The point nearest to a star in the path of a body orbiting that star.
- Also, relativistic advance of periastron has been studied and confirmed in certain binary stars with elliptical orbits.
Mid 19th century: from peri- 'around' + Greek astron 'star', on the pattern of perigee and perihelion.
Definition of periastron in:
What do you find interesting about this word or phrase?
Comments that don't adhere to our Community Guidelines may be moderated or removed.