The surface temperature of a nearby star can be determined most precisely by measuring what parameters?
A) the position of the star on the H-R diagram
B) the Doppler shift of the star's spectral lines
C) the relative strengths of emission lines from different atoms and ions in the star's spectrum
D) the relative strengths of absorption lines from different atoms (e.g., H, Ca) and molecules (e.g., TiO) in the star's spectrum

Question

Quizplus · Accepted Answer

The relative strengths of absorption lines from different atoms and molecules in the star's spectrum can give us information about the temperature of the star's surface. The wavelengths and widths of these lines depend on the temperature of the gas that produced them, so by analyzing the spectrum of a star in detail, we can estimate its surface temperature to a high degree of accuracy.

The Surface Temperature of a Nearby Star Can Be Determined