Optical imaging of nova shells and the maximum magnitude-rate of decline relationship

An optical imaging study of 30 recent novae has been undertaken using both ground-based and space-based observations. Resolved shells have been detected around nine objects in the ground-based data, while another four objects have shells detected by Hubble Space Telescope observations; for RW UMi, we fail to detect a shell that was observed 5 years earlier. Images in H alpha, and when appropriate CO mi lambda 5007, are shown, and finding charts for novae without shells are given if no published chart is available. Expansion parallaxes for all systems with shells are derived, and absolute magnitudes for a total of 28 objects are presented, along with a discussion of the maximum magnitude-rate of decline relation. We find that separate linear fits for fast and slow novae may be a better representation of the data than a single, global fit. At minimum, most novae have similar magnitudes as those of dwarf novae at maximum and nova-like stars.