Also known as: au.
AU has various meanings in the Astronomy category. Discover the full forms, definitions, and usage contexts of AU in Astronomy.
The astronomical unit is a unit of length, roughly the distance from the Earth to the Sun. The astronomical unit is used primarily as a convenient yardstick for measuring distances within the Solar System or around other stars. The radius of the earth's orbit is defined as one astronomical unit.
AstronomyAngstrom , unit of length used chiefly in measuring wavelengths of light, equal to 10 10 metre, or 0.1 nanometer. It is named for the 19th-century Swedish physicist Anders Jonas Angstrom.
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