NGC 6357：龙虾星云
NGC 6357: The Lobster Nebula
Image Credit: CTIO/NOIRLab/DOE/NSF/AURA; Processing: T. A. Rector (U. Alaska Anchorage/NSF’s NOIRLab), J. Miller (Gemini Obs./NSF’s NOIRLab), M. Zamani & D. de Martin (NSF’s NOIRLab)
Explanation: Why is the Lobster Nebula forming some of the most massive stars known? No one is yet sure. Cataloged as NGC 6357, the Lobster Nebula houses the open star cluster Pismis 24 near its center — a home to unusually bright and massive stars. The overall red glow near the inner star forming region results from the emission of ionized hydrogen gas. The surrounding nebula, featured here, holds a complex tapestry of gas, dark dust, stars still forming, and newly born stars. The intricate patterns are caused by complex interactions between interstellar winds, radiation pressures, magnetic fields, and gravity. The image was taken with DOE’s Dark Energy Camera on the 4-meter Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile. NGC 6357 spans about 400 light years and lies about 8,000 light years away toward the constellation of the Scorpion.
Tomorrow’s picture: sun block
NGC 6357: 龙虾星云
图像提供: CTIO/NOIRLab/DOE/NSF/AURA; 图像处理: T. A. Rector (U. Alaska Anchorage/NSF’s NOIRLab), J. Miller (Gemini Obs./NSF’s NOIRLab), M. Zamani & D. de Martin (NSF’s NOIRLab)
说明：为何龙虾星云会形成现知最大质量的一些恒星呢？目前没人能说个准。龙虾星云（NGC 6357）中心的疏散星团Pismis 24，就是这些极端明亮泛蓝大质量恒星的家。而恒星形成区核心的弥漫泛红辉光，则是由电离氢气所发出的辐射。这幅主题图像里的周边星云，则是由云气、黝黑尘埃、形成中恒星、及新诞生恒星所聚成的复杂织锦。图像中这些错综复杂的图案，是星际风、辐射压、磁场和重力复杂交互作用下的产物。这幅图像是用4米口径布兰柯望远镜所搭载的美国能源部之暗能量相机，摄于智利的塞罗托洛洛美洲天文台。跨幅约400光年的NGC 6357，位在天蝎座方向约8,000光年远之处。
明日的图片: sun block
