One-Armed Spiral Galaxy NGC 4725
Image Credit &
Copyright:
Martin Pugh
While most spiral galaxies, including our
own Milky Way,
have two or more spiral arms, NGC 4725 has only one.
In this sharp color composite image,
the solo spira mirabilis seems to wind
from a prominent ring of bluish, newborn star clusters and red
tinted star forming regions.
The odd galaxy also sports obscuring
dust lanes a yellowish central bar structure
composed of an older population of stars.
NGC 4725 is over 100 thousand light-years across and lies 41 million
light-years away in the well-groomed constellation
Coma
Berenices.
Computer
simulations
of the formation of single spiral
arms suggest that they can be either leading or trailing
arms with respect to a galaxy's
overall rotation.
Also included in the frame, sporting a noticably more traditional
spiral galaxy look, is a more distant background galaxy.