Messier 49
Elliptical Galaxy M49 (NGC 4472), type E4, in
Virgo
|
Right Ascension |
12 :
29.8 (h:m) |
|
Declination |
+08 :
00 (deg:m) |
|
Distance |
60000
(kly) |
|
Visual Brightness |
8.4 (mag)
|
|
Apparent Dimension |
9x7.5
(arc min) |
Discovered 1771 by Charles Messier.
Elliptical galaxy Messier 49 (M49, NGC 4472) is one of the brightest
member galaxies of the
Virgo cluster.
M49 was the first member of the Virgo cluster of galaxies to be
discovered, by
Charles Messier, who
cataloged it on February 19, 1771. It is also the second galaxy
discovered beyond the Local Group after Lacaille's discovery of
M83.
Eight years later, on April 22, 1779, on the occasion of following the
comet of that year, and on the hunt for finding more nebulous objects in
competition to other observers,
Barnabas Oriani independently rediscovered this "nebula." In his
Bedford Catalogue of 1844,
Admiral William H. Smyth confused this finding with Messier's discovery
and erroneously stated, "This object was discovered by Oriani in 1771." This
error was repeated by
John Herschel in his General Catalogue of 1864 (GC), who also
erroneously assigned this object to "1771 Oriani," and also found its way
into
J.L.E. Dreyer's NGC.
M49 is one of the brightest Virgo Cluster member galaxies with its mag
8.5, which corresponds to an absolute magnitude of approximately -22.8,
regarding its distance of about 60 million light years. It is one of the
giant elliptical galaxies in this great cluster (besides
M60 and
M87), and is of type E4 in Hubble's classification scheme. Its extension
of 9 x 7.5 arc minutes corresponds to an ellipsoid with a projected major
axis of nearly 160,000 light years (we don't know the real extension along
the line of sight toward us, of course, as we don't know the spatial
orientation of the real ellipsoid axes), so it is actually a big ellipsoid.
Older estimates have suggested a mass which might be bigger than that of the
nearby giant M87, but now it is assumed that M87 is much denser. With its
integrated spectral class G7 and color index +0.76, it is yellower than most
galaxies in the Virgo cluster. Longer exposures show a system of globular
cluster, which however is much less crowded than that of M87 and more
comparable to that of M60. According to
W.E. Harris' list, this galaxy has a system of 6300 +/- 1900 globulars.
The fuzzy nebulosity near the brighter star in the upper right is
probably a faint, small companion, as it also appears in the
DSSM image (observe the reverse orientation of these images, however).
In that image, many more faint companions can be seen, among them the
relatively bright peculiar galaxy NGC 4470 (photographic mag 13.0). The
foreground star was first mentioned by John Herschel and is of mag 13, so
that it might be erroneously taken for a supernova by observers unfamilar
with this galaxy's appearance.
Halton Arp has included M49 as No. 134 in his
Catalogue of Peculiar Galaxies as an "Elliptical with Nearby Fragments".
A probable supernova, 1969Q, of mag 13.0 was reported in this galaxy in
June, 1969.
JACANA ASTRONOMY SITE
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SOLAR SYSTEM
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STARS
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GALAXIES
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NEBULAE
SUPERNOVAE |
CLUSTERS |
DOUBLE STARS
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COMETS
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ASTEROIDS
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DUST CLOUDS|
ILLUSTRATED MESSIER LIST