Essay Sample about Harvard “Computers” and their Categorizations
The earliest categorization of stars was established in the 1860s by Italian astronomer Angelo Secchi. He was able to discover four spectral star types. 20 years later, women working at the Harvard College Observatory were able to distinguish a more thorough system. Among these women were Williamina Fleming and Annie Jump Cannon.
Williamina Fleming was a teacher turned maid turned astronomer. She was hired by Professor Edward Charles Pickering to do housekeeping; Pickering became irritated with his Harvard collaborators and hired Fleming to do organizational work at the observatory. During this time, Fleming was able to create a structural system for stars according to the amount of hydrogen in their spectra. It was arranged alphabetically, with stars labeled “A” having the most hydrogen and stars labeled “Q” having the least.
Though Fleming’s system was groundbreaking, it was a bit convoluted. Annie Jump Cannon, after joining Pickering’s workforce of computationalists, resolved to create a simpler system of stellar classification. This stellar classification was established on the star's surface temperature. The star types were arranged from hottest to coolest, using the sequence “O, B, A, F, G, K, M.” A mnemonic that Cannon created in order to remember this order is “Oh Be A Fine Girl/Guy, Kiss Me.”
Class O stars usually have surface temperatures of 25,000-50,000 K; the stars are usually bluish white in color. Class B stars are usually 10,000 K-25,000 K; their coloring is also bluish white. The white class A stars are 7,400 K-10,000 K– in these stars, hydrogen is the most prominent. Yellow stars are class F, and are 6,000-7,400 K. An example of a class G star is the sun– vibrant yellow, and has a surface temperature of 5,000-6,000 K. Class K stars vary from yellow to orange, and are about 3,500-5,000 K, heat-wise. Class M stars are the darkest, looking red, and are about 3,000 K in surface temperature. To this day, Cannon’s classification is still influential, though current classification includes divisions, subdivisions, and is a combination of both Cannon’s and MK’s systems.
Transcribing the plates that astronomers like Cannon and Flemings wrote seemed like a daunting task. Indeed, it was difficult to distinguish between calculations, plate numbers, and observations. Additionally, some pages seemed to have multiple different plate numbers, while others had no plate numbers at all. Some pages had plate numbers scribbled out, while others left out the letters of the plate numbers. However, after going through pages after pages of these transcripted notes, one’s interest could only be piqued. Multiple times, I found myself not only looking for the plates, but also reading through the coordinates, and the little notes about stars. The effort that those women put into taking thorough measurements and calculations was inspiring. Though inputting plate numbers became tedious at times, it also allowed me to get a glimpse of those women’s everyday lives as “computers”, as multiple websites call them. They were able to compute and classify stars daily, in a consistent manner. I couldn’t help but wonder how they’d been able to be organized enough to create a whole classification system for something so vast as the stars in the sky.
A pencil, notepad, and a good eye for examining– these three tools were utilized by “computers” like Annie Jump Cannon and Williamina P. Fleming in order to create a star classification. Today, we use transcriptions, scanned notebooks, and our computers in order to read their contributions–contributions that continue to be valuable, as they are still used to this day.
