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.