Seventh- and eighth-grade students who need academic support have a new after-school program at the Chapman Middle School. The Chapman Campus Stars is funded by a $504,000 grant, spread over three years, from the state’s 21st Century Community Learning Centers initiative, according to a press release. Forty students will stay after school Mondays through Thursdays until 5:30 p.m. to get extra help. There also will be a six-week summer program, the release said. The program started in mid-March. It is run by Stars, a Weymouth-based, child development nonprofit, and is modeled after a similar program in the Randolph schools, according to Stars spokeswoman Jennifer Logue.