NGC5897
 6 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)=    22.633 +-  0.144
 a(1)=     2.797 +-  0.237
 a(2)=     0.769 +-  0.202
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c)^2, r_c=1.91
 a(0)=     9.2884
 a(1)=    -0.2672
 a(2)=     1.4116
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set