Not the " oldest-known white dwarf star", but as mentioned later "almost three times older than any other white dwarf known to have a dusty disk around it."
White dwarfs without a ring can be much older.
Gliese 223.2 is only 21 light years away ad is nearly 8 billion years old. The oldest known white dwarfs are around 12 billion years old.
Biting the hand that feeds IT
