English: Graphic rapresentation of JPL Horizons On-Line Ephemeris System output values.
RA = Right ascension; the distance on the celestial sphere eastward along the
celestial equator from the reference equinox to the meridian of the object.
RA is analogous to longitude, with the plane containing the equinox defining
zero RA much as the Greenwich meridian defines zero longitude. There are
different types of RA, depending on what coordinate system
and aberrations are requested. Values are expressed in sexagesimal time units
of hours, minutes, and seconds OR decimal angular degrees, as requested.
DEC = Declination; the angular distance on the celestial sphere north (positive)
or south (negative) of the celestial equator. It is analogous to latitude. As
with RA, there are different types of DEC depending on what
coordinate system and aberrations are requested. Usually expressed in decimal
angular degrees.