Cepheid variable stars pulsate regularly in size.During the contraction part of the cycle,when the star's temperature is increasing,the peak wavelength of the emitted radiation will:
A) shift from the visible to the UV part of the spectrum.
B) shift from the UV to the visible part of the spectrum.
C) remain unchanged.
D) shift toward longer or shorter wavelengths at random as the temperature changes.

Question

Quizplus · Accepted Answer

According to Wien's Law, as the temperature of a star increases, the peak wavelength of the emitted radiation shifts to shorter wavelengths. Therefore, during contraction when the temperature increases, the peak wavelength shifts from the visible to the UV part of the spectrum.

Cepheid Variable Stars Pulsate Regularly in Size