Left: comparison of the optical bolometric luminosity¹³ taken from Lin et al. (2023) and the γ-ray 100 MeV–100 GeV luminosity (this work) for SN 2017egm along with the TS in each 15-day time bin and with larger time blocks presented in Sect. 3.2 in black. Middle and right: γ-ray and optical luminosity observations and predictions from the magnetar model tailored to SN 2017egm by Vurm & Metzger (2021) for different nebula magnetization parameters (see Sect. 5.1). Hereafter the T₀ value is taken at the discovery date 23 of March 2017.