stairway to the heavens

Edwin Aguirre and Imelda Joson's backyard observatory sits on a wooden deck erected near the top of a 35° slope. In addition to visual observing they plan to carry out CCD photometry from the basement study of their house.

S&T / Edwin L. Aguirre

Ever since we first became serious about astronomy some 30 years ago, we dreamed of having our own backyard observatory. That dream came to reality when we bought a house in the suburbs of Boston. We started with a big challenge, however. Our entire backyard slopes at a steep 35° angle. What to do?

We decided to use the slope to our advantage and designed our observatory to sit on a massive 8-by-12-foot wooden deck near the top of the slope. This elevated the enclosed telescope some 20 feet above the ground — high enough for the view to clear the neighbors' trees and the roof of our house. Access to the deck is by a 22-step, L-shaped stairway.

We selected a 6-foot-diameter commercial dome to house our 10-inch f/6.3 Meade LX200 telescope for three reasons: a dome is more compact than the roll-off-roof design (which was important, since we didn’t want it to take up a lot of yard space); it offers protection from wind, dew, and stray light while observing; and it satisfies our concept of what an astronomical observatory should look like.

dome sweet dome

Joson and Aguirre's 10-inch Schmidt-Cassegrain telescope and its 80-millimeter guidescope are housed in a 6-foot-diameter fiberglass dome. A one-inch gap separates the telescope pier from the deck floor to isolate the instrument from vibrations. The pier, a recycled streetlamp post, is filled with sand to further dampen vibrations.

S&T / Craig Michael Utter

While the sight of such a structure might excite an amateur astronomer, we were concerned that our neighbors would take a different view. To introduce them to the idea of having an observatory in their midst, we held an all-night star party in our driveway on the night of a total lunar eclipse. (We even held an impromptu slide show beforehand to explain how and why such events happen.) Our neighbors, together with their children and friends, had a great time. When we casually brought up the virtues of a backyard observatory, they not only supported the idea but even offered to turn off their security lights when they see us out observing.

To comply with local zoning laws and building codes, we applied for a construction permit at city hall. In the application we described the structure as a "telescope shed." ("Observatory" sounds too technical and tends to invite a lot of probing questions.) All the required paperwork and inspections went smoothly.

Working after office hours and on weekends, it took us less than five months to finish the foundation and deck. To support the deck posts and telescope pier, we made concrete footings using 8- and 12-inch-diameter forms. Reinforced with ½-inch rebars, the footings are anchored 4½ feet into the slope. The deck and stairway were constructed mainly of 1-by-6, 4-by-4, 6-by-6, and 2-by-10 pressure-treated lumber. To prevent soil erosion we planted shrubs all around the observatory.

Our fiberglass Home-Dome was purchased from Technical Innovations, Inc. Assembling the base and dome was straightforward; the most time-consuming part was making sure the dome's base ring was perfectly level and circular.

Since we live only 15 miles northwest of downtown Boston — and less than 5 miles from a huge shopping mall — our skies are moderately light-polluted with a limiting magnitude of about 4 on a clear, moonless night. This won't seriously affect our activities since we plan on doing mainly CCD work. Our interest is imaging deep-sky objects, as well as doing astrometry and photometry of asteroids and comets.

The observatory is a work in progress. Ultimately we plan to operate the telescope and dome remotely from the house some 30 feet away. This means we need to automate the dome's rotation to keep the slit centered on the scope's aperture. Two networked computers will be used — one for operating the telescope, camera, and dome, the other for processing images and analyzing data. For safety, all cables and power lines from the house to the observatory will be buried underground.

Since we don't have a window facing the observatory in what will be our control room, we plan to install a small, security-type video camera and a "baby monitor" inside the dome so we can see and hear what's happening there. We also plan to hook up a simple weather station so we'll know what it's like outside before or during an observing run.


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