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The Caldwell Objects

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suggest that our universe may be only 12 or 13<br />

billion years old. NGC 5286 lies 28,000 light-years<br />

from the galactic center and 36,000 light-years<br />

from the Sun. In brightness, apparent size, and<br />

distance, NGC 5286 resembles M68 in Hydra. <strong>The</strong><br />

cluster is moving toward us at 58 km per second,<br />

a quarter of Omega Centauri's radial velocity.<br />

Interestingly, if you were to reel NGC 5286 in to<br />

Omega Centauri's distance, NGC 5286 would still<br />

appear about 2.5 times smaller, and 10 times<br />

fainter, than that great cluster.<br />

James Dunlop discovered this cluster from<br />

Australia with a 9-inch reflector. It is listed as the<br />

388th object in his 1827 catalog. Of it he writes:<br />

"A bright exceedingly well-defined rather<br />

elliptical nebula, about 1' diameter, exceedingly<br />

condensed almost to the very edge, and gradually<br />

a little brighter to the centre. This is about 6'<br />

north of Μ Centauri. — I have strong suspicion<br />

that this is resolvable into stars."<br />

From Hawaii I can see Μ Centauri with the<br />

unaided eye but I could not resolve the cluster<br />

next to it. I do not think it impossible to do so,<br />

however, especially for someone who observes<br />

from the Southern Hemisphere with younger<br />

eyes than mine. <strong>The</strong> globular reveals itself with<br />

the slightest of aperture. In 7x35 binoculars it<br />

84<br />

looks like a tiny ghost image of Μ Centauri, a<br />

dim puff of smoke wafting away from that<br />

alluring flame-colored star. At 23x in the 4-inch,<br />

the color contrast between the two objects is<br />

remarkable. Μ Centauri looks strongly yellow<br />

with a tinge of orange — like a dim Arcturus—<br />

while the globular cluster glimmers with a very<br />

pale ashen blue. Still, at this low magnification<br />

little else can be seen; the cluster looks like a<br />

circular wafer of uniform light, a breath spot on a<br />

mirror. <strong>The</strong> late, great comet discoverer Jack<br />

Bennett of South Africa included NGC 5286 as<br />

the 64th entry in his list of objects that looked<br />

cometlike through a 5-inch rich-field refractor.<br />

Indeed, I have spotted NGC 5286's misleadingly<br />

cometary form several times in my own comet<br />

sweeps of the Centaurus area.<br />

At 72x NGC 5286 appears as a moderately<br />

condensed glow with stumps of starlight poking<br />

out at the cardinal directions in a cruciform<br />

shape. <strong>The</strong>se are probably the "faint star points"<br />

that Ernst Hartung glimpsed with his 4-inch<br />

telescope. <strong>The</strong> cross lies on an elliptical bed of<br />

fainter suns. Under a dedicated gaze, star<br />

patterns seem to spiral out from the cluster's<br />

condensed core, which appears very mottled or<br />

patchy, as it is interspersed with dark veins. This<br />

view is rather reminiscent of Dunlop's discovery<br />

impression. And Dunlop's "strong suspicion" that<br />

this cluster would resolve into stars was most<br />

certainly justified. Although NGC 5286's<br />

horizontal-branch magnitude is 16.5, the cluster's<br />

brightest stars shine at a respectable magnitude<br />

of 13.5, so partial resolution can be obtained in<br />

good telescopes with apertures as small as 3<br />

inches.<br />

At high magnifications the cluster sports<br />

some seven arms. Two of them — one to the<br />

south and one to the east — form a counterclockwise<br />

spiral. <strong>The</strong> other arms look more rigid.<br />

Each is dappled by a few 13th- and 14th-<br />

<strong>The</strong> <strong>Caldwell</strong> <strong>Objects</strong> 337

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