NGC6254 (M10)
 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)=    21.512 +-  0.129
 a(1)=     4.745 +-  0.211
 a(2)=     0.938 +-  0.167
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c)^2, r_c=1.70
 a(0)=     6.9484
 a(1)=     0.6235
 a(2)=     0.7401
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set