Panchromatic HST/WFC3 Imaging Studies of Young, Rapidly Evolving
  Planetary Nebulae. I. NGC 6302
  We present the results of a comprehensive, near-UV-to-near-IR Hubble Space
Telescope WFC3 imaging study of the young planetary nebula (PN) NGC 6302, the
archetype of the class of extreme bi-lobed, pinched-waist PNe that are rich in
dust and molecular gas. The new WFC3 emission-line image suite clearly defines
the dusty toroidal equatorial structure that bisects NGC 6302's polar lobes,
and the fine structures (clumps, knots, and filaments) within the lobes. The
most striking aspect of the new WFC3 image suite is the bright, S-shaped 1.64
micron [Fe II] emission that traces the southern interior of the east lobe rim
and the northern interior of the west lobe rim, in point-symmetric fashion. We
interpret this [Fe II] emitting region as a zone of shocks caused by ongoing,
fast (~100 km/s), collimated, off-axis winds from NGC 6302's central star(s).
The [Fe II] emission and a zone of dusty, N- and S-rich clumps near the nebular
symmetry axis form wedge-shaped structures on opposite sides of the core, with
boundaries marked by sharp azimuthal ionization gradients. Comparison of our
new images with earlier HST/WFC3 imaging reveals that the object previously
identified as NGC 6302's central star is a foreground field star. Shell-like
inner lobe features may instead pinpoint the obscured central star's actual
position within the nebula's dusty central torus. The juxtaposition of
structures revealed in this HST/WFC3 imaging study of NGC 6302 presents a
daunting challenge for models of the origin and evolution of bipolar PNe.
