THE STRUCTURE OF THE REMNANT OF HR DEL

We present narrow-band [O III] and Halpha/[N II] CCD images of Nova HR Delphini 1967. The oval shape of the remnant is clearly apparent in the raw CCD images, although it is somewhat more extended than in the previously published photographic image due to its continuing expansion. Detailed structure within the nebula is investigated using both the maximum entropy method and CLEAN to enhance the image resolution by deconvolution of the point spread function. In the light of [O III] the remnant is revealed to possess a bipolar morphology, in which the emission-line regions on either side of the central object may be identified with polar 'blobs', a common feature of other more extended nova shells. In contrast, the remnant appears more 'ring-like' in Halpha/[N II] emission. We conclude that the remnant is prolate and that the morphology may be the result of the common-envelope phase during the nova outburst. From our deconvolved images we derive an estimated distance to HR Del of 1.1 +/- 0.1 kpc.