What will happen to the Solar System after our star’s death?
New discovery helps to understand the fate of our planetary system after the death of the star responsible for life on Earth.
If it were not for the sun, there would be no life on earth. But eventually stars like him run out of fuel, expanding until they collapse into tiny celestial bodies called white dwarfs.
So, what will happen to the Earth and other planets of our Solar System when the Sun dies? Christopher Manser, a postdoctoral researcher in Astrophysics at the University of Warwick in the UK, made some predictions based on recent findings.
The researcher and his team have developed a novel approach to probing gas around white dwarfs. The technique, called spectroscopy, identified a planetary fragment orbiting the white dwarf SDSSJ122859.93 + 104032.9, about 410 light-years away, using the Gran Telescopio Canarias – the largest and most advanced telescope in the world.
The discovery surprised astronomers, who did not believe that anything could survive so close to a white dwarf. It is only the size of the Earth but contains about 60-70% of the mass of the Sun, which makes it incredibly dense. If a body orbits too close to a white dwarf, immense gravity will destroy it, forming a disk of gas and debris around it.
How, then, did the fragment identified by astronomers survive without being torn apart? They calculated that the body should be very dense or have a significant internal strength to keep it whole.
According to the researchers, the fragment probably had a maximum diameter of 720 kilometers, which is the size of a small smaller planet – the dwarf planet Ceres, for example, is 946 kilometers in diameter.
The origin of the celestial body remains a mystery. One possibility is that it is the nucleus of a smaller planet that was pushed close to the white dwarf by a more massive, more distant planet. As the minor planet passed near the white dwarf, its layers of crust and mantle would have been torn.
Such discoveries can help researchers understand the future of our own planetary system. In about 5 billion years, the Sun will eventually begin to expand, encompassing Mercury, Venus and probably Earth – unless we can move our planet to a broader orbit, which in theory should be possible.
However, Mars, the asteroid belt and the rest of the Solar System will survive and continue to orbit as the Sun collapses into a white dwarf. During this process, planets like Jupiter could also spread asteroids, comets, or even smaller planets to the white dwarf, where they would eventually break.
It is unlikely that any living organism in planetary or lunar fragments can survive this process. And even if they could survive, they would fight to live in the dim light of a white dwarf.
For the next step, the researchers want to test whether the dust and gas disks around six white dwarfs are proof of the presence of smaller planets. The more worlds are found, the more one learns about the fate of planetary systems when their main stars die.
The technique developed by astronomers can also help to find out more about the composition of the exoplanets. Although the atmosphere of a standard white dwarf is pure, it becomes polluted while the white dwarf consumes planetary material, which allows researchers to calculate the amount of each element present.