Explanation: This gorgeous celestial vista is centered on one of the Milky Way's own planetary nebulae, M57, the famous Ring Nebula. The wide view is a composite of three exposures; one to record the details of the inner roughly one light-year span of the familiar nebula, one to record the surprisingly intricate but faint outer rings of glowing hydrogen gas, and one to pick up the rich assortment of distant background galaxies. By chance, one of the background galaxies, IC 1296 at the upper left, is close enough to show its barred, spiral structure making an attractive visual comparison with M57. Interestingly, though IC 1296 is 200 million light-years away compared to only 2 thousand light-years for M57, a faint ring is also apparent around the outer reaches of the distant spiral galaxy.
说明：这幅美丽的天文景观，主角是我们银河系的著名行星状星云M57；别名为环状星云。这一图像是由三张照片迭加而成，一张是纪录大约一光年宽的星云，另一张是精细而暗淡的外环，其中充满炽热的氢气，第三张是非常遥远的背景星系。其中一个背景星系IC 1296在左上角，很清楚可以看到棒状及漩涡状的结构，可以跟漂亮的M57互相辉映。M57距离我们只有2000光年，而IC 1296 距离我们则远达20亿光年，有趣的是，这个遥远的旋涡星系竟然也有个昏暗但仍可辨识的外环。
上海网上天文台 cliff编译
原文来自：
http://antwrp.gsfc.nasa.gov/apod/ap050723.html
备注：IC 1296 的一些资料。
Object name: IC 1296
Object type: Galaxy
Magnitude: 14.3
Size: 1.1'x0.8'
Position angle: 80° |
|
置顶卡
变色卡
千斤顶
显身卡