declination ( or DEC): degrees north of celestial equator.
ecliptic coordinates: ecliptic latitude and longitude.
equatorial coordinates: right ascension and declination.
galactic coordinates: galactic longitude and latitude.
heliographic coordinates: coordinates on the surface of the Sun.
horizon coordinates: azimuth and altitude.
hour angle (HA): [sidereal time].
right ascension ( or RA): hours, minutes, seconds east of the vernal equinox. Because the position of the vernal equinox changes due to precession, RA coordinates must be given with the date (epoch) for which they are appropriate.
selenographic coordinates: coordinates on the surface of the Moon.
sidereal time: the right ascension of the zenith.
zenith angle (ZA): the angle from the outward normal of the Earth to the object being observed.