NGC 2392：双层的行星状星云

2020 February 16

NGC 2392: Double-Shelled Planetary Nebula
Image Credit: NASA, ESA, Hubble, Chandra; Processing & License: Judy Schmidt

Explanation: To some, this huge nebula resembles a person’s head surrounded by a parka hood. In 1787, astronomer William Herschel discovered this unusual planetary nebula: NGC 2392. More recently, the Hubble Space Telescope imaged the nebula in visible light, while the nebula was also imaged in X-rays by the Chandra X-ray Observatory. The featured combined visible-X ray image, shows X-rays emitted by central hot gas in pink. The nebula displays gas clouds so complex they are not fully understood. NGC 2392 is a double-shelled planetary nebula, with the more distant gas having composed the outer layers of a Sun-like star only 10,000 years ago. The outer shell contains unusual light-year long orange filaments. The inner filaments visible are being ejected by strong wind of particles from the central star. The NGC 2392 Nebula spans about 1/3 of a light year and lies in our Milky Way Galaxy, about 3,000 light years distant, toward the constellation of the Twins (Gemini).

Tomorrow’s picture: fade to red

NGC 2392：双层的行星状星云
影像提供: NASA , ESA , Hubble , Chandra ;影像处理与授权: Judy Schmidt
说明: 有人认为这个庞大的星云，形似戴着帕可连颈帽的人头。这个编录号为NGC 2392的不寻常行星状星云，是由天文学家威廉．赫歇尔发现于1787年。在最近，哈伯太空望远镜在可见光波段为这个星云拍照，在此同时，钱德拉X射线天文卫星，也在X射线波段为它造影。上面这幅整合了可见光和X射线数据的主题影像，以粉红色泽呈现中心炽热气体发出的X射线辐射。这个星云里的气体云形状极为复杂，其成因目前仍未完全厘清。NGC 2392是个双层的行星状星云，它较外围的结构，是一颗类太阳近在10,000年前抛出的外层气壳。这个外围结构拥有一些不寻常，长度将近光年的橙色条状结构。而内围的条状结构，则是中心星抛射的强烈恒星风粒子。位在我们银河系里的NGC 2392，宽约1/3光年，座落在双子座方向约3,000光年远之处。

明日的图片: fade to red