#Parsec unit of distance Pc#

Multiples of parsecs like the kiloparsec, 1000 pc and megaparsec, 1 000 000 pc are used for larger distances.Ī light-year (ly) is the distance light travels in a vacuum in one year or how far it would travel in space in a year. Though many people would prefer using light-years, most astronomers prefer use parsecs to describe distance, as the distance in parsecs can be easily determined using the parallax angle. Parsecs are used to measure the distances to objects outside our solar system. An object with a distance of 4 parsecs would have a parallax angle of 0.25 arcseconds. The relationship between the distance in parsecs, d, and the parallax angle in arcseconds, p, can be described in the formulaįor example, an object with a parallax angle of 2 arcseconds would be 0.5 parsecs away.

An arcsecond is 1/3600 of a degree, or alternatively 1/60 or an arcminute. The parsec is defined as the distance to an object whose parallax angle is one arcsecond (Florida State College). One way to find out the distance of the Earth to the Sun (AU) is by using the parallax method. With astronomical units we can easily tell that Pluto is roughly 7.5 times further away from the Sun compared to Jupiter. For example, Jupiter is 5.2 AU from the Sun and Pluto is nearly 40 AU. The distance from Earth to the Sun is around 150 million kilometers.Īstronomical units are a convenient way of comparing distances of objects from the sun. It is considered an average because Earth orbits around the Sun and throughout this orbit the distance between the Earth and the Sun varies by around 3% (“Astronomical Unit,” n.d.). The length of an astronomical unit is roughly the average distance from the Earth to the Sun. These units are primarily used for measuring distances within the Solar System. Units of Distance Astronomical Units (AU) Īstronomical units (AU or au) are a common unit to measure distances in space. 2.2 Cosmological Redshift and Blueshift.

Parsec unit of distance