Overview about the spectroscopic behaviour at different phases of the light curve. Upper panel: mean OSMOS spectra from 2021 February and March. The top trace is the average of spectra taken near maximum light, and the bottom trace near minimum light. The vertical axis is the same for both traces. Lower panel: upper, black trace shows the same minimum-light spectrum as the top trace. The red trace is a scaled spectrum of a K2 V star, while the blue trace resultsfrom subtracting the scaled K-type spectrum from the observed spectrum.