astronomical unit

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astronomical unit

(AU), mean distance between the earth and sun; one AU is c.92,960,000 mi (149,604,970 km). The astronomical unit is the principal unit of measurement within the solar system, e.g., Mercury is just over 1-3 AU and Pluto is about 39 AU from the sun.

astronomical unit

(AU or au) A unit of length that is used for distances, especially within the Solar System. It is effectively the mean distance between Earth and Sun. It is defined formally in terms of Kepler's third law and the Gaussian gravitational constant. One astronomical unit is equal to 149 597 870 kilometers or 499.005 light-seconds.

astronomical unit

[‚as·trə′näm·ə·kəl ′yü·nət]
(astronomy)
Abbreviated AU.
A measure for distance within the solar system equal to the mean distance between earth and sun, that is, about 92,956,000 miles (149,598,000 kilometers).
The semimajor axis of the elliptical orbit of earth.

astronomical unit

a unit of distance used in astronomy equal to the mean distance between the earth and the sun. 1 astronomical unit is equivalent to 1.495 × 1011 metres or about 9.3 × 107 miles
References in periodicals archive ?
CNEOS predicted that 2006 QQ23 will be about 0.40769 astronomical units or roughly 38 million miles from Earth during its approach three years from now.
CNEOS estimated that it will be about 0.09142 astronomical units or 8.5 million miles away from the planet on its future flyby.
It is expected to be about 0.04977 astronomical units or around 4.6 million miles away from the planet during its flyby.
During this time, the asteroid flew at a much farther distance compared to its upcoming approach at 0.40667 astronomical units or roughly 38 million miles away from the planet.
As it flies by to Earth, its closest distance from the planet will be 0.03564 astronomical units or about 3.3 million miles.
Even in the tightly packed centers of globular clusters, where there might be up to 1,000 stars per cubic parsec (a cube 3.26 light-years on a side), the average distance between stars would still be 0.1 parsec, or about 21,000 astronomical units. Compare that to the size of our solar system, which is typically given as 100 a.u.
VVGOOGLING a runner Kuiper Belt 1.50 Newmarket A circumstellar disc in the solar system beyond the planets, extending from the orbit of Neptune to approximately 50 astronomical units from the sun.
This pair, in turn, is locked in a long-distance orbit with another pair of stars about 1,670 astronomical units away (an astronomical unit is the distance between Earth and the sun).
They noticed that beyond 150 astronomical units (150 times the distance from the sun to the Earth), 10 previously discovered objects, along with Sedna and 2012 [VP.sub.113], follow orbits that appear strangely bunched up.
When this view was obtained, Uranus was nearly on the opposite side of the Sun as seen from Saturn, at a distance of approximately 28.6 astronomical units from Cassini and Saturn.