Left column: SFR in M_⊙ Myr⁻¹ kpc⁻² for NGC 1326A, NGC 1425, and NGC 4548 over the last 100 Myr, based on the blue HeB stars. The blue HeB luminosity function has been normalized to account for the IMF and the changing lifetime in this phase with mass. We used the Salpeter IMF slope and the MESA evolutionary tracks. Right column: luminosity function of the blue HeB stars in NGC 1326A, NGC 1425, and NGC 4548. The bin width is 0.18 mag. The uncertainties in magnitude are derived by the artificial star tests. Plotted above the histogram is the age in megayears for the blue HeB stars as given by the MESA models.