When white dwarfs go berserk, their planets endure the ensuing mayhem. After consuming planetary and cometary debris, the evidence appears in and around the dying star's atmosphere much later.
This is the conclusion reached by a team of UCLA
astronomers after conducting a comprehensive analysis of the neighbouring white
dwarf G238-44. They discovered a case of cosmic cannibalism at this fading star
86 light-years away from Earth.
If this star were in the position of the Sun, it would
consume the Kuiper Belt's planets, asteroids, and comets. Meaning all the
planets from Mercury to Neptune would have been consumed by this star. This cannibalism crime is one of the most
common in history due to the extensive smorgasbord.
“We have never seen both of these kinds of objects
accreting onto a white dwarf at the same time,” said lead researcher Ted
Johnson, a physics and astronomy graduate of UCLA. “By studying these white
dwarfs, we hope to gain a better understanding of planetary systems that are
still intact.”
Johnson was a member of a team from UCLA, UC San
Diego, and the University of Kiel in Germany that studied chemical components
identified in the atmosphere of white dwarfs. NASA's defunct Far Ultraviolet
Spectroscopic Explorer, the Keck Observatory's High-Resolution Echelle
Spectrometer in Hawaii, and the Hubble Space Telescope's Cosmic Origins
Spectrograph and Space Telescope Imaging Spectrograph were utilized to collect
data. The researchers discovered and measured the existence of several
elements, including nitrogen, oxygen, magnesium, silicon, and iron.
Iron is especially intriguing since it forms the cores
of rocky planets such as Earth and Mars. Its existence indicates that planets
of a terrestrial composition originally orbited G238-44. High levels of
nitrogen indicate that the system also had a pool of ice corpses.
As stars like the Sun reach extreme old age, they
leave behind white dwarfs, which are their charred cores. Over billions of
years, these stellar remnants gradually cool down. However, before this moment,
the real dying throes may be rather violent and nasty. They then consume the
planets around them. The finding of "remnants" of these planets,
comets, and asteroids in the atmosphere of G238-44 is alarming for the future
of our solar system.
Reference: NASA
0 Comments