X-Ray of an Evolution
This stunning image is of the planetary nebula Abell 30, located about 5500 light years from Earth. You're looking at visible and x-ray light in a composite image from four telescopes: the Hubble Space Telescope, Kitt Peak National Observatory, and two orbiting x-ray telescopes, NASA's Chandra X-Ray Observatory and ESA's XMM-Newton. Abell 30 is what our neighborhood might look like in about four or five billion years, when our sun depletes its hydrogen supply. This sun-like star became a red giant, then pushed its outer layers away and began to cool, but as the Chandra team writes:
In rare cases, nuclear fusion reactions in the region surrounding the star's core heat the outer envelope of the star so much that it temporarily becomes a red giant again. The sequence of events -- envelope ejection followed by a fast stellar wind -- is repeated on a much faster scale than before, and a small-scale planetary nebula is created inside the original one. In a sense, the planetary nebula is reborn.
Image: Inset X-ray (NASA/CXC/IAA-CSIC/M.Guerrero et al); Inset Optical (NASA/STScI); Widefield X-ray (ESA/XMM-Newton); Widefield Optical (NSF/NOAO/KPNO)