Question

The surface of a star can be very well approximated by a blackbody. In particular, the color of the Sun is a white-yellow because of this. How does the color of a star compare to the sun if it is significantly colder than the sun?

A) Reddish
B) Bluish
C) Yellowish
D) Greenish

Answer 1

A colder star than the Sun would have a reddish color due to the shift towards the red end of the spectrum as per Wien's law. The correct option is A).

Step-by-step explanation:

If a star is significantly colder than the Sun, its color would appear reddish. According to Wien's law, which relates stellar color to stellar temperature, cool stars emit most of their visible light energy at red wavelengths.

Our Sun has a surface temperature of about 6000 K, and it peaks at a slightly greenish-yellow color; however, it appears white in space due to the equal amounts of reddish and bluish light. A cooler star, on the other hand, would shift towards the red end of the spectrum, hence appearing reddish. Option A) is the correct one.