Posterior probability distribution of Newton’s gravitational constant G_N for the galaxies in the SPARC database (Lelli et al. 2016). Following a similar analysis by Rodrigues et al. (2018a) for the acceleration scale g_†, galaxies are ordered by increasing value of G_N and flat priors are imposed on galaxy distances, stellar mass-to-light ratios, and G_N (see text for details). Black dots show the maximum of the posterior probability, together with 1σ, 2σ, and 3σ credible regions from the Python package GetDist. The expected value of G_N is represented by the dashed line. Of the selected 101 galaxies, 34 are incompatible with the expected G_N at the 3σ level. Taken at face value, this would imply that the gravitational constant is not constant.