[en] PLANETARY NEBULAE ; STELLAR EVOLUTION ; STELLAR SPECTROPHOTOMETRY ; VISIBLE SPECTRUM ; EMISSION SPECTRA ; H II REGIONS ; LINE SPECTRA
[en] Analysis of two medium dispersion (39 Å/mm) optical spectra of the compact planetary nebula HD 316248 is reported here. When compared with observations collected in 1968 - 70, the authors' data obtained in 1978 reveal a net increase of the [O III] lambdalambda4959, 5007 line intensities. Furthermore, despite showing unusual emission lines due to [Ti III], the low-excitation spectrum of HD 316248 presents striking similarities with that of a typical H II region. Direct plates taken through broad-band and interference filters at the prime focus of the ESO 3.6 m telescope clearly show that HD 316248 is an elongated (d â 4arcsec.4) and diffuse object as seen in the light of Halpha.