Figure 5-20 RIVUXG Stars with Three Planets (a) The star Upsilon Andromedae has at least three planets, discovered by measuring the complex Doppler shift of its starlight. This star system is located 44 ly from Earth, and the planets all have masses similar to Jupiter’s. (b) The orbital paths of the planets, labeled B, C, and D, along with the orbits of Venus, Earth, and Mars, are drawn for comparison. (c) Direct image of four planets orbiting the star HR 8799. (National Research Council of Canada; Reprinted by permission from Macmillan Publishers Ltd: Nature 468, 1080–1083, copyright 2010)