Stellar CIII emissions as a new classification parameter for [WC] central stars

We report detection of stellar C III lambda 1909 emission in IUE echelle sp ectra of early-type [WC] central stars of planetary nebulae (CSPNs). Additi onally, stellar C III emission at 2297 Angstrom is observed in early- and l ate-type [WC] CSPNs. Inclusion of these C III features for abundance determ inations may resolve a conflict of underabundance of C/O for early-type [WC 2]-[WC4] CSPNs. A linear dependence on stellar C III lambda 2297 equivalent widths can be used to indicate a new classification of type-[WCUV] central stars.