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Description of my roof observatory in the attic of a dwelling house

Here I describe my roof observatory in Kaufering (near Landsberg/Lech, Bavaria, Germany). Many images show the construction phase and additional information about operational experience is given.

  

In 2007 I had the golden opportunity to plan and build an astronomical observatory in a new building. At this point I had saved some money, the available budget is quite crucial . I got the permission to change the drawings for the roof to get a large penning with a sliding roof construction. The ridge of the new house is aligned to East-West direction. The roof inclination is low at 26°, given that I have a small limitation in the line of sight to East and West. The new house doesn't have a chimney, the heating installation is in the neigbouring house. For scheme, construction and installation local companies were assigned. A do-it-youself construction on the roof was out of the question.

• Dark place with high altitude; this is difficult to fullfill in Germany
• Important: stable telescope pillar free of vibration
• Separation between pillar and floor, steps should not ruin a running exposure
• Seeing: quick temperature compensation after opening the roof, air flicker is unwanted; this condition is met by thermic isolation of the whole observing room.
• The roof and the observing room itself shouldn't get hot due to solar radiation; the roof shouln't be a rooflight.
• Protection against wind, dew, scattered light; a dome would be best for this, but an observatory with an open roof gives only a very limited protection

• It can be reached quickly and comfortably
• No installation and adjustment of instruments before an observation, telescope will be set up once
• Observation is possible between cloudy periods or with limited amount of time
• For my roof observatory: I have free sight over buildings and trees in the neighbourhood, I am above the street lights, sometimes I can continue even if some ground fog forms
• Electrical current, phone, internet connection are available

• Light pollution from street lights and other sources
• In winter sometimes smoke from chimneys around is annoying
• Restricted line of sight in East and West due to end walls

• Construction of roof observatory (2007/2008, German)

• The street lights don't dazzle, they are below my "horizon". The height of my wooden floor is a compromize of a panorama view and protection from wind and light.
• My great concerns were unfounded. Steps inside observing room and other rooms in the house don't transfer vibrations to the telescope. But I see some jitter through telescope if somebody goes up or down the stairs outside.
• The roof itself doesn't save heat, I couldn't observe a degratation of seeing. In opposition I estimate, that the seeing is better than observing from ground level.
• If it's cold and almost calm then the smoke from nearby chimneys annoy me and it disturbes observing.
• If the snow cover is too high or snow is frozen, then the roof can't be opened. But this happens rarely.
• Conclusion: It was worth the trouble. Without my observatory, observation or astrophotography would be rare.

• Gregors astronomy page (German)

[ updated: 2016-10-20 | Gregor Krannich | Gregors astronomy page ]