CG4: 云球与星系

2024年5月21日

CG4: The Globule and the Galaxy
Image Credit: CTIO, NOIRLab, DOE, NSF, AURA; Processing: T. A. Rector (U. Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab)

Explanation: Can a gas cloud eat a galaxy? It’s not even close. The “claw” of this odd looking “creature” in the featured photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary globules are typically characterized by dusty heads and elongated tails. These features cause cometary globules to have visual similarities to comets, but in reality they are very much different. Globules are frequently the birthplaces of stars, and many show very young stars in their heads. The reason for the rupture in the head of this object is not yet known. The galaxy to the left of the globule is huge, very far in the distance, and only placed near CG4 by chance superposition.

Tomorrow’s picture: green sky arc

CG4: 云球与星系
影像提供: CTIO, NOIRLab, DOE, NSF, AURA; 影像处理: T. A. Rector (U. Alaska Anchorage/NSF’s NOIRLab), D. de Martin & M. Zamani (NSF’s NOIRLab)

说明: 这团气体云能吞下星系吗？当然办不到，体型差太多了。在这幅主题影像里，看似在伸展”触手”的怪异”生物”，其是一种名为彗星状云球的气体云。只不过，这团云气已然破裂。彗星状云球的典型特征为尘埃头和长尾，这让彗星状云球的外观和彗星有点相似，然而在本质上它们天差地别。云球经常是恒星形成之所在，有些云球的头部甚至还镶着很年轻的恒星。至于这团云球的头部为何会破裂，其原因仍然不明。云球左方的星系，其实非常庞大且遥远，它只是和CG4共视线方向因而恰好重叠入镜。

明日的图片: green sky arc