Astronomers Discover Remnants of a Powerful Supernova Explosion from Over 4,000 Years Ago Visible to the Naked Eye.
Remnants of the PKS 1209-52 explosion captured by the Spectrum-Roentgen-Gamma mission from Russia and Germany. (Photo: Max Planck Institute)
In the 42nd year of Emperor Yao’s reign (2356 – 2255 BC), a giant star in the constellation Centaurus approached the end of its life cycle. It exploded and illuminated the sky for at least 100 days, according to historian Wu Jiabi from Beijing Normal University, as reported by the South China Morning Post on December 22. Although no written records exist from the Xia dynasty, the first dynasty in Chinese history, a brief description of the event has been passed down and documented in later historical texts.
The remnants of the explosion, known as PKS 1209-52, are located over 3,000 light-years away from Earth and have been extensively studied using modern telescopes. For instance, scientists believe there is a rapidly spinning neutron star at the center of PKS 1209-52, which has a diameter of just 10 kilometers but a mass greater than that of Earth. “Based on astronomical calculations, PKS 1209-52 closely matches the supernova recorded in ancient history in terms of location, distance, and dating,” Wu stated.
Wu shared that there are about 20 candidates that fit the description in historical records. However, considering the brightness and dating of the star observed during Emperor Yao’s time, they identified PKS 1209-52 as the only viable option due to its position at a high galactic latitude. A high galactic latitude means the supernova explosion occurred in a relatively complex plane of the galaxy, an area that contains most of the galaxy’s mass, including dust that absorbs light. This allows the explosion to be observed from Earth with the naked eye.
Wu employed two different methods to date the explosion at approximately 4,500 years, with a margin of error of 900 years, coinciding with the reign of Emperor Yao. Emperor Yao was very interested in astronomical observations. According to historical texts such as the Records of the Grand Historian by Sima Qian, written in the 1st century BC, Emperor Yao sent officials to monitor celestial phenomena at various locations to observe the sunrise and sunset, creating a more accurate calendar.
