Actor Jackson Rathbone (R) signs autographs as several cast members visit fans camping out for the premiere of "The Twilight Saga: Breaking Dawn Part - 1" in Los Angeles, California November 13, 2011. (Reuters/Jason Redmond)

Jackson Rathbone is a first-time father after his girlfriend Sheila Hafsadi gave birth to a son on Thursday .

The Twilight hunk is now proud dad to little Monroe Jackson Rathbone VI, who weighed in at eight pounds, 11 ounces (3.9 kilograms).

Taking to Twitter.com to share his baby news, he writes, "Thank you ALL for the love & support! Sheila & I couldn't be happier to have such a beautiful, healthy baby boy, Monroe Jackson Rathbone VI.

"Feeling so blessed! What an amazing day! Love and respect, Bone Daddy."

Rathbone previously admitted he was ecstatic about the prospect of becoming a father, and had turned to his own parents for advice.

He said, "I'm going to be a dad! It's kind of the greatest, most exciting thing that's ever happened to me in my life, so I'm very excited.

"I've got amazing parents to learn from. I've been on the phone with them every day since (we got the pregnancy news)."