One-Armed Spiral Galaxy NGC 4725

Explanation: 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, a more traditional looking spiral appears as a smaller background galaxy.