Kiloparsec ($\mathrm{kpc}=10^3\mathrm{pc}$)

A kiloparsec is $10^3$ parsecs, approximately $3.086\times 10^{19}$ metres or $3262$ light-years. It is a useful unit for distances within and between galaxies: a length quoted as $8\mathrm{kpc}$ is $8000\mathrm{pc}$.

The underlying parsec is defined geometrically as $(648000/\pi )$ astronomical units. Consequently the stellar parallax relation $d(\mathrm{pc})=1/p(\mathrm{arcsec})$ makes a kiloparsec correspond approximately to a parallax of one milliarcsecond. The small angle illustrates why distant stars require precise astrometry.