Wild Duck Open Cluster M11
15.01.1996

Many stars like our Sun were formed in open clusters. The above open cluster, M11, contains thousands of stars and is just over three thousand light years distant. The stars in this cluster all formed together about 150 million years ago. The many bright stars in the cluster appear blue.

M45: The Pleiades Star Cluster
8.01.2006

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

M45: The Pleiades Star Cluster
17.11.2007

Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters.

The M7 Open Star Cluster in Scorpius
6.04.2005

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.

NGC 869 & NGC 884: A Double Open Cluster
28.01.1997

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

The Star Pillars of Sharpless 171
27.09.2005

Towering pillars of cold gas and dark dust adorn the center star forming region of Sharpless 171. An open cluster of stars is forming there from the gas in cold molecular clouds. As energetic...

NGC 7635: Bubble in a Cosmic Sea
28.04.2006

Seemingly adrift in a cosmic sea of stars and glowing gas, the delicate, floating apparition near the center (next to a blue tinted star) of this widefield view is cataloged as NGC 7635 - The Bubble Nebula.

Open Cluster NGC 6520 from CFHT
22.07.2002

Did you ever have a day when it felt like a dark cloud was following you around? For the open cluster of stars NGC 6520, every day is like this. On the left of the above picture are many of NGC 6520's bright blue stars.

Open Cluster NGC 290: A Stellar Jewel Box
1.05.2006

Jewels don't shine this bright -- only stars do. Like gems in a jewel box, though, the stars of open cluster NGC 290 glitter in a beautiful display of brightness and color. The photogenic cluster, pictured above, was captured recently by the orbiting Hubble Space Telescope.

The 37 Cluster
17.11.2005

For the mostly harmless denizens of planet Earth, the brighter stars of open cluster NGC 2169 seem to form a cosmic 37. (Did you expect 42?.) Of course, the improbable numerical asterism appears solely by chance and lies at an estimated distance of 3,600 light-years toward the constellation Orion.