ephemeris

[ ih-fem-er-is ]

noun

, plural e·phe·mer·i·des [ef-, uh, -, mer, -i-deez].

1. a table showing the positions of a heavenly body on a number of dates in a regular sequence.
2. an astronomical almanac containing such tables.
3. Archaic. an almanac or calendar.

ephemeris

/ ɪˈfɛmərɪs /

noun

1. a table giving the future positions of a planet, comet, or satellite
2. an annual publication giving the positions of the sun, moon, and planets during the course of a year, information concerning eclipses, astronomical constants, etc
3. obsolete.
   a diary or almanac

ephemeris

/ ĭ-fĕm′ər-ĭs /

, Plural ephemerides ĕf′ə-mĕr′ə-dēz′

1. A table giving the coordinates of a celestial body at specific times during a given period. Ephemerides can be used by navigators to determine their longitude while at sea and by astronomers in following objects such as comets. The use of computers has allowed modern ephemerides to determine celestial positions with far greater accuracy than in earlier publications.

Word History and Origins

Origin of ephemeris¹

1545–55; < Latin ephēmeris day book, diary < Greek ephēmerís diary, account book, derivative of ephḗmeros; ephemeral

Word History and Origins

Origin of ephemeris¹

C16: from Latin, from Greek: diary, journal; see ephemeral

Example Sentences

"Getting better orbits... particularly for the two planets that dominate the dynamics of our solar system, Jupiter and Saturn, improves the basis of the entire ephemeris," Dr Jones said.

From BBC

This is the offset to apply to Chariklo’s ephemeris to fit the observations.

From Nature

GPS’s battery draining behavior is most noticeable during the initial acquisition of the satellite’s navigation message: the satellite’s state, ephemeris, and almanac.

From Forbes

The astronomical ephemeris is the last outcome of their productive genius.”

From Project Gutenberg

The pictorial journalism of the "Comic Almanacks" is often delicious; no ephemerides, in my knowledge, equal them in sustained humorous effect.

From Project Gutenberg

Related Words

• calendar
• journal
• yearbook