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Latest News: The Stoneage Observatory is now fully operational.

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Sunday, 30 April 2017

Solar Safety

One of the things I can observe with my 80mm refracting telescope is the Sun.  I use a white light filter for this (the shiny metallic film in the picture below) which rejects something in the region of 99.99% of the incoming light.  The problem in my observatory is that the refractor isn't alone, it is mounted on a dual mount bar with a much larger (200mm) reflecting telescope. Unfortunately I lost the dust cover for the reflector some years ago so pointing the small scope at the sun whilst using the dual mount meant also pointing the large, unfiltered telescope at the sun, this is potentially extremely dangerous not only for anyone who might accidentally look into the wrong eyepiece but it could also easily set fire to the observatory!

So I made a dust cover out of left over scraps of plywood, which made me happy:

Now I can safely observe our nearest star :)

Friday, 28 April 2017


Last steps! All this time since we laid the foundations the pier has patiently been waiting for its scope and in this post it is going to finally arrive.

To get to the telescope we are going to need to start in the middle, work down then return to the top, all this will make sense shortly so stick with me.

In order to easily operate a telescope mount (and therefore the telescope on it) the mount needs to be fixed to a level surface.  How neatly did you set that pillar? how square is the cut end? Do you think the mount is going to be level fixed straight on there?  Probably not, so we need a levelling plate (two metal plates mounted one on top of the other such that the bottom one is fixed to the pier and the top one can be adjusted on three screw threads to get level.) Then we need to attach the levelling plate to the pier which - because welding things above you is a little fraught - will require you to cut a small section of pipe to weld to the bottom of the plate so you can do this upside down and outside the very flammable building you have just spent 18 months building! 
Cutting and shaping the pipe extension (levelling plate base visible to the right)

Welding the pipe to the levelling plate
Once you have joined the levelling plate to the pipe you can weld the pipe to the pier and you are ready to mount your telescope!

And there it is! My 8" Newtonian atop the HEQ5 pro mount (white bit) bolted to the levelling plates, welded to the pier, set in a cubic metre of concrete sunk into the ground beneath our feet, we are ready for first light.
Dome open and scope pointing, we have first light!
And with first light comes first capture:
Waxing gibbous moon on the night of first light
The plan is complete! We have a working observatory built from recycled materials and a fair dose of ingenuity!  If you decide to undertake your own build please make sure you get guidance on how to use any tools you are unfamiliar with and try not to shed as much blood as I did!  Above all don't be a slave to my design, experiment, adjust and build the observatory that suits your needs and your location.  Good luck and Dark Skies.