Final answer:
The union described in the question refers to a 'marriage' within the context of Nathaniel Hawthorne's short story 'The Birthmark,' which delves into the consequences of the husband's obsession with his wife's imperfection.
Step-by-step explanation:
The phrase 'Such a union accordingly took place, and was attended with truly remarkable consequences and a deeply impressive moral' is referring to a marriage that has significant and profound outcomes. From the context provided, where Aylmer gazes at his wife and the subsequent description of Georgiana's birthmark and its effects, it is clear that the text is discussing the complexities and consequences of their marital union.
The excerpts cited are from Nathaniel Hawthorne's short story 'The Birthmark,' which explores themes of obsession, imperfection, and the pursuit of scientific knowledge, all within the context of a husband's fixations on his wife's physical flaw and its ultimate removal with tragic results.