Exploring the Sky 2

Question 1

If a star is fainter, it’s magnitude will be…

Answer 1

Higher

Question 2

What is Betelguese’s magnitude?

Answer 2

0.45

Question 3

What is Rigel’s magnitude?

Answer 3

0.18

Question 4

What is Polaris’s magnitude?

Answer 4

1.97

Question 5

If the magnitude difference is 1, what is the brightness?

Answer 5

2.5

Question 6

If the magnitude difference is 2, what is the brightness?

Answer 6

6.3

Question 7

If the magnitude difference is 3, what is the brightness?

Answer 7

16

Question 8

If the magnitude difference is 4, what is the brightness?

Answer 8

40

Question 9

If the magnitude difference is 5, what is the brightness?

Answer 9

100

Question 10

What magnitude can the naked eye see?

Answer 10

6 magnitude and higher

Question 11

The area of a lens is proportional to the square of what?

Answer 11

It’s diameter

Question 12

Why do some stars have variable magnitude?

Answer 12

Because they pulsate

Question 13

In some cases, the period of pulsation is related to what of a star? (2 factors)

Answer 13

Size and Luminosity

Question 14

What have Cepheid vairables become important for?

Answer 14

Establishing the distance of external galaxies

Question 15

How are Cepheid variables used to establish the distance of external galaxies?

Answer 15

Their apparent magnitude is measured the matched with the intrinsic brightness of Cepheid variables in the milky-way

Question 16

Solar time is defined as what?

Answer 16

The hour angle of the sun plus 12 hours

Question 17

What does the hour angle of the sun depend on? (2 factors)

Answer 17

• The rotation of the earth

- The sun’s revolution around the ecliptic