In 2016 astronomers announced the discovery of an Earth-like planet orbiting Proxima Centauri, the closest star to the Sun.
The planet was detected because of the small movement of the star as the planet orbited.
The movement was detected using the Doppler shift in the frequency of light travelling to the Earth.
The graph shows how the component of the star’s velocity v towards the Earth varied over time.
Explain how the Doppler shift was used to obtain the data shown on the graph.
i) Use the graph to show that the angular velocity of the planet is about 6 x 10-6 radian s-1.
(3)
ii) The mass of Proxima Centauri is 0.12 times the mass of the Sun.
Determine the distance of the planet from Proxima Centauri.
mass of Sun = 1.99 x 1030 kg
Distance = ......................................... (3)
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