Johnny Galecki, best known for his role as Leonard from the now discontinued comedy series The Big Bang Theory , has become a father for the first time. The actor and his girlfriend Alaina Meyer have not yet shared their son's name.

"With a full and grateful heart we welcome our beautiful son to this wonderful world," Galecki writes with a photo showing the hands of his son. "Thanks for all the love and support."

The 44-year-old actor and his 21-year-old girlfriend announced in early May that they are expecting a child. During a so-called 'gender reveal party', a party that is particularly popular in America, where prospective parents announce the gender of kun baby, they announced that they would expect a son.

Galecki and his colleagues said goodbye to The Big Bang Theory earlier this year . The series came to an end in May after twelve seasons.