Zombie star survives Supernova blast but can Sun live through it too?
Premium- Our sun cannot become a zombie star, however, because it lacks the requisite companion star.
In an extraordinary feat, recently a star not only survived a stellar explosion called a supernova but emerged from it brighter than before the blast. The event in a relatively nearby galaxy was observed by astronomers with the Hubble Space Telescope. Considering our sun is also destined for a similar fate billion years later, the question is can it also become a Zombie star.
The "zombie star" is a kind known as a white dwarf, an incredibly dense object with about the mass of the sun crammed into the size of Earth. A white dwarf is the remaining core of a star that blew off a lot of its material at the end of its life cycle, as our sun is expected to do about 5 billion years from now.
"We were quite surprised that the star itself had not been destroyed but had actually survived and is brighter than before it exploded," said Curtis McCully, a senior astrodata scientist at California-based Las Cumbres Observatory, lead author of the research.
"During the explosion, radioactive material was produced. This is what powers the brightness of the supernova. Some of this material was left over in the surviving remnant star and acted as fuel to heat the remnant," McCully added. The study has been published in the Astrophysical Journal.
Why is it called a Zombie star?
There are various types of supernovae depending on the size and composition of the star and the power of the blast.
This star is helping scientists better understand what are called "type Iax" supernovae. In these, a white dwarf experiences runaway nuclear fusion of carbon and oxygen after gaining matter relatively quickly, as this one did by stealing from its companion. But the explosion does not destroy the white dwarf, leaving behind an "undead" remnant
"We have called these objects 'zombie stars' for this very reason. They died but not quite. Early on, many of the simulations of supernovae performed by scientists fizzled out before they were able to blow up the whole white dwarf star. It's exciting to think that was telling us something about the actual physics of these supernovas," McCully said.
Can our sun also become a Zombie star?
Our sun is destined to become a white dwarf, the fate of about 97% of stars.
"At the end of a star's life - for stars like our sun or a little bigger - the star runs out of fuel in the core and begins to collapse to a white dwarf. During this process, the outer layers of the star are puffed off into a nebula. The leftover core of the star is the white dwarf," McCully said.
Our sun cannot become a zombie star, however, because it lacks the requisite companion star.