Skip to main content
Glite Dictionary
periastron

periastron

9.9
The point in an orbit when a star or planet is closest to another object
  • noun
  • /ˌpɛriˈæstrɒn/
  • Specialized
translation icon : periastron
  • What we expect in this case is motion of this body essentially going back and forth and turning around at periastron and apoastron.

Examples

  • Astronomers calculate that the next periastron of the binary star system will occur in 2025, bringing the stars closer together than ever before.

  • During the periastron of the comet's orbit, it travels at incredible speeds as it approaches the Sun.

  • The periastron distance between the two stars allows for intense gravitational interactions, affecting their orbits significantly.

Synonyms

periapsis
vsperiastron
  • Specialized
9.9

The point in an object's orbit when it is closest to the body it goes around

is limited to orbits involving a star or planet
point of periapsis
vsperiastron
  • Specialized
9.9

A place in an orbit where an object is closest to the planet or star it goes around

is used only when the orbit involves a star or planet

How Close

periastron
  • Specialized
9.9
apastron
  • Specialized
9.9

Surface Forms

periastron singular
periastrons plural

Morphology

periastron = peri + astron

Formed from Greek combining elements peri- + -astron which are technical combining forms (not standalone English words), so an average B1 learner cannot reliably derive the meaning from the parts.

Etymology

The word periastron comes from the Greek parts peri- 'near' and astron 'star', the same root you see in astronomy and astronaut. So periastron is the point in an orbit when a star and its companion are closest to each other.