Professor Bailyn talks about formation of planets and why the inner planets (like earth) are different from the outer planets (like jupiter). He calculates the velocity of the sun caused by Jupiter (which is detectable) and the velocity of the sun caused by the earth (which is too small to be detectable). How we use Doppler shift to measure the velocity of distant stars. Data showing an exoplanet orbiting at a short distance from its star, but showing the characteristics of an outer planet: a "hot Jupiter".
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