An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 6 Search : perihelion
advance of perihelion
  پیشرفت ِ پیراهور   
pišraft-e pirâhur

Fr.: avance du périhélie   

The slow rotation of the major axis of a planet's orbit in the same direction as the revolution of the planet itself, due mainly to gravitational interactions with other planets. The perihelion of the planet Mercury advances about 9'.6 per century. The bulk of the advance was accounted by perturbations from other planets. However, a remaining small advance, by 43'' per century, was eventually explained as an effect predicted by Einstein's theory of → general relativity. In the case of close binary stars, the advance of pericenter may additionally be caused by mass transfer and the stars' distorted (elliptical) shapes. Advance of perihelion (or pericenter) is also known as → apsidal motion.

Advance, from O.Fr. avancer "move forward," from V.L. *abantiare, from L.L. abante "from before," from ab- "from" + ante "before," PIE *ant- "front, forehead;" → perihelion.

Pišraft "advance," from piš "forward; in front; before," Mid.Pers. peš + raft "going; walk, travel," from raftan "to go."

argument of perihelion
  آروزمان ِ پیراهور   
âruzmân-e pirâhur

Fr.: argument du périhélie   

The angular distance between the → ascending node of an object orbiting the Sun and its perihelion. Argument of perihelion is measured in the → orbital plane with respect to the Sun and in the direction of motion. It is one of the → orbital elements and usually shown with the symbol ω. See also: → argument of perigee, → argument of periapsis.

argument; → perihelion.

perihelion
  پیراهور   
pirâhur

Fr.: périhélie   

The nearest point to the Sun in an orbit around the Sun; opposite of → aphelion.

Perihelion, from L. perihelium, from → peri- + helios "sun," cognate with L. sol, Skt. surya, Av. hvar-, Mod.Pers. xor, hur, O.H.G. sunna, Ger. Sonne, E. sun; PIE *sawel- "sun".

Pirâhur, from pirâ-, → peri-, + hur "sun," as above;

perihelion advance
  پیشرفت ِ پیراهور   
pišraft-e pirâhur

Fr.: avance du périhélie   

advance of perihelion.

advance of perihelion.

perihelion distance
  اپست ِ پیراهوری   
apest-e pirâhuri

Fr.: distance au périhélie   

The distance between the → Sun and an → object in orbit around it when they are at their closest approach.

perihelion; → distance.

perihelion precession
  پیشایانِ پیراهوری   
pišâyân-e pirâhuri

Fr.: précession du périhélie   

advance of perihelion.

perihelion; → precession.