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by Jay Reynolds Freeman
I was late getting to work in the morning, so I grabbed the handiest complete telescope I could lay hands on for our close-in mid-week star party on Wednesday, July 7, 1999. Fortunately, my Vixen 70 mm f/8 fluorite was set up in the living room, mounted on a light altazimuth mounting with telescoping legs. It took but a moment to carry it outside, fully assembled, and set it on padding in my car's cargo area. One more run for observing brief case, eyepieces, a few atlases, and -- mustn't forget essentials -- the coffee thermos, and I was off.
With clear, warm weather, eight telescopists gathered at dusk at the Montebello Open Space Area main parking lot, atop the hills south of Palo Alto, California. We had nine for a moment, as a local resident trotted up within thirty meters, looking for a handout, but no one had any spare munchies, so the coyote left. That's probably just as well -- wild animals habituated to humans run risk of disease and violence -- but I like to tip musicians, especially those as talented as the one the Navajo called "song dog". Perhaps it was this animal who serenaded us from time to time as the night wore on.
Distant cirrus traced a faint moire across the western sky as the sun set, but soon dissipated. I spotted Venus in early twilight, as a jet flew past it. I had only brought two eyepieces, but one was the versatile Vixen 8-24 mm zoom unit, which gives a quite useful magnification range of 23-70x with the 70 mm, as well as a wide enough field, at low magnification, to make finding things a cinch. The planet showed a lovely medium crescent at 70x, with enough variation in brightness between sunlit limb and terminator to create a wonderful three dimensional effect. There was no trace of extra color -- little Vixen fluorites have truly exquisite optics.
Mars and Spica emerged next, so I turned to the pink planet. 70x showed shadowy detail, but 70 mm isn't much for Mars, and I was in no mood for planets, anyway. So I put in my other eyepiece -- a 5 mm Pentax SMC-ED Orthoscopic (112x) and found Antares. With the star still low, seeing was poor: I thought I could see the companion from time to time, amid the scintillating flares off the giant star, but I knew where it was, and there were lots of flashes, so I didn't log it. Conditions were better at nu Scorpii, a few degrees up: At 112x, I easily split the wide, faint pair of this fine quadruple, and found the close, bright pair noticeably elongated. The current separation of the latter is 1.3 arc seconds, and Dawes's limit for 70 mm is about 1.6 arc seconds, so the instrument was doing well.
The sky had darkened enough for observers with equatorial mounts to find Polaris and align. Meanwhile, armed with the double-star listing from Sky Catalog 2000 and with Millennium Star Atlas, I nosed out a few fainter doubles, near the Scorpius / Ophiuchus frontier, that I had not yet seen. I had checked off stars viewed, in the catalog, so I just flipped through atlas pages, looking for doubles, glancing at the catalog to see whether they were new to me. The sky was still bright, so I confined my search to the area near Antares, which gave an easy jumping-off point for star-hopping. After five such doubles, it was dark enough for serious deep-sky work, so I dug out the "cats and dogs" list (a motley collection of mutts from diverse sources) that I use with my Celestron 14.
One wonderful thing about amateur astronomy is that after years observing, I can still find lots of new things to look at, even with a 70 mm telescope at a close-in site. My evening targets were open clusters. There are vast numbers of them strewn up and down the Milky Way, that no one -- including me -- ever seems to look at.
The reason why stems from an equipment-based bias of early visual observers. The NGC catalog is a compilation of for the most part visual work, and it forms the basis of most of the lists, catalogs, and databases from which today's amateurs select targets. We tend to think that stuff not in the NGC is "beyond" it -- lots harder to observe than NGC objects. It isn't so.
Early deep-sky viewers mostly used relatively large telescopes, at relatively high magnification, with relatively narrow fields of view. They missed scads of open clusters, not because they were too hard, but because they were too easy. William Herschel, scanning a narrow sky strip at medium magnification on an 18-inch telescope, might not have noticed or noted the few extra stars that signaled the passage of his field of view through a coarse cluster, but at lower magnification with a smaller instrument, such a loose clump of suns becomes very obvious, even to folks like me, with far less talent than Sir William.
Pick up a good modern catalog of open clusters, like the listing in Sky Catalog 2000.0, and see how many lack NGC numbers. Many of those are large, coarse and relatively bright. They bear the names of later catalogs, like Trumpler and Collinder, or arcane abbreviations like Do, DoDz, and Ru. Many are cheap shots, even with just 70 mm of aperture.
I looked for sixteen, all in the Scorpius and Sagittarius Milky Way, and found all but one. I had never observed any of them before. Most were resolved, or at least granular, in the 70 mm at 70x. The zoom eyepiece and the wealth of bright stars in that area made locating their positions very easy, and the clear, dry air mass kept the sky dark along my line of sight, even only a few miles from one of the world's major metropolitan areas. And I found so many things, so quickly. After only an hour and a half of observing, I had to go home, if I was to get enough sleep for work the next day. I set the little telescope back in the car and closed the hatchback. Looking up, I caught sight of epsilon Lyra, high in the sky, and for a few moments my eyes, glasses, and the atmosphere all worked together, and I could see it as two stars.
What a wonderful night.