apastraとは 意味・読み方・使い方

名詞

apastra

1. plural of apastron
   • 1892, J[ohn] Ellard Gore, “The Meteoritic Hypothesis”, in The Visible Universe: Chapters on the Origin and Construction of the Heavens, London: Crosby Lockwood and Son, […], page 114:

     If we suppose the apastra of the two stars to occur simultaneously, there will be two minima, “but the maxima will be constant.”

   • 1976, Soviet Astronomy, volume 19, page 336:

     But if both motions proceed in the same sense, then the binary stars will traverse that half of their galactic orbit with their apastra forward.

   • 2007, Edwin Budding; Osman Demircan, Introduction to Astronomical Photometry (Cambridge Observing Handbooks for Research Astronomers; issue 6), second edition, Cambridge University Press, →ISBN, page 291:

     The rotation involved is that of the location of the peri- and apastra, i.e. the line of apsides of the ellipse: it is thus called apsidal motion.