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Windy Mountain Observatory (WMO)
Sierra Vista, Arizona
 Map and directions to WMO.
Owners: Rich and Jill Swanson
The WMO is Finished! (March 2008)
"First Light"
HAC Member Star Party: Saturday, April 5, 2008
The WMO Almost Finished (February 2008)
The Equipment
Open for Business: Images from the WMO
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The Rosette Nebula. An image with very little processing, except for some brightness and contrast. (Approx. 4-minute exposure, shot through the 80 mm Stellarvue, guided with the Meade using the Meade Lunar Planetary Imager (LPI).)
Medium resolution (600x450).
High resolution (3264x2448). |
Clear Skies : 12th Magnitude Images from the WMO
The Windy Mountain Observatory HAC Presentation
On Feb. 15, 2008, Rich Swanson gave a presentation to the HAC about the construction of the “Windy Mountain Observatory,” located in Sierra Vista, Arizona. The observatory, built on a concrete pad, has a roll-off roof and is 14’ x 10’ with a warm room. Rich mentioned that he used the Bill Arnett website on building observatories (http://obs.nineplanets.org/obs/obslist.html) to get ideas for plans.
When building an observatory, planning is essential. First lesson learned: don’t use Sutherland’s. Their plan for a shed kit was inadequate. This was not entirely their fault—it was a plan for a shed kit, not an observatory. Doing some more research, Rich came up with some new plans. The first observatory’s dimensions, 10’x8’, were decidedly inadequate; therefore, the second observatory is 14’x10’. Other lessons learned: always build your observatory on a concrete pad, and site location is important. If you have neighboring houses that are nearby, then the heat coming off their roofs may cause problems with seeing. If you want to see certain objects, such as Omega Centauri (NGC 5139), then make sure there are no obstructions, such as buildings, walls, or trees. Many observatories include the “Omega Flap,” or the “Omega Window,” or some device, which allows the southern wall of the observatory to be lowered enough or opened up, to see the spectacular Omega Centauri globular cluster, which never rises very high above the horizon (in the northern hemisphere). When selecting an observatory location, also remember that a tree may grow taller and wider over the years.
For a roll-off roof design, the manner in which the roof runners are attached to the observatory is very important. With Rich’s first design, the runners were attached with brackets only, and these proved inadequate, as the roll-off roof actually ended up rolling off and landing on the ground, which is undesirable, because it forced Rich to build a second observatory. The second time around, Rich came up with a better design for the roll-off roof rails, making them integral to the walls of the observatory.
The observatory is almost all 2x4 construction. The location of nearby light-pollution sources, such as streetlights, influenced the height of the walls. The walls were increased to about 80 inches (6 ½ feet) in height to block the streetlight’s beams from entering the observatory. The previous observatory’s walls were not tall enough to block the streetlight, and too much light was entering. This situation was unsatisfactory, because Rich plans to do astrophotography.
For the roof, Rich used half-inch foam with aluminum on each side. The material is a rigid foam thermal insulation board composed of foam bonded to a durable aluminum facer and a reflective reinforced aluminum facer. This material proves to be very good at reflecting heat. According to Rich, on the hottest day of the year, you can put your hand up to the underside of the roof and it is cool to the touch.
The runners for the roof are each fourteen feet long. Rich looked at Bill Arnett’s website to get ideas for the runners. Inside, he used 14-foot long, 2x6 J-grade fascia boards. These were very straight and proved to be very adequate for the job. Rich said it was key for him to have J-grade, because it is dried already—it’s not going to warp on you—and it’s perfectly straight. He was able to find these at Home Depot. Five-inch wheels came from Lowe’s. They were on brackets and have ball bearings. Rich through away the brackets and mounted the wheels on 2x4s. Eight-inch wide 1x6s on the outside provide overlap on each side to seal the interior from outside wind, dust, and insects. There is about a half-inch to an inch of clearance between the 1x6s and the top board, and about an inch of overhang that acts as a guide for the wheels on the runner. It performs very well at keeping the roof rolling straight. The whole roof weighs about 375 pounds, and can be hand-pushed to open and close it. There are four wheels on each side, with each wheel rated at 500 pounds apiece, so they are well within tolerance for the weight of the roof. A space was left at the apex of the roof to allow heat to escape. The exterior of the roof was finished with metal panels. The interior will be painted black to reduce the effect of any stray light that does make its way in.
The current astronomical equipment setup at the WMO includes an 80 mm Stellarvue (a loaner from Keith) for astrophotography, mounted on the back of the 14-inch Meade GPS LX200R, being used as a guide-scope. The camera is a Canon 20Dh (Hutech-modified). Rich hopes to acquire an Astro-Physics 1200GTO in the future. Rich has been able to image a mag. 15.7 galaxy with his current equipment, and so hopes to image the Abell clusters!
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