Confessions of a Superhero
This bittersweet documentary looks at four would-be movie stars (including the son of actress Sandy Dennis) who eke out their livings dressing up as superheroes and posing with tourists for tips in front of Grauman’s Chinese Theatre on Hollywood Boulevard. Artistic and affecting, it’s as much about the American mania for celebrity as it is about the people profiled. Monday, April 13, at 9 p.m., Sundance Channel

Independent Lens: Taking Root
In 1977, environmentalist and activist Dr. Wangari Maathai started the Green Belt Movement, a grass-roots operation that has planted more than 30 million trees in Kenya to prevent soil erosion. This inspiring documentary about the first African woman to receive the Nobel Peace Prize shows how her organization even helped bring about the downfall of a 24-year-old dictatorship. Tuesday, April 14, at 10 p.m., PBS; check local listings

Planet Forward
CNN’s Frank Sesno and Carol Browner, President Obama’s assistant for energy and climate change, host this “virtual public square” on energy issues, showcasing suggestions submitted via the Web. Among the panelists who will appear before a live audience at George Washington University are alternative-energy entrepreneur Shai Agassi, former Bush environment advisor James Connaughton, and author L. Hunter Lovins. Wednesday, April 15, at 8 p.m.; PBS; check local listings

The Courageous Heart of Irena Sendler
During World War II, the daring Polish Catholic social worker Irena Sendler saved some 2,500 Jewish children from Nazi death camps by smuggling them out of the Warsaw Ghetto. Finally she herself was captured and tortured by the Gestapo. Anna Paquin portrays Sendler in this Hallmark Hall of Fame presentation, which co-stars Marcia Gay Harden and Nathaniel Parker. Sunday, April 19, at 9 p.m., CBS

The Tudors
It’s Christmas 1536, and Henry VIII (Jonathan Rhys Meyers) is on wife No. 3, Jane Seymour—but he’s already found a new mistress, whom he wants Hans Holbein to paint in the nude. He also reacts, with characteristic ruthlessness, to a provincial rebellion against his religious reforms. In its third season, this well-acted and handsomely mounted series continues to deftly mix historical drama with liberal doses of sex. Sunday, April 19, at 9 p.m., Showtime

Other highlights

Doing da Vinci
In a six-part series, contemporary engineers construct Leonardo da Vinci’s inventions from his 500-year-old plans. Monday, April 13, at 10 p.m., Discovery

A new, 13-part series looks at hopeful tinkerers who invent and sell household gadgets. Wednesday, April 15, at 10 p.m., Discovery

Russell Simmons Presents Brave New Voices
This series follows teams of young people vying for a chance to compete in a national poetry slam competition. Sunday, April 19,
at 11 p.m., HBO