An astronomer wants to know whether a particular star has a greater surface temperature than the Sun. What does she need to know about this star to determine its temperature?
A)the wavelength at the peak of its spectrum
B)its distance from the Sun
C)its size
D)its age

Question

Quizplus · Accepted Answer

The wavelength at the peak of the star's spectrum indicates its color and therefore its temperature. A hotter star would have a peak at shorter (bluer) wavelengths while a cooler star would have a peak at longer (redder) wavelengths. The other options (B, C, D) are not relevant for determining surface temperature.

An Astronomer Wants to Know Whether a Particular Star Has