Saoirse Ronan's Irish heritage has figured prominently into her Oscar-nominated role in Brooklyn, about an immigrant's journey stateside (she's up for Best Actress). The actress' own upbringing has made her Irish background a key topic when discussing Ronan on the silver screen and IRL , since Ronan was born in the Bronx, but raised in Ireland from age three onwards. But Ronan's Celtic pride even dictated her Oscars dress selection.“I’m very proud to be Irish!" Ronan said on the red carpet, in explaining how she chose the deep green hue of her spangled, slinky Calvin Klein Collection gown. "I didn’t want to think about what I was wearing to the Oscars before being nominated – I’m very superstitious." The nominations were announced in mid-January, so the label spent a month and a half crafting the custom gown.So, it wasn't just the dress itself that reflected Ronan's background. Even the process nodded to her roots (since believing in a plethora of superstitions is pretty common in Irish culture .) This is Ronan's second Oscar nomination; she was up for Best Supporting Actress for Atonement back in 2008.Perhaps the emerald-hued getup will be the actress' lucky charm (sorry, we couldn't help it) tonight...