How many light-year in 1 au? The answer is 1.5812507409821E-5. We assume you are converting between light year and astronomical unit. You can view more details on each measurement unit: light-year or au The SI base unit for length is the metre. 1 metre is equal to 1.0570008340246E-16 light-year, or 6.6845871222684E-12 au. Note that rounding errors may occur, so always check the results. Use this page to learn how to convert between light years and astronomical units. Type in your own numbers in the form to convert the units!
1 light-year to au = 63241.07708 au
2 light-year to au = 126482.15417 au
3 light-year to au = 189723.23125 au
4 light-year to au = 252964.30834 au
5 light-year to au = 316205.38542 au
6 light-year to au = 379446.46251 au
7 light-year to au = 442687.53959 au
8 light-year to au = 505928.61667 au
9 light-year to au = 569169.69376 au
10 light-year to au = 632410.77084 au
You can do the reverse unit conversion from au to light-year, or enter any two units below:
A light year, abbreviated ly, is the distance light travels in one year: roughly 9.46 × 1012 kilometres (9.46 petametres, or about 5.88 × 1012 (nearly six trillion) miles). More specifically, a light year is defined as the distance that a photon would travel, in free space and infinitely far away from any gravitational or magnetic fields, in one Julian year (365.25 days of 86400 seconds each).
The astronomical unit (AU or au or a.u. or sometimes ua) is a unit of length defined to be exactly equal to 149,597,870,700 metres. Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its modern redefinition.
The symbol "ua" is recommended by the Bureau International des Poids et Mesures, but in the United States and other anglophone countries the reverse usage is more common. The International Astronomical Union recommends "au" and international standard ISO 31-1 uses "AU".
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