distances and magnitude

Question 1

what is the luminosity of a star?

Answer 1

total energy emitted per second in watts

Question 2

what is the intensity of a star?

Answer 2

amount of power received per unit area at earth (also known as effective brightness)

Question 3

What is the apparent magnitude scale?

Answer 3

classification of brightness of stars according to naked eye from earth
the smaller the magnitude, the brighter the star

Question 4

how does the difference in apparent magnitude relate to the brightness

Answer 4

a difference in magnitude of 1 is a factor of 2.512 in brightness
difference of magnitude 2 is 2.512^2

Question 5

what is one astronomical unit equivalent to?

Answer 5

average distance from the earth to the sun

Question 6

what is the definition of a light year?

Answer 6

distance travelled by EM waves in a vacuum in one year

Question 7

what is the definition of a parsec?

Answer 7

distance that results in a parallax of one arc second

Question 8

what is absolute magnitude?

Answer 8

the apparent magnitude of a star if the star were 10 parsecs away from earth. (based only on luminosity of the star)