What does a parsec mean, and what is a unit of parsec

The parsec (abbreviated PC) is an astronomical unit of length. Seconds are one of the oldest and most standard methods of measuring the distance between stars. It is based on trigonometric parallax.

The inner angle of the triangle corresponding to the mean radius (one astronomical unit, au) of the Earth's orbit is the base edge is called parallax. When the size of this angle is 1 second, the length of one side of the triangle (since the difference in length between the two sides corresponding to the angle of 1 second is completely negligible, therefore, this triangle can be thought of as a right triangle or an isosceles triangle) is called a 1 second difference.

Seconds: A unit of distance used in astronomy. It is mainly used to measure the distance of extrasolar objects. 1 second difference Schematic diagram of a one-second difference.

The distance from the time when the annual parallax of the celestial body is defined as 1. The parsec is the reciprocal of the annual parallax, which is 0 for celestial bodies1 , its distance is 10 parsecs, and the annual parallax of the celestial body is 0

At 01, the distance is 100 parsecs, and so on. A 1 parsec is equal to a light-year, or 206265 astronomical unit, or a trillion kilometers. When measuring distant galaxies, parsecs are too small, and are often measured in kiloparsecs (kpc) and millions.

Parsec is one of the oldest and most standard methods of measuring the distance between stars.

It is based on trigonometric parallax. The inner angle of the triangle corresponding to the average radius of the Earth's orbit (one astronomical unit, au) as the base is called parallax. When the size of this angle is 1 second, the length of one side of the triangle (the distance from the Earth to this star) is called 1 second because the difference in the length of the two sides corresponding to the angle of 1 second can be guessed at a long time, so this triangle can be imagined as a right triangle or an isosceles triangle).

From this, it can be seen that 1pc = 360 60 60 2 1au = 206265au = (light year, 1 parsec difference is equal to 206265 astronomical unit, that is, light years or 308568 billion kilometers. Astronomers usually use parsecs rather than astronomical units to describe the distance of celestial bodies. This is not only because it is easier to calculate using a parsec digital spike and smaller spikes, but also for historical reasons.

The greater the parallax of a celestial body, the closer it is.

Conversely, the smaller the parallax, the farther away from us. Proxima Centauri, the closest star closest to us (except the Sun), has a parsec-gap of about light-years). The parsec is the reciprocal of the annual parallax, and the first parallax of the celestial body is", its distance is 10 parsecs, and the annual parallax of an celestial body is", the distance is 100 parsecs, and so on.

Seconds unit conversion.

A parsec of one is equal to a light-year, or an astronomical unit, or a trillion kilometers. <>