A white dwarf provides insights into the systemic chaos that occurs when a star dies
Violent dying convulsions of a nearby star have caused such a severe disruption in its planetary system as the dead star left behind – known as a white dwarf – draws in fragments from both the inner and outer range of the system, astronomers and colleagues from UCLA report.
This is the first case of cosmic cannibalism in which astronomers observed a white dwarf star devouring both rocky-metallic material, probably from a nearby asteroid, and ice material, probably from bodies similar to bodies in the Kuiper belt at the edge of our solar system.
“We’ve never seen objects of these two types coalesce into a white dwarf at the same time,” said lead researcher Ted Johnson of UCLA. “We hope the study of these white dwarfs will help us better understand planetary systems that are still intact.”
The conclusions are based on an examination of materials captured by the atmosphere of G238-44, a white dwarf that is about 86 light-years from Earth, using archival data from the Hubble Space Telescope and other NASA satellites and observatories. Ours sheds its outer layers and stops burning fuel through nuclear fusion.
As surprising as the white dwarf’s diet may be, the findings are also intriguing because astronomers believe that ice objects crashed into dry, rocky planets in our solar system and launched them – including Earth. It is estimated that billions of years ago, comets and asteroids brought water to our planet, and evoked the conditions necessary for life. The composition of the material rainfall falling on G238-44 suggests that ice reservoirs may be common in planetary systems, said co-author of the study Benjamin Zackerman, professor of physics and astronomy at UCLA.
“Life as we know it requires a rocky planet covered in a variety of volatile elements like carbon, nitrogen and oxygen,” Zackerman said. “It seems that the abundance of elements we see in this white dwarf came from a rocky parent body and also from a volatile parent body – the first example we found from hundreds of studies of white dwarfs.”
Theories of the evolution of planetary systems describe the death of a star as a turbulent and chaotic event, which begins by first inflating very much into what is called a red giant and then rapidly losing its outer layers and collapsing into a white dwarf – a very dense star about the size of the Earth. our. The process dramatically disrupts the orbits of the remaining planets, and smaller objects – asteroids, comets, moons – that are too close can disperse like billiard balls and move powerfully toward the white dwarf.
This study confirms the true magnitude of chaos, and shows that 100 million years after the beginning of its white dwarf phase, the star can simultaneously capture and consume material from its nearest asteroid belt and distant Kuiper belt-like regions.
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