Fact Sheet
Shell Game
Filaments of hot gas glow brightly in this combined optical and X-ray image of NGC 6888, a shell of gas around a hot, massive star. The star is just 4.5 million years old -- one-thousandth the age of our Sun -- and should explode as a supernova within the next 200,000 years or so. As it evolved, the star expelled two shells of gas into space -- one moving slowly, and a second, faster one that rammed into the first. This collision heated the gas. The hottest gas produces X-rays, which are shown in blue. Cooler gas glows red and green. [Credit: NASA/UIUC/Y. Chu, R. Gruendl, et al.; SDSU/MLO]
|