NGC6496
21 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)=    20.892 +-  0.323
 a(1)=     0.938 +-  0.502
 a(2)=     0.301 +-  0.420
 a(3)=     0.139 +-  0.341
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c), r_c=1.79
 a(0)=     9.6693
 a(1)=     2.0232
 a(2)=    -4.4886
 a(3)=     4.7949
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set