What is 81AU in Light Years?

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What is 81 Astronomical Units (81AU) in Light Years (ly)?

What is 81AU in ly? Convert 81 Astronomical Units (81AU) to Light Years (ly) and show formula, brief history on the units and quick maths for the conversion.

Enter Astronomical Units to convert to Light Years


Quick Reference for Converting Astronomical Units to Light Years

Formula
ly = AU / 63239.82
Quick Rough Maths
To get the Light Years, divide the number of Astronomical Units by 63.2 thousand
Astronomical Units (AU) in 1 Light Year
There are 63239.82 Astronomical Units in 1 Light Year
Light Years (ly) in 1 Astronomical Unit
There are 0 Light Years in 1 Astronomical Unit

Unit Information

Astronomical Unit
/astrəˈnɒmɪk(ə)l ˈjuːnɪt/
Symbol: AU
Unit System: Astronomical system of units

What is the Astronomical Unit?

The astronomical unit is a unit of length and is used in the Astronomical system of units and denoted by the symbol au.

It represents the average distance between the Earth and the Sun which is approximately 150 million kilometres (or 93 million miles).

It's used mostly to express distances within our Solar System.

Light Year
/lʌɪt jɪə,jəː/
Symbol: ly
Unit System: Astronomical System of Units

What is the Light Year?

The light year is a unit of length in the Astronomical system of units. It uses the symbol ly.

Often confused with a unit of time as it contains the word "year", it is actually defined by the International Astronomical Union (IAU) as the amount of distance that light travels in a vacuum in one Julian year (365.25 days).

Using the speed of light (299,792,458 m/s or 'c') and the Julian year (as apposed to the Gregorian year which is 365.2425 days), we can equivalate 1 light year as 9,460,730,472,580,800 metres or ≈ 9.46 trillion kilometres.


Conversion Tables for Astronomical Units (AU) to Light Years (ly)