The mystery of the name given by Nicole Kidman and Keith Urban to their baby girl has been solved. Sunday Rose, as the newborn has been poetically named, is in celebration of an early 20th-century artist’s muse and of the father’s late grandmother.

It was Dr. Antony Kidman, father of actress Nicole Kidman, who revealed what the significance behind his newborn granddaughter’s name is.

Speaking to Sydney’s Daily Telegraph, Kidman said it was he that came up with the idea of naming the baby Sunday, inspired by Australian artist Sidney Nolan’s muse Sunday Reed.

Kidman explained that the name “struck me as being a nice name for a woman, so my wife and I mentioned it.”

Spouses and arts patrons John and Sunday Reed were well known in Australia’s art scene during the early 20th century and became notorious for their three-way triangle with painter Sidney Nolan in the 1930s.

Kidman described Sunday Reed as a “key mover and shaker in the arts.”

He explained that the expecting parents had been considering several names and were ultimately smitten with Sunday.

The second part of the baby’s name is a nod to Keith Urban’s late grandmother Rose, adds People.com.

The Daily Telegraph also reported that Nicole Kidman and Keith Urban visited an exhibition by Sidney Nolan earlier this year during a trip to Sydney and were impressed with the artwork.

Among works exhibited was a quote about birth, saying, “When you are young you are given a good view of life, because of your closeness to birth.”

The couple, who celebrated two years of marriage last month, welcomed their baby girl Monday morning in Nashville, where they reside far from the prying eye of the media. The baby weighed 6 lbs., 7.5 oz, Kidman’s publicist told People.

Sunday is the actress’s first, and much yearned after, biological child. She has two teenage children Isabella, 15, and Connor, 12, adopted during her 10-year marriage to Hollywood superstar Tom Cruise.