Quoted from SEDS:
Discovered 1781 by Charles Messier.
Messier 90 (M90, NGC 4569) is one of the brighter spiral galaxies
situated in the
Virgo Cluster of Galaxies.
Spiral galaxy M90 is one of the eight galaxies found and
cataloged on March 18, 1781 by
Charles
Messier in the Coma-Virgo region, in addition to
M92, the Hercules
globular, to round up score to nine newly cataloged objects on that day.
M90 is one of the larger (9.5x4.5') spirals in the
Virgo Cluster of
Galaxies. It has tightly wounded, smooth bright spiral arms, which
appear to be completely "fossil", meaning that currently no star
formation appears to take place, with the only exception of the inner
disk region, near the darker dust lanes. J.D. Wray speculates that this
galaxy may be on the way to evolve into a state similar to
M64, and then into
a lenticular (S0) system.
Although M90 is conspicuous and big, Holmberg has derived quite a low
value for its mass, which implies that this may be a very low density
galaxy.
As it is approaching us at 383 km/sec, it must have the very high
peculiar velocity of nearly 1500 km/sec through the Virgo cluster into
the direction pointing to us, and possibly is just in process of
escaping the cluster; some sources have speculated it may already have
left the cluster and be now a considerable distance nearer to us. Only
one Messier galaxy is faster in approaching us,
M86.
M90 was included by Halton C. Arp in his
Atlas of
Peculiar Galaxies as No. 76 because it is a "Spiral with a High
Surface Brightness Companion", 14-mag IC 3583, which is well visible in
larger-field views of this galaxy such as the
DSSM image of
this galaxy, and appears somewhat distorted.
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