NGC 5474 is an asymmetric spiral galaxy and
it it is being dramatically disturbed by its much larger
neighbor M101. At first glance, it might appear that M101 is
somehow gravitationally dragging the nucleus right out of NGC
5474. However, astronomers that model these kinds of galactic
interactions on a computer find a slightly different story. When
using tens (if not hundreds) of thousands of point masses for
stars, astronomers found that the asymmetry displayed in NGC
5474 is probably relatively short lived. We just happen to be
looking at this galaxy in a state of "sloshed" agitation. As NGC
5474 orbits M101, the amount of asymmetry depends of the
relationship between the direction of orbital revolution about
M101 and the sense of rotation for NGC 5474's disk. If the
revolution is opposite that of disk rotation, as it is in the
case of NGC 5474, then the lopsided state can survive for many
galactic rotations after an initial (strong) tidal perturbation.
