CMD of the open cluster IC 4651, built from Gaia DR2 photometry. Black filled circles are all the stars from CG18 with P_memb ≥ 50%. Blue filled circles and yellow filled circles are the catalogued blue and YSS, respectively. The black solid line represents the PARSEC isochrone of solar metallicity and log(age) = 9.27 (Bressan et al. 2012), set at E(B − V) = 0.36 and (m − M)₀ = 9.82. The second curve is the same isochrone displaced 0.75 mag, which helps constrain the region of the binaries. See also Table 4.