Ptolemy’s Cluster

M7Messier 7 (aka M7 or  Ptolemy’s Cluster) is an open cluster of stars in the constellation of Scorpius. The cluster is visible to the naked eye, close to the “stinger” of Scorpius.

M7 has been known since antiquity; it was first recorded by the 1st-century Greek-Roman astronomer Ptolemy, who described it as a nebula in AD 130. Italian astronomer Giovanni Batista Hodierna observed it in the mid 17th-century and counted 30 stars in it. In 1764, French astronomer Charles Messier catalogued the cluster as the seventh member in his list of comet-like objects. This image was recently taken by the 2.2-metre ESO telescope in Chile.

Image Credit: ESO

NGC 299

The Toucan and the clusterNGC 299 is an open star cluster located within the Small Magellanic Cloud about 200,000 light-years away. Open clusters are groups of stars  of which formed from the same massive cloud of gas and dust and are loosely held together by gravity. All the stars have roughly the same age and composition, but they vary in their mass because they formed at different positions within the cloud.

Image Credit: ESA / NASA

NGC 3603

NGC 3603NGC 3603 is an open cluster of stars situated in the Carina spiral arm of the Milky Way around 20,000 light-years away from the Solar System. It’s the densest concentration of very massive stars known in the galaxy, and their strong ultraviolet radiation and stellar winds have cleared the gas and dust, giving an unobscured view of the cluster.

Image Credit: ESO

M47

The star cluster Messier 47This picture of the star cluster Messier 47 was taken using the Wide Field Imager camera, installed on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. The young open cluster is dominated by a sprinkling of brilliant blue stars but also contains a few contrasting red giant stars.

Image Credit: ESO