A spectacular (314Ј ϫ 4Ј) bipolar nebula, with a symmetric and rotating, high-velocity collimated outflow, with episodic outburst properties, has been discovered in the Cassiopeia-Cepheus region. A compact object classified as the planetary nebula KjPn 8 is located at the center of symmetry of this extraordinary nebula. The angular extent of this bipolar structure is now the largest one known associated with a planetary nebula (PN). A mosaic of H␣ images covering the full extent of the nebula

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... presented, as well as [N II] 6584, [S II] 6724, [O II] 3729, and [O III] 5007 images of the central (35Ј ϫ 5Ј) region. These images reveal symmetric pairs of bow shocks which are located at different position angles, in a way expected from a rotating, episodic jet. Low-dispersion spectroscopy of regions of the bipolar lobes confirms their shock-excited nature. The core is of low excitation class and seems nitrogen enriched. Our 3.5 cm VLA observations yield a first radio detection of the core of KjPn 8. Subject headings: ISM: jets and outflows -planetary nebulae: individual (KjPn 8)