Confidence: I'm as sure as I can be.
Notes: I hope there is enough of the underside of the hindwing visible here to determine this as CU and not Svensson's CU. The copper colouration on the outer area of the hindwing stops at the dark crossband on CU but continues further down the trailing edge of the hindwing on Svensson's. Tricky to hold the moth gently and show the correct feature- my thumb may be obscuring too much hindwing. Svensson's hasnt been recorded in Ireland yet but this may be due to difficulty in checking enough Copper Underwings to find it?