IMAGING AND SPECTROSCOPY OF EJECTED COMMON ENVELOPES .1.

Imaging and spectroscopy are presented for four planetary nebulae know n to contain close binary central stars resulting from a recent phase of common-envelope evolution. All the objects appear to exhibit axisym metric nebulae which may be interpreted as inclined bipolar nebulae. I n at least one object the bipolar caps can be seen, demonstrating the tightly collimated nature of the PN having an aspect ratio of similar to 7. Determinations of the nebular abundances show that He is signifi cantly enhanced in all of the objects. These results are in agreement with theoretical expectations. Uncertainties in the nebular electron t emperature constrain other abundances less well. The Line fluxes indic ate that N is unexpectedly underabundant. This effect is probably not real and may be an artefact of electron temperature fluctuations withi n the nebulae.