This recently-released image of a planetary nebula in Hercules was taken by the Hubble telescope. Phil at Bad Astronomy Blog explains (in a detailed but easily understood manner) what happens to cause a planetary nebula, and why this one is so pretty. Link
This recently-released image of a planetary nebula in Hercules was taken by the Hubble telescope. Phil at Bad Astronomy Blog explains (in a detailed but easily understood manner) what happens to cause a planetary nebula, and why this one is so pretty. Link