astronomical unit


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Related to astronomical unit: parsec

astronomical unit

n. Abbr. AU
A unit of length used in measuring astronomical distances within the solar system or other planetary system equal to the mean distance from Earth to the sun, approximately 150 million kilometers (93 million miles).

astronomical unit

n
(Units) 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

astronom′ical u′nit


n.
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]

as·tro·nom·i·cal unit

(ăs′trə-nŏm′ĭ-kəl)
A unit of length equal to the average distance from Earth to the sun, approximately 93 million miles (150 million kilometers). It is used to measure distances within the solar system.

astronomical unit


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1. (au) The mean Sun to Earth distance, equal to 92,955,807 mi (149,597,870 km). Agreed internationally in 1964, but its value has altered.
2. (au) A unit of measure based on the distance between the Earth and the Sun. Approximately equal to 1.5 x 108 km.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.astronomical unit - a unit of length used for distances within the solar systemAstronomical 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)
astronomy unit - a linear unit used for astronomical distances
Translations
Astronomische Einheit
References in periodicals archive ?
Scientists already knew this primary star was locked in a gravitational tango with another star, about 0.7 light-years away, or 44,000 astronomical units. That's relatively far apart for a pair of stellar companions.
As it flies by to Earth, its closest distance from the planet will be 0.03564 astronomical units or about 3.3 million miles.
Saturn will reach the farthest point from Earth during its conjunction with Sun, where the distance between Saturn and Earth will be 11.04 Astronomical Units (AU).
It is about 120 astronomical units (AU) away - one AU is defined as the distance between the Earth and the Sun.
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.
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.
The Solar Orbiter satellite, scheduled for launch in 2017, will carry out the first observations of the Sun and its environment at a distance of just 0.28 Astronomical Units (i.e., 28% of the mean distance between the Earth and the Sun).
These proceedings from the May 2006 meeting include papers include research on structures observed at scales from astronomical units to kilometers.
Previously, astronomers knew that planets could form in exceptionally wide binary systems, in which stars are 1,000 times farther apart than the distance between Earth and the sun, or 1,000 astronomical units. Of the approximately 200 planets discovered so far outside our solar system, about 50 orbit one member of a wide stellar duo.