A planetary nebula (so called because it looks like a planet when viewed with a small telescope) is formed when a dying red giant star puffs off its outer layer, leaving behind a hot core that will eventually collapse to form a dense star called a white dwarf. According to theory, a “hot bubble” is formed when a new, two-million-mile-per-hour wind emanating from the hot core rams into the ejected atmosphere, producing energetic shocks and heating the interaction region to temperatures of millions of degrees. NASA’s Chandra X-ray Observatory has imaged for the first time a “hot bubble” of gas surrounding a dying, sun-like star. This large region of very hot gas in the planetary nebula BD+30 3639 has a peculiar shape and contains elements produced in the core of the dying star. “The new Chandra image offers conclusive proof for the existence of the ‘hot bubble’ that theorists have long predicted,” said research team leader Joel Kastner of the Rochester Institute of Technology.