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Tuesday, November 13, 2012

Stars young and old?



This colorful view of the globular cluster NGC 6362 has been with the Wide Field Imager on the ESO / MPG 2.2-meter telescope was added to the ESO La Silla Observatory in Chile. Together with a new recording of the central region of the cluster, which has delivered the Hubble Space Telescope by NASA and ESA, this picture conveys the best to date view of this little-known globular cluster. The majority of stars in globular clusters is very old. In this bunch there are also some stars that act unusually young.


Globular clusters are among the oldest objects in the universe. NGC 6362 is also on this recording does not hide his age: the many yellowish-looking stars have the majority of their lives already behind and have become known as red giants. Nevertheless, globular clusters are not venerable relics of a distant past. Still play there under the stars from extraordinary events.

Sun NGC 6362, for example, is home to many so-called blue stragglers (English Blue Stragglers): Stars who look much younger than they really are. The background is the following: All the stars of a globular cluster have formed within a short time from the same molecular cloud. The typical age of a globular cluster is about ten billion years. The blue stragglers are, however, much hotter, more luminous and more massive than one would expect for ten billion years old stars, because blue stars consume their nuclear fuel storage is typically very fast. If the blue stragglers have actually been thus formed ten billion years ago, they should have been all died. How they survived so long?

Astronomers are very interested in what's behind the youthful appearance of the blue stragglers. Currently there are two explanations: Either the relevant star meantime collided with another star or he has pulled off another stellar matter. Two explanations is common that the blue stragglers are not incurred with its present mass. Instead, they say get a transfusion of matter, and thus the chance for a new life.

Although he is less well known than the brighter globular clusters, NGC 6362 is still of great interest to astronomers. Accordingly, it has been studied in recent years, very thorough. For example, he was selected as one of 160 fields for the Pre-FLAMES Survey - a 1999 to 2002 with the MPG/ESO-2 0.2-meter telescope at La Silla Observatory conducted campaign, with the appropriate star for an investigation with the FLAMES spectrograph on the VLT should be identified. The image shown here was created from the data of these observations.

The picture shows the entire globular cluster before starry background of the Milky Way. The central region of NGC 6362 has been studied in detail and with the NASA / ESA Hubble Space Telescope. The two images - the overall record and a high-resolution details - complementary.

The bright ball of stars is located in the southern constellation of Ara (the Altar) and is already easily seen in small telescopes. NGC 6362 was in 1826 by the Scottish astronomer James Dunlop discovered with a 22-centimeter telescope from Australia.

For more information

The MPG / ESO 2.2-meter telescope was commissioned in 1984 and is on loan from the Max Planck Society to ESO. Its Wide Field Imager, an astronomical camera with a particularly large field of view and a detector with 67 million pixels, delivers pictures that are not only of scientific but also of aesthetic value.

In 2012, celebrating the ESO (European Southern Observatory), the 50-year anniversary of its founding. ESO is the leading European organization for astronomical research and the most productive astronomical observatory in the world. It is supported by its 15 member countries. Belgium, Brazil, Denmark, Germany, Finland, France, Italy, the Netherlands, Austria, Portugal, Spain, Sweden, Switzerland, the Czech Republic and the United Kingdom The ESO allows astronomers to research by designing powerful ground-based telescopes, construction and operation. Also in promoting international cooperation in the field of astronomy, the organization plays a major role. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope (VLT), the world's astronomical observatory in the range of visible light and two telescopes for sky surveys: VISTA, the largest survey telescope in the world works in the infrared, while the VLT Survey Telescope (VST ) for heaven designed to exclusively in the visible light. ESO is the European partner for the construction of the telescope ALMA, the largest astronomical project in existence. Currently being developed by ESO telescope with a large diameter of 39 meters for observations in the visible and infrared light, which will be once the largest optical telescope in the world: the European Extremely Large Telescope (E-ELT).

The English translations of ESO Press Releases are a service of the ESO Science Outreach Network (ESON), an international network for astronomical public relations, in which scientists and science communicators from all ESO Member States (and other countries) are represented. German nodes of the network is the home of Astronomy in Heidelberg.

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