Henaughen search

My second great grandfather was born in Ireland in 1827 according to the Scotland census of 1871. His name was John Henaughen, which I've also seen spelled asHanaughan. I'm hitting a wall and am wondering if this might be one of the surnames that had some typical variations like Hanigan. The family migrated to Scotland in one of the waves between 1840 and 1850. I unfortunately have no information as to whether they were from Northern Ireland or the Republic.