National Historic Landmark - Cincinnati Observatory

In the late-nineteenth century, the Cincinnati Observatory was known worldwide for its endeavors in the field of proper motions, gravitational studies, and sidereal astronomy, including double stars, nebulae and clusters.

It is nationally significant for the publication of Stellar Proper Motions, which provided data important in determining the structure and rotation of the Milky Way, and provided data utilized in modern cosmological theories, such as the Big Bang.

It is also significant for its association with internationally renowned astronomer Paul Herget, who was director of the Observatory from 1946 to 1978.

Courtesy National Park Service National Historical Landmarks