This is the Sombrero Galaxy (also known as M104 or NGC 4594), it is an unbarred spiral galaxy found in the constellation Virgo (about 28-million light-years from Earth). The galaxy itself, which we are viewing almost perfectly edge-on, is about 60,000 light-years across. From this vantage point, one of the most prominent features of the Sombrero Galaxy is its magnificent dust lane. This thick band of dust makes up the rim of the sombrero. In contrast, the extremely bright starry bulge engulfs the galaxy with the diffuse glow of billions of stars.
In the foreground of the picture, near the bottom-right corner, is a star that appears very large. It is located within our own Milky Way. The large spikes protruding from the star is caused by the "diffraction of light around the struts holding one of Hubble’s mirrors in place." (per hubblesite.org).
Finally, in the background of the image, about a fifth of the way in from the bottom-left corner, is a pair of spiral galaxies. Astronomers believe they are in the process of gravitationally interacting with one another. Whereas these galaxies are probably the same size as Sombrero, they are much further away and, thus, appear much smaller.
Download a larger image here.