Astronomical Almanac

An almanac designed primarily for use by professional astronomers, published jointly since 1981 by the United States Naval Observatory, Washington DC and the Royal Greenwich Observatory in the UK. It replaced the American Ephemeris and Nautical Almanac and the Astronomical Ephemeris. The data listed include the phases of the Moon, sunrise and sunset, eclipses, the positions of the Sun, Moon and planets, information about bright stars, locations of observatories and astronomical constants.