Muriel E. Mussells Seyfert

Muriel E. Mussells Seyfert (1909-1997) was an American astronomer whose accomplished career focused on identifying and classifying galaxies as well as nebulae within the Milky Way. She attended Radcliffe College for her undergraduate degree, graduating in 1931. Mussells Seyfert worked at the Harvard College Observatory from 1927-1936¹.

While working as a Computer at Harvard, Mussels Seyfert was credited with the discovery of three new planetary nebulae in the Milky Way in 1936². She also worked closely with Harlow Shapley and Carl Keenan Seyfert to search for and identify new galaxies³. This analysis involved determining the apparent photographic magnitude, position, and classification for each galaxy, which would often number over 1,000 and sometimes as much as 3,000 on a single 14x17 inch plate. Her work contributed to the understanding of the density and distribution of galaxies in space⁴. Over the course of her career she would identify over 100,000 galaxies, being uniquely skilled at identifying faint galaxies that were difficult to detect⁵. 

She was born Muriel Elizabeth Mussells in Danvers, Massachusetts to George Albert Mussells and Stella Frances Gifford. Her sister, Sylvia Mussells Lindsay, also worked at the Harvard College Observatory. In 1935, Mussells Seyfert married fellow astronomer, Carl Keenan Seyfert. He became the founding director of the Vanderbilt Dyer Observatory in 1946. At Dyer, she continued her astronomical research and pursued fine arts painting⁶. They had two children. She passed away at age 88 on November 9th, 1997 in Hall, Georgia.

Written by Lisa Bravata, 2025

Footnotes

¹Zrull. “Women in Glass: Women at the Harvard Observatory during the Era of Astronomical Glass Plate Photography, 1875–1975.” 137.

² “Three New Planetary Nebulae Discovered in Milky Way.” 199.

³Seyfert and Shapley. “A study of faint northern galaxies.” 219-236. 

⁴Shapley “Thirty-six thousand galaxies in the south polar CAP.” 147. 

⁵ibid, 138. 

⁶Marian. “Muriel Mussells Seyfert – Jack of All Trades.”

Bibliography

Marian, Cate. April 7, 2020.  “Muriel Mussells Seyfert – Jack of All Trades.” Dyer Observatory. Vanderbilt University. Accessed June 24, 2025. https://dyer.vanderbilt.edu/2020/04/07/sf040720/

Seyfert, Carl Keenan and Harlow Shapley. 1937. “A study of faint northern galaxies.” Annals of the Astronomical Observatory of Harvard College 105 (10): 219-236. https://ui.adsabs.harvard.edu/abs/1937AnHar.105..219S

Shapley, Harlow. 1937. “Thirty-six thousand galaxies in the south polar CAP.” Annals of the Astronomical Observatory of Harvard College 105 (8): 137-208. https://ui.adsabs.harvard.edu/abs/1937AnHar.105..137S

“Three New Planetary Nebulae Discovered in Milky Way.” March 28, 1936. The Science News-Letter 29 (781): 199. https://www.jstor.org/stable/3912345.

Zrull, Lindsay Smith. 2021. “Women in Glass: Women at the Harvard Observatory during the Era of Astronomical Glass Plate Photography, 1875–1975.” Journal for the History of Astronomy 52 (2): 115–46. https://doi.org/10.1177/00218286211000470.