NGC6333 (M9)
 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)=    20.836 +-  0.199
 a(1)=     3.953 +-  0.335
 a(2)=     0.503 +-  0.292
 a(3)=    -0.204 +-  0.207
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c), r_c=1.54
 a(0)=     7.1726
 a(1)=     0.0747
 a(2)=     1.9548
 a(3)=    -0.3473
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set