Giant 'soap bubble' found floating in space

 作者:夔珥     |      日期:2019-03-08 10:08:02
By Jeff Hecht IT LOOKS like a soap bubble or perhaps even a camera fault, but the image at right is a newly discovered planetary nebula. Planetary nebulae, which got their name after being misidentified by early astronomers, are formed when an ageing star weighing up to eight times the mass of the sun ejects its outer layers as clouds of luminous gas (see Why stars go out in a blaze of glory). Most are elliptical, double-lobed or cigar-shaped,