In 1181, a new bright spot the size of Saturn was seen in the skies of China and Japan. This ancient light was visible to Chinese and Japanese observers for more than six months before disappearing. Now, the following year, researchers have finally found the source of this mysterious light. The Crab Nebula It was difficult to see the remains of 1181.
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Nevertheless Historical records provide some clues to light from 900 years ago that have been useful to astronomers today. First, the time: This "guest star" is visible in the sky for 185 days from August 6, 1181 (August 15, 560 solar) to February 6, 1182 (February 6, 560 solar).
This report also Its location in the sky indicates that it was somewhere between the two Chinese constellations "Chuanshe" and "Huagai" near the familiar constellation Cassiopeia.
These puzzle pieces , Led a research team to the root cause of this ancient light: a supernova whose remnants now form a rapidly expanding nebula called Pa30. The nebula's clouds are moving so fast that scientists have found in new research that Pa30 dust and gas can travel the distance from Earth to the moon in five minutes. They also used this velocity and inverse calculation to determine that the nebula was suitable for adapting to a supernova that occurred in 1181.
According to the research team The Pa30 is a rare, relatively faint supernova called the Iax supernova. "Only about 10% of supernovae are of this type and therefore are not yet well known," said Albert Zijlstra, an astrophysicist at the University of Manchester in the United Kingdom. The fact that the SN1181 was weak but gradually declined indicates that it is of this type. "
P30 Nebula and Parker Star
Credit: The University of Hong Kong
Scientists also found that the Parker star It is considered to be the hottest star in the Milky Way, a possible companion of this supernova. The nebula and star are thought to have formed as a result of a massive collision and merger of the two remnants of Commonwealth stars known as white dwarfs. Zilstra added: "It's possible, and it makes me happy to be able to solve both a historical mystery and an astronomical mystery."
Published in France on September 15 in the Astrophysical Journal Letters. Cover photo: Pa30 nebula in changed colors Credit: The University of Hong Kong/p>