In the summer of 1996, while perusing Sky and Telescope, I came across ads describing solar eclipse vacations to Aruba in February 1998. Having never viewed a total solar eclipse and considering the Caribbean a good place to be in February, I asked my wife if she wanted to do this for a vacation (No arm twisting there!). So we sent in a deposit and are now anxiously waiting to depart in less than two months. Once the excitement of having made these plans settled down, I realized that, in addition to the novel experience of a total solar eclipse, this was the farthest south, by far, that I had ever been. Omega Centauri etc. beckoned! My first thought was to take my 8x56 binoculars (and probably will), but upon reflection realized this was a great opportunity to do something I had always wanted to do: Build a telescope!

As I am a member of the National Capital Astronomers in addition to NOVAC, I was aware of the mirror grinding classes run by Jerry Schnall at American University (Fridays) and the Chevy Chase Community Center (Tuesdays). I went to the next Tuesday night session the week before Thanksgiving (1996), bought a 6-inch mirror blank and tool and, with Jerry's expert direction, started grinding. My plan was to make a short-focus f/5 mirror and to build a two-truss telescope with a Dobsonian mount. Critical to the plan was the fact that the whole telescope (minus the optics) must come apart, pack in a suitcase and transport, unbroken, on an airplane. The optics (primary and secondary mirror) needed to end up in a small box to be carried on the plane as hand luggage. Of great additional technical help in this project were three sources: a web site called The ATM Page (in particular the design of a 'Scope Like Alice' by Ron Ravneberg), the book 'Build Your Own Telescope' by Richard Berry, and Bob Bunge of  NOVAC. I consulted each frequently.

Jerry Schnall warned me that making a short-focus mirror was much more difficult than the normal 'first mirror' which is usually a 6-inch f/8. His warning proved to be entirely correct as my mirror grinding went quite slowly compared to others in the class who started after I did, ground and figured their 6-inch f/8 mirror, and went on their way. All the time I would grind and measure, grind and measure, and grind and measure. This extra work was, of course due to the fact that a short-focus mirror requires a much deeper 'hole' to be ground out of the flat blank. When I got my mirror spherical (the first goal) it was late February and I had spent perhaps fifteen 3-hour sessions grinding. Next came polishing and figuring, which I had seen my classmates do in 6-8 hours. However, once again, because I had a short-focus mirror these processes were much more difficult and time-consuming. I kept polishing until the Ronchii test indicated a smooth mirror and I kept figuring until the Focault test indicated that my mirror was the required parabola within 1/10 of a wavelength of light. These processes took me through the end of April but it appeared by the bench tests that Jerry had helped me make a good mirror which turned out to be an f/4.85, close to my original goal. Jerry aluminized it for $15.

At this point I faced the daunting (to me) challenge of building the telescope and mount. This appeared difficult to me as I had no wood-working experience or big power tools such as a drill press and table saw. Jerry Schnall, however, came to the rescue once again. The workshop at Chevy Chase Community Center has many wood-working tools and the workshop at American University has many metal-working tools. Using these tools, and Jerry's expert help, I cut the wood for my mirror box (8x8x10 which carries on the plane and stows under the seat), rocker box, and tripod. With a few iterations, these each came out OK and assembled and dissassembled in about 30 minutes. I then talked to Jerry about how to cut good circles of wood to use as altitude bearings. He introduced me to the lathe and we made two perfect 7-inch wooden circles whose edges I surfaced with formica and attached to the mirror box with bolts that allow detaching for transportation. The formica surfaces of these altitude bearings ride on teflon pads which I attached to the rocker box in the classical Dobsonian fashion. Similarly, the the azimuth bearing was generated by surfacing the bottom of the rocker box with formica which rides on teflon pads attached to the top of the short (23") tripod. Although most Dobsonian telescopes do not have tripods, the 'tube' of my short-focus telescope was only going to be 30" long and to avoid having to be on my knees to observe, the tripod was added. Lastly, I had to consider the secondary mirror and focuser. In talking with Jerry he convinced me it is not worth trying to make a secondary mirror so I bought one from Orion. Jerry had made a single stalk support for such mirrors from brass which I attached to a flat board along with an excellent 2" focuser I purched from Astro Systems. Two hardwood trusses were made that attach the focusing board to the mirror box. Using directions in Richard Berry's book, with modifications suggested by Jerry, I built a mirror cell and glued in the primary mirror. I bought some black rip-stop nylon, learned the rudiments of sewing, and made a shroud supported by four threaded posts that blocks stray light from entering the eyepiece. Finally, I was finished and it was the weekend after Thanksgiving (1997). One year of fun!

