Horizontal to Equatorial

Equatorial Coordinates

The Equatorial Coordinate System is based on the celestial sphere and uses two primary coordinates: right ascension (RA) and declination (Dec). Right ascension is analogous to longitude and measures the angular distance of an object eastward along the celestial equator, typically expressed in hours, minutes, and seconds. Declination is similar to latitude and measures the angle of the object above or below the celestial equator, expressed in degrees. This system is fixed relative to the stars, making it useful for locating objects regardless of the observer's position on Earth.

Horizontal Coordinates

The Horizontal Coordinate System is based on the observer's local horizon and uses two coordinates: altitude and azimuth. Altitude measures the angle of the object above the horizon (0° at the horizon to 90° at the zenith), while azimuth measures the angle along the horizon from a reference direction, typically north (0°), moving clockwise to 360°. This system changes with the observer's location and the time of observation, making it more suitable for locating objects in the immediate sky. Both systems serve distinct purposes in astronomy, with the equatorial system being more suitable for celestial navigation and long-term observations, while the horizontal system is useful for real-time observations.

Horizontal to Equatorial Converter