Michelle Tractenberg, who starred in “Gossip Girl” and “Harriet the Spy,” was found dead in her luxury Midtown Manhattan apartment early Wednesday, police sources said. Tractenberg, 39, was found unconscious by her mother inside her Columbus Place apartment at 8 a.m. and died a short time later, the sources said.

Michelle Trachtenberg, star of “Buffy the Vampire Slayer” and “Harriet the Spy,” has passed away at age 39, according to the New York Police Department. The cause of death was not immediately disclosed,