The apparent magnitude of star at distance of 100 parsec is 7. what is its absolute magnitude?
The absolute magnitude is magnitude the object would have ifit was at distance of 10 parsecs. This is 10 times closer then object is. At this distance it would have 100 times larger luminocity. The difference in magniеudes can be find as m1-m2 = -2.5 lg(L1/L2) Hence, its absolute magnitude is m1 = 7-2.5 ln(100) = 7-5 = 2