Final answer:
By analyzing starlight, scientists can infer a star's temperature from its peak wavelength, the composition of its atmosphere from dips in the spectrum, and its radial velocity and rotation speed from the Doppler effect.
Step-by-step explanation:
We can learn a great deal by analyzing starlight using various astronomical tools. By examining stellar spectra, astronomers can uncover the following:
- Peak wavelength: By determining the peak wavelength of a star's emission, one can deduce the star's surface temperature, which follows from Wien's Law.
- Dips in spectra: The specific locations and patterns of dips, or absorption lines, in stellar spectra allow us to identify the elements present in a star's atmosphere.
- Doppler shift: The Doppler effect comes into play when a star is moving toward or away from us, causing a shift in the observed wavelengths. This shift can be measured to determine the star's radial velocity — its speed along the line of sight.
Furthermore, by measuring the width of spectral lines, astronomers can deduce the rotation speed of stars; rapid rotation results in broader spectral lines due to the spread of Doppler shifts. Analyzing Doppler shifts can also reveal the presence of binary star systems and their characteristics.