Left: R-band Afρ values measured for target comets (open squares) compared to values derived for several minor bodies: SPCs (dots), active Centaurs (stars), and LPCs (triangles). Literature was searched for both snapshot and monitoring observations: Mazzotta Epifani & Palumbo (2011, and references therein), Mazzotta Epifani et al. (2008, and references therein), Solontoi et al. (2012), Szabó et al. (2002), Ivanova et al. (2011), Jewitt (2009), Mazzotta Epifani et al. (2011, 2006), Bauer et al. (2003), Lara et al. (2003), Mazzotta Epifani et al. (2010), Korsun et al. (2010), Mazzotta Epifani et al. (2009, and references therein), Meech et al. (2009). (Right) Median R-band Afρ values in heliocentric distance ranges of 1 AU for SPCs (black diamonds) and LPCs (red diamonds). The number of values available to compute the median is indicated close to each symbol. The black vertical dashed lines indicate the “cloud” (min-max values) for each point in the SPCs’ sample.