The Caldwell Objects

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Centaurus A
NGC5128
Type: Peculiar Galaxy (SOp)
Con: Centaurus
RA: 13 h 25.5 m
Dec:-43° 01'
Mag: 6.7; 6.6 (O'Meara)
Dim: 16.7' x 13.0'
SB: 13.7
Dist: 16 million light-years
Disc: James Dunlop, included
in his 1827 catalog
J. H ERSCHEL: A most won-
derful object; a nebula very
bright; very large; little elon-
gated, very gradually much brighter in the middle; of
an elliptic figure, cut away in the middle by a perfectly
definite straight cut 40 arcsec[onds] broad; position
angle] = 120.3°; dimensions of the nebula 5' x 4'[.] The
internal edges have a gleaming light like the moon-
light touching the outline in a transparency, (h 3501)
NGC 5128 IN C ENTAURUS IS THE MOST
dynamic and intriguing galaxy in the heavens. It
is virtually a superlative in every region of the
electromagnetic spectrum. It is one of the
brightest naked-eye galaxies; by far the nearest
and most violent Seyfert-type galaxy known; one
of the most intense radio sources in the heavens;
and a wellspring of infrared, X-ray, and gammaray
radiation. The very sight of its photograph
tells us it is the epitome of mystery, a rebel
against extragalactic conformity. Its background
glow resembles that of an elliptical (E0) galaxy,
but its face is masked, Zorro-like, by a severely
warped, highly opaque band of dust — one much
wider and more chaotic than that found in any
edge-on spiral. Compare this celestial Faberge
egg with any other galaxy
The Caldwell Objects
GC: Remarkable, very bright, very large, very much extended
toward position angle 122.5°, bifurcated.
NGC: Remarkable, very bright, very large, very much extended
toward position angle 122°, bifurcated.
in the Caldwell and Messier catalogs and you
will see why NGC 5128 has been the nerve center
of astronomical debate ever since James Dunlop
discovered it almost two centuries ago.
Dunlop first encountered this visual oddity
while observing from Parramatta, New South
Wales. His description of it is rather lengthy:
A very singular double nebula, about 2½' long, and 1'
broad, a little unequal: there is a pretty bright small
star in the south extremity of the southernmost of the
two, resembling a bright nucleus: the northern and
rather smaller nebula is faint in the middle, and has
the appearance of a condensation of the nebulous
matter near each extremity. These two nebulae are
completely distinct from each other, and no
connection
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