Example of a system where a double detonation supernova occurs during the shell burning phase of the donor. The panels display the evolution of different parameters as in Fig. 2. The background colors yellow, and green represent the gravitational-wave inspiral phase (GW-inspiral), and mass transfer phase during the He shell burning phase (Shell-MT), respectively. This system begins interacting during a later expansion phase, where the donor’s expansion rate is slower, resulting in lower accretion rates of around 10⁻⁸ M_⊙ yr⁻¹. This lower accretion rate leads to He ignition in the dense (< 10⁶ g cm⁻³) layers of the WD, ultimately getting classified as a double detonation supernova. For more details, see Sect. 4.3.2.