different between periastron vs perihelion

English

Etymology

From Ancient Greek ???? (perí, “around”) + ?????? (ástron, “star”).

Pronunciation

• IPA^(key): /p????æst??n/

Noun

periastron (plural periastrons or periastra)

1. (astronomy) That point of the orbit of a celestial body which is closest to the star around which the body is orbiting.

Antonyms

• apastron

Related terms

• see periapsis

Anagrams

• Pretorians, patroniser, portainers, pretorians

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