深空影像:人马座内的星云
影像来源与版权:Emilio Rivero Padilla

说明:这三个明亮的星云经常出现在人马座的望远镜巡天过程和中央银河系的致密星场中。实际上,18世纪的宇宙旅行者查尔斯·梅西耶对其中的两个星云进行了编录:庞大的星云M8位于影像中央左侧,多彩的M20位于左上方。第三个发射星云NGC 6559则位于M8右侧。这三个恒星孕育场都距离我们约5000光年远。广阔星云M8的直径超过了一百光年,它也被称为礁湖星云。M20的俗称为三裂星云。炽热氢气发出的红光使发射星云呈现出红色。与之形成鲜明对比的是,三裂星云的蓝色色泽是由尘埃反射的星光造成的。最近形成的亮蓝色恒星在附近可见。这幅合成的多彩天空影像是2018年在西班牙加那利群岛的泰德国家公园拍摄而成。
翻译:北京天文馆

Deep Field: Nebulae of Sagittarius
Image Credit & Copyright: Emilio Rivero Padilla

Explanation: These three bright nebulae are often featured on telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way. In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the large nebula just left of center, and colorful M20 on the top left. The third emission region includes NGC 6559 and can be found to the right of M8. All three are stellar nurseries about five thousand light-years or so distant. Over a hundred light-years across, the expansive M8 is also known as the Lagoon Nebula. M20’s popular moniker is the Trifid. Glowing hydrogen gas creates the dominant red color of the emission nebulae. In striking contrast, blue hues in the Trifid are due to dust reflected starlight. Recently formed bright blue stars are visible nearby. The colorful composite skyscape was recorded in 2018 in Teide National Park in the Canary Islands, Spain.
Astronomy Picture of the Day 05/21/2019