NGC6293       c
 3 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)=    18.333 +-  0.092
 a(1)=     3.422 +-  0.171
 a(2)=     0.956 +-  0.130
 a(3)=     0.146 +-  0.123
Power-of-x coeffients a(0)+a(1)x+a(2)x^2+..., where x=r
 a(0)=     6.8300
 a(1)=     0.8777
 a(2)=     0.3858
 a(3)=     0.2702
log r(arcsec)   mu_V    mu_V(fitted)  residual   weight  data set