The globular cluster M5 (NGC 5904) in Serpens will be well placed, high in the sky. It will reach its highest point in the sky at around midnight local time.
From Armagh, it will be visible all night. It will become visible around 23:20 (BST) as the dusk sky fades. It will then reach its highest point in the sky at 01:28. It will be lost to dawn twilight around 03:20.