NGC7492
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)=    23.756 +-  0.134
 a(1)=     2.974 +-  0.222
 a(2)=     0.911 +-  0.197
 a(3)=     0.527 +-  0.172
 a(4)=    -0.347 +-  0.161
 a(5)=     0.144 +-  0.159
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=1+(r/r_c), r_c=1.35
 a(0)=     8.7907
 a(1)=     9.9886
 a(2)=   -18.6400
 a(3)=    14.2903
 a(4)=    -4.6110
 a(5)=     0.5598
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set