High-Resolution Images of the Ring Nebula Taken with the Subaru Telescope

We present high-resolution images of the Ring Nebula in the Hα , V, and B bands taken with the Subaru telescope. The Hα image reveals the fine structure of the inner and outer halos in unprecedented detail. The innermost part of the inner halo just outside of the main ring may be identified as a new component in terms of the surface brightness hierarchy seen in the Ring Nebula. A filamentary structure consisting of loops and knots, which gives a petal-like appearance to the inner halo, is also seen in this new component. The outer halo is found to show a limb-brightened knotty structure similar to the inner halo, but at much fainter levels. The typical size of the knots, however, is clearly different between the two halos. The median size measured on the Hα image is 1.^''2 and 3.^''2 in the inner and outer halos, respectively. The corresponding lifetime, which is defined by the size divided by the thermal velocity, is 400 years and 1200 years. The tri-color image was made with Hα , V, and B images after being sharpened by the maximum-entropy method. The image shows the fine structure of the main ring and the enhanced bands of emission running across the central hole with a resolution comparable to the image taken with the Hubble Space Telescope. The features newly found in the present images may give some support, but more challenges, to the unified model proposed by Guerrero et al.