Giant stars lurk the heart of the Westerlund 1 cluster.
Great Attractor
There a region of space about 150 million light years away that is gravitationally attracting the galaxies in its region, including ours. It is known as the great attractor, and we’re not entirely sure what’s there. The problem is it happens to lie in the direction of the zone of avoidance, so our own galaxy is blocking our view.
Push Me, Pull You
If the universe is expanding, how is it possible that galaxies can collide with each other? It turns out that not only are colliding galaxies possible in an expanding universe, the fact that they occur is due in part to dark matter and dark energy.
Iron Giant
The Perseus cluster is a cluster of nearly 200 galaxies about 240 million light years away. It is the advantage of being a large cluster of galaxies at a relatively close distance, so it is often the focus of investigations on the behavior and evolution of galactic clusters.