It was discovered on 27 July 1933, by Belgian–American astronomer George Van Biesbroeck at Yerkes Observatory in Wisconsin, United States.

[11] In November 2011 American amateur astronomer David Higgins obtained a rotational lightcurve of Vassar from photometric observations taken at the Hunters Hill Observatory (E14) in Australia.

[a] In 2016, two modeled lightcurves were derived using data from the Lowell photometric database and other sources, giving a concurring period of 7.93189 and 7.93190 hours and a spin axis of (104.0°, −50°) and (251.0°, −23.0°) in ecliptic coordinates, respectively (U=n.a.).

[5][6][7] The Collaborative Asteroid Lightcurve Link agrees with the results obtained by IRAS and derives an albedo of 0.0703 and a diameter of 36.32 kilometers with an absolute magnitude of 10.7.

Makemson, who computed the asteroid's orbit, was a teacher at the private elite school and director of its Vassar College Observatory.