A research team has discovered a new type of supernova and thus also a medieval ratsel solved. The now analyzed star explosion with the name SN 2018ZD had been discovered in marz 2018 and is the group, according to the first secure example for a so-called electron-catching supernova ("electron capture supernova"), which falls under none of the known types.
Theoretically, the occurrence of this supernova type had already been described decades ago, but only now was a truly secured proof. In addition, the team means that it was also at the explosion, which in the year 1054 took the emergence of the cancer nebel, has been such a supernova. Previous models could not completely explain.
Exactly between the two known types
Supernovae actually fall into two categories, explores the team around daichi hiramatsu from the university of california, santa barbara now. These are thermonuclear supernovae, in which a high-level star mass has accumulated up to eight sun masses and achieves dwarf as a women’s dwarf. After the explosion, no compact object remains more abundant. At nuclear collapse supernovae, a star of at least 10-fold sun mass collapses, which has used its nuclear fuel – it creates a black hole or a neutron star.
The now proven electron catch supernova, on the other hand, is the fate of stars whose mass is exactly in between. Their core consists mainly of oxygen, neon and magnesium and from a certain density begins the process called "electron catch", explains the research team. The core collapses and a gigantic explosion crushes the star. Goods that have only been a bit of massive, had the elements in the core fusation and the life of the star can be demanded. With a little less mass, he would escape the core collapse. Theoretically described the 1980 a team around ken’ichi nomoto from the universitat tokyo.
The supernova with the label SN 2018ZD now had a lot of strange characteristics, some of which had been observed for the first time. Once you have amed that it has been an electron-catching supernova, but all could be explained. In the analysis helped that the explosion has occurred only in 31 million light years removal and the space telescope hubble had previously made shots from the place in the sky. So one has the probably exploded star can be detected accordingly.
Hubble shot of the cancer nebul
Answer an old question
The discovery presented in the trade magazine nature astronomy also makes a rating of the most famous supernova of the past, explain the researchers still explain. In the year 1054 occurred in the milk strain and was described by chronists in japan and china. She was so bright so that she was even seen for 23 days in the day and over two years at the night sky. Even so far, the supernova was considered the best candidate for an electron-catching supernova, but the new analysis increased the security again. So it was explained why it has been so unusually bright: the material drained in the explosion could be collided with matter that had stewed the original star. That was also observed at SN 2018ZD.
The cancer fog spreads further.