It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 3 August 1918 and given the provisional designations A918 PG and 1918 EA.

[3] Hildegard is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.

[4][6] In April 2008, a rotational lightcurve of Hildegard was obtained from photometric observations by Australian amateur astronomer David Higgins.

[8] Previously in June 1999, observations by Brian Warner at his Palmer Divide Observatory (716) in Colorado only gave a period of above 24 hours and an amplitude larger than 0.3 magnitude (U=1).

In 2016, a modeled lightcurve gave a concurring sidereal period of 24.8544±0.0005 hours using data from a large collaboration of individual observers (such as above).