气泡与星团
The Bubble and the Star Cluster
Image Credit & Copyright: Lorand Fenyes
Explanation: To the eye, this cosmic composition nicely balances the Bubble Nebula at the right with open star cluster M52. The pair would be lopsided on other scales, though. Embedded in a complex of interstellar dust and gas and blown by the winds from a single, massive O-type star, the Bubble Nebula, also known as NGC 7635, is a mere 10 light-years wide. On the other hand, M52 is a rich open cluster of around a thousand stars. The cluster is about 25 light-years across. Seen toward the northern boundary of Cassiopeia, distance estimates for the Bubble Nebula and associated cloud complex are around 11,000 light-years, while star cluster M52 lies nearly 5,000 light-years away. The wide telescopic field of view spans about 1.5 degrees on the sky or three times the apparent size of a full Moon.
Tomorrow’s picture: The Red Square Nebula
气泡与星团
影像提供与版权: Lorand Fenyes
说明: 这幅的宇宙影像，乍看很均衡的呈现疏散星团M52与右方的气泡星云。不过这对伙伴在其他尺码上，其实并不对等。又名为NGC 7635、嵌在星际尘埃与气体云复合体内的气泡星云，是一团由O型星的恒星风所吹成、宽仅有10光年的气泡。相较之下，M52是个宽约25光年，拥有约1千颗成员星的疏散星团。位在仙后座北缘的气泡星云，它与周围的星云复合体，距离约有11,000光年袁，而疏散星团M52的距离则只有5,000光年而已。这幅宽约1.5度的大视野望远镜影像，大概涵盖3个满月视张角的天空。
明日的图片: The Red Square Nebula
