The woman stabbed to death Monday in her Germantown apartment was a retired astronomy and astrophysics professor at Villanova University.

Carol Ambruster, 69, was found about 9 p.m. Monday with stab wounds to her neck and chest in the blood-spattered kitchen of her second-floor apartment at Wayne Avenue and School House Lane. Medics declared her dead at the scene. Police recovered the knife used to kill her at the scene.

Police have questioned her male roommate, who found her, but say they have no motive nor suspects yet. Investigators said the apartment's door did not appear to be forced open. Detectives aim to scour surveillance footage from the building for clues, police said.

Ambruster was an assistant astronomy and astrophysics professor at Villanova from 1987 until 2011, when she retired, Villanova spokesman Jonathan Gust said. Her expertise was cool stars, dwarf stars, archaeoastronomy and flare stars, according to a university web page.

"The university was saddened to learn of the death of Carol Ambruster, and our thoughts and prayers go out to her family and friends," Gust said.

Tipsters can call homicide detectives at (215) 686-3334 or -3335.