M15: Dense Globular Star Cluster
4.08.2000

Life might get dull at the core of M15 but the sky would always be bright with stars! In fact, only 40,000 light-years away in the constellation Pegasus, M15 is one of the most densely packed globular star clusters in our Milky Way Galaxy.

The M7 Open Star Cluster in Scorpius
5.04.2000

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of Scorpius.

The Perseus Cluster s X Ray Skull
31.10.2000

This haunting image from the orbiting Chandra Observatory reveals the Perseus Cluster of Galaxies in x-rays, photons with a thousand or more times the energy of visible light. Three hundred twenty million light-years distant, the Perseus Cluster contains thousands of galaxies, but none of them are seen here.

Clusters and Nebulae of the Hexagon
4.04.2003

At first, the bright stars of the large asterism known as the (northern) Winter Hexagon might be hard to pick out in this gorgeous deep sky mosaic from December 2002. But placing your cursor...

Giant Cluster Bends, Breaks Galaxy Images
3.05.1997

What are those strange blue objects? Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. Cluster galaxies here appear yellow and -- together with the cluster's dark matter -- act as a gravitational lens.

Giant Cluster Bends, Breaks Galaxy Images
24.04.1996

What are those strange blue objects? Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. Cluster galaxies here appear yellow and -- together with the cluster's dark matter -- act as a gravitational lens.

The Coma Cluster of Galaxies
28.03.1999

Almost every object in the above photograph is a galaxy. The Coma Cluster of Galaxies pictured is one of the densest clusters known - it contains thousands of galaxies. Each of these galaxies house billions of stars - just as our own Milky Way Galaxy does.

Abell 1795: A Galaxy Cluster s Cooling Flow
8.12.2000

Throughout the Universe, galaxies tend to swarm in groups ranging from just a handful of members to casts of thousands. Astronomers have realized since the early 1970s that the larger swarms, immense clusters of galaxies millions of light-years across, are immersed within tenuous clouds of hot gas which glow strongly in x-rays.

X-Rays From The Perseus Cluster Core
15.06.2000

The Perseus Cluster of thousands of galaxies, 320 million light-years distant, is one of the most massive objects in the Universe. At its core lies the giant cannibal galaxy Perseus A (NGC 1275), accreting matter as gas and galaxies fall into it.

N81: Starbirth in the SMC
27.07.1998

A very young star cluster has been discovered in a neighboring galaxy. The stars found in this cluster, dubbed N81, are so young and massive that they furiously eject matter and light up the surrounding nebula. The ejected stellar winds combine and interact to sculpt beautiful and complex structures.