Rathenower Refraktor

In the heart of Rathenow, Brandenburg, Germany, lies an extraordinary piece of astronomical history and engineering marvel—the Rathenower Refraktor. This impressive instrument, often referred to as the Rolfsche Riesenfernrohr, is not just any telescope; it is a Schupmann-Medial telescope, a hybrid of mirror and lens technology, embodying the innovative spirit of its creator, Edwin Rolf.

The Ingenious Design of the Schupmann-Medial Telescope

The Schupmann-Medial telescope is a testament to the ingenuity of Ludwig Schupmann, who aimed to combine the best of both mirror and lens telescopes to correct each other's optical errors. Traditional telescopes, whether using mirrors or lenses, suffer from certain aberrations—geometric distortions in mirrors and chromatic aberrations in lenses. Schupmann sought to mitigate these issues by creating a hybrid system that would deliver clearer and more accurate astronomical observations.

The Rathenower Refraktor, specifically, is a Schupmann-Brachymedial Type B telescope. It features a non-achromatic crown glass lens as its objective, which in itself would introduce chromatic aberrations. However, the ingenious design includes a corrective system comprising a biconcave flint glass lens and a spherical concave mirror at the lower end of the tube. This setup effectively neutralizes the chromatic errors, providing stunningly clear images of celestial objects.

A Brief History of the Rathenower Refraktor

The construction of this remarkable telescope began in the post-World War II era, from around 1949 to 1953. Edwin Rolf, an engineer and amateur astronomer originally from Arnau in what is now the Czech Republic, built the telescope in his garden in Rathenow. His passion for astronomy and dedication to the project saw him enlist the help of local craftsmen, who contributed their skills and labor in exchange for the opportunity to be part of something extraordinary.

Rolf’s telescope was not just a personal project; it also played a significant role in the scientific community. In 1953, the Academy of Sciences of the GDR (German Democratic Republic) reimbursed Rolf for the material costs, recognizing the importance of his work. The Rathenower Refraktor was used to compare various optical systems, including the Maksutov and Schmidt cameras, to determine the best instrument for a new large observatory in Germany. Ultimately, the observatory built in Tautenburg, Thuringia, was equipped with a 2-meter Schmidt camera, but the groundwork for this decision was laid in Rathenow.

Technical Marvels and Innovations

The Rathenower Refraktor is not only impressive for its optical design but also for its technical innovations. Rolf incorporated several ingenious features to enhance the telescope’s performance and usability. For instance, the telescope’s tube is sealed at both ends, creating a self-contained environment with its own microclimate. This design protects the optical components from external weather conditions, such as humidity and temperature fluctuations, which can affect the quality of astronomical observations.

Moreover, Rolf equipped the telescope with sensors to monitor the internal climate, including temperature and humidity levels. He also installed devices to control and adjust the internal atmosphere, such as desiccators to remove moisture and a fan system to circulate air when necessary. These features ensured that the telescope could operate effectively even in the challenging environmental conditions of Rathenow, which were often affected by industrial pollution and agricultural activities.

Preservation and Legacy

The Rathenower Refraktor’s significance was officially recognized in 1990 when it was declared a protected monument by the city of Rathenow. Despite its protected status, the telescope underwent several relocations and restorations. In 1994, it was restored and placed on the grounds of the Bruno-H.-Bürgel-Gesamtschule, a local school. Finally, in December 2008, the telescope found its permanent home in the Optikpark Rathenow, a park dedicated to the region’s rich optical heritage.

Today, the Rathenower Refraktor stands as a symbol of human curiosity and ingenuity. It is a reminder of the relentless pursuit of knowledge and the remarkable achievements that can arise from passion and dedication. Visitors to the Optikpark Rathenow can marvel at this extraordinary instrument and reflect on the profound impact of astronomy on our understanding of the universe.

Technical Specifications

The Rathenower Refraktor boasts some impressive technical specifications that highlight its significance in the world of astronomy:

• Aperture: 70 cm, making it one of the largest telescopes of its kind globally.
• Focal Length: 20.80 meters, second only to the Riesenfernrohr in Berlin-Treptow.
• Tube Length: 10.15 meters, remarkably compact for its focal length due to the folded light path design.
• Overall Height: 11.50 meters, towering above its surroundings and making a striking impression.

In conclusion, the Rathenower Refraktor is not just a telescope; it is a piece of history, a marvel of engineering, and a testament to the human spirit of exploration. Whether you are an astronomy enthusiast or simply a curious visitor, the Rathenower Refraktor offers a fascinating glimpse into the world of celestial observation and the incredible legacy of Edwin Rolf and Ludwig Schupmann.