For the following, suppose a star is at a distance of 20 parsec from Earth. Compute the following (only numbers and units are needed):
1) What is its apparent magnitude m?
2) If the star has the same luminosity as Sun, what is its absolute magnitude M?
3) By how much (what angle) does the apparent direction (relative to the fixed background of faraway stars) to this star change over one year?
4) How far away would a 100 W light bulb have to be to have the same apparent brightness (magnitude) as this star? (Note: L sun = 3.84.1026 W and M sun = +4.74 and m2-m1 = 2.5 lg (F1/F2))