Coordinate system
The Celestial Sphere
The imaginary sphere of arbitrarily large radius, centred on the observer, onto which all celestial bodies appear projected. It is the geometric stage on which every astronomical coordinate system is drawn — the sky treated as a two-dimensional surface whose points are fixed by pairs of angles.
Highlights
- ›The imaginary sphere onto which the sky is projected
Related systems & concepts
Across the reference systems
Knowledge connections
- Associated withThe Equatorial Coordinate System
- Associated withThe Horizontal Coordinate System
- Associated withThe Horizontal Coordinate System
- Associated withAtmospheric Refraction
Sources
The primary and reference sources this topic draws on.
- IAUInternational Astronomical Union
Official naming, definitions, constellation boundaries, and astronomical nomenclature.