By Adam Easton
BBC News, Warsaw
Researchers in Poland say they have solved a centuries-old mystery and identified the remains of astronomer Nicolaus Copernicus.
A comparison of DNA from a skeleton in Poland and strands of the astronomer's hair found in a book in Sweden almost certainly confirm it is his skeleton.
Archaeologists found the skeleton in north-eastern Poland three years ago in a cathedral where Copernicus lived.
He worked in Frombork Cathedral on the Baltic Sea coast in the 16th Century.
Copernicus was one of the key proponents of the idea that the Earth orbits the Sun.
For many years he was a canon and only carried out his astronomical studies in his spare time. People had speculated about his final resting place for centuries.
Three years ago, archaeologists dug up a skull and partial remains of a man aged about 70, Copernicus' age when he died, near an altar at the cathedral.
Jerzy Gassowski, the leader of the archaeologists' team, said forensic facial reconstruction of the skull found that it bore a striking resemblance to existing portraits of the father of modern astronomy.
Scientists then matched the DNA from one of the skull's teeth and a femur bone with two strands of Copernicus' hair.
The hair was found in a book once owned by the astronomer now kept in Sweden's Uppsala University.