by Jay Reynolds Freeman
For me, astronomical binoculars are special-purpose instruments, for quick and easy wide-field views, so I almost always use them hand-held. My Orion "Giant" 14x70 -- one of the last before the current, lighter, 15x70 was introduced -- is perhaps the best of the half-dozen or so that I have owned. It is almost too large and too powerful to hold, which means it has almost exactly as much performance as I can handle. (By the way, be warned: The edge at which a hand-held binocular becomes unwieldy is sometimes very sharp, and varies from person to person.) I know several tricks for holding it unbraced, but when circumstances permit, I like to lean either myself or the binocular against something solid when I am using it, or prop my arms on a rigid surface, or something like that.
My rented Isuzu Rodeo had a two-piece back door. The rear window tilted up, and the lower door panel was hinged at the side. I parked it facing north -- toward the summit of Mauna Kea -- and sat on the rear threshold with the door pulled toward me, half closed. Thus I could brace arms and binocular on the top of the door for observing, and also get some shelter from the wind. From this position, I surveyed the part of the heavens that I had swept with the 10-inch. Sometimes I would look to see how a specific object appeared in the binocular. Sometimes I would notice something, and have to check my charts to see what it was. I also paid attention to large features, like star clouds, rifts, and dark nebulae, that were too big for the field of the Dobson.
I have been mentioning binocular observations of southern objects along with descriptions of them in the larger telescope, so I don't have a great deal to add that is new. Yet there is certainly plenty to do with a binocular in these skys. I logged more than fifty observations of southern objects with the 14x70, plenty to warrant having it along. The large, bright, and famous stuff -- the eta Carina complex, omega Centauri, the Jewel Box, and numerous of the open clusters that I have already mentioned -- all showed interesting detail. Alpha Centauri was resolved. And the prime object for binocular astronomy was the galaxy itself, as a whole.
If I had had no telescope, I would have been disappointed, but a night or two with a large binocular would have been very satisfying. You northerners who have an opportunity to travel south, but who do not have a portable large telescope, or are limited in budget or baggage allowance, by all means bring a binocular, and be prepared to enjoy yourself. A smaller one would do. For real saving in space and weight, consider a large-aperture monocular, if you can find one, and if you can't, you might get a suitably sized binocular with individually focusing eyepieces, and take it apart at the hinge. One of the popular small f/5 refractors, which come in 80, 90, and 100 mm aperture, might make an even more versatile package, but I suspect you would need a tripod for it. A monopod with a simple tilt head might make a good, compact support, for a binocular or for a low-magnification telescope.
Again wishing to use a familiar yardstick to evaluate both site and southern celestial wonders, I decided to review some Messier objects. I got carried away. In an hour or so cumulatively, spaced over the night, I went through eighty-three of them, from the Beehive and M67 all the way around to M2, M15, M30, and M39. That was easier than it sounds -- I have been through the Messier catalog more than twenty times, and can find most of them without charts, and a 70 mm binocular of modest magnification is probably the easiest instrument for a Messier survey: It is capable enough to show them all without difficulty, and has a wide enough field to make finding them a cinch.
The southern objects fared very well in comparison. Except for the Beehive, and for the Messier objects in the Scorpius, Sagittarius, and Scutum Milky Way, the patch of heavens that was new to me had more stuff with interesting detail for the binocular, than that part of the Messier catalog that I could see.
The Messier objects also fared very well. As I cross-indexed my observations onto file cards, back at home, I noted that the cryptic notes I append to each such reference often indicated less detail seen in previous views of these objects with the 14x70, when I was doing a Messier survey with it not long after I bought it, than I could see from the Visitor Center. What's more, many of the observations for the 14x70 Messier survey were made from very dark sites in the southern Cascade Mountains, near Lassen Peak, at altitudes of 1.5 to 2.5 Km. I may have said it before, but let me say it again: The Onizuka Visitor Center on the side of Mauna Kea is a wonderful place for visual amateur astronomy.
Two hints of detail were particularly interesting. Both M83 and M51 showed what I would call anisotropic structure, whose nature I could not quite determine. That is, in binoculars of similar size, I regularly see these objects as diffuse patches whose brightness varies radially, and I can routinely see the companion to M51, NGC 5195, as well. But on this night, both galaxies showed hints of structure -- something like filaments in the fuzz -- that I had not noticed before with similar instruments. Clearly, the spiral arms were on the verge of resolution. Yet even knowing that these galaxies are spirals, I could not say that I saw spiral structure with the 14x70, only that there was structure present, just beyond my ability to detect precisely what it was.
I also used the binocular to push on the southerly limits of my main survey. As I said before, the Southern Pleiades, surrounding theta Carinae, was blocked from my big telescope by the wall of the Visitor Center observing patio. I had a nice view of it in the 14x70. I also saw a few other, more difficult, southerly objects. Peering south of Crux, I found several stars in Musca, and then noticed that alpha Musca, at beyond 69 degrees south declination, was visible to the naked eye -- did I say that Mauna Kea was a good site? A bit more than half a degree north of alpha, I detected the barest hint of open cluster Harvard 6 in the binocular's field. I think that was the most southerly deep-sky object I observed during the entire trip.
I usually have a binocular handy when I observe, but only rarely use one much. This night was an exception. I logged 155 observations with the 14x70, more than on all the previous ones with it, put together.
As I drove down the access road from the Visitor Center, I noticed Alpha Centauri setting toward the summit of Mauna Loa. Shortly before I reached the Saddle Road, it winked out, and I knew that my astronomical vacation had truly ended. But the next day had one more pleasant surprise. As I staggered to the departure gate at Hilo's airport, wondering why I had made a reservation for the absurdly early hour of 9:28 in the morning, two of the friends I had met on the island stepped forward to greet me. They presented me with a lei -- a real one, made with real flowers, in the finest Hawaiian tradition! How wonderful!
They say aloha can mean both "farewell" and "greetings". As my flight winged across the broad Pacific, away from Hawaii's frigid temperatures, thin air, and inky darkness, home to the soft sunshine and warm breezes of central California, that seemed appropriate. For I was already planning to return.