Absolute integrated V-band magnitude as a function of the log of the half-light radius for local low-luminosity stellar systems. Galactic globular clusters, represented as open grey triangles, are from the 2010 version of the Harris (1996) catalogue. Confirmed and candidate dwarf galaxies, represented as filled circles colour-coded according to their heliocentric distance, are taken from the 2021 version of the catalog by McConnachie (2012). The same colour-coding is applied to the filled square marking the position of Sextans II, that is also highlighted with a red contour. The stellar systems with M_V and r_h values that are most similar to Sextans II have been labelled. The diagonal lines are loci of constant surface brightness, from at μ = 24.0 mag arcsec⁻² (top) down to μ = 34.0 mag arcsec⁻² (bottom), in steps of μ = 2.0 mag arcsec⁻².