It's easy to <a href="http://en.wikipedia.org/wiki/File:Fundus_photograph_of_normal_left_eye.jpg" rel="nofollow">see</a> why this bipolar nebula is called the Retina Nebula. It is one of the most detailed in the archive. Because it's so <a href="http://adsabs.harvard.edu/abs/2002AJ....123.3329O" rel="nofollow">close</a>, fine details which might otherwise be lost are visible.

The reticulated pattern of dust, which appears to form a toroidal shape around the star puzzles me since it is not quite like anything else. There are <a href="http://apod.nasa.gov/apod/ap130607.html" rel="nofollow">dust structures in other bipolar nebulas</a>, just not quite like this. They remind me of <a href="https://www.flickr.com/photos/geckzilla/9597685537/">NGC 7027</a> but with finer structure and not in the form of dual rings. The NGC 7027 image has the advantage of near infrared data from NICMOS, which makes it much easier to see its dust structures. Knowing that makes me wonder what an Infrared image might reveal in IC 4406.

Also visible is a faint arc above the core which is also present below but less well defined. I didn't notice it in many other images of this nebula because it's so faint and easily lost to the background.

Both pc and wf data was combined from two different years (2001 & 2002).

Red: f658n Green: f656n Blue: f502n