Predictions for the MF of stars that could host a Gaia-detectable planet (MF﹩{}_{\star }^{{{\rm{s}}}}﹩) in DR5. Plots in the left column show MF﹩{}_{\star }^{{{\rm{s}}}}﹩, in units of ﹩{M}_{\odot }^{-1}﹩, vs. stellar mass for a fixed orbital radius and three different choices of planet mass. Plots on the right show MF_⋆ vs. stellar mass for planets with a fixed mass and three different choices of orbital radius. As the stellar mass rises, MF_⋆ is initially constant before suddenly falling as ﹩1{0}^{-2.5{M}_{\star }}﹩. The transition occurs when the searchable stars cross G = 14, the breakpoint in our model of Gaia’s astrometric precision (see Figure 4). The black arrows illustrate how MF﹩{}_{\star }^{{{\rm{s}}}}﹩ scales with m_p and a. Millions of stars could host detectable planets, most of which are less massive than the Sun.