The New York Times noted the first publication of the Vassar Observatory, Catalogue of the Stars Within One Degree of the North Pole and Optical Distortion of Helsingfors Astro-Photographic Telescope, Deduced from Photographic Measures, by Caroline E. Furness ’91. In 1889, one of Maria Mitchell’s first group of six astronomy students—known as “the Hexagon”—Mary Watson Whitney ’68, succeeded Mitchell as professor of astronomy and director of the observatory. Having studied with mathematician Benjamin Peirce at Harvard, done research at the Dearborn Observatory at the original University of Chicago and studied celestial mechanics at the University of Zürich before returning to Vassar in 1881 as Mitchell’s assistant, Whitney was more acquainted than her mentor with the wider world of scholarship and scholarly publication, and this publication marked her expansion of the observatory's mission.

Caroline Furness was Watson's assistant at the Vassar Observatory in 1894, and the following year Watson had arranged for her to study at Columbia with the recently appointed acting professor of astronomy and director of the observatory, Harold Jacoby. She was the first woman admitted for PhD studies in astronomy at Columbia. In collaboration with Jacoby and with financial support from Vassar trustee Frederic Ferris Thompson and philanthropist Catherine Bruce, Whitney acquired equipment necessary for Furness's work. The results of this joint study, of which the first volume was Furness's doctoral thesis, were published in four volumes, two from Vassar and two from Columbia. With Whitney's retirement in 1915, Caroline Furness became director of the observatory, and the following year she was appointed Alumna Maria Mitchell Professor of Astronomy.