Yunnan Observatory of the Chinese Academy of Sciences confirms the fastest-rotating near-Earth asteroid known

China News Service, Kunming, October 27 (Du Xiaoxiao, Zhang Xiliang) A reporter learned from the Yunnan Observatory of the Chinese Academy of Sciences on the 27th that recently, its team, together with domestic and foreign collaborators, has made breakthrough progress in the observation and research of ultra-fast rotating near-Earth asteroids, confirming the fastest-rotating near-Earth asteroid known. Relevant research results have been published in the international astronomical journal "The Astronomical Journal".

In the early morning of December 4, 2024, the near-Earth asteroid 2024 XA1 fell into the Earth's atmosphere from over eastern Siberia. The entire process from discovery to fall only took about 10 hours. In order to efficiently obtain the brightness information of 2024 XA1, the Yunnan Observatory team used the Lijiang 2.4-meter telescope to adopt the "wait and wait" observation method, and successfully monitored the pre-fall image of 2024 XA1 during the precious window of one hour before it entered the atmosphere.

Near-Earth asteroids refer to asteroids whose perihelion distance is less than 1.3 AU (astronomical units). Near-Earth asteroids with a diameter greater than 140 meters (absolute magnitude H<22) and a minimum orbit intersection distance of less than 0.05AU from the Earth are defined as potentially hazardous asteroids. The destructive power caused by the impact of near-Earth asteroids has attracted more and more people's attention and attention. Therefore, the monitoring, early warning and defense of near-Earth asteroids are related to the common security of all mankind.

Research results show that the rotation period of the near-Earth asteroid 2024 XA1 is only 1.63 seconds, making it the fastest-rotating near-Earth asteroid currently known. This research work not only confirmed the fastest-rotating near-Earth asteroid known, but also independently developed a set of reliable trail image analysis methods, which can efficiently analyze the rotation period, shape, structure and other characteristic information of near-Earth asteroids from trail images, providing opportunities to study the internal material structure of meter-scale, fast-rotating and fast-moving near-Earth asteroids, while improving the ability to obtain the physical properties of short-term warning asteroids.

Based on basic research, focusing on international frontiers and national needs, the research team used the Yunnan Observatory's Lijiang 2.4-meter telescope and independently developed research methods to complete the research on the near-Earth asteroid 2024 XA1. This marks that the Yunnan Observatory has the ability to monitor and research such near-Earth asteroids, and can provide scientific support for the deployment and development of planetary defense missions, and contribute China's strength to the protection of the earth and human security.