A spectroscopic binary shows periodic variations in its

Question

Quizplus · Accepted Answer

A spectroscopic binary is a system in which two stars orbit around each other, but their separation is too small to be resolved by telescopes. Instead, astronomers measure the periodic variations in the radial velocity of the stars, which can be inferred from the Doppler shift of spectral lines. As the stars move towards and away from Earth in their orbits, their spectra show a periodic blue/redshift, which can be used to determine the orbital period, mass ratio, and other properties of the system. Therefore, the correct choice is A) radial velocity.

A Spectroscopic Binary Shows Periodic Variations in Its