Kuffner Observatory

Originally a private research institution, it was converted into an educational astronomy facility after World War II as buildings and city lights had encroached to a degree that severely hampered scientific nightsky observations.

During the years leading up to World War I the observatory became one of the most important astronomy sites in the Austro-Hungarian monarchy, and established a considerable international reputation.

During his assistantship at the Kuffner observatory, Schwarzschild – who would later become the “grandfather of black hole theory”—developed a formula that allowed to calculate the relation between the intensity of faint astronomical light sources, the exposure time, and the degree of opacity created in photographic emulsions.

The great refractor is a double telescope, with a primary of 270 mm (27 cm) aperture objective lens, and was built by Repsold and also Steinheill; it was installed at the observatory in 1886.

[4] Besides its function as a scientific museum and its ongoing mission concerning popularization of astronomy, the Kuffner observatory serves as the Austrian national host for the INES (International Ultraviolet Explorer New Extracted Spectra) database.