Check Out the Nuns Who Charted the Stars

Nuns mapped the night sky at the Vatican Observatory.

On April 26, the assistant to the Vatican Observatory, Jesuit Father Sabino Maffeo, told Catholic News Service that while looking through the observatory archives, he came across the names of four nuns who, back in the 1800s, were part of a global effort to survey the night sky.

Check Out the Nuns Who Charted the Stars[/tweetthis]

Born in the late 1800s, these four Sisters of the Holy Child Mary: Sisters Regina Colombo, Emilia Ponzoni, Luigia Panceri and Concetta Finardi, were from the Northern Lombard region, near Milan. They helped the Vatican catalog and map almost half a million stars for its part of an international “map and catalog” of the stars.

Until now, these four women had been merely a nameless group of nuns appearing in a preserved black and white photograph. In the photo, they are leaning over microscopes and a ledger, wearing ironed habits.

Back in 1887, and then again, in 1889, some of the world’s then top astronomers from all over the globe met in Paris in order to organize the formation of a photographic “Celestial Map” (Carte du Ciel) and an “astrographic” catalog that would pinpoint the positions and locations of the stars.

Pope Leo XIII was effortlessly convinced by Barnabite Father Francesco Denza, an Italian meteorologist and astronomer, to allow the Holy See to participate in the enterprise. The observatories taking part in the project were assigned to photograph, map and catalog a specified area of the sky.

According to Father Maffeo, who was the archivist of the observatory, and an expert in its history, Pope Leo thought of the Vatican’s participation in the initiative as a way of showing the rest of the world that “the church supported science” and was concerned with more than just religion and theology.

Over the next several decades, the Vatican and about 17 other observatories utilized telescopes to take thousands of “glass-plate photographs” and cataloged their data. But, after Father Denza’s death in 1894, the efforts of the Vatican Observatory started suffering.

According to father Maffeo, Pope Pius X discovered that the new observatory director wasn’t performing well on the task, he requested that Archbishop Pietro Maffi of Pisa restructure the observatory and find a good replacement.

In 1906, Father Hagen, known for his research on “variable” stars, was selected by the archbishop. However, he didn’t have experience in the type of work required for the astrographic catalog, so he visited Europe to find out how they did it. While there, he saw that there were women who read star positions and wrote the precise coordinates down in a book.

The astronomers informed the Father that after the young women had been shown how to do it, they’d been very diligent. They were even called “lady computers” at the Royal Observatory in Greenwich because of the level of skill required to calculate the coordinates according to set formula.

Father Hagen contacted the Sisters of the Holy Child Mary, a nearby convent, and in a letter to Mother Angela Ghezzi, the superior general, dated July 13, 1909, to the superior general, Archbishop Maffi said the Vatican Observatory "needed two sisters with normal vision, patience and a predisposition for methodical and mechanical work."

The first two sisters started work in 1910, and soon a third and a fourth joined the team. The Vatican was one of around 10 observatories that completed its assigned “slice of the sky.” From 1910 to 1921, the nuns surveyed the brightness and positions of 481,215 stars off of hundreds of glass plates.

In 1920, the nuns were given a gold chalice and eight years later, they were awarded a silver medal.


Follow the Conversation on Twitter