ephemeris Definition
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
ephemeris Usage Examples
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- time: Ephemeris time has been superseded by relativistic timescales for current purposes, but for historical purposes the concept of ephemeris time is still valid.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
- ephemeron ›
- Ephesian ›
- Ephesians ›
- Ephesus ›
- ephod ›
- ephor ›
- Ephorus of Cum× ›
- Ephraim ›
- Ephraimite ›
- Ephron, Nora ›

