Understanding Parallax and Parsecs

What is the average distance between the Earth and the Sun called?

• Astronomical unit

• Parsec

• Light year

• Arc second

How is the parallax angle related to the distance of a star?

• It decreases with distance

• It increases with distance

• It is unrelated to distance

• It remains constant

What is an arc second?

• A fraction of a degree

• A type of star

• A unit of distance

• A unit of time

What is a parsec defined as?

• The distance light travels in a year

• The distance subtended by one astronomical unit at an angle of one arc second

• The average distance from the Earth to the Sun

• The distance between two stars

How many meters are in one parsec?

• 2.5 x 10^18 meters

• 3.1 x 10^16 meters

• 1.5 x 10^11 meters

• 9.5 x 10^15 meters

What is the formula to calculate distance in parsecs from a parallax angle?

• Distance = Parallax x Arc seconds

• Distance = 1 / Parallax

• Distance = Parallax / Arc seconds

• Distance = 1 + Parallax

In the formula for distance in parsecs, what unit should the parallax angle be in?

• Arc minutes

• Degrees

• Arc seconds

• Radians

If a star has a parallax of 0.72 arc seconds, what is its distance in parsecs?

• 0.72 parsecs

• 1.38 parsecs

• 2.78 parsecs

• 0.5 parsecs

How do you convert parsecs to meters?

• Multiply by 1.5 x 10^11

• Divide by 3.1 x 10^16

• Divide by 1.5 x 10^11

• Multiply by 3.1 x 10^16

What is the distance in meters for a star with a parallax of 0.72 arc seconds?

• 4.3 x 10^16 meters

• 2.5 x 10^18 meters

• 3.1 x 10^16 meters

• 1.5 x 10^11 meters