A seemingly serene landscape of gas and dust is hopping with star formation behind the scenes.
NASA, ESA, and K. Stapelfeldt (Jet Propulsion Laboratory); Processing: Gladys Kober (NASA/Catholic University of America)
While this eerie NASA Hubble Space Telescope image may look ghostly, it’s actually full of new life. Lupus 3 is a star-forming cloud about 500 light-years away in the constellation Scorpius.
White wisps of gas swirl throughout the region, and in the lower-left corner resides a dark dust cloud. Bright T Tauri stars shine at the left, bottom right, and upper center, while other young stellar objects dot the image.
T Tauri stars are actively forming stars in a specific stage of formation. In this stage, the enveloping gas and dust dissipates from radiation and stellar winds, or outflows of particles from the emerging star. T Tauri stars are typically less than 10 million years old and vary in brightness both randomly and periodically due to the environment and nature of a forming star. The random variations may be due to instabilities in the accretion disk of dust and gas around the star, material from that disk falling onto the star and being consumed, and flares on the star’s surface. The more regular, periodic changes may be caused by giant sunspots rotating in and out of view.
T Tauri stars are in the process of contracting under the force of gravity as they become main sequence stars which fuse hydrogen to helium in their cores. Studying these stars can help astronomers better understand the star formation process.
这片看似宁静的气体与尘埃景观，其幕后实则暗潮涌动，正活跃地孕育着新生的恒星。
影像来源: NASA, ESA, and K. Stapelfeldt (Jet Propulsion Laboratory); 图像处理: Gladys Kober (NASA/Catholic University of America)
尽管这张由NASA哈勃太空望远镜拍摄的影像透着一种幽灵般的诡谲气息，但其中实则生机盎然。豺狼座3（Lupus 3）是一个距离地球约500光年的恒星形成云，位于天蝎座方向。
画面中，白色的气体如缕般盘旋缭绕，左下角则盘踞着一团暗黑的尘埃云。明亮的金牛座T型星（T Tauri stars）在左侧、右下角及中上方熠熠生辉，其他年轻的恒星天体也如繁星般点缀其间。
金牛座T型星是正处于特定演化阶段的活跃新生恒星。在这一阶段，在辐射和恒星风（即从新生恒星喷涌而出的粒子流）的作用下，包裹在恒星周围的气体与尘埃会逐渐消散。金牛座T型星的年龄通常不到1000万年。受其所处环境及恒星形成特性的影响，它们的亮度会呈现出随机或周期性的变化。
这种随机的亮度变化可能源于恒星周围尘埃与气体组成的吸积盘发生了不稳定，或是吸积盘中的物质坠入恒星被吞噬，亦或是恒星表面爆发了耀斑。而那些较为规律的周期性变化，则可能是由巨大的黑子随恒星自转出入视野所致。
金牛座T型星目前正处于引力收缩的过程中，它们最终将演化为主序星，并在核心通过核聚变将氢转化为氦。研究这类恒星有助于天文学家更深入地理解恒星的形成过程。
