Coordinates

Definition

Coordinates are numerical values that define a specific point in a space or on a surface. In astronomy, coordinates are used to pinpoint the location of celestial objects in the sky.

5 Must Know Facts For Your Next Test

1. Celestial coordinates often use systems like Right Ascension and Declination, similar to longitude and latitude on Earth.
2. The Equatorial Coordinate System is one of the most commonly used systems in astronomy for locating stars and planets.
3. Right Ascension (RA) is measured in hours, minutes, and seconds along the celestial equator.
4. Declination (Dec) is measured in degrees, arcminutes, and arcseconds north or south of the celestial equator.
5. Astronomy also uses Altitude-Azimuth coordinates for local observations, where altitude measures the angle above the horizon and azimuth measures the compass direction.

Review Questions

• What are the two main components of celestial coordinates in the Equatorial Coordinate System?
• How is Right Ascension different from Declination?
• When might astronomers use Altitude-Azimuth coordinates instead of Equatorial coordinates?

Related terms

Right Ascension:

A coordinate that measures an object's position eastward along the celestial equator.

Declination:

A coordinate that measures an object's position north or south of the celestial equator.

Equatorial Coordinate System:

A system that projects Earth's latitude and longitude onto the celestial sphere to locate objects.