A new, evolved bipolar planetary nebula

Optical imaging and spectroscopy reveal that the ionised region No.252 in the list of Marsalkowa (1974), whose photograph is presented in the ''Atlas of Galactic Nebulae'' by Neckel & Vehrenberg (1990), is actually a planetary nebula. According to Acker et al. (1992), the object should therefore be named as PN G321.6+02.2. The nebula has the following properties: it is located at 2.0+/-0.5 kpc from the Sun, has a bipolar morphology, a giant size (similar to 4 pc!), low densities, a hot (unobserved) central star (T>130000 K), and extreme He and N overabundances (He/H=0.147+/-10.029, log(N/O)=0.47(-0.38)(+0.20)). The nebula is likely to be in a very evolved evolutionary stage.