Images by Date
Images by Category
Solar System
White Dwarfs
Neutron Stars
Black Holes
Milky Way Galaxy
Normal Galaxies
Galaxy Clusters
Cosmology/Deep Field
Images by Interest
Space Scoop for Kids
Sky Map
Photo Blog
Top Rated Images
Image Handouts
Fits Files
Image Tutorials
Photo Album Tutorial
False Color
Cosmic Distance
Look-Back Time
Scale & Distance
Angular Measurement
Images & Processing
Image Use Policy
Web Shortcuts
Chandra Blog
RSS Feed
Email Newsletter
News & Noteworthy
Image Use Policy
Questions & Answers
Glossary of Terms
Download Guide
Get Adobe Reader
Animations: Planetary Nebula: Misnamed but Not Misunderstood
Tour: Planetary Nebula: Misnamed but Not Misunderstood
(Credit: NASA/CXC/A. Hobart)
[Runtime: 2:42]

With closed-captions (at YouTube)

Sometimes the names of objects are deeply misleading. For example, starfish are not actually fish. They are, in fact, echinoderms. And guinea pigs are not related to pigs in any way -- they are rodents. Similarly, planetary nebulas have nothing to do with planets. They were misnamed when scientists looked through small telescopes in the 19th century and thought these objects looked like planets.

Today, astronomers know that a planetary nebula actually represents a phase that stars like our Sun experience when they use up much of their fuel. After the star cools and expands, it sheds its outer layers. The core of the star left behind at the center is a dense and smaller star called a white dwarf. The shells of gas linger around the white dwarf for a relatively short time in cosmic terms – tens of thousands of years – before dissipating into space. During that time, the white dwarf can illuminate and energize these jettisoned layers.

NASA’s Chandra X-ray Observatory contributes to the understanding of planetary nebulas by studying the hottest and most energetic processes still at work in these beautiful objects. X-ray data from Chandra reveal winds being driven away from the white dwarf at millions of miles per hour that create shock waves during collisions with slower-moving material previously ejected by the star. Chandra’s exceptional vision in X-rays contributes to the understanding of this brief, yet important, stage of stars’ lives.

This gallery contains half a dozen planetary nebulas that have been observed both by Chandra and NASA’s Hubble Space Telescope. While all six nebulas originated from similar physical conditions and evolved by similar processes, they currently appear somewhat different from others. The differences in the shapes and structures of these planetary nebulas may be due to the complexities of a slew of physical properties including how much of the star’s winds flow from its poles, whether the star wobbles as it spins, if the star has a companion or not, and other factors.

Quick Look: Planetary Nebula: Misnamed but Not Misunderstood
(Credit: NASA/CXC/A. Hobart)
[Runtime: 0:45]

A new gallery of planetary nebulas with X-ray and optical data is being released.

As stars like the Sun run out of fuel, they jettison their outer layers.

Winds from the dying star slam into the material, generating X-rays.

NASA’s Chandra X-ray Observatory and Hubble Space Telescope captured these images.

Return to Planetary Nebula: Misnamed but Not Misunderstood (December 6, 2021)