Question

Which of the following might be evidence for an extrasolar planet?
---->  A. Doppler-Shifted stellar spectrum and physics calculations that indicate low-mass object
B. X-ray observations emanating from the star
C. Direct Visual observation of the planet transiting the star
D. Doppler-shifted stellar spectrum nd physics calculations that indicate a high-mass object
(I guessed my own question lol and got it right)

Answer 1

From the term itself extrasolar, this refers to the planet that revolves around a star outside from our own solar system. And the evidence that would show an existence of an extrasolar planet is a low-mass object as indicated in the Doppler-shifted stellar spectrum and physics calculation. The answer is option A.

Answer 2

Answer:

D. Doppler-shifted stellar spectrum and physics calculations that indicate a high-mass object

Explanation:

Doppler-shifted technique is the ideal method to detect high-mass planets that are close to their star. That is because the gravitational effect that it will have the planet over its host star will be greater. This effect can be seen as a wobble in the star as a consequence of how they orbit a common center of mass¹. The center of mass will be closer to the most massive object, So, if an extrasolar planet with masses like Jupiter (Jovian) is used this point will be a little bit farther from the star, making the wobble more notable than in a system with a low-mass planet.  

When the star moves away from the observer, the spectral line² will be shifted to the red part of the spectrum³ and when it moves toward the observer, they will be shifted to the blue part of the spectrum (Doppler shift).

¹Center of mass: A geometrical point in which the mass from a whole system is summed

²Spectral line: An absorption or emission in a specific wavelength in the spectrum. Each of these lines represents an element in the photosphere of a star.

³Spectrum: Decomposition of light in its characteristic colors.