Astronomers have sifted through data acquired by NASA's Hubble Space Telescope and have honed in on one star called G238-44.
A team of astronomers looked through Hubble data, along with other observations from various NASA telescopes, and studied the white dwarf star G238-44. The analysis researchers found evidence of a water reservoir after they scanned the elemental properties of the white dwarf star. This led the team to believe that the star must be siphoning debris from nearby objects.
For those that don't know, a white dwarf star is a star that was once like our sun, but it has exhausted all of its nuclear energy. The closest white dwarf star to our sun is Sirius B, located approximately 8.6 light years away. As for G238-44, the astronomers believe that the corpse star is siphoning material from a nearby asteroid belt as well as icy celestial bodies, which leads the researchers to suggest that water may be more common in distant planetary systems than initially anticipated.
Planetary system G238-44.
NASA writes that this research is particularly important as it's a great example of the chaotic nature and planetary process systems go through. The space agency points out the evolution of this particular system, with G238-44 being a red giant star, transitioning to a white dwarf star where it loses its outer layers and impacts the orbit of all smaller objects. Some of these small objects' orbits are changed drastically, where they then can collide into.
"After the red giant phase, the white dwarf star that remains is compact - no larger than Earth. The wayward planets end up getting very close to the star and experience powerful tidal forces that tear them apart, creating a gaseous and dusty disk that eventually falls onto the white dwarf's surface,"Ted Johnson, the lead researcher and recent University of California, Los Angeles (UCLA) bachelor's graduate.
Notably, NASA states that G238-44 hasn't consumed a large amount of mass, with the researchers estimating that the dead star has eaten mass proportionate to an asteroid or a small moon. Additionally, the researchers were able to detect what type of objects the star has consumed - one is likely a metal-rich asteroid, and the other is an icy body, such as a comet.
"The team measured the presence of nitrogen, oxygen, magnesium, silicon and iron, among other elements. The detection of iron in a very high abundance is evidence for metallic cores of terrestrial planets, like Earth, Venus, Mars and Mercury. Unexpectedly high nitrogen abundances led them to conclude the presence of icy bodies," wrote NASA.
"The best fit for our data was a nearly two-to-one mix of Mercury-like material and comet-like material, which is made up of ice and dust. Iron metal and nitrogen ice each suggest wildly different conditions of planetary formation. There is no known solar system object with so much of both," said Johnson explained.