Rest-frame energetics of GRB 210905A in the E_peak, z − E_iso and E_peak, z − L_iso planes (red stars). Brown stars in the left panel show the values derived for the individual Pulses 1, 2, and 3. The rest-frame parameters of 315 long KW GRBs with known redshifts (Tsvetkova et al. 2021) are shown with circles; the colour of each data point represents the burst’s redshift. In the left plot, rest-frame peak energy values are derived from time-averaged spectral fits (E_p, i, z). In the right plot, they are derived from spectra, corresponding to the burst’s peak count rate (E_p, p, z). The ‘Amati’ and ‘Yonetoku’ relations for this sample are plotted with dashed lines and the dark- and light-grey shaded areas show their 68% and 90% prediction intervals, respectively. The error bars are not shown here for reasons of clarity.