The Caldwell Objects

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nearly 3°-wide field, the dipper dominates the
western and central parts of that field. Now
return to the galaxy, but do not increase the
magnification just yet. Give your eye some time
to adjust to its faint light. With time, some subtle
details might start popping out at you. The
longer you look the more you should see. For
instance, one thing that should become
immediately apparent is that the galaxy is not
round but slightly elliptical, oriented northwestsoutheast.
That round section is just the very
bright core that John Herschel noticed.
Concentrate on the galaxy's core. It should
suddenly look like a bright star embedded in a
soft oval glow. Stay with it longer and look for an
arc of light in the galaxy's northwestern quadrant
as well as a knot to the southeast. Few galaxies
allow us to study them at such low power and
yet see so much detail.
At 72 x the galaxy, though tiny, starts to
break up into a series of knots and gaps. It looks
like it is on the verge of exploding. The knots
come and go with the seeing. To make sure I'm
not straining my eyes, I'll frequently get up and
start walking around my telescope, taking deep
breaths and replenishing the oxygen supply to
my brain and eyes. Back at the eyepiece, I look at
the object for brief periods rather than
incessantly. With NGC 1097 your vision needs to
be tack-sharp and your mind alert enough to
record the most fleeting of details. Once I spot
something curious, I immediately take my eye
away from the eyepiece and pencil in that detail.
By repeating this procedure over and over again,
I build up a decent visual record of fleeting
glimpses. This is also how I have recorded
planetary details at the limit of my vision: by
waiting out the atmospheric turbulence and
exploiting those fine moments of steady seeing. It
takes time and practice, but the rewards are
usually satisfying. This is how anyone observing
a galaxy
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through a small telescope can see details that
other observers casually see in larger instruments.
I say "casually" because observers with
big scopes can see even more if they take the time
to do it right. Seasoned amateur Tom Polakis
indirectly confirms my suspicions. Of observing
NGC 1097 with a 20-inch reflector he writes: "My
impression before going out into the field to
observe it was that the outer arms would be
difficult, and the inner structure spectacular. The
object yielded the opposite result. Using a 20-inch
at a dark desert site, the outer arms were quite
visible even to a novice observer. The bright
inner spiral was only a bright, mottled disc. This
detail may be more seeing dependent than
anything — sort of like looking for detail on
Jupiter."
What other details can be seen in NGC 1097
in a 4-inch from a dark Hawaiian site? With
moderate power the galaxy's nucleus is a bright
pinprick of light surrounded by a tight lens in the
middle of a clumpy bar. A dark lane can be seen
on the northeastern side of the bar, while the
bar's southeastern end has two bright beads in it.
A single enhancement of fuzzy light lies just
southwest of the nucleus. The southeastern part
of the bar looks crooked
Deep-Sky Companions: The Caldwell Objects