But, did it really work? Using a laser collimator I have for my other telescope, I lined up the optics and with great trepidations I took it out into the cold November night and quickly found Saturn. All I could get was a blurry image! How could this be after all the bench tests indicated I had a good mirror? Leaving the telescope outside, I went back into my house and thought about it. Having finally realized that the mirrors had just been taken from 76 degrees to 25 degrees, I decided to wait an hour for the mirrors to cool. Upon returning to the back yard and finding Saturn again there now was a crisp image of the beautiful planet in the eyepiece. All those stories about letting your optics cool down are true! I wanted to see how this rich field telescope would do on deep sky objects but since the limiting magnitude from my back yard is around 2 at best I knew it was useless. As we were planning a trip to my brother's for Christmas and as he lives in the dark skies of the California desert near Palm Springs, I decided to do a road test of the whole scope and take it with us.

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Ready to board the plane! 6-inch mirror box contains primary and secondary mirror as well as the focusing board and focuser At right is the scope completely dissassembled and packed.

My wife, Jacki, 12 year-old son, Andy, and the telescope arrived safely in California on Christmas day. The next morning I assembled and collimated it and at sunset took advantage of the proximity of Mars and Uranus (less than a degree apart and fitting easily into the 1 degree field of the 9 mm Nagler at 82x) to show everyone 5 planets (including Venus, Jupiter, and Saturn). The real interest for me, however, came several hours later when the sky got really dark and the winter Milky Way could easily be seen from the backyard. Quite a contrast to my backyard!

I was able to readily find several Messier objects because the short-focus of the mirror translated into an extremely wide field of view (1.8 degrees at 46x for the 16 mm Nagler). The great Orion Nebula was fantastic with or without a filter. The open clusters in Auriga (M36, 37, 38) were big and bright as was M35 in Gemini and M41 in Canus Major. The double cluster in Perseus was fantastic and it was the first time I had ever been able to get both clusters in the same eyepiece. I checked out the galaxies M81 and M82 in Ursa Major and they were easy, bright objects. Even the tiny globular cluster M79 in Lepus and the dim supernova remnant M1 in Taurus were easy objects that showed some detail.

All this made my year of work on this telescope a resounding success. My hopes of bagging many new southern objects from Aruba are high. The total solar eclipse almost seems secondary to me now, but I am sure that when the shadow approaches, it will be very exciting. I'll let you know.

