BOSTON — A Massachusetts Institute of Technology student with a fake bomb strapped to her chest was arrested at gunpoint today at Logan International Airport, officials said.

Star Simpson, 19, had a computer circuit board, wiring, and a putty that later turned out to be Play-Doh in plain view over a black hooded sweat shirt she was wearing, the commanding officer at the airport, Police Major Scott Pare, said.

Mr. Pare said authorities had not determined a motive. Ms. Simpson was charged with disturbing the peace and possessing a hoax device, and was to be arraigned in East Boston District Court later in the day.

“She’s extremely lucky she followed the instructions or deadly force would have been used,” Mr. Pare said. “And she’s lucky to be in a cell as opposed to the morgue.”

Ms. Simpson is an MIT sophomore from Hawaii, officials said. A spokeswoman for MIT had no immediate comment.

She was arrested about 8 a.m. outside Terminal C, home to United Airlines, Jet Blue, and other carriers.

A Massachusetts Port Authority staffer manning an information booth in the terminal became suspicious when Ms. Simpson — wearing the device — approached to ask about an incoming flight, Mr. Pare said. Ms. Simpson then walked outside, and the information booth attendant notified a nearby trooper.

The trooper, joined by others with submachine guns, confronted her at a traffic island in front of the terminal.

Mr. Pare said Ms. Simpson took a subway to the airport, but he was not sure if she had the device on at that time.

“She was allegedly picking somebody up,” Mr. Pare said.

The major praised the booth attendant but said the incident is a reminder of the terrorism threat confronting the civil aviation system. Two of the four passenger jets hijacked on September 11, 2001, took off from Logan.

“In this day and age, the threat continues to be there,” Mr. Pare said. “She certainly jeopardized her own safety by bringing this to the airport, as well as the safety of everybody around her.”