Planetary nebulae are not as airy and tranquil as their images suggest. 行星状星云(PN)并不如影像中所显现的那麽飘逸宁静。
Until recently, it was thought that such shells around planetary nebulae were a rare phenomenon. 到目前为止,人们依然在思考行星式星云周围产生这种壳的罕见现象的原因。
Planetary nebulae are a type of isolated gaseous nebulae possessing a fair degree of bilateral symmetry. 行星状星云(PN)是一类孤立的气体星云,具有相当程度的双侧对称性。
Astronomers used the Hubble Space Telescope to make a series of images of planetary nebulae in the mid-1990s, including this one. 上世纪九十年代中期,天文学家们运用哈勃太空望远镜拍摄到了这一星云的众多图像,其中便包括了这一张。
The intriguing result implies that the massive star's explosion has produced a shape similar to what is seen in some planetary nebulae associated with lower mass stars. 这个很有趣的结果指出,大质量恒星爆炸所产生的碎片云,其外观和某些小质量恒星所产生的行星状星云(PN)相似。