Diamonds in the Sky

Written for the NOVAC newsletter; April 1998

For the upcoming eclipse we had to fly from D.C. to Maimi to Aruba.  My newly constructed 6" reflector, my wife Jacki, and I arrived in Aruba late on the Monday prior to the Thursday eclipse. We immediately noticed not only the beautiful turquoise water and white sand beaches but also the high (20-40 mph) and steady trade winds, each of which the island is famous for. Tuesday we used our rental car to scout the island for potential night-time observing sites, keeping in mind that we had to escape the light pollution of Oranjestad as well as the prevalent winds. The latter was really critical as the Teflon/Formica bearings on the Dobsonian mount combined with the nylon shroud used for a tube make the little scope a great weathervane. Finally, on the eastern, uninhabited side of the island we found what looked like an old pirate castle which turned out to be an abandoned gold smelting plant a hundred yards from the rugged coast. It had high stone walls that blocked the wind and no roof with several levels inside. That evening, I went to bed early and set my alarm for 1:30 am. In the dark drive back to the 'castle' I found myself lost several times. Stopping to consult a map proved to be a harrowing experience as packs of dogs immediately congregated around the car and chased me away. It was clear that I needed to get completely away from civilization (and dogs). Finally arriving at the site about 2:45, I climbed to the uppermost level and set up. The sky at zenith had a visual limiting magnitude of 6.5 with skyglow only to the west. Through a tumbled-down section of the south wall was a great southern exposure with Centaurus and Crux just culminating! These constellations were both new to me and proved to contain several beautiful gems. Omega Centauri, my main target, was visible to the naked eye as a dim star-like object. At 82x and 1 degree field of view it filled more than half of the eyepiece with stars. For comparison, I looked at M13 and realized just how incredible Omega really is. That evening, as well as another on Thursday night, was filled with great objects like Centaurus A, whose dust lane was clearly visible, the nearby NGC4945, a cigar-shaped, edge-on spiral, and NGC4755 or K-Crux, the Jewel Box cluster. On Thursday evening I was introduced to a group of 'new', and quite dazzling, objects in the tail of Scorpius, NGC6231, H12, and NGC6227, which were all high in the south by 5 am. Sagittarius, Scutum and the summer Milky Way were up high enough to catch many of their great objects before the approach of morning twilight chased us out by about 6:15 each day. All-in-all, my new little home-made portable telescope performed beautifully which made its year of construction seem like time well-spent. An additional memorable, and unique, moment came that Thursday night when I was looking through my companion's 80 mm refractor when, bang!, a meteor streaked through the field and its glowing, greenish, trail lasted 3-4 seconds. It turned out we saw several other meteors (not through the eyepiece) that night in the inky sky of the Caribbean.

Thursday dawned bright and beautiful and found a number of people already set up with cameras and telescopes for the upcoming eclipse with totality scheduled to begin about 2:10. We set up around 10:30 in a protected (from the wind) courtyard at the Sonesta Hotel in downtown Oranjestad with several groups of photographers. There turned out to be a tension-filled prelude to the eclipse as by 12:30 heavy, dark clouds had covered the entire sky and a bit of rain was spattering down. Spirits were sinking. By 1:00 it began clearing and a small bite was missing from the sun. By 1:20 the dark clouds returned (The crowd groaned!) but at 1:25 small breaks began to appear and the bite now consumed about 30-40% of the sun. By 1:40 it seemed as if the clouds were breaking up but I noted in my log that this may be wishful thinking. By 1:50 there was lots of blue sky and about 70% of the sun was gone. Thin clouds reappeared at 2:00 and the sun was down to a sliver. At 2:04 a big blue patch of sky surrounded the sun but a fast-moving cloud covered it for a minute, clearing by 2:06 (The crowd cheered!). At 2:09 Bailey's beads appeared for a few seconds followed quickly by a beautiful diamond ring (Loud cheers!). Then totality plunged us into darkness. Mercury and Jupiter, both about 3-4 degrees away, framed the sun. The milky white corona was very large and asymmetrical with long streamers coming out mainly to the east and west. In addition to the naked eye, we viewed it at 25x with 2 degrees of field and it filled the eyepiece. Great detail was seen in the streaming corona. One large and one small prominence could be seen in the chromosphere on the leading edge of the sun. The colors of the prominences were quite beautiful blending reddish orange and pink. Several hotel employees begged a view and we gave them (7) each about 5 seconds. We were thanked profusely afterwards. Near the end of totality several prominences on the trailing edge of the sun became visible displaying the same beautiful colors. The reemergence of the second diamond ring came too quickly! The whole town seemed to be cheering and fireworks were going off. Although the clouds had threatened to hide the eclipse, in the end it all turned out wonderfully. I was asked at a dinner two nights later what my most memorable viewing experience had ever been and it was easy to answer that the view of the totally eclipsed sun with its delicate corona and beautiful prominences was the clear winner.

    Diamond Ring                Totality                 Bailey's Beads