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A star has a surface temperature of about 6000 K. In a colour photograph, what colour would it appear?

1. yellow
2. red
3. cyan
4. blue

Correct answer: yellow

Solution

By Wien's law lambda_max approx 2.9e-3 / 6000 approx 480-500 nm, near the yellow-green region, so a 6000 K star (like the Sun) appears yellow.

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