Ferdinand attended High School in Belleville, Illinois,[2] then moved to Chicago and was employed at the James S. Kirk Company,[3] a soap manufacturing business.

[6] The two likely first met during the initial meeting for the Chicago Section of the Astronomical Society of the Pacific, in November 1890, and Ellerman may have first worked as a volunteer for Hale.

[8]: 28  Much of Ellerman's observation time was spent with the Rumford spectroheliograph,[10] as well as photographing the stellar spectra of Secchi's Fourth Type,[11][3] later termed carbon stars.

[16] Ellerman's work with Hale resulted in the discovery of solar vortices, which in turn led to the identification of the magnetic fields of Sun spots in 1908.

[3][17] In 1910, Ellerman was granted a leave from the Carnegie Institution to undergo a one-man expedition to the Hawaiian Islands for the observation of Halley's Comet during its passage.

[19][20] While at the Mount Wilson Solar Observatory in 1915, Ellerman studied an unusual phenomenon observed at multiple locations in the lower chromosphere layer of the Sun.

[24] During the spring of 1929, Ellerman accompanied E. Hubble and M. L. Humason in a series of trips to find a suitable location for the proposed Hale Telescope.

These journeys were made to a hilly region to the south of Los Angeles and to Arizona, with the goal of checking the viewing conditions.