distance measurement and absolute magnitude

Question 1

what is the symbol for apparent magnitude

Answer 1

m

Question 2

what is the symbol for absolute magnitude

Answer 2

M

Question 3

what is the definition for apparent magnitude

Answer 3

its a measure of its brightness as it appears in the sky from earth

Question 4

what is the definition for absolute magnitude

Answer 4

the apparent magnitude the star would have if it were 10pc away

Question 5

what is the equation for apparent/absolute magnitude

Answer 5

m-M = 5log(d/10)

m = apparent magnitude
M = absolute magnitude
d = distance [pc] to the object
(10 comes from the 10pc distance in absolute magnitude)
(5 comes from 2.51^5 = 100 which is the times 1 is than 6 in the hipparcos scale)

Question 6

what is the equation to find 1 ly

Answer 6

1 ly = speed of light (c) x no. of seconds in a year

Question 7

what is 1 A.u in meters

Answer 7

1.5x10^11m

Question 8

What is the inverse square law for intensity

Answer 8

I ∝ 1/d^2