User:Bob K31416/P

The name parsec is "an abbreviated form of 'a distance corresponding to a parallax of one second'." It was coined in 1913 at the suggestion of British astronomer Herbert Hall Turner. A parsec is the distance from the Sun to an astronomical object which has a parallax angle of one arcsecond. Mathematically, in a right triangle with an included angle θ equal to one arc second, and side opposite θ equal to 1 AU, a parsec is the length of the side adjacent to θ.