M3: Inconstant Star Cluster
12.10.2004

Star clusters appear constant because photographs of them are frozen in time. In reality, though, cluster stars swarm the center and frequently fluctuate in brightness. Although the time it takes for stars to cross...

Globular Cluster M3 from WIYN
12.03.2006

This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy.

Globular Cluster M3
19.07.1998

This huge ball of stars predates our Sun. Long before mankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy.

Globular Cluster M3
15.09.2003

This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy.

The Center of Globular Cluster Omega Centauri
14.09.2009

What is left over after stars collide? To help answer this question, astronomers have been studying the center of the most massive ball of stars in our Milky Way Galaxy. In the center of globular cluster Omega Centauri, stars are packed in 10,000 times more densely than near our Sun.

NGC 5139: Omega Centauri
19.04.2007

Centaurus is one of the most striking constellations in the southern sky. The Milky Way flows through this celestial expanse whose wonders also include the closest star system to the Sun, Alpha Centauri, and the largest globular star cluster in our galaxy, Omega Centauri (aka NGC 5139).

Omega Centauri
26.05.2006

Centaurus, the Centaur, is one of the most striking constellations in the southern sky. The Milky Way flows through this celestial expanse whose wonders also include the closest star to the sun, Alpha Centauri, and the largest globular star cluster in our galaxy, Omega Centauri.

Globular Cluster M3
6.12.1996

This huge ball of stars predates our Sun. Long before mankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy.

NGC 1818: A Young Globular Cluster
14.02.1997

Globular clusters once ruled the Milky Way. Back in the old days, back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy. Today, there are perhaps 200 left. Many globular clusters were destroyed over the eons by repeated fateful encounters with each other or the Galactic center.

Globular Cluster M5
19.10.1995

The globular cluster M5, pictured above, contains roughly 100,000 stars. These stars formed together and are gravitationally bound. Stars orbit the center of the cluster, and the cluster orbits the center of our Galaxy. So far, about 160 globular clusters are known to exist in a roughly spherical halo around the Galactic center.