The new 36" f/6.3 mirror makes
its public debut at the Warren
Rupp
Observatory, and I am there
All images and
text Copyright Mike Lockwood, 2012. May not be used without
permission.
Introduction
Being
an amateur astronomer and living in a particular part of the country,
there are certain telescopes that you hear about. Stories
about
them are told by fellow club members who heard them from their friends.
Observing stories are overheard at star parties and other
events.
Over the years they develop a reputation in your mind even
though
you have never seen them in person, or used them for a night of
observing.
For
me, the 31" f/7 telescope, nicknamed "Big Blue" at the Warren Rupp
Observatory was one of those telescopes, along with instruments
like
Tom Clark's 42". (To my surprise, by the end of the year I
will have worked on the optics for both.)
An email one September evening dashed that hope, but at the
same time started a new chapter in its history.
It
was the evening of September 13th (no, not a Friday, a Tuesday!), and I
was in my shop getting some work done. An email came in from
Mark
Vanderaar, the president of the Richland
Astronomical Society at the time, bringing
the news that the 31" primary had been broken when the secondary mirror
assembly fell and hit it, splitting the mirror literally in half.
I was on the phone with him within an hour, and we talked
about
options over many phone calls in the coming day. Fortunately
there was insurance that could cover the damage.
Eventually, a
plan was hatched to improve the telescope, by adding a new mirror cell
to handle a larger, but thinner 36" f/6.3 mirror. Obviously
improvments to the secondary mirror holder and a new secondary mirror
were needed, too.
My "In the Shop" installment about making the primary mirror can
be found here,
and soon it was
time to head for Ohio to go visit what I began calling "Bigger Blue".
A
trip to Ohio
It was a beautiful day for a drive as I made my way from Illinois
to Ohio. A blue sky and comfortable temperatures hinted at a
good
night's observing ahead, and I arrived at Hidden Hollow about 3:30pm,
in advance of my 5pm talk.
In
the back of my Outback was the crate holding the two pieces of the 31"
mirror. We had hoped to have some other blanks machined from
it,
but after the coating was removed it showed a lot of bubbles and some
interesting internal strain. So, this was a first
- I
pointed out that I "had never delivered a broken mirror
before" as
we solemnly unloaded the crate.
The terrible event still weighed
on the minds of some that I was almost afraid to make any kind of a
joke about it, but sometimes you just have to find a way to laugh.
However, with the new mirror and other improvements,
we all
knew that the telescope had been born again and improved, and that this
was an incredibly happy occasion, not one for mourning.
I took a short tour of the area, and took some photos before giving my
talk and having dinner.
Welcome to the Warren Rupp Observatory, and thank you Warren.
Let's have a walk through the doors......
Oh my, that's one BIG telescope (though the perspective and lens
distortion makes it look smaller from this viewpoint).
OK, I need some people to get into the shot for scale, any volunteers?
That's
better. Pictured from left to right are John
Neumann, Mark Vanderaar, and
Bruce Scodova. The hydraulic lift used for observing
frames
the
photo on the right side, with the polar axis of the telescope at upper
left. A massive counterweight (outside the photo at left)
balances the massive instrument. The walls are painted black,
the
inside of the dome is its natural aluminum color, and the telescope is
a very pretty shade of blue.
Here's
a look at the brand new mirror cell/tube extension that holds the new
36" mirror, complete with back and side cooling fans. The
three
hand-wheels are the collimation adjustments. Some
experimentation
regarding directions, speeds, etc., was done with the fans, but this
was one of the first nights of the scope's operation, and there was not
much time for it because there was a line of people waiting to use the
telescope!
Note the small white rollers on the left and right
sides of the mirror - they are part of the mirror's edge support, which
is formed by whiffletrees that go all the way around the mirror.
This is an equatorial telescope, so edge support is not as
simple
as with an alt-azimuth telescope like a Dobsonian-Newtonian.
I gave my talk in the lower floor of the Sky High
Lodge, and then some of us went out for dinner. We returned
and
waited to darkness to fall as more people arrived.
As
darkness fell, people began observing inside and outside the dome.
With a line forming, I was able to do some quick star testing
to
see that the correction of the mirror was quite good, and after the
mirror cooled off a bit and was given a little nudge away from the edge
supports (which need a little adjustment), stars were as round as could
be expected at 500x while looking through the slit of a cooling dome.
The cell
and cooling fans are working quite well, though the edge
supports will need a little more adjustment to
perform at
their best, as expected. Large telescopes always require some
tuning to work at their best. Another possibility is some
fans in
the dome itself to help draw outside air through and reduce "dome
seeing".
Overall
I was pleased with the images, though I did not get to
see M27,
which seemed to be the favorite object of most, through the 36" until
some high clouds had come in and obscured it somewhat.
Later on
Friday night, the scope was turned to Stephen's Quintet which showed
more detail than I could recall, with the possible exception of a 32"
telescope at a darker site. M57 showed its central
star
quite obviously at times, going in and out with the seeing conditions.
Gradually clouds increased, so I turned my attention towards taking
some nighttime shots of the telescope and the dome.
Rotating
the dome acts as a shutter, so with the camera's shutter open, the
entire inside can be seen. The light to the right of the dome
is
the path of someone's red flashlight during the exposure.
Light
pollution from Mansfield, OH, is seen above the dome, to the northwest
of the observatory site.
This version shows the telescope in more detail, and aimed a bit
differently.
