在天文学领域，大质量恒星一直是研究重点。这类恒星通常可以达到太阳质量的几十倍甚至上百 倍，但目前对于这一类恒星"诞生"与"终结"的研究，依然存在一些理论分歧。 人们预测，生命末期的大质量恒星会形成由不同元素组成的壳状结构，较重的元素预计会更靠近核 心，但这很难被观察到。 科技日报北京8月20日电 （记者张梦然）《自然》20日刊登的论文报告了一次罕见的宇宙事件：一 颗大质量恒星在超新星爆发时，"自曝"其内部结构，从而向人们揭示了大质量恒星生命结束之谜。该研 究对恒星演化提供了新见解，证实了对恒星临近生命末期结构的预测。 在同时发表的新闻与观点文章中，天文学家认为这项发现"直接证实了理论预测的恒星壳结构，一 直延伸到富含硅和硫的层"。 研究人员提出，恒星暴露出的内部结构，挑战了现有关于大质量恒星质量损失和剥离机制的理论， 并提出这可能涉及一种罕见的机制。 美国西北大学研究人员此次报告了他们对超新星2021yfj的观察。其前身恒星似乎已剥离了大多数 外层，超新星爆发揭示了其内部恒星层。研究人员观察到一个厚且大质量的富含硅和硫的壳，在超新星 爆发前不久被原恒星排出。但他们还检测到了氦，这有些出乎意料，因为人们认为较轻 ...

Core Insights - The James Webb Space Telescope (JWST) has been operational since July 2022, capturing approximately 550 terabytes of cosmic data and generating over 1,600 significant research findings, enhancing humanity's understanding of the universe [1] Group 1: Discoveries and Observations - JWST is designed to observe the "cosmic dawn," the first billion years after the universe's birth, revealing early bright galaxies existing just 300 million years post-Big Bang [2] - The telescope has identified "baby" galaxies that are only 600 million years old but already exhibit structures similar to the Milky Way [2] - JWST discovered mysterious "small red dots," which are distant, dense, bright, and red star clusters, with potential explanations for their brightness being dense young star groups or heated gas from supermassive black holes [3] Group 2: Atmospheric Studies - JWST has advanced the study of exoplanet atmospheres, detecting complex chemical compositions such as hydrogen sulfide, ammonia, carbon dioxide, methane, and sulfur dioxide in gas giant planets [4] - The telescope successfully detected traces of carbon monoxide or carbon dioxide in the thin atmosphere of the rocky exoplanet 55 Cancri e, located 40 light-years away [5] Group 3: Stellar Evolution and Planetary Systems - JWST may have detected planetary candidates orbiting white dwarfs, suggesting that planets can survive the death of their stars [6] - The telescope revealed the scale of water plumes on Europa, showing a massive cloud structure over 9,600 kilometers in diameter, significantly larger than previously observed [7] Group 4: Future Exploration - JWST is expected to continue its operations for over 20 years, providing opportunities for further exploration of cosmic mysteries and enhancing our understanding of the universe [7]

Core Insights - Chinese scientists have discovered a rare millisecond pulsar using the FAST telescope, which orbits another star and is obscured for one-sixth of the time by its companion star [1][3] - This unique binary star system is extremely rare and difficult to observe, contributing significantly to the understanding of stellar evolution and gravitational wave sources in binary systems [1][5] Group 1: Discovery Details - The discovered pulsar has a rotation period of 10.55 milliseconds and orbits a companion star with a period of 3.6 hours [1][3] - The companion star is at least one solar mass and is identified as a burning helium star, not a typical star [3][5] Group 2: Significance of the Discovery - The rarity of such systems is highlighted, with only a few dozen similar systems identified in the Milky Way, which contains over a hundred billion stars [5] - The discovery aids in understanding the specific processes of binary star evolution, stellar evolution theories, and the physics of compact star accretion, potentially leading to breakthroughs in astronomical research [7]

Core Viewpoint - Chinese scientists have discovered a rare millisecond pulsar using the FAST telescope, which orbits another star and is obscured for one-sixth of the time by its companion star. This discovery is significant for the study of stellar evolution and gravitational wave sources in binary star systems [1]. Group 1 - The discovery involves a unique binary star system that is extremely rare and difficult to observe [1]. - The research findings were published in the international academic journal "Science" on May 23 [1]. - The study has important implications for understanding stellar evolution and gravitational waves within the Milky Way [1].