Astronomers have identified a white dwarf star as being over 10 billion years old.
Britain's University of Warwick led a study which looked at two unusual white dwarf stars.
Abbigail Elms is the lead author - she says one star had remnants of a planetary system around it:
"We can basically just see by studying these really cool and old white dwarfs what the chemical composition of the galaxy was in the past".
