In a first-of-its-kind astronomical activity, a hibernating-star has exploded, providing important details to scientists about the evolution of these star eruptions.
According to reports, the explosion has revealed significant insights about nova cycle and a team of astronomers has landed upon evidence that additional mini-outbursts lead to the classical nova. This data has also validated the nova hibernation hypothesis, a theory which talks about the cyclical evolution of such stars and suggests that after the explosion, the mass-transfer rate increases, and then decreases significantly over a million years.
The revelations are the result of the long-term observations by the Optical Gravitational Lensing Experiment (OGLE), a project at the University of Warsaw that has been studying the universe since 1982. Astronomers at the university had been observing the nova V1213 Cen aka Nova Centauri 2009 from 2003.
It exploded in 2009 but as the scientists were supervising its source star since 2003, they were able to collect huge data spanning over years, before as well as after the star's eruption. The recording helped them study the evolutions of this type of nova in detail. According to Prof. Przemek Mróz, the lead author of the study, nova eruptions are the brightest and the most frequent stellar eruptions in the galaxy and they can be, in most cases, seen with naked eye.
The smaller explosions that were seen in the years before the final explosion of Nova Centauri 2009 are known as dwarf novas. Mróz along with his colleagues studied these very dwarf nova explosions and it gave them clinching evidence about nova hibernation hypothesis.
It is worth mentioning here that classical novas occur in binary star systems i.e. systems that have twin stars orbiting a common centre of mass. The twin stars are a white dwarf (a stellar leftover mostly made up of electron-degenerate matter) and another small star.
The former pulls matter away from the latter, leading to accumulation of hydrogen on the surface of the white dwarf. This results in fusion and then causes explosion. The explosions that are powerful in nature are a signal of the demise of stars but nova eruptions do not necessarily indicate the death of their stellar parents.
