Question

A star has apparent magnitude 10.0 and absolute magnitude 4.5.

How far away is it?

Express your answer using two significant figures.

Answer 1

As

d = 10^[(mapp - mabs + 5) / 5] parsecs

Then, as mapp = 10.0, mabs = 4.5, then

d = 125.9 parsecs [ANSWER]

Answer 2

SOLUTION :

Distance of a star based on difference of apparent magnitude and absolute magnitude can be calculate by using the following formula :

Distance 

= 10 ^[ ((apparent magnitude - absolute magnitude) + 5) / 5 ]

= 10^[ ((10 - 4.5) + 5) / 5 ]

= 10^[ 10.5 / 5]

= 10^2.1

= 125.89 parsecs  (ANSWER)