Michelle Trachtenberg, an actress who starred in “Gossip Girl” and “Harriet the Spy,” was found dead in her luxury Midtown Manhattan apartment early Wednesday, police sources said. Trachtenberg, 39, was found unresponsive by her mother in her apartment near Columbus Circle at 8 a.m.

Police officers, responding to a 911 call, found her unresponsive in a Manhattan apartment on Wednesday morning, the authorities said.

Michelle Trachtenberg was found in her New York City apartment, and the death is not believed to be suspicious, police said.