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The Caldwell Objects

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2 1<br />

Box Galaxy<br />

NGC 4449<br />

Type: Irregular Barred<br />

Dwarf Galaxy (IBm)<br />

Con: Canes Venatici<br />

RA: 12 h 28.2 m<br />

Dec: +44° 06'<br />

Mag: 9.6<br />

Dim: 5.4' x 4.2'<br />

SB: 12.8<br />

Dist: 10 million light-years<br />

Disc: William Herschel, 1788<br />

W. H ERSCHEL: [Observed<br />

27 April 1788] Very bril-<br />

liant. Considerably large.<br />

Extended from south pre-<br />

ceding to north following<br />

[from southwest to north-<br />

east]. With difficulty resolv-<br />

able. Has 3 or 4 bright compressed spots. (Η I-213)<br />

GC: Very bright, considerably large, moderately<br />

extended toward position angle 15°, well resolved, star<br />

of magnitude 9 following [to the east] 5'.<br />

A S ONE CAN GLEAN FROM THE HERSCHEL,<br />

GC, and N G descriptions C tabulated above, NGC<br />

4449 is one object that deceived 19th-century<br />

astronomers into believing they had resolved a<br />

"nebula" into stars. At the time galaxies as island<br />

universes were unknown to astronomers. Many<br />

of these systems belonged to what they<br />

considered the realm of "spiral nebulae," which<br />

seemed to fit a cosmological model introduced by<br />

the French mathematician Pierre Simon Laplace.<br />

Laplace's model postulated that our solar system<br />

condensed out of a nebulous vortex, and the<br />

spirals, many presumed, were solar systems<br />

being born. Indeed, not until 1923, when the<br />

outer regions of M31<br />

<strong>The</strong> <strong>Caldwell</strong> <strong>Objects</strong><br />

NGC: Very bright, considerably large, moderately extended,<br />

double or [bifurcated?], well resolved, clearly consisting of<br />

stars, star of magnitude 9 following [eastward] 5'.<br />

21<br />

were first resolved with the 100-inch reflector on<br />

California's Mount Wilson, was the true nature of<br />

the mysterious spirals revealed. In fact, until that<br />

time M31 was commonly referred to as the Great<br />

Spiral N e b in u Andromeda. l a<br />

Unfortunately, no 19th-century telescope<br />

was powerful enough to reveal individual stars<br />

in a distant galaxy like NGC 4449. Looking at a<br />

photograph of this irregular system, it's easy to<br />

understand how the astronomers of that era were<br />

deceived; the galaxy looks like a clouded<br />

hourglass wrapped in knotty stellar filigree. One<br />

can only imagine the excitement these<br />

astronomers must have felt when they imagined<br />

the galaxy resolved into stars. Of course,<br />

89

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