THE DISCOVERY OF A BIPOLAR, ROTATING, EPISODIC JET (BRET) IN THE PLANETARY-NEBULA KJPN-8

A spectacular (similar or equal to 14' x 4') 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 alpha images covering the full extent of the nebula is presented, as well as [N II] lambda 6584, [S II] lambda 6724, [O II] lambda 3729, and [O III] lambda 5007 images of the central (similar or equal to 5' x 5') 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.