Word origin · etymology
Modern product name.
Swiss identifies the Swiss-developed Astrodienst ephemeris library; ephemeris is the older word for a table of celestial positions.
Astrodienst: Swiss Ephemeris programming manual ↗Merriam-Webster: ephemeris ↗
How we know · epistemology
Documented software implementation
The library documents positional algorithms and selectable conventions. Matching its output establishes implementation agreement; checking returned flags and independent references is still necessary before making an accuracy claim.
Connected concepts
Mentioned in 11 other entries
Sources & provenance
Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.