An astrophysicist from San Diego State University helped find evidence of a massive residue around an exploding star. We are talking about the shell of such a huge material that the eruption should occur regularly for millions of years.
When a white dwarf (the core of a dead star) resides next to another star, it is fed by its gas. As a result, the gas heats up, shrinks and explodes, forming a new one. The explosion increases the stellar brightness of a million times, throwing material at a speed of thousands of miles per second. From the ejected volume, a shell is created around the new one.
Researchers have carefully studied the new M31N 2008-12a in the neighboring Andromeda galaxy. It seems unusual because it erupts much more often than any other known new. Surprisingly, it erupts every year, showing a typical picture every 10 years.
This is believed to be a regular process that has been going on for millions of years. Frequent eruptions over time created a “super-remnant” phenomenon around the new one, which is 400 light-years in size. Using the Hubble Space Telescope and ground-based vehicles, researchers attempted to determine the chemical composition of the residue and confirm its relationship with M31N 2008-12a. Ia-type supernovae are among the most powerful and brightest objects in the universe. Appear when a white dwarf with power exceeds the maximum permissible mass. At the critical moment it breaks apart (other stars pass through a series of surface explosions). Such objects are extremely rare and invisible in the Milky Way.
Theoretical models show that new ones passing through frequent explosions surrounded by large remnants should hide white dwarfs approaching a critical mass. So, M31N 2008-12a should explode as a supernova.
Finding large residues around other new ones will allow you to find systems with repeated eruptions. This will help to understand how many Ia-type supernovae are created and how often this happens.