Nucleus brightness of 41P. Top panel: apparent magnitude m(r, Δ, φ) of the nucleus of 41P vs. time to or from perihelion as determined through filters SDSS gri. Bottom panel: absolute magnitude H(1, 1, 0) of the nucleus of 41P at unity Sun and Earth distance vs. time for a linear phase angle correction of 0.03 mag deg⁻¹. For both panels, results in SDSS g filter are plotted as green squares, in SDSS r filter as red circles, and in the SDSS i filter as black triangles.