The reason that most extrasolar planets discovered by the Doppler technique are found close to their parent stars is
A)the wavelength shift of the star's spectrum is larger.
B)they transit more frequently, and have thus been more likely to be detected in the short time we have been searching for them.
C)more of the starlight is blocked by the planet when it transits the star.
D)the closer to a star, the hotter and therefore brighter the planet is.
E)planets that are close to a star are heated up and therefore larger.

Question

Quizplus · Accepted Answer

The Doppler technique relies on detecting small shifts in the wavelength of a star's spectrum caused by the gravitational pull of an orbiting planet. The larger the wavelength shift, the easier it is to detect the planet. Planets that are closer to their parent stars have a larger gravitational influence and thus cause a larger shift in the star's spectrum. Therefore, it is easier to detect planets that are closer to their parent stars using the Doppler technique.

The Reason That Most Extrasolar Planets Discovered by the Doppler