When we left Mina, she had just been hired to be a human “computer” at the Harvard Observatory.
Some years before Mina’s exploration into the field of astronomy, Henry Draper directed an expedition to photograph the 1874 transit of Venus, and was the first to photograph the Orion Nebula, and the spectrum of Jupiter in 1880.
After Draper’s death in 1882, his widow funded the Henry Draper Medal for outstanding contributions to astrophysics. The Harvard Observatory used these funds to prepare the Henry Draper Catalog of stellar spectra, which are the pattern of lines caused by the dispersion of a star’s light through a prism placed before a telescope lens. This project would define Mina career.
It is left to question whether Mina assisted Pickering in developing a new system to catalogue the plates so they would be easily accessible and the data readily available, or if she developed the system herself as many sources state.1
This classification system, known as the Pickering-Fleming system, divided the stars into classes based on complexity of the spectrum lines. Using the system, Mina classified the tens of thousands of celestial photographs taken for the Draper Memorial.
While Mina was busy at her cataloging work, she discovered 79 stars, 10 novae, 59 gaseous nebulae, 9r Wolf-Rayet stars, and 222 long-period variables. She is also noted for her discovery of the Horsehead Nebula, a dark nebula in the constellation Orion, which is 1500 light years from us. I cannot even think in those distances.
“In 1910 Fleming published her discovery of “white dwarfs” –hot, dense compact stars, usually white or bluish in color, which are in what is believed to be their final evolutionary stage.”2
In the next blog, we will see more of Mina’s accomplishments in the field of astronomy.
1http://en.wikipedia.org/wiki/Williamina_Fleming (accessed January 6, 2015), http://www.womanastronomer.com/wfleming.htm (accessed January 6, 2015)
2Phyllis J. Read, Bernard L. Witlieb. The Book of Women’s Firsts: Breakthrough Achievements of Almost 1,000 American Women. (New York: Random House, 1992), 159