Concept explainers
What two factors determine how bright a star appears to be in the sky?
Two factors that determines the brightness of the star.
Explanation of Solution
Introduction:
Luminosity and distance are the two factors that determines the brightness of the star.
Luminosity
Luminosity is the total radiative power radiated by stars into space. It is total amount of electromagnetic power emitted by galaxy, star or astronomical object. It gives direct indication of brightness of the stars. It is a logarithmic measure of brightness of the stars. Distance
Brightness of the stars depends upon the amount of starlight reaching to the earth. More the distance lesser will be the amount of starlight and hence lesser will be the brightness of the stars. So, the distance is also important factor to measure the brightness of the stars.
Conclusion:
Luminosity and distance are the two factors that determines the brightness of the star.
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