The Doppler Technique Can Be Used to Measure the Eccentricity

Multiple Choice

The Doppler technique can be used to measure the eccentricity of a planet's orbit by

A) measuring the time it takes for the star's line- of- sight velocity to cycle from peak to peak, and using Newton's version of Kepler's Third law.
B) measuring the amount by which the starlight is reduced when the planet transits.
C) measuring the asymmetries in the velocity curve.
D) measuring the speed at which the star orbits the mutual center- of- mass of the star and planet, and using Newton's theory of gravity.