望远镜清洁在斯图加特天文台
星光视线
可以使用现代大型望远镜在夜空中制作大约100亿颗恒星 - 从斯图加特乌哈兰山山上可以看出，斯图加特天文台自1921年以来，斯图加特天文台已经站立。在南部中间的山上德国国家资本，交通噪音和火车站公告在山谷和街灯的光线上迅速回声，从夜间的天空徘徊在整个城市的钟声上。这种光明污染只能使天文台的自愿团队能够通过望远镜看到10亿颗恒星的一小部分。但这不仅仅是光明污染，掩盖了天体的视野：细尘，昆虫，花粉和风化的沉积物使得其中一个望远镜的大镜子如此肮脏，恒星出现湾和沉闷。
Ulrich Teufel, engineer and passionate amateur astronomer, loved to gaze at the stars through the attic window of his bedroom as a boy, which is why he joined the society that looks after and maintains the observatory early on. He was no longer able to see through the dirty telescope. The 49-year-old is standing in the sunshine on the plateau of the water container one Tuesday and pulls the 150 kg, rail-mounted telescope out of the metal shelter. "Today we are going to start cleaning the telescope mirror," says Teufel. And what sounds like a simple task proves to be somewhat more challenging.
高精度表面
The heart of the telescope is a 30 kg, 50 cm wide, high-precision mirror. It is attached to the lower end of the telescope and reflects the incident light of the stars onto a second mirror. This directs the view via an eyepiece, then into the eye of the observer. The surface of the large mirror is handled with extreme care so that irregularities only occur in the nanometre range. Every irregularity ultimately leads to an inaccurate image. Such a high-precision surface is naturally sensitive. If you were simply to wipe it with a cloth, the fibres would leave countless tiny scratches. "The image would be even worse than with a dirty mirror," says Teufel. "So it is better to work with a dirty mirror than a poorly cleaned one."
但泥土来都是一样的,和投入en the delicate nature of the mission, it is best left to the professionals. Ulrich Teufel and two of his colleagues in the society have taken a day off for this, as they expect the project to last several hours. Once the telescope has been moved onto the courtyard, they get to work. First of all, the rear cover is unscrewed and the mirror is carefully removed together with its mount. As soon as the mirror has been removed, it becomes clear how heavy the dirt is that has built up over the years. A clearly visible grey film and numerous dark spots cover the surface. And no wonder: after all, the telescope was last cleaned in 2008.
耐心和正确的技术
现在需要微妙的触感。镜子放置在一个大容器中，污垢浸泡在蒸馏水中。“标准自来水会留下石灰污渍 - 这是我们想要避免的，”Teufel说。然后应用已经专门开发用于太阳能装置的少量清洁剂。它非常温柔，设计用于去除花粉，烟灰和灰尘等顽固的污垢。现在需要耐心，因为必须留下混合物工作两个小时。
与此同时，Ulrich Teufel将在望远镜管上工作。一个或两个蜘蛛网，灰尘和花粉都收集在黑丝绒内部。线望远镜内部的材料还用于吸收散射光，以确保恒星的透明视图。毫不犹豫地，他达到多功能吸尘器。使用抽吸刷，他设置了拆除污垢。
闪闪发亮
回到镜子：污垢现在浸泡得很好，并且在很大程度上已经脱落而无需触摸敏感的表面。通过用无绒布轻轻擦拭表面来除去残余物。最终治疗涉及醇的混合物来打击油腻的残基。
球队笑了笑，因为沉重的镜子再次从容器中取出而且它们会遇到令人眼花缭乱的景象。再次需要微妙的触感：使用天鹅绒手套，精致的设备拧回其安装并安装在望远镜的管中。
清晰的景观
晚上已经到了，充满活力的城市山谷在周围山丘的阴影中长长的莱恩，附近有照明的斯图加特电视塔突出到夜空中。该团队设定在当天的最终任务上工作：恢复望远镜。
This involves precisely adjusting the different mirrors of the telescope: the main mirror axis, secondary mirror and focuser are aligned with one another and every tilt eliminated. After around one hour, this task is complete and the stars can once again be observed with clarity. "That was really worth it," conclude the enthusiastic amateur astronomers. All of the school classes and visitors who regularly visit the Uhlandshöhe hill can now get a clear view of at least some of the more than 10 billion stars. And Ulrich Teufel can now see his favourite constellation, Orion, again.