Reproducing the observed lcıs:
excellents fits for RXJ 0806 and RXJ 0420
Epic-PN lc of RXJ 0806, rev 618 (April 2003). (0.12-1.2 keV). Haberl et al, 2004
B0quad = -0.47 Bdip    s = 0.06
B1quad  =  0.11 Bdip     s = 0.04
B2quad = -0.33 Bdip    s = 0.03
B3quad =  0.44 Bdip    s = 0.01
B4quad = -0.17 Bdip    s = 0.02

c = 44.9    s = 1.6
x = 90.6    s = 1.2
Epic-PN lc of RXJ 0806, rev 570 (Jan 2003). (0.12-0.7 keV). Haberl et al, 2004
B0quad =  0.44 Bdip   s = 0.06
B1quad = -0.36 Bdip   s = 0.06
B2quad =  0.03 Bdip   s = 0.06
B3quad = -0.42 Bdip   s = 0.06
B4quad =  0.37 Bdip   s = 0.06

c = 58.1    s = 2.3
x = 0.0      s = 0.1
c2= 0.002
c2= 0.002