2025年1月29日
Dust Shells around WR 140 from Webb
Image Credit: NASA, ESA, CSA, STScI, E. Lieb (U. Denver), R. Lau (NSF NOIRLab), J. Hoffman (U. Denver)
Explanation: What are those strange rings? Rich in dust, the rings are likely 3D shells — but how they were created remains a topic of research. Where they were created is well known: in a binary star system that lies about 6,000 light years away toward the constellation of the Swan (Cygnus) — a system dominated by the Wolf-Rayet star WR 140. Wolf-Rayet stars are massive, bright, and known for their tumultuous winds. They are also known for creating and dispersing heavy elements such as carbon, which is a building block of interstellar dust. The other star in the binary is also bright and massive — but not as active. The two great stars joust in an oblong orbit as they approach each other about every eight years. When at closest approach, the X-ray emission from the system increases, as, apparently, does the dust expelled into space — creating another shell. The featured infrared image by the Webb Space Telescope resolves greater details and more dust shells than ever before. Images taken over consecutive years show the shells moving outward.
Tomorrow’s picture: open space
韦伯影像: 恒星WR 140的尘埃壳
影像提供: NASA, ESA, CSA, STScI, E. Lieb (U. Denver), R. Lau (NSF NOIRLab), J. Hoffman (U. Denver)
说明: 这些奇怪的环是什么？这些富含尘埃的环，可能是3维的壳层，然而它们到底是如何产生的，目前仍然是科学研究的课题。不过，它们的诞生之处则众所周知；在天鹅座方向6,000光年远的一个双星系统内，该系统的主宰天体为沃尔夫-拉叶星WR 140。明亮大质量的沃尔夫-拉叶星，以星124著称。它们亦擅长于合成和散布重元素（诸如碳），这些元素最终成为星际尘埃的成分。此双星里的另一颗恒星也是既亮又重，只是较不活跃。这两颗巨星各自在椭圆轨道上飞奔，大约每8年发生近距离互扰。在最接近时，此系统的X射线 辐射会增加，同时尘埃也会被排放到太空中，形成另一个新壳层。这幅由韦伯太空望远镜所拍摄的红外光主题 影像，解析出前所未见的细节及更多尘埃壳。而分别于前后二年拍摄的影像，更证实这些壳层会向外扩张。
明日的图片: open space
