Potsdam Great Refractor
[2][4] An observatory had been established in the late 1870s near Potsdam, and had gained notice for its work on photographic spectroscopy of stars.
The telescope mostly survived to the 21st century with an archive of photographic plates, and is a popular tourist destination in the modern day after the site was restored.
[7] Other projects of the observatory include solar observations, spectroscopy, and a stellar luminosity catalog with many stars from the Bonner Durchmusterung (BD) .
[10] The 30 cm Schrodeder telescope was used to take the spectrum of stars photographically, and the observatory became known for its work on stellar spectrographs.
[12] Major discoveries that the observatory was recognized for, were determining that Spica was spectroscopic binary in 1878, and also breakthrough on understanding of Algol.
Therefore when the spectrographic method shall have been thoroughly applied with great modern telescopes, we may confidently look forward to an enormous expansion of our knowledge of motions in the stellar universeAlso, while the newer 32 cm astrograph was felt to be adequate for photography, the director of the observatory was unhappy with its performance in spectroscopy.
The two objective lenses were completed by the firm Steinheil of Munich, figured from glass blanks made by Schott in Jena.
[4][3] The 50 cm was designed optical for the human visual range, and was intended as a guide for the photographic telescope.
[25] The astronomer Professor Hartmann determined from observations of the binary star Mintaka in Orion, that there was the element calcium in the intervening space.
[24] A foundation for preservation and function of the Great Refractor was founded in 1997, and with a considerable donation the telescope and site were refurbished with increased quality and made available for public observation programmes.
[5] These photographic plates, which in some cases date back to the late 19th century, are valued in modern times for software driven searches.
[19] In 2017, after a year of restoration work on the dome and building, the Great double lens telescope facility was re-opened.
[26] In 2019, the double refractor building hosted a reception for dignitaries, including Dutch royals, politicians, and bureaucrats from various organizations.
[32] An ultraviolet spectrograph was commissioned by the observatory and built by Toepfer and Son, however the 80 cm was limited to 360 nm wavelength light.
