Actor James Darren, known for his roles in Gidget, T.J. Hooker, and Star Trek: Deep Space Nine, has died at 88.

TMZ reports he passed away in his sleep at Cedars-Sinai Hospital in Los Angeles on Monday.

His cause of death is unknown, but his son, Jim Moret, stated Darren had heart issues and was undergoing treatment for aortic valve replacement before being deemed too weak for the procedure.

Darren gained fame as the teen idol Moondoggie in Gidget and appeared in its sequels.

He also had a recurring role in T.J. Hooker, and enjoyed a career as a singer and director on shows like Melrose Place and Beverly Hills, 90210. Rest in peace, James Darren.