Surnames of Ireland by Dr. Edward Maclysaght gives the following explanation for MacGuckian - Guckian and Hackett
Guckian is found in County Leitrim - Page 139;
Hackett: Haiceid in Gaelic. Families of this name have been in Ireland since the Anglo-Norman invasion, mainly in Counties Kilkenny and Kildare. A Branch in Connacht became completely hibernicized and was known as MacHackett and also as Guckian. In Counties Armagh and Tyrone Hackett has been used as a synonym of MacCahey - 141 Page.