# astronomical unit

> mean distance between Earth and the Sun, common length reference in astronomy

**Wikidata**: [Q1811](https://www.wikidata.org/wiki/Q1811)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Astronomical_unit)  
**Source**: https://4ort.xyz/entity/astronomical-unit


## References

1. ISO 80000-3:2006 Quantities and units — Part 3: Space and time
2. Integrated Authority File
3. ISO 80000-1:2009 Quantities and units—Part 1: General
4. Freebase Data Dumps. 2013
5. [Source](https://www.iau.org/static/resolutions/IAU2012_English.pdf)
6. Recommendation N. 20 - Codes for Units of Measure Used in International Trade - Revision 13 (Annexes I to III)
7. [Source](https://encyklopedia.pwn.pl/haslo/astronomiczna-jednostka;3871871.html)