AstroInfo: Table of Contents
The Sky and Coordinate Systems
Celestial Coordinate Systems
Celestial Equator
Celestial Poles
Celestial Sphere
The Ecliptic
The Equinoxes
Geographic Coordinates
Great Circles
The Horizon
Hour Angle
Local Meridian
Precession
The Zenith
Time
Julian Day
Leap Years
Sidereal Time
Time Zones
Universal Time
Physics
Blackbody Radiation
Dark Matter
Flux
Luminosity
Parallax
Retrograde Motion
Astrophysics
Elliptical Galaxies
Spiral Galaxies
The Magnitude Scale
Stars: An Introductory FAQ
Star Colors and Temperatures