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.
Some conditions for a roof observatory:
- 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
An observatory nearby has many advantages:
- 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
There are some disadvantages:
- 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
Images and Reports from construction phase:
- 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.
Instruments, observations and astrophotography:
[ 2016-10-20 | Gregor Krannich |
Home page Gregor & Cornelia Krannich ]