Astronomers find fragments of Earth-like planets

Scientists from the University of Warwick in the UK have discovered fragments of ancient planets around two unusual white dwarfs, including an Earth-like world that has existed for almost 10 billion years back. Scientific work this discovery was published in the journal Monthly Notices of the Royal Astronomical Society.

When most stars, including our Sun, run out of hydrogen to burn, they turn red. giants, and then eventually shed their outer layers and leave behind a dense core known as white dwarf. Any planets that might have orbited the original star would have had a hard time surviving this process, so usually their remnants fall to the surface of the celestial body and "contaminate" it.

In a new study, astronomers from the UK examined data on two strange white dwarfs, including one unusually blue and one dimmer and redder than most known. Analysis of the light from these stars can reveal how old they are and what elements are burning up in their atmospheres, which helps reveal the composition and type of planets in the system.

After analyzing all the data from these objects, the scientists found that the blue-white dwarf known as WD J1922+0233, formed about 9 billion years ago, which means that its planets existed and faced the apocalypse even earlier. And their fragments had a composition similar to the continental crust of the Earth.

A redder white dwarf known as WDJ2147-4035 is only 90 light-years away, about 10.7 billion years old, and became a white dwarf about 10.2 billion years ago. His light analysis revealed a strange mixture of elements from the planet's debris, including sodium, lithium and potassium. It is also the coldest white dwarf ever discovered, with a surface temperature of just 2777°C.

Scientists also notethat it is the oldest known planetary system around a white dwarf in our galaxy. For comparison, both of these white dwarfs are more than twice the age of our solar system (about 4.57 billion years).