What are right ascension and declination?
To identify a point on earth you can use latitude and longitude. To identify a point in the sky, imagine the sky to be one big sphere of stars that rotates, while earth stands still. The equator of the celestial sphere is called the ecliptic and is the path taken by the sun in the sky. Right ascension is the equivalent of longitude and is measured eastwards around the ecliptic from the point in the sky where the sun is at the vernal equinox, which is in Aries. It is usually measured in units of time corresponding to the amount of rotation. Declination is the equivalent latitude of gives the angle above the ecliptic.
