13.1 Trigonometric Parallax

Question 1

How long is an Astronomical Unit?

Answer 1

1.5 x 10^11 m

Question 2

What is an astronomical unit?

Answer 2

The mean distance between the Earth and the Sun

Question 3

What is the distance of one light year? What is the speed

Answer 3

9.5 x 10^15 m

3 x 10^8

Question 4

What is a light year?

Answer 4

The distance travelled by light in one year

Question 5

What is 1 Parsec in m?

Answer 5

3.1 x 10^16m

Question 6

How to calculate 1 Parsec ?

Answer 6

Set up a triangle with opposite side of 1 AU and an angle of 1 arc second. Parsec is the value of the adjacent side.

Question 7

What is the value of an arc second?

Answer 7

1 / 60^2

Question 8

What is trigonometric parallax ? What does it depend on ?

Answer 8

The show of closer objects changing positions more relative to objects further away from us.

It depends on the size of the parallax angle.

Question 9

What does greater parallax angle mean?

Answer 9

Object is closer , so it will have more movement relative to other objects.

Question 10

What is a ‘wobble’?

Answer 10

The difference between angles of parallax of the earth to a star in positions six months apart.