The Hydra Cluster of Galaxies
16.04.2001

The Hydra Cluster of Galaxies contains well over 100 bright galaxies - but perhaps fewer galaxies than might be expected from its mass. Clusters of galaxies are the largest gravitationally bound objects in the universe.

The Large Cloud Of Magellan (LMC)
23.01.1998

Ferdinand Magellan and his crew had plenty of time to study the southern sky during their famous voyage around the world. As a result, two fuzzy cloud-like objects, not visible to northern hemisphere dwellers, are now known as the Clouds of Magellan.

When Black Holes Collide
10.04.2021

What happens when two black holes collide? This extreme scenario occurs in the centers of many merging galaxies and multiple star systems. The featured video shows a computer animation of the final stages of such a merger, while highlighting the gravitational lensing effects that would appear on a background starfield.

Galaxy Cluster Abell S1063 and Beyond
21.07.2016

Some 4 billion light-years away, galaxies of massive Abell S1063 cluster near the center of this sharp Hubble Space Telescope snapshot. But the fainter bluish arcs are magnified images of galaxies that lie far beyond Abell S1063.

A Bulls Eye Einstein Ring
30.03.1998

Can one galaxy hide behind another? Not in the case of B1938+666. Here the foreground galaxy acts like a huge gravitational lens, pulling the light from the background object around it, keeping it visible.

Weighing Empty Space
8.07.2002

Sometimes staring into empty space is useful. Pictured above is a region of sky that was picked because it had, well, nothing: no bright stars, no bright galaxies, and no picturesque nebulas. What could not be avoided, however, were a few stars in our own Galaxy, and many distant galaxies strewn across the universe.

The Large Cloud of Magellan
18.09.1995

Magellan and his crew had plenty of time to study the southern sky during their famous voyage around the world. As a result, two fuzzy cloud like objects, nestled among the southern constellations of Doradus and Tucana are now known as the Clouds of Magellan.

A Network of Microlensing Caustics
14.12.2002

A virtual sky map like this would be of interest to astronomers studying gravitational microlensing. In microlensing, the gravity of stars near the line of sight can act to magnify the light of background objects such as distant stars, or quasars. Nowhere is this magnification greater than near a gravitational lensing caustic.

X Rays Indicate Star Ripped Up by Black Hole
23.02.2004

What could rip a star apart? A black hole. Giant black holes in just the right mass range would pull on the front of a closely passing star much more strongly than on the back.

A Network of Microlensing Caustics
24.08.1999

A virtual sky map like this would be of interest to astronomers studying gravitational microlensing. In microlensing, the gravity of stars near the line of sight can act to magnify the light of background objects such as distant stars, or quasars. Nowhere is this magnification greater than near a gravitational lensing caustic.