The Last Nights of Summer

At 10:30 on a September evening, I go out with my binoculars. Not to some pristine mountain observatory, but to a backyard within the city limits of Portland. Nor am I using the binoculars as a supplement to a larger telescope; they're all I've got right now. I am forced to pick a spot that cuts off as many light sources (house lights, yard lights, streetlights, headlights) as possible, while still providing a reasonable area of visible sky. With relative darkness located, I raise my binoculars for the first time. Jupiter provides a good focus test, and I fine-tune my binoculars until it is a sharp disk with just a bit of flaring and false color. Three moons are easily visible, but is that a fourth to the left, so close to the planet as to be invisible with the slightest shakiness in my hands? I am almost sure of it, but will have to check later.

Unless a power blackout occurs, this yard isn't likely to get any darker. Portland proper lies to the north and west; Gresham to the east and northeast. There is a relative "sweet spot" in the southeast, but with an emphasis on "relative". The night is warm, but autumn is fast approaching. The rest of nature knows, from the suddenly active birds to the woolly bear caterpillars on the roads to the yellow jackets that have come inside the house to die in a desperate attempt to over-winter. The sky shows the colors of fall, too, with dim Pisces and Aquarius dominating the southern view.

My natural inclination is to turn towards the zenith; it is fairly dark there as well. Cygnus rules here, a vestige of summer flying down an attenuated but obvious Milky Way. Its head, Albireo, is easily split into two stars even at 8x. I can't see any blue color in the fainter one tonight. Cygnus also boasts two Messier open clusters: the bright, triangular M39 and the inconspicuous M29, both of which are easy binocular objects even in poor skies. I try for the Veil Nebula, but can't see it. Maybe my eyes aren't fully dark-adapted yet, or maybe the sky just isn't dark enough.

Aquila sits in the Southwest; below it, the Scutum star cloud loses out to light pollution. M11 and M26 are visible in this area; M11 a triangular patch with a few stars visible and M26 just barely made out. Above Aquila are a few standout objects: M27, the Dumbbell, is a bright fuzzy; M71 a dim one. The Coathanger doesn't lose anything to the light pollution, and perhaps its shape is actually more apparent without competition from faint background stars. Continuing into Lyra, the Ring Nebula is visible; only its memorized location helps me separate it from the rest of the 9th-magnitude stars in the area. Moving on to Hercules, I find the globulars M13 and M92 to be easy targets. Binoculars may not be the best instruments to view these with, but M13 especially has a striking 3D spherical nature even at 8x. Nu Draconis is another neat double star for binoculars.

It is time to swing eastward. Saturn is rising through the tall trees, and is saucer-shaped and harvest-colored in the binoculars. M31 is visible to my unaided eye and very large in binoculars, but is a dim core of what it is from a dark site. M33 is only plain with averted vision in the binocs.

So, just how dark is it? A star count of the lower left diagonal half of the Great Square gives a limiting magnitude of 6.3. When I pick out individual stars with my binoculars, and then try to view them with my naked eye, I can see down to 6.4. Not bad, for a city site, but deep-sky objects tend to be less visible in light-polluted skies than a stellar limiting magnitude would suggest. A short, sharp meteor cuts through the Great Square as I am thinking about this. Patient, concentrated observing, the kind that is learned over years, can often cut through the muck more readily than a large telescope. I return to Cygnus, and finally make out the curve of the Veil, faint and ghostly.

Cassiopeia and Perseus are up in the northeast, another sign of time's passing. There are lots of clusters here, but many that are magnificent in dark skies get washed out here. The Messiers: M103, M52, and M34; survive, along with NGC 663, NGC 457, and the Double Cluster. The rising Pleiades and the linear asterism Kemble 1 are nice, big sights. Great binocular objects are large as well as bright.

I return to Jupiter; the fourth moon is no longer there. Either it started transiting the disk, went into eclipse, or wasn't really there in the first place. (I find out later that Io had just moved onto the disk, and that I actually had seen it before.) I catch a couple of globs, M15 and M2, before trying for a difficult object. NGC 7293, the Helix, is some 40 degrees down from my star count area in Pegasus, and the sky is bad down there. Visible in the humblest binoculars from a rural site, it appears only as a "maybe." I will go in soon.

A stray cat runs across the yard, and the city sings out its unnatural songs of horns and sirens. Another clear night, but how many more will there be before the year is out? Will the ominous signs of fall and winter doom my attempts to view the fall's meteor showers: the Draconids, the Orionids, the Leonids and the Geminids? I gaze again at Saturn and Jupiter, then walk through the door and pick up my notebook to record what I have just seen and thought.

Copyright Info.