SZ Cen
Gronbech1977 - Gronbech1977y (Stromgren y)
Solution is directly from Gronbech, Gyldenkerne, and Jorgensen (1977) except the radii they give are “unperturbed radii” which I’m assuming are closest to the side radii (b radii), so I modified the input values for the radius so that the side radii would be equal to their unperturbed radii.