NGC6544       c?
 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)=    19.515 +-  0.167
 a(1)=     2.581 +-  0.310
 a(2)=     0.191 +-  0.274
 a(3)=     0.358 +-  0.226
 a(4)=    -0.184 +-  0.175
 a(5)=     0.185 +-  0.136
 a(6)=    -0.086 +-  0.109
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c), r_c=1.09
 a(0)=     6.5280
 a(1)=    11.0323
 a(2)=   -23.3078
 a(3)=    24.2438
 a(4)=   -12.5236
 a(5)=     3.1672
 a(6)=    -0.3106
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set