Astronomical Almanac
The Astronomical Almanac is an official astronomical yearbook of international astronomy ( International Astronomical Union , IAU) and geosciences ( International Union for Geodesy and Geophysics , IUGG). It is published in the USA ( United States Naval Observatory ) and in Great Britain (Her Majesty's Nautical Almanac Office) and, together with the ephemeris of the star catalog FK6 (see Apparent Places of Fundamental Stars ), forms the fixed reference system for the celestial and earth sciences.
Content
Like the APFS (Apparent Places of Fundamental Stars) yearbook, the Astronomical Almanac also has around 500 pages. As a detailed supplementary volume, the Explanatory Supplement is published at irregular intervals , in which all theoretical questions of the reference system are discussed, as well as the underlying data, formulas and astronomical calculation models of the individual ephemeris. Physical ephemeris are discussed mathematically as well as the natural satellites of the planets.
The most important content of the Astronomical Almanac - which has been the internationally edited successor of the Berlin Astronomical Yearbook since the 1960s - are precise projections ( ephemeris = " calculated on the day" ) of all larger bodies in the solar system , in particular
- of the sun (solar path as a mirror image of the earth's orbit ), solar rotation ( heliographic coordinates ) and position angle of its north pole
- of the moon (moon phases and lunar orbit ), selenographic coordinates
- of the 8 large planets (orbital elements, geocentric locations, rotation data) and their larger moons
- several dwarf and minor planets
- Star locations of selected fundamental stars
- basic data on sidereal time , precession , nutation (astronomy) , etc.
- as well as a detailed explanation and introduction to astronomical coordinate systems .
history
- 1766: First edition of The Nautical Almanac and Astronomical Ephemeris for 1767 in England;
- 1852: First edition of The American Ephemeris and Nautical Almanac for 1855 in the United States;
- 1960: English edition changes title to The Astronomical Ephemeris and both editions become identical in content, with each country contributing about half of the content;
- 1981: Both editions change the title to The Astronomical Almanac and a chapter with asterisks is added.
See also
literature
- The Astronomical Almanac for the Year 2010. ISBN 978-0-7077-40829 .