We predict the number of black holes with stellar companions that are potentially detectable with Gaia astrometry over the course of its five-year mission .
Our model estimates that nearly 2 \times 10 ^ { 5 } astrometric binaries hosting black holes and stellar companions brighter than Gaia ’ s detection threshold , G \sim 20 , should be discovered with 5 \sigma sensitivity .
Among these detectable binaries , systems with longer orbital periods are favored , and black hole and stellar companion masses in the range M _ { BH } \sim 6 - 10 M _ { \odot } and M _ { * } \sim 1 - 2 M _ { \odot } , respectively , are expected to dominate .