The Caldwell Objects

shattered remains of their diminutive host
galaxies.
To find NGC 6352 first locate 2nd-magni-tude
Theta (θ) Scorpii and 3rd-magnitude Eta (η)
Scorpii in the southernmost part of the Scorpion's
Tail. Now look for 3rd-magnitude Alpha (α)
Arae, which forms the southern tip of an acute
triangle about 7° south-southeast of the midpoint
between Theta and Eta Scorpii. NGC 6352 is 1¾°
northwest of Alpha Arae. There's a fine stellar
pair nearly 15' to the southeast of our 8thmagnitude
cluster, and the two stars seem to
point to our target. Look also for a beautiful star
chain some 15' or 20' to the southwest; it spans 20'
and comprises six 8th- to llth-magnitude stars.
(Be sure to not confuse NGC 6352 with the
brighter, more conspicuous open cluster IC 4651
just Γ west of Alpha Arae.) NGC 6352 can be seen
in 7x35 binoculars, but I doubt that this can be
achieved from the city or from some suburbs; the
cluster's surface brightness appears very low, and
I needed averted vision to clearly make it out
from Hawaii's dark skies. At 23x NGC 6352 spans
7' (38 light-years) and appears round; at this
magnification, it is more conspicuous than some
of the fainter Messier globulars in Sag-
81
ittarius. I can see a distinctly mottled texture with
averted vision but no bright central condensation,
though the cluster does have a slight
enhancement toward the center. With a glance
the cluster appears perfectly round, but spend a
few minutes with it using averted vision and see
if it doesn't look slightly oval. The cluster also
possesses a gray sheen, as if it has silvered with
age.
At 72x the cluster is a terribly soft glow —
but wait a while and don't give up. With time I
spotted a very curious detached bar of light to
the southwest of the main milky globe, then a
very weak and curved arm to the south. Hints of
other arms jutted out from the core with filigreed
stellar clumps, especially a Crux-like
gathering in a dim arm in the cluster's southwestern
quadrant. When James Dunlop discovered
this cluster from the Southern Hemisphere,
he recorded a similar appearance through his 9inch
telescope, seeing a "rather faint nebula, of an
irregular round figure, 4' diameter, slightly
branched; easily resolvable into stars, with slight
compression of the stars to the centre." The
cluster's entire central body is surrounded by a
soft glow. The view is disturbingly asymmetrical,
and the asymmetry shifts with your gaze; the
more you concentrate on one section of emerging
detail, the more lopsided that part of the cluster
appears. It's like watching a kitten playing under
a sheet. Ernst Hartung saw this cluster as
"irregularly round . . . and resolved into very
faint stars, some of which can be seen with [a sixinch]
scattered through the haze and the outlying
region." "It is surprising," he added, "that John
Herschel's thorough sweeping missed this
conspicuous object."
A more coherent picture seems to emerge if
you sketch details as you see them. Do we record
the same features? For instance, to my eye the
cluster's eastern side looks smooth and gracefully
curved, while the western half looks
The Caldwell Objects 325