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Noctua fimbriata
Backyard
Your suggestion is 100% right. I did see the hindwings and it matches N. fimbriata plus N. tirrenica is not found in Denmark. So thanks a lot.
Noctua sp., and looking at the range, most probably N. fimbriata. N. tirrenica is a similar species only differentiated in 1983, and is only distinguishable by the hindwings. As of now, N. tirrenica is only believed to be found in the Mediterranean and southern France, but that might change, so it may be best to keep this as Noctua sp., or Noctua fimbriata/tirrenica, however that may cause confusion that they are synonyms.