Translation guide
AU is the astronomical unit, a standard measure of distance in astronomy equal to the average distance from the Earth to the Sun. In Japanese, it is almost always referred to by the direct loanword 天文単位 or the abbreviation AU.
Expressing the astronomical unit of distance, approximately 150 million kilometers.
The standard Japanese term for astronomical unit. Used in scientific and educational contexts.
The distance from the Earth to the Sun is about 1 astronomical unit.
The abbreviation AU is widely recognized in Japanese astronomy, pronounced エーユー. Often used in technical writing or when space is limited.
This planet orbits at a distance of 0.5 AU from its star.
In Japanese, the term 天文単位 is the full formal term, while AU is the common abbreviation. When speaking, AU is pronounced as エーユー (ēyū). In written Japanese, both are used, but AU may be more common in technical contexts. There is no native Japanese unit equivalent; the concept was adopted from Western astronomy.