Hubble-type outflows of the high-excitation poly-polar planetary nebula NGC 6302 -: from expansion proper motions

The outflowing proper motions of 15 knots in the dominant northwestern lobe of the high-excitation poly-polar planetary nebula NGC 6302 have been determined by comparing their positions relative to those of faint stars in an image taken at the San Pedro Martir Observatory in 2007 to those in a South African Astronomical Observatory archival plate obtained by Evans in 1956. The Hubble-type expansion of this lobe is now directly confirmed in a model-independent way from these measurements. Furthermore, an unambigous distance to NGC 6302 of 1.17 +/- 0.14 kpc is now determined. Also, all the velocity vectors of the 15 knots (and two others) point back to the central source. An eruptive event from within the central torus approximate to 2200 yr previously must have created the high-speed lobes of NGC 6302.