Watercooling and Seeing
The construction of the 'Himmelwarte' resulted in the opening of the roof to the south. During the observation of the sun, the roof of observatory heats up to very high temperatures, even using bright stainless steel as a surface.
The warmed up metal generates a local thermic airflow, which modifies additionally the seeing, exspecially at 10 a.m. and later. This was unfortunately clearly visible in the H-alpha solartelescope, normally pointing over the south opened roof. I decided to install, in front of the 'solar-optics', a small water cooling device on top of the metal surface, which is technically based on a selfmade sprinkler system.
A 2000mm long aluminium tube with 60 drilled 1mm holes (30 mm distance to each other) is mounted on top of the sliding roof. The waterflow is adjustable right on the tube and the water rinses over the whole surface of the roof down to the grass in the garden. The tap allows the finetuning of waterflow, down to enviromental friendly dripping. It is directly controlled from the internal workspace in the 'Himmelwarte'
The watercooling stabilizes dramatically the seeing in front of the solarscope, even with a low amount of water.
Fazit: If you construct an observatory and you also plan to observe the sun, be aware of not placing any sun-collecting surface in front of your optics or you may have to prevent its heating...
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