La Belle Étoile

(The Beautiful Star)

Please be lenient with this english translation… I'm french speaking

Yves Marchand's Observatory

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Latitude: 46° 23' 13" N

Longitude: 72° 33' 23" W

La Belle Étoile (The Beautiful Star), it is the name I gave to my observatory. By building it, I realized an old dream.

But why did I build an observatory in a city?

First of all, even if I live in the new amalgamated city of Trois-Rivieres in Quebec, my residence is located in fact in the Cap-de-la-Madeleine sector. By looking at the images which follow, you will agree that it is not what we call a "large city"!

Of course, there is luminous pollution, a beautiful street lamp gives ligth to my backyard! It is precisely one of the reasons which persuaded me to begin the construction of an observatory. I wanted an observatory which would allow me to be sheltered from this light, while protecting my equipment which would be always available to observe. Without a permanent installation, that takes certainly about fifteen minutes to correctly settle a telescope. And I say nothing of time necessary to dismount and store it after observation.

The life without an observatory

There are some beautiful ground with a blacker sky, thirty minutes away from my home, where I can build my observatory… But in my opinion, the best observatory is as the best telescope… it is the one we will use often! Therefore, in my backyard, as soon as the stars appear I can observe for a few minutes or a few hours. Sometimes, I use a webcam (unfortunately broken now), a digital camera or my new DSI to take some photos.

 

The choice of the model

I hesitated between two different models. In the first one the roof is a roll-off design. Passably easy to build and not expensive it can be made from a prefabricated shed. But it won't fix up my problem of bothering street light. I opted for a more standard model with circular rotary dome. Much more difficult to build and more expensive it permits the opening of a part of the roof who may be oriented to avoid undesirable lights. I picked up few ideas here and there on internet but I had to conceive the design by myself . That was a big challenge for me!

The construction

 The site

There was old cypress behind the house. A few one were being broken during the winter, so I cut all of them. When it be done, that gave to me the necessary space to realize an old dream: to build my observatory.

The column

I found the ideal column at Mercier Highway 40 in Champlain: 8 foot in height , 4-by-6s large, with a plate of 8-by-10-inch at one end and 12-by-14-inch at the other end. After sandblasted and painted, it looks like a new one… Many peoples were thinking that it was custom-made !

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I began works on May 22, 2004.

The first step in building my observatory was to bury 3 1/2 foot deep pier well straight.

 

  

 The floor

I used 2-by-4s 12' long to do the floor. This one measures 11-by-12-foot, what will permit me to do a small step in front of the door.

It lies on blocks of concrete.

I put 2-inch isolating sheet near the column to reduce the depth of the freeze in the soil.

The dome

I began to build the dome before the wall, directly on the floor. Since this was the most difficult part to do, I wanted to work to an easily accessible height.

Each part of the dome has a different ray. The base has a 5' ray what gives a 10' diameter for the observatory. Everything has been cut up to the jigsaw in 3/4-inch plywood according to necessary rays. For each arc, I have to cut 2 times; one cut for the outside of the arc and a second one for the inside. I assembled arcs to have a double thickness.

 You see the dome base is terminated, both primary arcs too. These ones will delimit the opening. The secondary arcs make a 90º angle with the first ones. 

There is now two tertiary arcs inserted between them. The structure of the dome is terminated.

I have to make a shutter and cover the dome with 1/4-inch plywood.

 

 

 The shutter

The dome will open with two parts. The principal part is provided with slides rearward. It will even clear the zenith. This is the section I will use mostly for the observation.

 The inferior part of the shutter opens forward with hinges. When this part will be closed, it will protect of surrounding street light. It will be lowered only to observe near the horizon.

 

 

 

 The dome is now completed and the shutter works well.

 

 

 

The base

I removed completely the shutter and separated the dome in two parts. I had done joints near the shutter order to facilitate the separation.

Everything is ready to built the base: arcs are cut (behind sawhorses) and the uprights are in front of them.

 

The structure of the base is completed.

The wall measures almost 5-foot-height and the diameter is slightly inferior to dome diameter. The 2-by-4s uprights are spaced of 16-inch relative to the exterior circumference and the space for the door is put forward . It remains diagonals to install between uprights before replacing the dome.

