# 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