Ephemeris

An ephemeris (plural: ephemerides; from the Greek word ἐφημερίς ephēmeris "diary", "journal") is a table of values that gives the positions of astronomical objects in the sky at a given time or times. Different kinds of ephemerides are used for astronomy and astrology. Even though this was also one of the first applications of mechanical computers, an ephemeris will still often be a simple printed table.

The position is given:

• to astronomers in a spherical polar coordinate system of right ascension and declination or
• to astrologers in longitude along the zodiacal ecliptic, and sometimes declination.
  

Astrological positions may be given for either noon or midnight.

An astronomical ephemeris may also provide data on astronomical phenomena of interest to astrologers and astronomers such as eclipses, Apparent retrograde motion/planetary stations, planetary ingresses, sidereal time, positions for the mean and true nodes of the moon, the phases of the Moon, and sometimes even the position(s) of Chiron, and other minor celestial bodies.

Astrologers also use other ephemerides that include Lilith, a term they use variously for the apogee of the Moon or the second focus of the Moon's orbit. Some ephemerides also contain a monthly aspectarian, while others often include the declination of the planets as well as their longitudes, right ascensions, or Cartesian coordinates.