I am constantly amazed and awed by the sheer beauty of planetary nebulae - the gorgeous structures created as stars die. Among the most astonishing of them is NGC 7026, a youngish nebula about 6000 light years away in the constellation Cygnus, the Swan. Here's a stunningly beautiful picture of it from the Hubble Space Telescope:
[Click to enlepidopterate.] Planetary nebulae (or PNe for short) like this are sometimes called "butterfly nebulae" because of their shape. It's easy to see why; there are two big lobes that are roughly shaped like butterfly wings. The history of those lobes is complex. You can see the central star, right in the middle. That used to be a star much like the Sun, though more massive and hotter. As it ran out of fuel in its core, it swelled up to become a red giant. It started to blow a slow, dense wind ...
