different between perihelion vs periapsis

English

Etymology

From perihelium (“perihelion”) (obsolete) +? -on (suffix forming nouns) (from Ancient Greek -?? (-on)). Perihelium is borrowed from Late Latin perihelium, from Ancient Greek ????- (perí-) (a variant of ????- (peri-, prefix meaning ‘around; surrounding’), ultimately from Proto-Indo-European *per- (“before, in front; first”)) + ????? (h?lios, “sun”) (ultimately from Proto-Indo-European *sóh?wl? (“sun”) or a pre-Hellenic language), which was modelled after perigeum (“point in an orbit about the Earth that is closest to the Earth, perigee”).

Pronunciation

• (Received Pronunciation) enPR: ?p?r-?-?h?l-(?)-y?n, IPA^(key): /?p?.???hi?.l?.?n/
• (General American) enPR: ?p?r-?-?h?l-(?)-y?n, IPA^(key): /?p?.???hi.lj?n/
• Rhymes: -?lj?n (GA)
• Hyphenation: pe?ri?he?li?on

Noun

perihelion (plural perihelia or (deprecated) perihelions)

1. (astronomy) The point in the elliptical orbit of a comet, planet, etc., where it is nearest to the Sun.

   Synonym: (symbol) ?

   Antonym: aphelion
2. (figuratively) The highest point or state; the peak, zenith.

   Synonyms: see Thesaurus:apex

Hypernyms

• periapsis

Coordinate terms

Derived terms

• perihelial (rare)
• perihelian (archaic)
• perihelic

Translations

See also

• Appendix:List of astronomical terms

References

Further reading

• apsis on Wikipedia.Wikipedia

Esperanto

Noun

perihelion

1. accusative singular of perihelio

English

Etymology

peri- +? apsis

Noun

periapsis (plural periapsides)

1. (astronomy) The point of a body's elliptical orbit about the system's centre of mass where the distance between the body and the centre of mass is at its minimum.

Usage notes

In the case of some particular celestial bodies, specialised terms are used.

Synonyms

• pericenter

Antonyms

• apoapsis

Related terms

Translations

See also

• Apsis on Wikipedia.Wikipedia

Finnish

Pronunciation

• IPA^(key): /?peri?psis/, [?pe?ri??ps?is?]
• Rhymes: -?psis
• Syllabification: pe?ri?ap?sis

Noun

periapsis

1. (astronomy) periapsis

Declension