Peninsula Players Theatre, in conjunction with its production of “Silent Sky,” by Lauren Gunderson, will host members of the Door County Astronomical Society as they lead a discussion on “measuring distances in the universe” on Thursday, August 29 at 6:30 p.m. in the theater. “Silent Sky” lead character, Henrietta Swan Leavitt, contributed many discoveries that assisted future astronomers. Tickets to performances are available; admission to the pre-show seminar is free. For more information, call the Peninsula Players Box Office at (920) 868-3287 or visit www.peninsulaplayers.com.
“Silent Sky” tells the story of unsung astronomer Leavitt and her discoveries at the Harvard Observatory in the late 1890s to 1921. Leavitt’s work provided astronomers with the first “standard candle” with which to measure the distance to faraway galaxies. After her death, Edwin Hubble used her luminosity–period relation, together with the galactic spectral shifts first measured by Vesto Slipher at Lowell Observatory, to establish that the universe is expanding.
Leavitt attended Oberlin Conservatory of Music until her hearing problems manifested. She continued her studies in the liberal arts for two years and then transferred to Radcliff where she excelled in mathematics, from algebra to geometry to calculus. In her final year at Radcliff, she became interested in astronomy. She graduated in 1892 at the age of 23.
Qualified Radcliffe astronomy students caught the attention of the Harvard Observatory and were offered unpaid assistantships. Dr. Edward Pickering used them to measure and catalog the brightness of stars as they appeared in the observatory’s photographic plate collection. With her parents support, Leavitt started volunteering as a “human computer” at the Harvard College Observatory in 1895.
Pickering put Leavitt to work on his new project in photometry. Seated at her light lectern, she studied several years’ worth of glass plates and tracked stellar pathways, noting in journals their brightness by assigned numbers. As her hearing faded, her musical training lingered substituting musical notes for a star’s brightness variable.
Leavitt left the observatory between 1896 and 1897 to tour Europe and worked as an art assistant at Beloit College in Wisconsin while balancing nearby family obligations. She was also recovering from an unknown illness that aggravated her hearing problems.
She returned to the observatory in 1903 and began to earn a salary of $10.50 a week, or about 30 cents an hour. Pickering employed about 80 women at the observatory, with a majority earning 25 cents an hour. The women, all well-educated, carried out their time-consuming calculations and data analysis that are now performed by electronic computers.
Upon Leavitt’s return, Pickering assigned her to study variable stars of the Small and Large Magellanic Clouds, as recorded on photographic plates. She identified 1,777 variable stars.
A newspaper article that circulated across the country in 1905 titled “She Saw Stars” stated:
“Miss Henrietta S. Leavitt, the young Radcliffe graduate who has startled the world of science by discovering more than 400 variable stars, according to the Boston Transcript, must be possessed naturally of the gift which enables some girls to find four-leaf clovers.”
Pickering distributed and signed a published work prepared by Leavitt in 1912 on the Magellanic Clouds which included a table of the periods of 25 Cepheid variables. Leavitt was a member of Phi Beta Kappa, the American Association of University Women, the American Astronomical and Astrophysical Society, the American Association for the Advancement of Science, and an honorary member of the American Association of Variable Star Observers. In 1921, when Harlow Shapley took over as director of the observatory, Leavitt was made the head of stellar photometry.
In 1924, a member of the Swedish Academy of Sciences tried to nominate her for the Nobel Prize, only to learn that she had died of cancer three years earlier. Unfortunately for Leavitt, the Nobel Prize is not awarded posthumously.
“Silent Sky” performs through September 1 and is sponsored by Main Street Market.
Peninsula Players Theatre is committed to providing educational programming for the community. The Players has a long history of educational initiatives, including an intern program that dates back to the founding days of the theater in the 1930s. The theater offers backstage tours and post-show discussions as listed in the program and website. Contact the Box Office at (920) 868-3287 for more information on free seminars, tours or to purchase tickets.