Hong Taiji died suddenly in September 1643 without a designated heir. As the Jurchens had traditionally "elected" their leader through a council of nobles, the Qing state did not have in place a clear succession system until the reign of the Kangxi Emperor. The leading contenders for power at this time were Hong Taiji's oldest son Hooge and Hong Taiji' half brother Dorgon. A compromise candidate in the person of Hong Taiji's five-year-old son, Fulin, was installed as the Shunzhi Emperor, with Dorgon as regent and de facto leader of the Manchu nation.

Answer this question, if possible (if impossible, reply "unanswerable"): When did Hong Taiji die?
September 1643