What is the Doppler shift used to detect in astronomy?
The Doppler Shift, or Doppler Effect, is used to detect spectroscopic binaries.
The Doppler Shift in Astronomy
The Doppler Shift, also known as the Doppler Effect, is used to find spectroscopic binaries. These stars are detected based on the blue-shift and red-shift of their spectral lines, signifying that they are moving towards or away from us, respectively.
Explanation
The Doppler Shift, also known as the Doppler Effect, is used to find spectroscopic binaries. Spectroscopic binaries are star systems that are too close to each other to be separately identified even with powerful telescopes, so we distinguish them by the Doppler Effect on their spectral lines. When one star in such a pair moves toward us, its spectral lines shift to the blue end of the spectrum (blue-shift), and when it moves away from us, the spectral lines shift toward the red end (red-shift). This back and forth motion indicates that the star is orbiting a companion.