In today's image, we see two examples of planetary nebulae in the direction of the constellation of Cassiopeia. A planetary nebula is the end state of a star much like our own Sun. It has exhausted the hydrogen fuel in its core and the outer layers expand. The glow because they are energized by ultraviolet light from the white dwarf star forming in the core.

My podcasts are available in video form through this YouTube Channel.

This Podcast is an authorized New Media Mirror Site for APOD. You can access the image and website directly at: Astronomy Picture of the Day. You can use the archive link below the image to select the photo corresponding to the date of this podcast.

I welcome comments and suggestions about these podcasts. I can be reached here: wagnerastronomy@gmail.com

This work is licensed under a Creative Commons Attribution 4.0 International License.