====== Zunderman reflector====== {{ :zunderman.jpg? 150|}} ==== Short facts ==== * Reflector Nasmyth optical design * Building started by chief of the workshop Zunderman in 1937 * Operational in 1947 (after WW-II) === Main telescope === * Focal length: 6918 mm * Primary mirror: 453 mm * Focal ratio: F/15 * Field of view: 20' * Limiting magnitude: 15 * Magnification: max 330x * Resolution: 1,8" {{ :telescopes:xxx.png?200|}}{{ :telescopes:zunderman_spiegel.jpg?200|}} === Tracking scope === * Lens diameter: 150 mm * Field of view: 42' * Magnification: === Finder scope === * Field of view: 5⁰ * Magnification: ---- ==== History of telescope ==== The Zunderman reflector was built in 1937/1938. During the Second World War the Germans wanted to take this telescope back to Germany. Therefore, Leiden astronomers decided to take the telescope apart and store the pieces in their basements. This way the Germans would not be able to do anything with the telescope. When the telescope returned once again to the Old Observatory in 1947, the pieces were reassembled. The Zunderman is one of the largest reflecting telescopes in all of the Netherlands and the only reflector at the Old Observatory. This telescope has a primary mirror with a diameter of 45 centimeters and a focal length of 7.04 meters. The eyepiece has a focal point of approximately 70 millimeters. A magnification of 500 times is achievable with the optics of the telescope. Originally the telescope was a (two mirror) Newton telescope (=225 cm), but now it consists of a (three mirror)Nasmyth-Coudé design. The mounting is equatorial. The telescope also has a finder scope and a tracking scope. The tracking motor itself can be found one floor below the telescope. The telescope was intended for photometry of variable stars. A few projects were carried out, but the instrument was soon disregarded when optical observations were transferred to more favourable located sites, especially those of ESO. On the wall of the dome hangs a large poster summarizing the photometric observations of a double star made in 1962 by dr. Van Genderen, now retired. In the dome you can also find a mirror holder that can be placed underneath the telescope so that the primary mirror, which weighs in at 30 kilograms, can be easily removed and maintenance, such as a new aluminum layer, can be administered. The main mirror tubing weighs in at 50 kilograms! (taken from, but it is Sunday professor) ==== History of the Heliometrische toren (dome) ==== {{ :telescopes:zunderman_heliometer.jpg?100|}} {{ :telescopes:zunderman_toren_schets.jpg?100|}} {{ :telescopes:zunderman_toren.gif?100|}} The heliometer tower was built in 1878 and renovated in 1932. It’s original purpose was to house a heliometer from Mertz. Hence the name. However, the use of such an instrument, which measured angular distances in the sky, was replaced by photographic astrometry, before it was installed in the dome. The dome then housed smaller instuments before the Zunderman reflector was placed there. \\ The building itself was designed by the well known architect P.J.H. Cuypers, who also designed the central station and the Rijksmuseum in Amsterdam. It is one of the few buildings by him in Leiden. For this reason the effort was warranted to put the tower on a new pile foundation. The original ones were rotting and the building started to stoop by already 5⁰. The yellow jacks on the photograph did the job. ---- ==== Stories ==== The original mirror was ground by Mr. Kleibrink before WW-II, but cracked when it was aluminized. The final mirror was made in France after the war.\\ [[http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1949BAN....11...17W&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf|Paper]] made with data taken by the Zunderman (called 19" reflector in this paper, 48 cm elsewhere in reports). ---- ==== Myths ====