Spectrophotometry of the planetary nebula KjPn 8

Flux-calibrated low-resolution spectra covering the optical wavelength range from 3400 to 7500 Angstrom have been obtained over the central region and the surroundings of the extraordinary planetary nebula (PN) KjPn 8 (PNG 112.5-00.1). The spectrum from the core is of low excitation with T(e)(N II)= 8000 K and n(e)(S II)= 550 cm(-3). KjPn 8 is found to be a Type IPN according to the original classification scheme of Peimbert & Torres-Peimbert, with enriched He/H and N/O ratios with respect to mean values for PN. Increased O/H, Ne/H and Ar/H ratios over those of average PN reflect the possible metal-rich environment from which the progenitor star formed, and also are similar to those found in the extreme Type I PN He 2-111. The N/H ratio is found to be only moderately high compared to the average PN and consequently, the large O abundance pulls the N/O ratio towards the lower limit of the criterion for Type I planetary nebulae (PNe) in this case. In addition, the spectra of some knots and faint regions ia the KjPn 8 surroundings are presented, which show only a few spectral lines. Low electron densities ranging from 100 to 300 cm(-3) have been derived in these outer regions.