦ Apoapsis ♦ Aphelion ♦ Einstein ♦ Perturbation ♦ Kepler's Laws
The point for an orbiting Body where it is closest toits central focal point. The point where an orbiting body in the Solar System makes its closest approach to the Sun. For the Earth and the Sun this occurs at the Summer Solstice. This is also referred to as: "The Point of Perihelion".
See also:Perihelion [DeVore]
♦ Periapsis ♦ Apoapsis ♦ Aphelion ♦ Einstein ♦ Perturbation ♦ Kepler's Laws
At the closest point to the Sun. v. Orbit.
See also:Perihelion, Longitude of [Astro*Index]
♦ Orbit
The zodiacal longitude of a body's perihelion.
See also:Perihelion, Longitude of [Munkasey M.]
♦ Zodiacal Longitude ♦ Perihelion
The Zodiacal Longitude of a Body's Perihelion.
See also:Perihelion to Node Angle [Munkasey M.]
♦ Astronomy ♦ Perihelion ♦ Perihelion Passage ♦ Perihelion to Node Angle
The Clockwise (Eastward) angular measurefrom a Body's Perihelion to its Ascending Node.
See also:Perihelion Passage [Astro*Index]
♦ Astronomy ♦ Perihelion Passage ♦ Perihelion Longitude ♦ Perihelion
The moment of time when a body is at its perihelion.
See also:Perihelion Passage [Munkasey M.]
♦ Perihelion
Also referred to as "The Time of Perihelion Passage". The Sidereal Time at which the Body is at its Perihelion.
See also:
♦ Perihelion
Astro*Index Copyright © 1997 Michael Erlewine
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