Margherita Hack, an astrophysicist who explained her research on the stars in plain language for the public and who championed civil rights in her native Italy, has died. She was 91.

President Giorgio Napolitano's condolence message hailed her as a "high-level personality" in the scientific world and praised her "civil passion." The Italian news agency ANSA quoted family friend Marinella Chirico as saying Hack died in a hospital in Trieste after being treated for heart problems.

Hack long headed an astronomical observatory in Trieste and was a popular commentator in Italian media about discoveries in astronomy and physics. An atheist who decried Vatican influence on Italian politicians, Hack helped fight a successful battle to legalize abortion. She unsuccessfully lobbied for legalized euthanasia and also championed gay rights and animal protection.