The parsec in Hazeron is defined as the distance travelled in ten minutes at the speed of light ("terminal velocity" of a spacecraft). It is equal to 90 525 600 km, or 125 AU, or ten light-minutes (per definition), although the manual states "the galaxy has a diameter of 10 kiloparsecs, which equals about thirty-two thousand light years".
Real-world definition: Edit
The parsec (parallax of one arcsecond) is a unit of length, equal to just under 31x10^12 kilometres, 206265 AU, or about 3.26 light-years. It is defined as the length of the adjacent side of an imaginary right triangle in space. The two dimensions that specify this triangle are the parallax angle (defined as 1 arcsecond) and the opposite side (defined as 1 astronomical unit (AU), the distance from the Earth to the Sun). Given these two measurements, along with the rules of trigonometry, the length of the adjacent side (the parsec) can be found.