The Caldwell Objects

12th-magnitude double star. The cluster's eastern
hemisphere is broken by what appears to be a
large, dark lane, past which a wedge of starlight
continues eastward. The longer I look, the more
complicated the view becomes. As my eye
becomes accustomed to the view, all manner of
star strings, dark halos, faint extensions, and
tangles of interacting starlight take shape and
follow seemingly random paths. The cluster
becomes even more dramatic at high power,
when swarms of 13th-magnitude suns sparkle
forth from the background haze. A series of at
least three dark patches can be seen to the east,
each separated by a narrow bar of starlight. A
dark patch also stains the northwestern quadrant
of the inner core.
Well-resolved globulars can be visually
maddening. The eye-brain combination tends to
work overtime trying to connect streams of
79
starlight, which come and go with the seeing. It's
like watching snow fall through an open window
in a heated room. Whenever I get overwhelmed
with the view, I gently place the cluster out of
focus and look for the strongest concentrations of
starlight. Doing this also helps the dark areas to
stand out more clearly from the stellar quagmire.
Although regarded as a fine "southern"
object, NGC 3201 is theoretically visible as far
north as London, Ontario, though from there it
would be a horizon-kisser at best. If you return to
low power and look 1½° to the south of the
cluster, you'll see a red ember glowing just west
of a gently curving stellar trio trending northeast
to south. That's the light of the type-M3
semiregular variable star WZ Velorum, whose
brightness oscillates between photographic
magnitudes of 9.0 and 10.0 every 130 days.
The Caldwell Objects 317