Actually, it’s the image of a nebula surrounding a young pulsar known as PSR B1509-58, as taken by NASA’s Chandra X-ray Observatory. Phil Plait of Bad Astronomy blog explains:

If you look at the wrist of the hand, you’ll see a brighter swirl of gas. In the center of that blob is a tiny object, a neutron star called B1509: an incredibly dense sphere of subatomic particles, leftover when a massive star goes supernova. While the outer layers of the star explode outwards, the core of the star collapses, cramming twice the mass of the Sun into a ball only a few kilometers across. This newly born neutron star — called that because the pressure is so great in the collapsed object that electrons and protons are rammed together to form neutrons — is basically the definition of the word incredible: it spins several times per second, has a surface gravity millions of times that of the Earth (if you were on the surface you’d be crushed flatter than a good science fiction program’s chances to be renewed on Fox), and has a magnetic field 30 trillion times that of the Earth’s.

Link | Chandra X-Ray Observatory