Observatory
After retiring in 2011 I decided to resume my childhood hobby of astronomy and to also add astrophotography to the mix. It sounded simple at the time - buy a telescope, put a camera on it and you're in business... Building an observatory never crossed my mind as I naively entered the hobby. It did not take long however until I was spending a lot of time researching observatories and their construction. In order to take good images the telescope and mount have to be carefully aligned to the north celestial pole. And since my equipment was on a portable tripod I had to align the mount every time I set the equipment up. Fighting the cold Wisconsin winter winds was a battle I was not going to win, so I decided early in the winter of 2011-12 that if I was to enjoy this hobby I needed a permanent home for my equipment. Thus, in the spring of 2012 construction of my observatory began. The plans were developed with countless hours spent researching on the Cloudy Nights forum where strange people (like me) discuss everything imaginable related to observing and photographing the Cosmos.
Construction took about 2 1/2 months and first light was celebrated in mid june. "First light" is a mystical ritual celebrated by astronomers when they gaze through a new telescope for the first time, image through a new camera, christen a new observatory, etc. We are a strange bunch...
All observatories, like ships, require a name. I have no idea why - they just do... Many names were considered but I eventually settled on one that seemed to fit. We live in the rolling hills of Southern Wisconsin about 5 miles from the nearest small village and wildlife is abundant. Because construction began in spring the birds were nesting. On day one of construction, and every day thereafter, we were watched by a resident meadowlark. It turned out she had a nest about 75 feet away and she made it very clear we were not to get any closer. As the days passed, and she realized we were not a threat, she alternately watched and serenaded us. Thus... Meadowlark Ridge Observatory became the name.
The images and text below chronicle the building process. With the aid of highly talented carpenters and electricians the project went smoothly and was done ahead of schedule. Not
only to I use the observatory on clear nights, I find myself going over there often during the day to process astro-images or to just plain relax....
This spot was chosen for the observatory - view to north
View from our house looking to the west at the site of the future observatory.
Trenching for the power cable was one of the first things done. A temporary panel was installed at the site for the contractors. A 60 amp service was provided to the observatory. You can see the concrete piers in the distance.
The foundation for the building itself consisted of ten 12 inch diameter reinforced piers extending 48 inches below ground. The four piers toward the top of the photo (west) are to hold the framing that will support the roof when it is rolled off the observatory. The taller pier in the center is for the telescope. The base below ground is 30 inches in diameter and 42 inches deep. When this base was poured the 12 inch column you see was poured monolithically with the base. It will be extended vertically to the proper elevation above the observatory floor. My pal Duke is in the foreground.
The anchor bolts for the telescope mount and adapter were carefully set. For alignment reasons you need to determine celestial north which is very close to the "north star" Polaris.
Floor framing came next with insulation being installed under the control room portion of the structure. Electrical conduit was positioned under the floor between the control room and the telescope pier.
Wall framing next - you are looking north and a little east. The south wall is taking shape. You can see the wall in the telescope room is being held down about 30 inches. This portion of the wall will be on hinges allowing it to fold inward after the roof has been retracted. This will allow me to image objects low in the south - like the target rich area around Sagittarius.
After the wall framing was completed the next step was to install the inverted angle track on top of the north and south walls. Casters were then installed on the bottoms of each beam (that support the trusses) and a test roll was performed to make certain the beams rolled smoothly over the entire length of the track. Best to find out if there is a problem before the roof is installed.
The inverted angle track runs the entire length of the north and south (bearing) walls. The beam/caster system rolled very smoothly over the entire length.
A closeup showing the beam/caster/angle track system. This particular shot is SE corner of the observatory.
The next step was the installation of the trusses and roof system. After the trusses were in place a layer of Reflectix foil insulation was fastened on top. You can also see this insulation in the photo above this one. The purpose of this is to reflect heat away and up through the ridge vent. The observatory needs to be kept as cool as possible. If the telescope optics get too hot they will need to cool down prior to imaging. Purlins were nailed over the insulation and will be used to secure the metal roofing.
Permanent framing for the overhang support system on the west side of the observatory. It is very important to brace the beams securely so the inverted track system cannot move horizontally.
Things seem to be coming together quickly now with the installation of the metal roofing, windows and textured plywood wall systems.
View from the SE corner of the telescope room looking NW into the control room. Electrical rough in is basically complete.
In this photo you can see how I finished the walls of the telescope room. I installed screening to the top and bottom of the north east and south walls then placed a horizontal sheet of plywood in the center portion. The screening was meant to keep wasps, flies and other critters from nesting and to keep heat from building up inside the walls in summer. The plywood give me space to mount things. This photo was taken in the NW corner of the telescope room looking to the SE. You can see how the drop down wall (on the south wall) was framed/hinged. I have also installed the mount adapter on the telescope pier. Also visible are the "normal" and red lights on the walls. These are on separate circuits. The red lights do not ruin your night vision.
The color scheme was developed by my color consultant who doubles as my wife... :-)
View showing how the sliding roof system works. Toothed gear rack was installed along the side of the truss beam on the north wall. The electric motor has a pinion which pulls the roof on and off the observatory. In its fully retracted position about 2 feet of roof remains supported on the main building which you can see in one of the following photos.
Time to install the telescope mount - a Celestron CGEM-DX. The adapter that secures it to the anchor bolts was obtained through Starizona in Tucson. Now the fun begins....
The next order of business is to polar align the mount - that is to say the axis of the mount must be aligned almost perfectly to the north celestial pole. This is a must if you will be
doing astrophotography. If you are simply observing then perfect alignment is not necessary.
Note: this mount has since been replaced with an Astro Physics Mach1 GTO.
Birds eye view of a basically completed observatory. The control rooms floor, walls and ceiling have been insulated. I have a window mounted air conditioner which is used in July/August. Electric heaters keep it toasty warm during the fall/winter/early spring seasons. The strange round black thingy you see hanging on the wall is a Bahtinov mask and is used to focus the telescope. You will also note the red rope lights that run along the bottom of all walls in the telescope room. They are controlled via a dimmer switch and help me from stumbling into things at 3 am... :-)
One of the most difficult things I encountered during construction was figuring out how to develop a pulley/counterweight system to help counteract the weight of the south hinged wall. The tricky part was that I could not secure it to the trusses (they move) and I had very limited wall height. This photo shows the system I came up with. The 4 inch PVC pipe was filled with Sakrete to provide offset to the weight of the wall. I was quite amazed when I tried it for the first time - it actually works perfectly... :-)
There is one of these "gizmos" at each side of the drop down wall.
A view of the control room from the NW corner of the observatory. The telescope, mount and camera systems are all controlled via the laptop. The window allows me to keep an eye on the mount particularly the numerous control cables that hang off the camera, filter wheel, dew heaters and autoguiding equipment.
The control room measures 12' x 8' while the telescope room is 12' x 12'. Total observatory = 20' x 12'.
Everything complete with the exception of the landscaping! The observatory became functional in mid June of 2012.