Shoestring Observatory

Shoestring Astronomy by Doug Anderson

The Original Observatory

shoestring_old.jpg (90 kbytes) nameplate.jpg (36715 bytes)
From the name, it should be obvious, I haven't invested a life savings into this (yet). Through ebay, scrounging around, help from friends, and a lot of my own time, I have created a comfortably functional observatory without taking out a second mortgage.
My yard is heavily wooded, with no good place for observing. I am gratefully indebted to the Collins family who farm the ground across the road from me for giving up a corner of their field so I can sit out and enjoy the heavens while the rest of the world is asleep.
The 8-inch steel pier is actually a grain auger sleeve from my friendly farmer neighbor, sunk 6 feet into the ground. I then built an 8-by-8 foot deck with railings and some wind/light screen (landscape cloth) around the pier.
There is plenty of lawn around it for guests and more telescopes.

Shoestring Observatory Gets Remodeled

shoestring.jpg (55 kbytes) shed_closed.jpg (45 kbytes) shed_open.jpg (48 kbytes) shed_seal_out.jpg (50 kbytes) shed_backed.jpg (48 kbytes) shed_parked.jpg (52 kbytes)
Even though having a pier 200 feet away from the house made observing convenient, it was still taking 20+ minutes to setup and 20+ minutes to pack up, and even more time if I was planning on doing photography. So, the minimum investment was at least 45 minutes. I decided it was time for a permanent house for the scope to try and get setup time down to 5 minutes. A roll-off roof observatory would have been my preference, but I didn't want to invest that much money into a somewhat permanent structure on land that I don't own.
After putting some thought into the situation, I decided that the only thing that really needed full-time protection from the elements is the scope and accessories. This all fits nicely into a small closet inside my house, so I only needed to enclose the same volume out at the observatory. I decided a 'mini-rolloff' was the way to go. After doing a little Internet searching, I found out that Charles W. Brown had the same idea, so I knew I wasn't completely crazy.
I had to add to the north side of the deck to make some room to park the scope closet, so now the deck is 8 feet by 12 feet. There are vents in the floor of the closet, and under the eave on the high side of the roof. Convection currents naturally ventilate the closet like a chimney. Note the tight seal around the pier to prevent the closet from becoming a house for unwanted tenants. Another advantage of this design is there is very little thermal mass and no insulation, the scope is always very close to ambient temperature and ready to use. There is no cool-down time creating tube currents in the scope. The landscape cloth windscreen was replaced with plywood. A solar collector was added to charge a deep-cycle marine battery that will keep all the gear running through the night, and have it recharged by the next night.
Yes, it does resemble an outhouse. Fortunately that is where the similarity ends!

Shoestring Observatory Gets An Upgrade

obs_upgrade.jpg (100 kbytes)
The fork mount that came with my original C-8 scope was fine for visual use, and did alright for astropohotography, but it was a bit springy when loaded down with a guide scope, camera, counter-weights, etc while imaging. It was also impossible to use for imaging near the celestial pole. Thus, I decided to try an Orion Atlas EQ-G. I found a nice adapter to mount it to the top of my pier from Ken's Rings and Things. So far I am very pleased with this mount. Another advantage is that this mount is far more general purpose. I can mount the C-8, or ED80, or the 90mm, or just a camera, or any two of these in combination. In spite of the fact that I love to star hop, I find the GoTo capability very nice when imaging. The GoTo also gave me the final piece I needed so that once the observatory is set up for imaging for the evening, I can control everything remotely from inside the house.


BigBlue.jpg (170 kbytes) Home-built 12.5" Truss Tube Dobsonian - After getting a good deal on a used Meade 12.5" Starfinder from someone local, I decided to try my hand at converting it to a truss tube Dobsonian mount. Using Kriege and Berry's excellent book "The Dobsonian Telescope", I built this scope to improve the quality and portability. I kept the primary and secondary mirrors and spider from the Starfinder, but added a Moonlite focuser, Telrad, and 50mm finders. I also purchased Wheeley bars from JMI so that I can leave it set up in the house and quickly wheel it outside for use. Overall it was a very enjoyable project that I am glad I did.
celestron_c8.jpg (67 kbytes) Celestron C-8 Schmidt-Cassegrain - This is the real workhorse at Shoestring Observatory. I do most of my visual work through this scope, and some planetary and narrow field imaging. I've added a Williams Optics Crayford Focuser with JMI Motofocus, and a homemade dew heater on the corrector plate.
t80n90.jpg (77 kbytes) Orion ED-80 - This scope was purchased primarily to be used as a camera lens for wide-field imaging. I have added a JMI Motofocus. Shown here sitting on the Atlas mount along side the 90mm guide scope.
refractor_90mm.jpg (138 kbytes) Custom-built 90mm Refractor - I put this scope together by finding deals on the internet for all the components. It consists of a Meade 90mm f/11 objective and tube, a generic rack-and-pinion focuser, and an Orion SkyView Deluxe German equatorial mount. I wanted a decent second scope that I could use for outreach programs (school groups, scouts, community ed classes, etc.) so I could have two scopes going at once, but I didn't want to make a big investment. I also use this scope as a guide scope for imaging.
Edmund Scientific Astroscan - Another good deal on some used equipment. This scope is the ultimate in portability, ease of use and setup, and still has a generous 4.5-inch aperture. I use it for quick views, or when there is a young child around that wants to work the sky him/herself.