A new, evolved bipolar planetary nebula.

Corradi, R. L. M.; Villaver, E.; Mampaso, A.; Perinotto, M.
Bibliographical reference

Astronomy and Astrophysics, v.324, p.276-280

Advertised on:
8
1997
Number of authors
4
IAC number of authors
1
Citations
27
Refereed citations
21
Description
Optical imaging and spectroscopy reveal that the ionised region No.252 in the list of Marsalkowa (1974Ap&SS..27....3M), whose photograph is presented in the ``Atlas of Galactic Nebulae'' by Neckel & Vehrenberg (1990), is actually a planetary nebula. According to Acker et al. (1992ESOPN...1....1A), the object should therefore be named as PN G321.6+02.2. The nebula has the following properties: it is located at 2.0+/-0.5kpc from the Sun, has a bipolar morphology, a giant size (~4pc!), low densities, a hot (unobserved) central star (T>130000K), and extreme He and N overabundances (He/H=0.147+/-0.029, log(N/O)=0.47^+0.20^_-0.38_). The nebula is likely to be in a very evolved evolutionary stage.