Table of positions of astronomical objects at given times
For the 18th-century Greek newspaper, see Efimeris.
In astronomy and celestial navigation, an ephemeris (/ɪˈfɛmərəs/; pl. ephemerides/ˌɛfəˈmɛrədiːz/; from Latin ephemeris 'diary', and Greek ἐφημερίς (ephemeris) 'diary, journal')[1][2][3] is a book with tables that gives the trajectory of naturally occurring astronomical objects as well as artificial satellites in the sky, i.e., the position (and possibly velocity) over time. Historically, positions were given as printed tables of values, given at regular intervals of date and time. The calculation of these tables was one of the first applications of mechanical computers. Modern ephemerides are often provided in electronic form. However, printed ephemerides are still produced, as they are useful when computational devices are not available.
The astronomical position calculated from an ephemeris is often given in the spherical polar coordinate system of right ascension and declination, together with the distance from the origin if applicable. Some of the astronomical phenomena of interest to astronomers are eclipses, apparent retrograde motion/planetary stations, planetary ingresses, sidereal time, positions for the mean and true nodes of the moon, the phases of the Moon, and the positions of minor celestial bodies such as Chiron.
Ephemerides are used in celestial navigation and astronomy. They are also used by astrologers.[4] GPS signals include ephemeris data used to calculate the position of satellites in orbit.
^ἐφημερίς. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project.
^Gingerich, Owen (2017). Arias, Elisa Felicitas; Combrinck, Ludwig; Gabor, Pavel; Hohenkerk, Catherine; Seidelmann, P. Kenneth (eds.). "The Role of Ephemerides from Ptolemy to Kepler". The Science of Time 2016. Astrophysics and Space Science Proceedings. 50. Cham: Springer International Publishing: 17–24. Bibcode:2017ASSP...50...17G. doi:10.1007/978-3-319-59909-0_3. ISBN 978-3-319-59909-0.
celestial navigation, an ephemeris (/ɪˈfɛmərəs/; pl. ephemerides /ˌɛfəˈmɛrədiːz/; from Latin ephemeris 'diary', and Greek ἐφημερίς (ephemeris) 'diary, journal')...
The term ephemeris time (often abbreviated ET) can in principle refer to time in association with any ephemeris (itinerary of the trajectory of an astronomical...
third release of the JPL Ephemeris Tapes, and was a special purpose, short-duration ephemeris. The then-current JPL Export Ephemeris was DE19. These early...
Ephemeris and Nautical Almanac and The Astronomical Ephemeris, a new name for the old British title The Nautical Almanac and Astronomical Ephemeris....
Propulsion Laboratory as Development Ephemeris. The latest releases include DE430 which covers planetary and lunar ephemeris from Dec 21, 1549 to Jan 25, 2650...
themselves on a featureless ocean. Developmental Ephemeris or the Jet Propulsion Laboratory Developmental Ephemeris (JPL DE) is a widely used model of the solar...
Omoglymmius ephemeris is a species of beetle in the subfamily Rhysodidae. It was described by R.T. & J.R. Bell in 1982. "Omoglymmius ephemeris R.T. & J.R...
Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac, p. 9, ... defined ephemeris time ... [was] adopted by the International...
each ("ephemeris days"). This is the normal meaning of the unit "year" used in various scientific contexts. The Julian century of 36525 ephemeris days and...
acknowledged that the long-established JPL ephemeris time argument Teph, as implemented in JPL Development Ephemeris DE405, "is for practical purposes the...
languages are available) Ephemeris, online Latin newspaper: nuntii latini universi = news in Latin of the universe (whole world) Ephemeris archive, archived...
Paleontology Time Periods Eras Epochs Calendars Astronomic time Cosmic Calendar Ephemeris Galactic year Metonic cycle Milankovitch cycles Geologic time Chronological...
1879, Shaka Era, or 22 March 1957. India has adopted pie Ephemeris Time in the Indian Ephemeris from 1960 onwards in pursuance of the resolution passed...
collection of data called an ephemeris. NASA's Jet Propulsion Laboratory HORIZONS System provides one of several ephemeris computation services. In 1976...
Paleontology Time Periods Eras Epochs Calendars Astronomic time Cosmic Calendar Ephemeris Galactic year Metonic cycle Milankovitch cycles Geologic time Chronological...
States. (1961). Explanatory Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac, London: Her Majesty's Stationery Office...
Retrieved August 6, 2015. "Horizon Online Ephemeris System for Pluto Barycenter". JPL Horizons On-Line Ephemeris System @ Solar System Dynamics Group. Archived...
of IAU's Division F by the Minor Planet Center. The Natural Satellites Ephemeris Service is an online service of the Minor Planet Center. The service provides...
the ephemeris second (see Ephemeris time - redefinition of the second). In 1976, however, the IAU resolved that the theoretical basis for ephemeris time...
Retrieved 18 May 2011. Sliter, Robert (1652). A celestiall glasse, or, Ephemeris for the year of the Christian era 1652 being the bissextile or leap-year:...
as per International System of Units and are not to be confused with ephemeris seconds.) Each day, the sidereal time at any given place and time will...
Estadio Saroldi (full name: Parque Federico Omar Saroldi) is a multi-use stadium in Montevideo, Uruguay. It is currently used mostly for football matches...
frequency for the caesium transition, newly established, with the ephemeris second. The ephemeris second is a unit in the system of time that, when used as the...
as low as 13 Jupiters. The DE405/LE405 ephemeris from the Jet Propulsion Laboratory is a widely used ephemeris dating from 1998 and covering the whole...
Paleontology Time Periods Eras Epochs Calendars Astronomic time Cosmic Calendar Ephemeris Galactic year Metonic cycle Milankovitch cycles Geologic time Chronological...
ISBN 0-19-509539-1. Explanatory Supplement to The Astronomical Ephemeris and The American Ephemeris and Nautical Almanac. London: Her Majesty's Stationery Office...
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