Time evolution of the β_UV values fitted over the wavelength interval (1350, 3500) Å to the SEDs in the rest frame of the observed object in units erg^-1 cm^-2 Å^-1. The β_UV slope is M_UCD-independent, but not for the case of the MKDP IMF for which we plot the case of M_UCD = 10⁷ M_⊙ and 10⁹ M_⊙. Left panel: the time evolution of the β_UV slope over the time period of 200 Myr. Right panel: the zoom-in plot covers the first 50 Myr. The grey band shows the measurement from Vanzella et al. (2017) for their object GC1.