Markarian's Chain

In the constellation of Virgo. This shot shows the galaxy cluster closest to our Local Group, 50 million light-years away. The group is called a “chain” because of the slightly curved but roughly linear arrangement of the galaxies that make it up. The most distinctive is NGC 4438, a galaxy interacting with its neighbour NGC 4435, with which it forms the so-called “Eyes of Virgo”. The strong interaction with nearby galaxies distorts the disc of NGC 4438, giving it the curious shape also visible in this photo. This galaxy, together with its neighbour, is widely studied for the energy mechanism at work in its nucleus: there are two hypotheses, a black hole powering the galaxy's centre, or a starburst, a region of extremely high energy where star formation is especially intense.