Photoelectric photometry of CED 128 - A reflection nebula

In this work we present (B-V)sub(*-neb) curves along four radial directions relative to the illuminative star, νSco. Several plane-parallel model nebulae were combined with thirteen grain materials, which are thought to be constituents of the general ISM. The exact Mie theory of scattering by spheres was applied. It is derived from νSco is probably embedded in the nebula, and that its thickness is approximately 1.5 pc and the tilting angle is 10 deg, in good agreement with the expected location suggested by the star's color excess Esub(B-V) = 0.28. Ice, dirty ices and silicates give the best general fittings for all directions considered. Magnetite, silicon carbide and NH3 cannot however be excluded. (author)