college lever astronomy

Question

Any star's brightness ratio when 'moved to' a new distance, or any star's brightness when compared to any other star, has an associated change in Apparent Magnitude; this is based on another simple mathematical relationship. Using your Ratio of Stellar Luminosities chart, what is the magnitude change (difference) for Sirius in this case?

9

3

12

16

Answer 1

Based on the information given, I'm not sure you can answer this question. What mathematical equation are you referring to? Both Sirus A and B will continue to move to the lower right of the star chart.

Apparent magnitude is a measure of the brightness of a star as observed from Earth. Depending on it's distance from earth and the temperature determines the luminosity of the star (apparent magnitude).

Since Sirus A is a Main Sequence star it will continue to cool off and move to the lower right side of the chart, eventually turning into a red star (not Red Giant, it's too small.)

Sirus B is not a Main Sequence star either. It will continue to cool off until it fuses into nothing but iron.