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: 3 Search : synodic
synodic
  هماگمی   
hamâgami

Fr.: synodique   

Of or pertaining to the → conjunction of two or more heavenly bodies, especially the interval between two successive conjunctions of a planet or the Moon with the Sun.

From L.L. synodicus, from Gk. synodikos, from synodos "assembly, meeting," from → syn- "together" + hodos "a going, a way."

Hamâgam, literally "coming together," from ham-, → syn- "together," + -â- epenthetic vowel + gam from O.Pers. gam- "to come; to go," Av. gam- "to come; to go," jamaiti "goes," Mod.Pers. âmadan "to come," gâm "step, pace;" cf. Skt. gamati "goes;" Gk. bainein "to go, walk, step;" L. venire "to come;" Tocharian A käm- "to come;" O.H.G. queman "to come;" E. come; PIE stem *gwem- "to go, come."

synodic month
  ماه ِ هماگمی   
mâh-e hamâgami

Fr.: mois synodique   

The interval of 29.530 588 days (29d 12h 44m 2.80s), on average, between two successive → new Moons. Same as → lunation.

synodic; → month.

synodic period
  دوره‌ی ِ هماگمی   
dowre-ye hamâgami

Fr.: période synodique   

1) For planets, the mean interval of time between successive → conjunctions of two planets, as observed from the Earth. For → inferior planets (Venus and Mercury):
1/P = 1/E + 1/S.
For → superior planets (Mars, Jupiter, etc.):
1/P = 1/E - 1/S,
where P = → sidereal period of a planet, E = synodic period of the Earth, and S = synodic period of the planet. For example, the synodic period of Jupiter, calculated from the sidereal period of Jupiter (P), 11.856 years, via 1/11.856 = 1/1.0 - 1/S, is 398.9 days.
2) For satellites, the mean interval between successive conjunctions of a satellite with the Sun, as observed from the satellite's → primary.

synodic; → period.