2025年8月13日
Trapezium: In the Heart of Orion
Image Credit: Data: Hubble Legacy Archive, Processing: Robert Gendler
Explanation: What lies in the heart of Orion? Trapezium: four bright stars, that can be found near the center of this sharp cosmic portrait. Gathered within a region about 1.5 light-years in radius, these stars dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta-1 Orionis C powers the complex star forming region’s entire visible glow. About three million years old, the Orion Nebula Cluster was even more compact in its younger years and a dynamical study indicates that runaway stellar collisions at an earlier age may have formed a black hole with more than 100 times the mass of the Sun. The presence of a black hole within the cluster could explain the observed high velocities of the Trapezium stars. The Orion Nebula’s distance of some 1,500 light-years make it one of the closest candidate black holes to Earth.
Tomorrow’s picture: when the Sky is serene and the Moon absent
猎户座大星云中心的四边形星团
影像提供: 数据提供: Hubble Legacy Archive, 影像处理: Robert Gendler
说明: 猎户座大星云的中心有什么？有四边形星团（Trapezium），而隶属于此星团的4颗明亮恒星，就位于这幅清晰宇宙影像的中心附近。聚集在半径约1.5光年区域里的这4颗星，则是这个猎户座大星云紧密星团的众多恒星中，最引人注目的一群。源自四边形星团成员星、主要是其中最明亮的Theta-1 Orionis C的电离性紫外光辐射，驱动这个恒星形成区复合体发出各种波段的可见光。这个年龄约3百万年的猎户大星云星团，在形成之初更为紧实，而动力学研究指出，当初失控的恒星互撞，可能产生了一个质量超过100倍太阳的黑洞。而如果星团内有黑洞，就可以解释为何四边形星团成员星的运动会如此高速。猎户座大星云离我们约1,500光年远，因此这颗黑洞可能是离地球最近的黑洞。
