A Precessing Collimated Outflow in the Quadrupolar Planetary Nebula NGC 6881
We present high-quality (subarcsecond) optical narrowband CCD images of the planetary nebula NGC 6881, which reveal a highly collimated bipolar structure. A careful examination of the [N II] image and of the [N II]/[O III] and [N II]/Hα ratio images shows that NGC 6881 is a quadrupolar planetary nebula, that is, a twice bipolar planetary nebula
Guerrero, M. A. et al.
Fecha de publicación:
11
1998