... Tonight's Sky . ... Star Atlas . ... stars . ... A galactic fossil . ... An international team of astronomers led by Dr. Anna Frebel of The University of Texas at Austin McDonald Observatory recently measured the age of an ancient star in our Milky Way galaxy at an extraordinary 13.2 billion years. ... Astronomers can only accurately measure the ages of very rare old stars that contain huge amounts of certain types of chemical elements, including radioactive elements like thorium and uranium. ...