表示天体间距离的单位
parsec
n : a unit of astronomical length based on the distance from
Earth at which stellar parallax is 1 second of arc;
equivalent to 3.262 light years [syn: {secpar}]
PARSEC
Extensible language with PL/I-like syntax, derived from
PROTEUS. "PARSEC User's Manual", Bolt Beranek & Newman (Dec
1972).