Far-infrared fluxes of 2007 UK₁₂₆ with estimated 1σ uncertainties as measured by Herschel/PACS in three bands (see Table 4), in comparison to far-infrared fluxes calculated from the modeled thermal emission of all cases covered by our parametric study, discarding a flux contribution from the satellite and assuming P = 8 h. For clarity, flux predictions have been plotted with a slight offset in wavelength based on the applied surface roughness (s = { 0.1,0.5,0.9 } rms). In general, predicted fluxes increase with decreasing thermal inertia. The dashed line represents the best model obtained for an intermediate roughness (s = 0.5 rms) with Γ = 3 J m^-2 s^-0.5 K^-1, θ = 70° and a/c = 1.11, resulting in D_eff = 618 km. See text for details.