Question

Define par- sec and light year?​

Answer 1

Answer:

• Per second means, number of times in a second
• Light year is the time taken to travel across planets

Answer 2

Answer:

The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System. One parsec is approximately equal to 31 trillion kilometres (19 trillion miles),[a] or 210,000 astronomical units, and equates to about 3.3 light-years. A parsec is obtained by the use of parallax and trigonometry, and is defined as the distance at which one astronomical unit subtends an angle of one arcsecond[1] (

1

/

3600

of a degree). This corresponds to approximately

648000

/

π

astronomical units, i.e. 1 pc = 1 au/tan(1″).[2] The nearest star, Proxima Centauri, is about 1.3 parsecs (4.2 light-years) from the Sun.[3] Most of the stars visible to the unaided eye in the night sky are within 500 parsecs of the Sun.