e·phem·er·is 
(ĭ-fĕmər-ĭs)
(ĭ-fĕmər-ĭs)n. pl. eph·e·mer·i·des (ĕf′ə-mĕrə-dēz′)
A table giving the coordinates of a celestial body at a number of specific times during a given period.
[Late Latin ephēmeris, from Greek, diary, from ephēmeros, daily; see EPHEMERAL.]