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

TL;DR

This study confirms Hubble-type expansion in NGC 6302's lobes through proper motion measurements, determines its distance at 1.17 kpc, and traces the knots' velocities back to a central eruptive event 2200 years ago.

Contribution

First direct, model-independent confirmation of Hubble-type expansion in NGC 6302 using proper motions and precise distance measurement.

Findings

Hubble-type expansion confirmed in NGC 6302

Distance to NGC 6302 determined as 1.17 kpc

Knots' velocities trace back to central eruption 2200 years ago

Abstract

The ouflowing proper motions of fifteen 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 unambiguous distance to NGC 6302 of 1.17 +/- 0.14 kpc is now determined. Also all the velocity vectors of the fifteen knots (and two others) point back to the central source. An eruptive event from within the central torus, approximately 2200 years previously must have created the high speed lobes of NGC 6302.