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Glite Dictionary
📏 Half main axis 📏 Half longest diameter
semimajor

semimajor

8.6
Half of the longest line across an ellipse
  • noun
  • /ˌsɛmɪˈmeɪdʒər/
  • Specialized
translation icon : semieje mayor
  • In astronomy, understanding the semimajor axis is crucial for predicting the orbits of celestial bodies around a star.
  • semimajor axis

Examples

  • To determine the orbit of a planet, you must measure the length of its semimajor axis.

  • To the extent that the parent star's mass is known from its spectrum and luminosity, the periodicity of the Doppler signal yields the planetary orbit's semimajor axis a.

    Academic text (2004)

  • The length of the semimajor axis in this ellipse is essential for calculating its area.

Synonyms

semimajor axis
vssemimajor
  • Specialized
8.0

The distance from the center of an ellipse or oval to its farthest edge, equal to half the longest diameter

is the same meaning but uses the shorter form of the term

Compounds

semimajor axis
  • Specialized
8.0

The distance from the center of an ellipse or oval to its farthest edge, equal to half the longest diameter

How Long

major axis
  • Specialized
6.3
semimajor
  • Specialized
8.6
minor axis
  • Specialized
7.2

Surface Forms

semimajor singular
semimajors plural

Morphology

semimajor = semimajor (transparent) = semi + major

This noun is a zero-derived use of the adjective semimajor, so the form changes only in grammatical category.

Etymology

Semimajor is built from semi- 'half' and major 'large', and as a noun it names the half of an ellipse's longest diameter. So the semimajor is the distance from the centre to the edge along the biggest line across the ellipse.