In the 12th century, Chinese and Japanese astronomers saw a new light in the sky shining as brightly as Saturn. They described it as a powerful stellar explosion known as a supernova and marked its approximate position in the sky – but the cause remained a mystery.
Now, astronomers say they’ve solved the 840-year-old riddle: Two extremely dense stars collided. Milky Way and caused a supernova. The explosion likely resulted in the formation of a sizzling star now known as Parker’s star and a nebula with an expanding shell of gas and dust called Pa 30.
This supernova, or the so-called Chinese Guest Star of 1181 AD – remained visible from August 6 to February 6 of that year – is just one of nine historically recorded supernovae in our galaxy, according to research published in September. 15 inches Astrophysical Journal Letters. Astronomers have identified only a handful of remnants of these supernovas, but the Chinese Guest Star was the only supernova of the last millennium whose remnants have yet to be found.
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Some previous research has suggested that there may be remnants of another nebula known as 3C 58, located near the supernova’s marked location. But many factors, such as the nebula’s age, cast doubt on this theory. “Until now, there was no other known viable candidate for the residue,” the authors wrote in the study.
Astronomers discovered the nebula Pa 30 in 2013. Then, in the new study, the researchers calculated how fast Pa 30 was expanding. They found it inflated at a blistering speed of 684 miles per second (1,100 kilometers per second). Knowing this ratio, they calculated that the nebula should have been born about 1,000 years ago, which would place its origins in this ancient supernova time.
Researchers also had historical documents describing the star. “Historical reports position the Guest Star between two Chinese constellations, Chuanshe and Huagai. Parker’s Star fits the position very well,” said Albert Zijlstra, professor of astrophysics at the University of Manchester in England. said in a statement. “This means that both his age and location fit the events of 1181.”
Previously, researchers had suggested that Pa 30 and Parker’s star were caused by the merger of two white dwarfs, which are extremely dense stars that have consumed all their nuclear fuel, according to the statement. Such mergers give rise to a relatively weak and rare type of supernova known as Type loose supernova.
Zijlstra said in a statement that the AD 1181 supernova was faint and faded very slowly, suggesting it was likely a Type loose supernova. “Combining all this information, such as age, location, event luminosity, and historically recorded 185-day duration, shows that Parker’s star and Pa 30 are remnants of this ancient supernova,” Zijlstra said. Said.
“This is the only known type of loose supernova that astronomers can conduct detailed studies of the remaining star and nebula,” he added. “It’s nice to be able to solve both a historical and an astronomical mystery,” Zijlstra said. said.
Originally published on Live Science.
Editor’s note: This article has been updated to clarify that the collision of two superdense stars causes a supernova. Scientists say the nebula Pa 30, first discovered in 2013, is a supernova remnant.