High Spatial Resolution Mid‐ and Far‐infrared Imaging Study of NGC 2346

We present the first high spatial resolution mid-IR and far-IR images of the planetary nebula NGC 2346 using the Multiband Imaging Photometer for Spitzer (MIPS) on board the Spitzer Space Telescope. The morphology at 24 μm is strikingly similar to that seen in the optical image, with an additional unresolved hot dust component at the center. The 70 μm image reveals a torus-like structure near the narrow waist of the bipolar nebula, while the 160 μm image shows a very extended cold dust envelope around the nebula. Our new MIPS data provide direct evidence that the mass loss in the end of the asymptotic giant branch (AGB) phase diverts from spherical symmetry to axisymmetry and that the binary central star has played an important role in the bipolar nebular evolution.