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Astral Atlas
Wiki concept · Astronomy & calculated points

Stationary

Also called planetary station

A moment when apparent longitudinal motion passes through zero near a change between direct and retrograde motion.

In this entry

Word origin · etymology

Latin-derived English adjective.

Stationary belongs to the station family, from Latin statio, a standing. The term names an apparent pause in a body's longitudinal movement.

Merriam-Webster: station ↗

How we know · epistemology

Instantaneous motion criterion

A station is located by solving for zero longitudinal speed in a specified frame. A display that rounds a small speed to zero is not an exact station; practical station windows require a separately declared tolerance.

Swiss Ephemeris: technical documentation ↗

Connected concepts

Terms used in this explanation

These links connect subjects and terminology. They do not establish a shared historical origin.

Sources & provenance

Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.

Find these sources across the wiki →

  1. Swiss Ephemeris: technical documentation ↗
  2. Merriam-Webster: station ↗