Figure 5-8Planets and Their Stars (a) This figure shows the separations between some exoplanets and their stars. The corresponding star names are given on the left of each line. Note that many systems have giant planets that orbit much closer than 1 AU from their stars. (M_J is short-hand for the mass of Jupiter.) For comparison, the solar system is shown at top. (b) Drawings of the multiple-planet system Upsilon Andromeda. The star Upsilon Andromeda has at least three planets. (c) The orbital paths of the planets, labeled B, C, and D, along with the orbits of Venus, Earth, and Mars, are drawn for comparison. (d) Direct image of four planets orbiting the star HR 8799.