
Concept explainers
The star which has cooler surfaces.

Answer to Problem 1QAP
True.
Explanation of Solution
Stars behave like black body. Planck curve for black body
A cold star emits the red light at peak wavelength while hot star emits blue light at peak wavelength. The Sun has a surface temperature of 5800 K.
Greater the mass of star and temperature higher the luminosity of it, more the star appears blue and vice versa. H-R diagram gives the relationship between luminosity, surface temperature and radius of star. It shows the direct relationship between luminosity and radius of star.
Conclusion:
Red stars have cooler surfaces than blue stars. Thus the statement is true.
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Chapter 10 Solutions
Understanding Our Universe
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