Zytkow (Polish pronunciation: ['an?a '??tk?f], born 21 February 1947) is a Polish astrophysicist working at the Institute of Astronomy of the University of Cambridge.
Zytkow and Kip Thorne proposed a model for what is called the Thorne–Zytkow object, which is a star within another star.
Zytkow in 2014 was part of the team led by Emily M.
Levesque which discovered the first candidate for such an object.