PERIASTRON
Etymology
Noun
periastron (plural periastrons)
(astronomy) That point of the orbit of a celestial body which is closest to the star around which the body is orbiting.
Antonyms
• apastron
Anagrams
• Pretorians, patroniser, portainers, pretorians
Source: Wiktionary
Per`i*as"tron, n. Etym: [NL., fr. Gr. (Astron.)
Definition: That point, in the real or apparent orbit of one star revolving
around another, at which the former is nearest to the latter.
Source: Webster’s Unabridged Dictionary 1913 Edition