Astronomers are looking for the bones of dead planets inside the corpses of dead stars — and they may have just found some.
In a paper published Feb. 11 in the journal Nature Astronomy, a team of researchers described how they used data from the Gaia space satellite to peer into the atmospheres of four white dwarfs — the shriveled, crystalline husks of once-massive stars that burned through all their fuel. Swirling among the hot soup of hydrogen and helium surrounding those stars, the team detected clear traces of lithium, sodium and potassium — metals that are abundant in planetary crusts — in the precise ratio that they’d expect to find inside a rocky planet.
“Comparing all these elements together against different types of planetary material in the solar system, we found that the composition was distinctly different from all but one type of material: continental crust,” lead study author Mark Hollands, an astrophysicist at the University of Warwick in England, told Live Science in an email.
According to Hollands and his colleagues, the presence of these crusty metals suggests that each of the old, faded stars they analyzed may have once sat at the center of a solar system not so different from ours; then, in their dying eons, those stars ripped their solar systems to shreds and gobbled up the remains.