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

In the 1790s, he calculated ephemerides, predictions about the future positions of the sun, the moon, the planets and the stars over the course of the coming year.

From Washington Post

Not surprisingly, with such traumatic lessons, scientists have sweated over getting the ephemerides of solar-system objects pinned down better and better.

From Nautilus

Dictys (the full title of whose book is Ephemeris Belli Trojani) is not only the longer but the better written of the two.

From Project Gutenberg

For instance, under the entry newspaper occurs the attractive word ephemeris.

From Project Gutenberg

Knowing the location of Venus in the sky, which can be ascertained from the Ephemeris, the observer can find it by day.

From Project Gutenberg

Take in hand, then, the Ephemeris for the year of your birth and read this chapter with it in view.

From Project Gutenberg

Possibly the Latin Ephemeris was the work of Septimius himself.

From Project Gutenberg

Related Words

• calendar
• journal
• yearbook