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...

NGC 3293: A Bright Young Star Cluster
6.04.2015

Hot blue stars shine brightly in this beautiful, recently formed galactic or "open" star cluster. Open cluster NGC 3293 is located in the constellation Carina, lies at a distance of about 8000 light years, and has a particularly high abundance of these young bright stars.

Zooming in on Star Cluster Terzan 5
24.03.2019

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 less than 200 left. Over the eons, many globular clusters were destroyed by repeated fateful encounters with each other or the Galactic center.

Globular Star Cluster NGC 6752
5.07.2013

Some 13,000 light-years away toward the southern constellation Pavo, the globular star cluster NGC 6752 roams the halo of our Milky Way galaxy. Over 10 billion years old, NGC 6752 follows clusters Omega Centauri and 47 Tucanae as the third brightest globular in planet Earth's night sky.

Zooming in on Star Cluster Terzan 5
21.09.2016

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 less than 200 left. Over the eons, many globular clusters were destroyed by repeated fateful encounters with each other or the Galactic center.

M45: The Pleiades Star Cluster
1.09.2019

Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as dusty as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city.

Star Cluster NGC 362 from Hubble
11.10.2017

If our Sun were near the center of NGC 362, the night sky would glow like a jewel box of bright stars. Hundreds of stars would glow brighter than Sirius, and in many different colors.

Comet Hartley Passes a Double Star Cluster
26.10.2010

Most star clusters are singularly impressive. Open clusters NGC 869 and NGC 884, however, are doubly impressive. Also known as "h and chi Persei", this unusual double cluster, shown above, is bright enough to be seen from a dark location without even binoculars.

M3: Inconstant Star Cluster
15.04.2007

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...

M15: Dense Globular Star Cluster
15.06.2023

Messier 15 is an immense swarm of over 100,000 stars. A 13 billion year old relic of the early formative years of our galaxy it's one of about 170 globular star clusters that still roam the halo of the Milky Way.