The evidence for shell formation in V1016 Cygni.

Abstract

V1016 Cyg is a candidate for being one of the youngest planetary nebulae ever observed. Its evolution is therefore followed with particular attention. The authors have investigated the claim of Feibelman that, early in 1982, a splitting developed in the C IV λ1551 line, indicating shell formation. Careful scrutiny of the spectra shows that claim to be unfounded.