Top: same as Fig. 2 but assuming an orbital separation of 2.5 R_∗, corresponding to an orbital period of ~10.6 days. As this is only slightly larger than the CIR period (~10.3 days), the super-orbital modulation occurs on a much longer time-scale (~330 days). Bottom: same as above but using two CIRs. The super-orbital modulation is now characterized by a double asymmetric peak repeating every ~660 days, corresponding to the fact that the NS is crossing two CIRs with different density/velocity contrasts along its orbit.