University Lowbrow Astronomers

My Mak-Newt.

by Jim Forrester
Printed in Reflections: November, 2002.

Last December, my wife and I drove south to visit her aunt and uncle in central Florida and to spend several days camping in the Everglades.  We might have flown, but his would have made taking my six inch mak-newt telescope along very difficult.  After a two-day drive we arrived in Lady Lake, Florida and the following night I set up my Intes MN61 telescope in a suburban backyard.  This scope is supposed to produce refractor-like views, comparable to a TMB 105 or an AstroPhysics Traveler, but at less than a third the price.  I knew the design was capable.  I had looked through a Ceravolo 5.7 inch Maksutov-Newtonian on Peach Mountain a couple of years previously and had been very impressed, but it too carried an impressive price.  The design combines the deeply curved corrector plate of the Maksutov with the small secondary of the Newtonian.  The secondary is mounted to the inside of the corrector, thus eliminating any spider vane interference.  The secondary obstruction is about 18%, not at all noticeable or so the theory goes.

I had gotten the scope in August, and between pressure at work and bad luck, I had done only a little observing, and that usually through sucker holes.  Being the new guy with the new scope it was, of course, my fault when an open house got clouded out.  After the “Fog of the Century” wiped out the Leonid Star Party, I began to wonder if I would ever have a good night of observing.

I was finally set up under clear, steady skies.  No clouds, nowhere.  But would the scope perform?  I should not have worried.  A few months before, Sky and Telescope published a wonderful photograph of Jupiter with one of its moons casting its’ shadow on the planet below.  I thought to myself “No telescope I’m likely to own will show me anything like this.”  I was wrong.  Finding Jupiter at 30X with three of its’ moons was such a clear, bright sight I increased the magnification to 72X.  What I saw had me reaching for a 2X barlow.  There was one of Jupiter’s moons (I later learned it was Ganymede)--a bright, sharp disc against a very black sky.  And on the top of Jupiter’s clouds, near the planets’ horizon was the shadow of that moon.  I was amazed and elated.  I boosted the magnification with all the glass I owned at the time to about 370X.  The view, while larger, was not really improved--some sharpness was sacrificed, though not much, the air being remarkably steady.

I tried some deepsky objects--M42 showed the trapezium but much of the nebula was lost in the sky glow.  No nebulosity showed in M45 either and M1 was impossible (as it always had been for me) to find at all.  So I returned to Jupiter and by this time the moon had begun its’ transit.  I was quite happy to stay with the giant planet until it was time to pack up the gear for the night.

The next day found us on the road driving the 300 miles to Everglades National Park.  The park, though on a line only about 50 miles from Miami, is a wild place--full of waterfowl, alligators and mosquitoes.  December and January are the most bug free months in the park.  Most winters are cool enough to make them almost disappear.  Last December, being unusually warm, was not one of those years.  If you are one of those persons the only mosquito in a hundred miles will find, camping and observing in the Everglades will feel suicidal.  For the most part, though, the bugs were no worse than an average summer night on Peach Mountain.

We were camped on the shore of Florida Bay.  The sky south over the water and to the west was very dark.  But to the northeast the Miami Nebula played role the Ann Arbor Nebula plays here--you just have to wait until earth rotates the objects of your observing desire out of the sky glow.  The skies were not a great deal darker than Peach Mountain, but the air was very steady and transparent and a great deal warmer than home in December.

Being relatively new to observing (and having a rather flat learning curve), I was finding many objects for the first time.  The parade overhead of M34, M35, M36, M37 and M38 (though not in that order) was wonderful.  I was able to catch Ml5 before it disappeared in the west.  M42 was a wonderful sight.  I had known there were four stars in the trapezium.  But I saw six over Florida Bay.  At 250X, the extra two stars were clearly there, though fuzzy.  I’ve since learned there are actually eight stars in the trapezium, but as they’re rarely seen, I don’t feel too bad missing them.

The nebula itself was very bright, providing a lovely frame for the trapezium.  An OIII filter brought out more detail in the nebula, but as the brightness was cut back, I can’t really say it was a better view.  What was a better view in the OIII filter was NGC 2237--the Rosette Nebula-- in Monoceros.  The cluster (NGC 2244) that lies as a couple of line of stars in a kind of doughnut hole in the middle of the nebula can be seen in binoculars, but the nebula reveals itself as a large, spectral object in the OIII filter.  Some nebulosity in the Pleiades was visible at 56X.  And finally M1 was finally right where it was supposed to be nearer the end of the lower limb of the Taurus asterism.  The OIII filter turned something that was barely there into a marvelous tangle of wispy tendrils.  We drove back to Lady Lake Christmas Eve.  December 28 found me observing from the backyard again, this time over the rooftops to watch the Moon’s occultation of Saturn.  The pair was well over the houses when Saturn slipped behind the slim dark limb of the nearly full Moon.  Again, the Intes provided a bright image of great contrast even though the target was quite low in the sky.  The Moon slid below the line of houses just before Saturn was to reemerge, but I felt no regret as I had finally been able to put the scope through its’ paces with terrific results.

Some notes on the scope--I obtained my MN61 from Bill Burnett of Internet Telescope Exchange in Montana.  The scope comes with an optical certification.  (My mirror checks out at 1/7.5 wave with a 96% strehl ratio.)  The F6 focal ratio gives good deep space and terrific planetary views.  While the scope is built like a tank, I did manage to knock it out of collimation.  If you ship it back to them, ITE will recollimate the scope--they recommend you not do it yourself.  If you are stubborn and a bit adventurous AND FOLLOW THE DIRECTIONS THAT COME WITH THE SCOPE you can do the collimation yourself.  You can get a crayford of helical focuser.  I have the helical (I got a deal) and it was very stiff.  I cleaned it and put a tiny bit of synthetic gun oil on the threads.  It worked wonders and the focuser is now very smooth.  Be careful, though.  Solvents ruin paint jobs and optics.  Best practice is to remove the focuser to clean it.  Use as little lubricant as possible.  Oil simply attracts grit and the more you use, the more dirt you collect sooner.

Finally--This is a very good telescope.  As it weighs almost 10kg, be sure to have a mount and tripod sturdy enough to carry it.  Coupled with its’ length (about a meter), this scope is not airline carry-on luggage.  Which brings us to the end of this article and the beginning of the next--my TMB105 refractor.

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This page originally appeared in Reflections of the University Lowbrow Astronomers (the club newsletter).
This page revised Sunday, March 9, 2014 4:30 PM.
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