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Saturday, March 30, 2013

Young, hot and blue


The universe is very old - well 13.8 billion years. Our home galaxy, the Milky Way, is also very old - some of their stars bring it to more than 13 billion years (eso0425).

Nevertheless, there is much going on: New objects are created, others are destroyed. In this picture you can see some of the newcomers: young stars that make up the star cluster NGC 2547.

But how young these cosmic youngsters really are? Although her exact age remains uncertain,


astronomers estimated that the stars are between 20 and 30 million years old in NGC 2547. This sounds not so young. Our sun is already 4.6 billion years old and has not even reached the middle of their lives. If we think of the sun so as a 40-year-old man, then the bright stars in the image are just three months old infants.

Most stars are formed not in isolation but in clusters with a large number of stars. Their number ranging from several tens to several thousand stars. While NGC 2547 contains many hot stars that shine bright and blue, which is a sign of youth, it is also possible. Find one or two yellow or red stars that have already developed into a red giant since the stars are drifting apart, which make up the star clusters; open clusters such as these typically have a relatively short lifespan before they dissolve. This period ranges from a few hundred million years.

Star clusters are astronomers who study how stars evolve during their lifetime, particularly important. The stars of a star cluster, all of the same material and originated around the same time. This makes it easier to determine the effect of other properties of the stars in their development.

The cluster NGC 2547 is located at the southern sky in the constellation Vela (the Sails) and is about 1,500 light-years away from Earth. It is bright enough to see him effortlessly with binoculars can. In 1751, he was discovered by the French astronomer Nicolas Louis de Lacaille during an astronomical expedition to the Cape of Good Hope in South Africa by means of a tiny telescope with an aperture of less than two centimeters.

In this picture, you can choose between the bright stars recognize many objects, especially if you increase the view. Many of them are more distant or faint stars in the Milky Way. Some, however, appear as fuzzy extended objects are galaxies that are millions of light-years beyond the stars in the field of view.

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