Astronomers Solve 900-Year-Old Cosmic Mystery Surrounding Famous Chinese Supernova From 1181 AD

Figure 1. (a) WISE false color image of Pa 30 where blue and green represent 11 m emission and red 22 m. Here, the levels of the 22m component have been adjusted to improve the ring-shaped characteristic. (b) In this false color image, where green represents WISE 11m (as in the left panel) and red for WISE 22m (adjusted to show extended emission), the emission of the central star is highlighted in blue from the GALEX data in near UV, while the XMM-Newton contours (10 levels, linear scale) show that the majority of the X-ray emission comes from the core of the nebula. A background point source is seen west of the CS in the XMM-Newton contour map. (c) The 2.1 m KPNO [O iii] image, which we have stacked and grouped from individual frames to enhance the low light of the surface, the diffuse shell. The green cross in the center of the image marks the location of the CS. Panels (a) to (c) are reproduced at the same angular scale and in the same orientation. At the Gaia distance of Pa 30 of 2.30 ± 0.14 kpc, an angular scale of 45 “translates to approximately 100,000 au.

A 900-year-old cosmic mystery surrounding the origins of a famous supernova first spotted over China in 1181 AD has finally been solved, according to an international team of astronomers.

New research published today (September 15, 2021) indicates that a rapidly expanding cloud (or nebula), called Pa30, surrounding one of the hottest stars in the Milky Way, known as Parker’s Star, matches the profile, location, and age of the historic supernova.

There have only been five bright supernovae in the Milky Way in the last millennium (as of 1006). Among these, the Chinese supernova, also known as the “Chinese Guest Star” of 1181 AD, has remained a mystery. It was originally seen and documented by Chinese and Japanese astronomers in the 12^e century who said she was as bright as the planet Saturn and remained visible for six months. They also recorded an approximate sky location of the sighting, but no confirmed vestiges of the explosion have even been identified by modern astronomers. The other four supernovae are now well known to modern science and include the famous Crab Nebula.

The source of this 12^e The explosion of the century remained a mystery until this latest discovery made by a team of international astronomers from Hong Kong, the United Kingdom, Spain, Hungary and France, including Professor Albert Zijlstra of the University of Manchester. In the new article, astronomers discovered that the Pa 30 nebula is expanding at an extreme speed of over 1,100 km per second (at this speed, traveling from Earth to the Moon would take just 5 minutes). They use this speed to derive an age of about 1,000 years, which would coincide with the events of 1181 AD.

Professor Zijlstra (professor of astrophysics at the University of Manchester) explains: “Historical reports place the guest star between two Chinese constellations, Chuanshe and Huagai. Parker’s star fits the position well. This means that the age and location correspond to the events of 1181. “

Pa 30 and Parker’s Star have already been offered following the merger of two White Dwarfs. It is believed that such events lead to a rare and relatively weak type of supernova called “Iax-type supernova”.

Professor Zijlstra added: “Only about 10% of supernovae are of this type and they are not well understood. The fact that SN1181 was weak but faded very slowly fits this type. This is the only such event where we can study both the remaining nebula and the merged star, and also have a description of the explosion itself.

The fusion of residual stars, white dwarfs and neutron stars, gives rise to extreme nuclear reactions and forms heavy elements and very rich in neutrons such as gold and platinum. Professor Zijlstra said: “The combination of all this information such as age, location, brightness of the event and the historically recorded duration of 185 days indicates that Parker’s Star and Pa30 are the counterparts of SN 1181. It is the only Iax-type supernova where detailed studies of the remaining star and nebula are possible. It’s nice to be able to solve both a historical mystery and an astronomical mystery.

Reference: “The Remnant and Origin of the Historical Supernova 1181 AD” by Andreas Ritter, Quentin A. Parker, Foteini Lykou, Albert A. Zijlstra, Martín A. Guerrero and Pascal Le Du, September 15, 2021, The Journal of Astrophysics.
DOI: 10.3847 / 2041-8213 / ac2253