A) You can observe cyclic Doppler shifts of the spectral lines in a spectroscopic binary.
B) You can observe the orbits of both stars in a visual binary.
C) One star periodically blocks the light from its companion star in a spectroscopic binary.
D) You can only observe the orbit of one star in an astrometric binary because the companion is not bright enough to be seen.
B) You can observe the orbits of both stars in a visual binary.
C) One star periodically blocks the light from its companion star in a spectroscopic binary.
D) You can only observe the orbit of one star in an astrometric binary because the companion is not bright enough to be seen.