Color‐magnitude diagrams for the ULX counterpart and nearby bright stars. Both the data and isochrones are in the HST ACS/WFC VEGAmag system. The magnitudes are corrected for the Galactic extinction of ﹩E( B-V) =0.11﹩ mag. (a) M_F555W vs. ﹩\mathrm{F}\,435\mathrm{W}\,-\mathrm{F}\,555\mathrm{W}\,﹩. The ages for the isochrones are 10⁷, ﹩5\times 10^{7}﹩, ﹩2\times 10^{8}﹩, and ﹩5\times 10^{8}﹩ yr, respectively. (b) M_F555W vs. ﹩\mathrm{F}\,555\mathrm{W}\,-\mathrm{F}\,814\mathrm{W}\,﹩. The ages for the isochrones are 10⁷, ﹩5\times 10^{7}﹩, ﹩3\times 10^{8}﹩, 10⁹, and ﹩3\times 10^{9}﹩ yr, respectively.