WASHINGTON (AP).- Andy Warhol is known for soup cans and celebrity images, not so much for painting headlines and abstract works. The late pop artist has left much to be discovered in two shows that open Sunday on the National Mall. The National Gallery of Art is opening its first Warhol exhibit with “Warhol: Headlines,” an examination of his use of news headlines throughout his career. At the same time, the Smithsonian’s Hirshhorn Museum will feature “Andy Warhol: Shadows,” a 450-foot-long installation in the round museum that marks the first time all of Warhol’s 102 abstract “shadow” paintings will be shown together as the artist intended. “This might surprise people,” said Hirshhorn curator Evelyn Hankins. “They get two very different sides of Warhol.” Besides his obsession with celebrities and iconic images, it turns out Warhol was a news junkie. At a time when nearly everyone on the New York City subway had a newspaper in hand, Warhol was watching, fascinated by the consump