Two astrophysicists have identified and modeled the structure of a supernova documented a millennium ago and until now considered lost. The object, now known as ‘SN 1181’, not only has filaments that make it look like a dandelion flower, it also houses a star zombie in its center.
‘SN 1181’ is considered one of the few star explosions recorded before the era of telescopes. Astronomers from ancient Chinese and Japanese civilizations documented it precisely in the year 1181 under the classification of a “guest star” in the sky. Although the record is in the documents, contemporary scientists had not been able to locate it in space, as has happened in other similar cases.
Ilaria Caiazzo, a professor at the Austrian Institute of Science and Technology (ISTA), and Tim Cunningham, a researcher at the Harvard Center for Astrophysics and the Smithsonian, put together all the available clues from that legendary supernova to put together a model of what it should look like. The amazing work was published in the scientific journal The Astrophysical Journal Letters.
A new way of seeing supernovas
The explosion was not as lost as thought. In 2021, investigations led to a new nebula found by an amateur astronomer in 2013. Using the Keck Cosmic Web Imager (KCWI) instrument, an ultrasensitive spectrograph on a mountaintop in Hawaii, scientists investigated the remnant of the explosion stellar in that area.
The instrument makes it possible to measure the movement of matter in a stellar explosion to form a kind of “3D movie” of any supernova. KCWI’s sensitivity shaped the supernova’s dandelion-shaped filaments and indicated that they traveled a thousand kilometers per second. “This means that the ejected material has not slowed down or accelerated since the explosion. Therefore, from the measured velocities, looking back in time allowed us to pin the explosion almost exactly to the year 1181,” Cunningham explained.
the star zombie within it is “the remnant of the remnant” of the original star. The study explains that when the white dwarf that gave rise to the supernova ‘SN 1181’ exploded, it left behind a fragment of an ultradense dead star. It is a rare scenario, but there are records of others. Astrophysicists know this phenomenon as a type Iax supernova.
“Our first detailed 3D characterization of the velocity and spatial structure of a supernova remnant tells us a lot about a unique cosmic event that our ancestors observed centuries ago. But it also raises new questions and challenges for astronomers to address next.” , concludes Caiazzo.
#Dandelion #supernova #star #remnant
