NGC6717 (Pal9)c?
 9 iterations.
Chebyshev coeffients a(0)T_0(u)+a(1)T_1(u)+..., where u is log (r/arcsec) mapped to [-1,1]
 a(0)=    20.006 +-  0.099
 a(1)=     3.237 +-  0.133
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c), r_c=0.92
 a(0)=     6.7561
 a(1)=     2.0263
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set