ephemeris

ephem·eris (e fem′ər is, i-)

noun pl. eph′·emer′i·des′ef′ə mer′ə dēz′

a table giving the computed positions of a celestial body for every day of a given period
an astronomical almanac containing such tables
Obsolete a calendar or diary

Etymology: L < Gr ephēmeris, diary, calendar < ephēmeros: see ephemeron

Converse of object

use: Back to text 40 ] Eg, using the ephemeris to see when the Moon's aspect to the Sun becomes exact.
predict: During the 19th century observations of the positions of the planet Uranus were seen to be in disagreement with the predicted ephemeris.
base: A solar-system ephemeris based on UT1 or sidereal time would somehow have to include the unpredictable variations of the Earth's rotation.

Adjective modifier

personal: It is worth expending some energy on doing this personal ephemeris for a whole year.

Modifies a noun

datum: A set of ephemeris data is valid for several hours.
file: The Astrodienst site offers printable ephemeris files in Acrobat PDF format.
time: Ephemeris time has been superseded by relativistic timescales for current purposes, but for historical purposes the concept of ephemeris time is still valid.
entry: MJD The Modified Julian Date of the ephemeris entry.

Noun used with modifier

pulsar: UPDATE parameter FROM qualifier The UPDATE command is used to update one or more parameters of the pulsar ephemeris.

Browse dictionary entries near ephemeris