What does ephemerist mean?
An ephemerist is a rare noun for a person who prepares, maintains, or publishes an ephemeris. An ephemeris is a reference table—traditionally an annual calendar or almanac, and in modern astronomy a set of calculated positions and phenomena of celestial bodies. Thus, an ephemerist assembled information, checked calculations, or issued the resulting tables for consultation. The word is chiefly historical and occupational, although it can be used figuratively for a specialist who tracks changing positions or dates. In contemporary usage it is uncommon, and readers are more likely to encounter ephemeris itself, especially in astronomy, navigation, and calendrical contexts. The term remains useful because it names the person responsible for producing a data-rich reference work rather than the reference work itself.
nounA person who prepares, maintains, or publishes an ephemeris, especially a table of calculated celestial positions and events.
- A person who prepares, maintains, or publishes an ephemeris, especially a table of calculated celestial positions and events.
"The ephemerist revised the astronomical tables before each year's observations were published."
"An experienced ephemerist checked the tables for errors before they were sent to the printers."
"The manuscript described how the ephemerist had recorded eclipses and planetary movements for the coming year."
The standard plural is ephemerists.
"Several ephemerists contributed calculations to the new tables."
The planets move, the tables must be rewritten: an ephemerist was the person keeping celestial schedules up to date.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of ephemerist
The word entered English from French éphémériste, ultimately from Greek ephēmeristēs, meaning “keeper of an ephemeris.” Greek ephēmeris denoted a daily record or calendar and was derived from ephēmeros, “lasting one day,” formed from epi, meaning “on,” and hēmera, meaning “day.” The English occupational suffix -ist was ultimately added through the French borrowing.
Related word forms
How ephemerist is actually used
Rare, formal, and chiefly occupational or historical. The term is not the usual modern label for an astronomer; it specifically identifies someone who compiles or publishes ephemerides.
Easily confused with ephemerist
An ephemerist is the person who compiles or publishes an ephemeris; an ephemeris is the table or reference work itself.