Definition of ephemeris in English:



Astronomy Astrology
  • A table or data file giving the calculated positions of a celestial object at regular intervals throughout a period.

    ‘you can compute an ephemeris for any comet that is discovered and plot an accurate finder chart’
    • ‘The navigation message contains the satellite ephemeris, which is a numerical model of the satellite's orbit.’
    • ‘The GPS position solution can be improved by using a better satellite ephemeris.’
    • ‘It's not commonly realised that there is a strong notional element in some of the times so confidently listed in the ephemeris, as will become clear if you compare the times given for aspects of the major planets in different ephemerides.’
    • ‘Timing an occultation to a fraction of a second allows the observed location to be referenced against the predicted position from the computed ephemeris, perhaps leading to an update.’
    • ‘Global networks of tracking stations produce the observations that make generation of the precise ephemerides possible.’


Early 16th century: from Latin, from Greek ephēmeros lasting only a day.