哈勃望远镜观测到一个正在膨胀的宇宙云

A small, dense cloud of gas and dust called CB 130-3 blots out the center of this image from the NASA/ESA Hubble Space Telescope. CB 130-3 is an object known as a dense core, a compact agglomeration of gas and dust. This particular dense core is in the constellation Serpens and seems to billow across a field of background stars.

Dense cores like CB 130-3 are the birthplaces of stars and are of particular interest to astronomers. During the collapse of these cores enough mass can accumulate in one place to reach the temperatures and densities required to ignite hydrogen fusion, marking the birth of a new star. While it may not be obvious from this image, a compact object teetering on the brink of becoming a star is embedded deep within CB 130-3.

Astronomers used Hubble’s Wide Field Camera 3 to better understand the environment surrounding this fledgling star. As this image shows, the density of CB 130-3 isn’t constant; the outer edges of the cloud consist of only tenuous wisps, whereas at its core CB 130-3 blots out background light entirely. The gas and dust making up CB 130-3 affect not only the brightness but also the apparent color of background stars, with stars toward the cloud’s center appearing redder than their counterparts at the outskirts of this image. Astronomers used Hubble to measure this reddening effect and chart out the density of CB 130-3, providing insights into the inner structure of this stellar nursery.

Text credit: European Space Agency (ESA)
Image credit: ESA/Hubble, NASA & STScI, C. Britt, T. Huard, A. Pagan

一个被称为CB130-3的小型致密气体和尘埃云遮住了这张来自NASA/ESA哈勃太空望远镜的图像的中心。CB 130-3是一种被称为致密核的天体，是气体和尘埃的紧密聚集体。这个密度特别大的核心位于巨蛇座，似乎在背景恒星的视野中翻腾。

像CB 130-3这样的致密核是恒星的诞生地，是天文学家特别感兴趣的地方。在这些致密核的坍缩过程中，足够的质量可以积累在一个地方，达到点燃氢聚变所需的温度和密度，这标志着一颗新恒星的诞生。虽然从这张照片上看不太明显，但在CB 130-3的深处有一个在成为恒星的边缘的紧凑物体。

天文学家使用哈勃望远镜的广域照相机3来更好地了解这颗刚诞生的恒星周围的环境。如图所示，CB 130-3的密度并不恒定；星云的外边缘仅由纤细的缕状物组成，而在其核心部分，CB 130-3完全遮蔽了背景光。组成CB130-3的气体和尘埃不仅影响背景恒星的亮度，也影响了其表面的颜色，在这张图片中，靠近云层中心的恒星比图中外围的恒星显得更红。天文学家使用哈勃望远镜测量了这一变红效应，并绘制出了CB130-3的密度图，从而对这颗恒星诞生地的内部结构提供了见解。

文字来源：欧洲航天局（ESA）
图片来源：欧空局/哈勃、NASA和STScI、C.Britt、T.Huard、A.Pagan