Sommers–Bausch Observatory is an astronomical observatory located on and owned by University of Colorado Boulder. The building was initially completed in 1953 and named after Elmer E. Sommers and Carl L. Bausch. It is operated by the university's Department of Astrophysical and Planetary Sciences (APS), which primarily utilizes the facilities and equipment of the observatory for teaching as well as some research. Telescopes include two 20" Planewave CDK telescopes on Software Bisque Taurus 500 encoder mounts, a 24" Boller and Chivens Cassegrain reflectors, and a 10-inch aperture heliostat (solar telescope). The observatory also possesses multiple smaller telescopes and ancillary equipment. The observatory also houses the lab classroom and the computer lab for the APS department. History In 1949 the University of Colorado received a bequest of $49,054 from the estate of Mayme Sommers in memory of her husband Elmer E. Sommers. These funds were used to construct the observatory, which was built in an adapted rural Italian style to match buildings on the campus. Construction began in 1950 and was completed in 1953, which was delayed because of manpower and material shortages due to the Korean War. The building was dedicated on August 27, 1953, during the 89th meeting of the American Astronomical Society. The 17 foot, 10-inch Bausch refractor, originally from the Bausch & Lomb building in Rochester, New York, was installed in the dome the same year. In 1957, the Department of Astro-Geophysics, now Astrophysical & Planetary Sciences, was formed and used Sommers-Bausch Observatory as its research and teaching facility. Harvard University’s High Altitude Observatory also had office space inside the Observatory, which was then moved to the new HAO Building constructed next to the Observatory in 1960. In 1973, the current 24-inch reflector telescope was installed in place of the previous 10-inch Bausch & Lomb refractor. As a result of the decrease in length of the telescope, modifications had to be made to the interior of the dome. The 10-inch lens of the Bausch telescope was fitted onto the heliostat on top of the Duane Physics Building on the University’s campus. The telescope itself was displayed in the lobby of Fiske Planetarium until 2013 when it was replaced by the Fritz Star Projector. In 1981, an addition was built to provide space for a new observing deck that hosted an 18-inch teaching telescope along with four darkrooms, a laboratory, offices and a workshop. The heliostat was also