The Crab Nebula from the Nordic Optical Telescope [Image: Walter Nowotny]

The Large High Altitude Air Shower Observatory (LHAASO), one of China’s key national science and technology facilities, has accurately measured the brightness over 3.5 orders of magnitude of the standard candle in high-energy astronomy, thus calibrating a new standard for ultra-high-energy (UHE) gamma-ray sources. The standard candle is the famous Crab Nebula, which evolved from the “guest star” recorded by the imperial astronomers of China’s Song Dynasty (960-1279).

Results were published in Science on July 8. The LHAASO International Collaboration, which is led by the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences, completed this study. 

Historical records of the guest star in 1054 [Image: IHEP]

Source: Institute of High Energy Physics (IHEP),

Chinese Academy of Sciences