Comparison between the J-PLUS DR3 photometry (𝒳_J-PLUS; colored points) of GD 153 and its synthetic photometry (𝒳_standard; black outlined circles) estimated from the standard spectra in CALSPEC (left panel) and Gaia SPSS (right panel). In both panels, the standard spectrum is shown with the black solid line. The magnitude difference ∆𝒳 = 𝒳_J-PLUS − 𝒳_standard is shown in the lower panels. The dotted line marks a zero difference. The progressively lighter gray areas show differences of 0.01, 0.02, and 0.03 mag, respectively.