Task: Question Answering
Input (English): Context : Iota Horologii b (ι Hor b / ι Horologii b), often catalogued HR 810 b, is an extrasolar planet approximately 56 light-years away in the constellation of Horologium (the Pendulum Clock). 
Question : Of which constellation is Iota Horologii b a part?
Output (English): Horologium