With this data, we can work out the distance of stars. The difference in angle between the measurements is twice the parallax angle, an angle formed by drawing imaginary lines from the Sun and Earth that meet at the star. Astronomers have long calculated the distance of stars by measuring their positions above Earth at two different points, six months apart. Using the principle of parallax, some stellar distances can be found by measuring their tiny shift in position as the Earth undergoes its yearly orbit around the Sun. Hello and welcome to What Da MathIn this video, we will investigate the idea of ParSec and I will explain how it's calculated, what it means and why it's im. The unit has its origins in one of the first methods of determining the distance to the stars. The opposite side is one astronomical unit – the distance from Earth to the Sun. A parsec is equal to about 3.26 light-years or roughly 31 trillion kilometres (19 trillion miles). A parsec is the distance from the Sun to an astronomical object that has a parallax angle of one arcsecond (not to scale). An arc-second is one-60th of an arc-minute, which is one-60th of a degree in a 360-degree circle. The angle opposite the right angle is one arc-second. It is defined as 360×60×60/2 astronomical. The word ‘parsec’ is derived from ‘parallax’ and ‘arc-second’. In the real world, a parsec is a measurement of distance based on apparent stellar motion as observed from Earth. The term was coined by British astronomer Herbert Hall Hoover in 1913, and it’s the distance from the Sun to an object (like a star) that has a parallax angle of one arc-second.

It’s the equivalent of 30.9 trillion kilometres (19.2 trillion miles), or about 3.26 light years. A parsec is a unit of length in astronomy.

Whats a parsec