Gaia CMD for white dwarfs within 100 pc from Earth and within the SDSS footprint (Kilic et al. 2020), where the x-axis depicts the difference between the Gaia BP and RP bands, and the y-axis the absolute magnitude in the Gaia G filter. Solid lines show theoretical cooling tracks (interpolated over the white dwarf’s mass with the WD_models package, Cheng 2024) for white dwarfs with masses between 0.6 M_⊙ (top) and 1.28 M_⊙ (bottom), equally spaced in mass; the atmosphere is assumed to be hydrogen-dominated (Holberg & Bergeron 2006) and the interior composition to be carbon-oxygen (Fontaine et al. 2001) for M < 1.1 M_⊙ and oxygen-neon (Camisassa et al. 2019) for M > 1.1 M_⊙. ZTF J2008+4449 is shown as a red star, and its location in the CMD reveals its high mass and high temperature. Reddening corrections were applied only to ZTF J2008+4449; as the objects in the sample are close to the Solar System, reddening is expected to be small. 1σ error bars are smaller than the size of the colored marker, and are omitted for the black background dots for clarity.