(Dec. 11) — World, get ready for Viggo Moriah Hanson.

The newest Hanson is child number four for musician Taylor (the 25-year-old middle brother of the pop trio). PEOPLE exclusively reports that Viggo was born on Dec. 9 and tipped the scales at 8 lb., 5 oz. Get the Full Scoop at PEOPLE

Celebrity Baby Boom

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Michael Lockwood and Lisa Marie Presley
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World, meet Henry Story Driver, the son of Minnie Driver and a mystery man the ‘Good Will Hunting’ actress hasn’t named. Minnie slipped a photo of Henry into her MySpace blog at the end of September.

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Mark Wahlberg and Rhea Durham
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‘The Happening’ star and his longtime girlfriend have two other kids together: daughter Ella, 4, and son Michael, 2.

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“Viggo is doing great. He is the perfect early Christmas gift,” the couple tells PEOPLE. “We look forward to being home to enjoy the holidays with him and his very excited brothers and sister.”

Baby Viggo is the latest in a growing Hanson brood. He joins two older brothers (Ezra, 6, and River, 2) as well as his 3-year-old sister Penelope. He also has a handful of cousins thanks to the other Hanson brothers having babies recently (three in total).

Hanson will be back in the studio in 2009, looking to release an album in the summer.