Final answer:
The Doppler shift effect on stars caused by planets is measurable through high-resolution stellar spectroscopy, detecting redshifts and blueshifts in the star's spectrum. These shifts, associated with the star's wobble due to gravitational interaction with planets, can reveal the mass and orbital period of the planets. The method is particularly sensitive to large planets close to their stars and can also measure stellar rotation rates.
Step-by-step explanation:
To understand how to measure the effect of Doppler shift on stars exerted by planets, one must consider the star and planet system. The high-resolution stellar spectroscopy utilizes the Doppler effect to observe changes in the star's radial velocity. As a planet orbits a star, the gravity of the planet induces a wobble in the star's movement. This wobble, albeit small, manifests as tiny redshifts and blueshifts in the star's spectrum, corresponding to its movements away from and towards us. Such shifts in spectral lines allow scientists to measure the radial velocity changes over time.
To extract information about a planet's mass and orbital period, one would monitor these periodic shifts in the star's radial velocity. When multiple planets are in the system, sophisticated techniques can separate their individual contributions to the observed Doppler shifts. This method has proven successful in the detection of numerous exoplanets, even those orbiting distant stars, as long as the planetary system induces a measurable effect on the star's radial velocity, most notably for large planets in close proximity to their host stars.
The Doppler effect is also used to measure stellar rotation rates by observing line broadening in the star's spectrum, which occurs due to portions of the star moving towards or away from us as it rotates. The greater the rotational speed, the broader the spectral lines will appear, revealing the star's rotation velocity.