Concept
Parallax
Apparent shift of a nearby object against a distant background.
The shift in a star's apparent position as Earth orbits the Sun; trigonometric parallax is the foundation of the cosmic distance ladder.
Overview
The shift in a star's apparent position as Earth orbits the Sun; trigonometric parallax is the foundation of the cosmic distance ladder.
See also
Kozai–Lidov Mechanism
A distant perturber pumping inner-orbit eccentricity.
Ecliptic
The Sun's apparent annual path across the sky.
Altitude
Angle of an object above the horizon.
Hour Angle
How long until/since an object crossed the meridian.
Radial Velocity
An object's velocity along the line of sight.
Blueshift
Light shifted to shorter wavelengths.