astronomy unit

/əˌstrɑnəmi ˌjunət/

Definitions of astronomy unit

1. noun

   a linear unit used for astronomical distances
   types:

   light year, light-year

   the distance that light travels in a vacuum in 1 year; 5.88 trillion miles or 9.46 trillion kilometers

   light hour

   the distance light travels in a vacuum in one hour; approximately one billion kilometers

   light minute

   the distance light travels in a vacuum in one minute; approximately 18 million kilometers

   light second

   the distance light travels in a vacuum in one second; approximately 300,000 kilometers

   AU, Astronomical Unit

   a unit of length used for distances within the solar system; equal to the mean distance between the Earth and the Sun (approximately 93 million miles or 150 million kilometers)

   parsec, secpar

   a unit of astronomical length based on the distance from Earth at which stellar parallax is 1 second of arc; equivalent to 3.262 light years

   type of:

   linear measure, linear unit

   a unit of measurement of length