With
a small tripod in hand, I took the camera into the dome, set it up near
floor-level, and did some exposures with a wide-angle lens. I
even managed to capture M31, the Andromeda galaxy, just peeking over
the top
end of the telescope tube, just above the finderscope that is on the
bottom/right of the tube.
The scale of the telescope can truly
be appreciated when notes how high up the lift is positioned, and the
relative size of the person standing on its platform. A
computer
and monitor are secured to the lift, and the computer interfaces with
encoders on the telescope to show where it is pointed. It's a
very nice system.... so long as one of the hand controller buttons
doesn't stick when it is handed to yours truly to help center up a
star, who then panics when the telescope won't stop slewing toward the
lift! (Luckily the scope has a clutch drive, and there was a
spare hand controller.)
After observing a bit more and continuing to shoot photos,
at about 3:30am I had to turn in due to fatigue. I had
gotten
up fairly early to get a good start on the 6+ hour drive, and it was
time to sleep. I did so for quite a while.
Saturday
morning was beautiful, and after sleeping very late, a small, late
breakfast was rapidly followed by my lunch of leftovers from the
previous night's dinner. After some more caffeine, I was
ready to
walk
around and get some daytime photos. The shot above shows the
hill
that the observatory is situated on, with a club building built into
the hill (to the left in the photo) to warm up in. It also
has a
nice restroom.
If you ever observe there, be aware that after
coming down from the tall lift that gets you to the eyepiece, and after
exiting the observatory, there is a rather steep hill that can be fun
to negotiate in the dark! There are stairs on the right side
of
the club room, behind the hedge. The hedges to the right up
on
the hill surround a fire pit area that has to be really nice on a cool,
cloudy October night.
But what's that in the extreme right of the photo, amongst the hedges?
Get to that in a minute.
Up
on the hill lies a sign that makes one's location obvious. I
am
standing on the side of the hill to take this photo. Now
let's go
over to the right a bit and see what that mysterious object was.....
Hey, it's a 20" f/3.3 Starmaster
telescope, known as a
20" Super FX-Q!
I make the all-quartz optics for these no-ladder-required
telescopes. When the line is long at the 36" scope, I know
where
I'll be headed.
Walking
past the dome, a view from the other side of the club building shows
the hill. The restroom is on the near side of the club room.
Seriously, though, can we get some photos from a different perspective,
I wonder? Turns out, that is not a problem.
One
of the club members drove the lift carefully through the exit to the
observatory, and up we went just outside the dome on the sidewalk.
Oh, and I decided to put a fisheye lens on my camera, and
shoot
multiple exposures of various exposures. These were combined
with
software to form HDR (high dynamic range) images that show the dark
inside of the dome, as well as the very bright outside environment
around the dome.
These shots also capture a full 180-degree
view
from the camera's perspective, including part of the lift, a lens and
lens cap, some tools, and my feet at the bottom of the image!
The
building at left is a club building for telescope outreach, various
meetings, educational outreach/classes, and telescope storage.
Looking
the other way, we see Bruce standing in the dome to show the scale of
the 31", as well as the large concrete observing pad where members can
set up telescopes. There is also an observing table,
picnic
table, and a storage room above the club room in the "attic" of that
building built into the side of the hill.
Another view of the telescope with the lift, with the very patient
Bruce
standing by its base for scale.
Here's the telescope pointed nearly vertical for a slightly different
shot.
Charlie
Warren, the publisher/editor of Amateur
Astronomy Magazine, also shared
the lift with me, so no doubt you'll see some of his shots and possibly
mine in a future issue of that magazine. Charlie's astronomy
home
on wheels is just to the left of his head.
Finally, I couldn't resist the shot with my reflection in the primary
mirror. (No, the mirror did not break.)
How did the new mirror cell get to be that beautiful blue color?
John Pratte of JPAstrocraft.com,
who built the cell, mixed up a bottle to match the original color.
I'm guessing there are not too many bottles of "Big Blue
Blue"
sitting on the shelves of your local hardware store......
Now we
move on down the road a bit from the observatory to the Sky High Lodge,
where vendors were located and my talks were given.
On the way you will see plenty of cabins for the campers that occupy
this
part of the property for most of the summer. The camp is
operated by Friendly House,
and is quite popular in the summer months.
This cabin gave me a sugar craving.
Here
we are at last, the Sky High Lodge, situated on the top of a hill
overlooking a valley. This is a large building with plenty of
space for vendors, presentations, and other things. Turning
around, we see the view below.
This is the view from the side of the lodge shown above. We
saw a number of deer at the bottom of the hill near the woods.
The
inside of the lodge had plenty of space for lots of activities, and a
darker room on the floor below was set up for talks using a projector.
I gave another talk on Saturday afternoon.
After dinner on
Saturday, clouds began to increase. The public enjoyed the
views
through the 36", but the sky got worse by the hour. By
midnight,
the summer triangle stars were just about all that could be seen.
So, of course at that point people sit around talking, and
this
can turn out to be one of the most enjoyable times at a star party.
We spent some time playing around with an image intensifier,
looking around to see what was going on around us as some off in the
shadows enjoyed a tasty beverage, or perhaps several. People
were
gradually turning in, and with a long drive on the following day, I did
too.
I packed up on Sunday, pleased with how the telescope was
performing, but hoping to get back for some more observing under
clearer skies.
So,
if you can make it over to north central Ohio, stop by and enjoy the
views, and if you can, leave a donation to help Bigger Blue operate and
be improved in the future.
