Astronomical unit — This article is about unit of length. For the full system of units, see Astronomical system of units. 1 astronomical unit = SI units 149.60×10^6 km 149.60×10^9 m Astronomical units 4.8481 … Wikipedia
astronomical unit — Astron. a unit of length, equal to the mean distance of the earth from the sun: approximately 93 million miles (150 million km). Abbr.: AU [1900 05] * * * ▪ unit of measurement Comparative data for the Sun, planets, and other solar system… … Universalium
Constant — Con stant, n. 1. That which is not subject to change; that which is invariable. [1913 Webster] 2. (Math.) A quantity that does not change its value; used in countradistinction to {variable}. [1913 Webster] 3. (Astron.) A number whose value, when… … The Collaborative International Dictionary of English
Constant of aberration — Constant Con stant, n. 1. That which is not subject to change; that which is invariable. [1913 Webster] 2. (Math.) A quantity that does not change its value; used in countradistinction to {variable}. [1913 Webster] 3. (Astron.) A number whose… … The Collaborative International Dictionary of English
Constant of integration — Constant Con stant, n. 1. That which is not subject to change; that which is invariable. [1913 Webster] 2. (Math.) A quantity that does not change its value; used in countradistinction to {variable}. [1913 Webster] 3. (Astron.) A number whose… … The Collaborative International Dictionary of English
Astronomical distance — Astronomical distances are distances in outer space, occurring on a much larger scale than those on Earth. For instance, the distance to (Proxima Centauri), the closest star to our solar system, is about 40,000,000,000,000 kilometers.For this… … Wikipedia
Astronomical seeing — Schematic diagram illustrating how optical wavefronts from a distant star may be perturbed by a layer of turbulent mixing in the atmosphere. The vertical scale of the wavefronts plotted is highly exaggerated. Astronomical seeing refers to the… … Wikipedia
Astronomical units of length — Astronomers use a number of different length units for different objects. The length unit used is typically determined by two criteria: #the unit should create manageable numbers #the unit should be easily derivable from observationThe distances… … Wikipedia
astronomical unit — noun The mean distance from the Earth to the Sun (the semi major axis of Earths orbit), approximately 149,600,000 kilometres (symbol AU), used to measure distances in the solar system.<! do not include encyclopaedic information; this is not… … Wiktionary
astronomical mean sun — An imaginary body, which is assumed to travel around equinoctial at a constant rate, completing one orbit in the same time the earth takes to complete one orbit around the ecliptic. Also known as the mean sun … Aviation dictionary
