Introduction:
Building an observatory has been a dream of mine since my high
school days with a 6" Newtonian back in 1981. Vedeler
observatory is the culmination of over a decade of dreaming, planning and deliberate moves in my life.
The structure is a 10 foot by 12
foot raised platform with 6 foot high walls and a roll off 3/12
pitch roof. While in the design phase of building this
observatory I looked seriously at buying a traditional dome.
Dome's are synonymous with observatories and offer a much greater
aesthetic appeal to most astronomers. However, I went with a roll
off roof for the following reasons:
• A roll off roof design is
simpler and less costly to build than a dome.
• A roll off roof does not require complex motors and
electronics to move as the telescope moves.
• A roll off roof reaches thermal equilibrium faster than a
dome, and does not create a chimney effect as hot air rises out
the open slit of the dome.
• A roll off roof permits an unobstructed view of the sky
for naked eye observations and wide field piggy back
astrophotography.
• A roll off roof building can be disguised as a shed to
camouflage the expensive equipment inside.
The only practical advantages of a
dome are that they require less real-estate for a given sized
observatory, and that they shield wind and light better. My house
is on 1.5 acres, and so an extra 120 square feet of land to
accommodate the roll off roof was trivial, and I built my
observatory behind a small hill to help shelter it from traffic
light and wind. Night time winds are fairly rare here, and on
those occasions it is usually due to a storm and thus I would not
be using the observatory.
My 10" f/10 Meade LX200 sits
upon a 5 foot high 12" diameter concrete pier. The concrete
pier is connected to a 1 cubic yard, 4000 pound concrete deadman
which is sitting 3 feet in the ground. This massive weight is
necessary to act as an inertial dampener for vibrations and to
aid in the stability of the telescope. The floor of the
observatory is raised about 2 1/2 feet off the ground. This was
done to get the telescope up and away from the radiating heat
from the desert ground, and in the hope of making it more
difficult for unwelcome visitors like scorpions and snakes to
make a home of the observatory. The roof rolls off by a push of a
button using a Sears 1/2 HP electric garage door opener.
Originally I was going to simply move the roof by hand, but by
the time I had put shingles on the roof it became too massive to
move easily by hand. The garage door opener makes opening and
closing the roof easy and precise.
The telescope and CCD cameras are controlled with a
computer I bought for this sole purpose. I used to have a Macintosh in the
observatory to control the telescope and CCD cameras, but I found that telescope
control software and CCD camera control software is much better on the PC
platform. The current computer is an IBM Aptiva 133Mhz Pentium MMX with
32MB of RAM, and a 2GB hard drive. The computer can control the telescope and ST4 via a
serial connection, and can control the ST7 via the parallel port. The software used is TheSky
level 5, and
CCDOPS from SBIG. A Cat5 Ethernet cable also connects from the
observatory to the house which permits me to remote control the
observatory computer from my office computer using a software
package called PC Anywhere. This permits me to control both CCD
camera and the telescope from inside my house about 100 feet
away.
Since finishing this observatory I
am using my telescope like I never could before. Deciding to
observe is simply a matter of walking out to the observatory,
pushing a button to roll off the roof, powering on the scope, and
syncing the computer to a known star. The scope is already nearly
perfectly polar aligned and ready for imaging.
Construction: Click
here to see a pictorial construction history.
The observatory was built in about 3 months starting in late
January 1999 until late March 1999. No contractors where used for
any stage of construction, and only on one occasion did I need
help from a neighbor. The only power tools used where a Skill Saw
and a 1/2" drill.
Far more hours went into the
planning and design than into the actual construction. This
greatly reduced cost by saving on wasted lumber and saved a great
deal of construction time as most of the details where worked out
before I ever picked up a hammer or a saw. All of the CAD
drawings I used for the construction are available in the pictorial constriction
history page. There were several
modifications necessary from the original drawings such as adding
additional support for the structure that the roof rolled off
onto, and how the roof rafters connect to the track rollers but
the drawings give a good basic plan for the observatory.
The cost of the observatory from
plans to completed product (not including the telescope,
camera's, or computer equipment) was about $2800. This was almost
3 times my original budget of only $1000. This was due to my
serious miscalculation as to the cost of lumber and as I worked
on the construction I decided not to skimp on anything as this
was something I had wanted to do for so long.
Since the observatory was built in
the winter, I wasn't sure how well it hold up to the extreme
Tucson summer heat. The observatory is not insulated to remain as
close to the outside temperature as possible. In the heat of the
summer however, this can pose a problem since even though the
observatory is very well ventilated, it still builds up heat
during the day. I installed a thermometer which records the high
and low temperature. On the first 100 degree F day on May 27th
1999 the inside of the observatory got up to 112 F. This kind of
heat is not good for the electronics of the telescope, CCD camera
or the computer. It is not uncommon for mid summer high
temperatures to reach 110 F here so it quickly became obvious
that I needed to do something about the heat buildup inside the
observatory. I did this by adding a 14" powered attic fan to
the roof of the observatory. This seems to have done the trick as
I am now seeing only about a 2 or 3 degree delta between the
inside and the outside on hot days.
Back to Astronomy Gallery
6/6/99