The Parallax-Second or Parsec. Distance to an objectparsecs dimensionless p. The distance from the Sun of a body with a parallax angle of 1 arcsecond was thus defined as a unit and thanks to Turner named the parsec.
The parallax of an object can be used to approximate the distance to an object using the formula.
A parsec is defined as the distance at which an object has a 1-arcsecond stellar parallax. Recall the small angle approximation formula from the Parallax Lab Object size in parsecs distance in parsecs x angular size in radians If you need more help see the Quick Summary of how to relate Angular Size. D If a stars distance can be determined in light-years it can be figured out in parsecs. Displaystyle log _ 10 d1 frac mu 5 m 5 log 10 d 5.