 

 

The dome lies on the foot and is reassembled.

Thanks a lot to my brother-in-law René for his help. That would have been a little difficult to raise the dome all alone !

I had installed the door and pulleys for the rotation of the dome before this installation.

 

The walls are covered with 1/4-inch plywood..

Unfortunately, the plywood can only be curved in the width side.

It makes more joints that way.

  

 

I applied silicone on each interior and exterior joint.

I painted the door with elastomeric roof coating to test it.

 

 

The finish

I used elastomeric roof coating on the dome to seal the joints and to make a good finish.

I spread three coats to give more resistance.

I applied a latex acrylic stain everywhere inside the observatory and on the exterior floor to have a better wood protection.

 I covered the base with vertical vinyl. That permits to follow the circumference without problem and makes a beautiful finish.

Finally I painted the exterior floor to match the colours of my house.

I finished the works on July 22, 2004.

Two working months (132 hrs of travaux manual, without counting the plans conception and numerous visits to the hardware shop) have been necessary for the realization of this fine project.

I had an initial budget of $2500 but I didn't calculate the cost of motorise the rotation of the dome, so it cost a little bit more than I expected.

Happily that I didn't have to pay for manpower, that would have easily doubled costs!

The final touch

My wife Lyne has given to me two beautiful mural plates in the theme of the astronomy.

The sun flirts with the moon on the first.

The second one shows the moon and stars.

A beautiful feminine touch to decorate my observatory!

 

 

Using observatory

This is a night when I used my observatory. The inside is lit by a red light to avoid the dazzle.

The south-western horizon the is most free. My principal observations are made in this sector and in the zenith.

This is an other view of the dome with the shutter lower part partially opened. I like to observe the sun and planets in the daytime .

The equipment

This is my telescope inside the observatory, the shutter completely open. My telescope looks small, but it is a 8" diameter.

The observatory has been made large enough to make a 14" telescope comfortable.  Is worth best to build oversized rather than tight ! One day, perhaps that will be useful!

My principal telescope, a 203mm Celestron Schmidt-Cassegrain, is installed on an equatorial mount goto Meade LXD-55.

A small 80mm Skywatcher refractor is parallel mounted .

Among the others astronomic equipments that I have, there is a small travelling 4 1/2" Bushnell telescope, an Orion solar filter, many Meade eyepieces, a telrad and a Solarscope.

This is an interior view of my observatory during the lunar eclipse on October 27, 2004. Moon picture is oversized of course!

The main difficulties

The plans

In the first plan I drew up, the dome was being more that half a sphere.

The base was 4-foot-height and the dome was 6-foot-height.

The principal problem, doing the door only in the base, it would have less than 4-foot-height. With a telescope on a pier, I could make an higher base.

So, I made a 5-foot-high base and a dome in half-sphere of 5-foot-high.

Here is a few links who have helped me to do plans of my observatory.

 

 

The shutter

What a puzzle for me to open easily the shutter… Finally, I have installed a system of two pulleys;

the first one pulls out when the other one holds back the shutter.

That permits me to stop it in any position.

 

 

The rotation of the dome

The dome lies on a set of small wheels.

I had not expected to motorize the system.

I was believing that pushing simply on the dome, this would be easy to turn it.

But this was much more difficult than expected.

In the first system that I have installed, I have used an old photocopier tray motor. A small belt was used to drive a small wheel.

This was not the ideal situation:

the motor was to weak, I had to push on the dome to help it.

The system of belt and small wheel was not being either optimum .

I replaced everything by a motor of electric winch on which I fitted a pulley and a rollers chain.

I found a robust wheel robust in an agricultural equipment shop.

It was serving for animal food distributors on rail.

A directional interrupter permits to choose the sense of rotation.

I have installed four interrupting who permit to start or to stop the rotation all around the observatory.

I completed everything by fixing a protective guard over the motor

and pulleys.

The dome takes about 1 minutes 45 seconds to complete a full rotation.

Everything works wonderfully !

After a few weeks of use, I am fully satisfyed of my observatory.

My equipment is sheltered , always to outdoor temperature , ready to be used.

I can do my observances in any time, being protected of street light, wind and humidity.

For a visit or building advices , you can contact me by email at

ymarchand@astrosurf com