One way that astronomers detect planets around distant stars is by observing to see if there is a _________ in the light that reaches us from a particular star. The reason that the star moves away or toward us is a ________ due to the gravitational effects of the planet.

A. signal, contraction

B. Doppler shift, contraction

C. signal, perturbation

D. Doppler shift, perturbation

Question

One way that astronomers detect planets around distant stars is by observing to see if there is a _________ in the light that reaches us from a particular star. The reason that the star moves away or toward us is a ________ due to the gravitational effects of the planet.

A. signal, contraction	

B. Doppler shift, contraction	

C. signal, perturbation	

D. Doppler shift, perturbation

anonymous · Answer

I chose D.

anonymous · Answer

When a star collapses to form a black hole, its mass _____.

A. decreases	

B. remains the same	

C. increases	

I'm not sure about this one