HR diagram of Gaia DR3, where grey points represent samples from Gaia DR3, red points depict stars with spectral classifications in SDSS DR17, and blue points indicate samples of known hot subdwarfs. The two black dashed lines mark the concentrated distribution region of known hot subdwarfs (G_BP − G_RP ~ −0.35 and M_G ~ 4.5). It is worth noting that the stars plotted on the figure have been filtered according to the criteria used for constructing the Gaia HR diagram, as detailed in Eq. (18).