This image shows four planetary nebulas as captured by NASA’s Chandra X-ray Observatory. As explained in Chandra’s website, a planetary nebula represents a phase of stellar evolution:
“When a star like the Sun uses up all of the hydrogen in its core, it expands into a red giant, with a radius that increases by tens to hundreds of times. In this phase, a star sheds most of its outer layers, eventually leaving behind a hot core that will soon contract to form a dense white dwarf star. A fast wind emanating from the hot core rams into the ejected atmosphere, pushes it outward, and creates the graceful, shell-like filamentary structures seen with optical telescopes.”
Beautiful, isn’t it? Click on the image to enlarge it.
Source: Chadra X-ray Observatory
Photo: X-ray: NASA/CXC/RIT/J.Kastner et al.; Optical: NASA/STScI