Physics

Physics

Problem

Star X shows a peak in its emission spectrum at 480 nm480\,\text{nm}, while Star Y peaks at 640 nm640\,\text{nm}. If the surface temperature of Star X is 6000 K6000\,\text{K}, the surface temperature of Star Y is approximately a) 8000 K8000\,\text{K} b) 3375 K3375\,\text{K} c) 4500 K4500\,\text{K} d) 5200 K5200\,\text{K}
Intuitive explanation

Wien's displacement law connects a star's peak wavelength to its surface temperature—hotter objects emit their peak light at shorter wavelengths. Since Star Y's peak is redder (longer wavelength) than Star X's, Star Y must be cooler. The key is that wavelength and temperature are inversely proportional, so you can set up a simple ratio using the two stars' data to find Star Y's temperature.

Intuitive explanation

Wien's displacement law connects a star's peak wavelength to its surface temperature—hotter objects emit their peak light at shorter wavelengths. Since Star Y's peak is redder (longer wavelength) than Star X's, Star Y must be cooler. The key is that wavelength and temperature are inversely proportional, so you can set up a simple ratio using the two stars' data to find Star Y's temperature.

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