It's the end of the world, not as we know it.
Scientists from the University of Warwick and other universities have studied the impact that white dwarfs – the final stars in their burnt-out state – have on planetary systems such as our own solar system.
As asteroids, moons, and planets approach white dwarfs, their massive gravity tears these tiny planetary bodies into smaller and smaller pieces and continues to collide, eventually grinding them into dust.
Although researchers say that Earth may be swallowed up before it becomes a white dwarf, other parts of our solar system, including the asteroids between Mars and Jupiter and Jupiter's moons, could eventually be ripped apart. Sun in the form of a white star.
Dr Amornrat Angwerojvit from Naresuan University in Thailand, who led the study, said: Previous research has shown that as asteroids, moons and planets approach white dwarfs, the immense gravity of these stars can tear them into smaller and smaller pieces. .”
Collisions between these fragments eventually grind them into dust that eventually falls into the white dwarf, helping researchers determine what kind of material the original planetary bodies were made of.
Professor Boris Cansike, from the University of Warwick's Department of Physics, said: “The simple fact that we can detect asteroids, possibly moons or planetary debris, orbiting a white dwarf every hour is very mind-blowing. But our research shows that the behavior of these systems can evolve rapidly over a few years.
„While we think we are on the right track in our study, the fate of these systems is more complex than we imagined.”
For the new research, scientists studied changes in the stars' brightness over 17 years to shed light on how these bodies are disrupted. They focused on three different white dwarfs, all of which behaved very differently.
The first white dwarf studied — known as ZTF J0328-1219 — appeared stable and „well-behaved” over the past few years, but the authors found evidence of a major cataclysmic event in 2010.
Another star – ZTF J0923+4236 – appears to dim irregularly every two months, and these dim states show a disturbing variation on time scales of minutes.
A third white dwarf analyzed – WD 1145+017 – behaved closer to theoretical predictions by the Massachusetts Institute of Technology (MIT) in 2015, with wide variations in numbers, shapes and transit depths. Astonishingly in this latest study, traffic has now completely disappeared.
„Overall, the system brightens very slowly as the dust formed by the cataclysmic collisions in 2015 dissipates,” Cansike said. „The unpredictability of these transits can drive astronomers crazy – one minute they're there, the next minute they're gone. And this points to the chaotic environment they exist in.
When asked about the fate of our own solar system, Kensike said: “The sad news is that Earth will be swallowed up by the expanding sun before it becomes a white dwarf.
„For other parts of the Solar System, some asteroids located between Mars and Jupiter, and some of Jupiter's moons, may migrate and undergo the fragmentation process we investigated, eventually moving closer to the white dwarf.”
The study is published in the journal Monthly Notices of the Royal Astronomical Society (MNRAS).