“The stars are like music,” says Henrietta Leavitt in “Silent Sky,” the lyrical play in which writer Lauren Gunderson shows us Leavitt was right.

Leavitt was an actual astronomer a century ago. Like the trailblazing female mathematicians in the movie “Hidden Figures,” she was referred to as a “computer” and she was a lot more important than that sounds. Leavitt is at the center of this fictionalized drama, in which she moves from rural Wisconsin to Harvard to help map the solar system despite coming from a background in which her sister insists, “There are women these days and they wear pants and they are ridiculous.”

Henrietta (warm, witty Victoria Pyan) does not wear pants in “Silent Sky” but she asserts herself in Cambridge. Despite being told she can’t touch the telescope because she’s not a man, she works obsessively to chart the universe while falling, almost by accident, into a romcom-y relationship with less-gifted colleague Peter Shaw (Carl Swanson). The flirtation sometimes feels like a distraction from the real work of “Silent Sky” (and of Leavitt) but, as charmingly played by Pyan and Swanson, their halting intimacy grounds the science in humanity. As Shaw says, “You have been the brightest object in my day since we met. And we work with stars!”

The idea that all of us are made of stars is not a new one, of course, but Theatre Pro Rata gives that idea extra oomph by staging “Silent Sky” (the title comes from Walt Whitman) in the planetarium at the Bell Museum. Director Carin Bratlie Wethern and her nimble cast adjust smartly to the timing and spatial requirements of a venue that has no backstage or exits, work that pays off handsomely.

Gunderson’s ironic humor doesn’t always feel like a fit for the period but her play gains grandeur by taking place entirely in the planetarium. The overhead dome sometimes works as a backdrop, filled with projections that establish where we are, and sometimes reveals the starry sky where Leavitt does her research.

It feels special to experience a play in the sort of space usually devoted to the Big Dipper or a Pink Floyd laser light show. The cast is always worth watching but there’s something about putting your head back and gazing up at the stars that lends “Silent Sky” a majesty that Gunderson’s script doesn’t always have.

The playwright nails it in Leavitt’s final monologue, though, an argument for the import and beauty of her work that she delivers while two of her fellow female “computers” stand by. Reflective threads in all three of their costumes (created by Samantha Kuhn Staneart) glitter under a celestial canopy, reminding us that these starry-eyed women were able to see things the rest of the world couldn’t even imagine.