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Stellar portrait takes imaging technique to new levels
Posted: December 3, 2009

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The young star cluster Trumpler 14 is revealed in exquisite detail thanks to the Multi-conjugate Adaptive optics Demonstrator (MAD) on ESO’s Very Large Telescope – the first time that such a large patch of sky has been imaged using adaptive optics.

This image of the Carina Nebula shows the position of the Trumpler 14 cluster of stars. Image: ESO.

Thanks to MAD, which performs the correction for the blurring effects of the atmosphere over a much larger patch of the sky than any other current adaptive optics instrument, astronomers were able to obtain a wide, crystal-clear view of star cluster Trumpler 14.

Trumpler 14 is hosted by the Carina Nebula, which is also home to the massive star Eta Carinae that is nearing the end of its life. Trumpler 14 is the youngest of the Carina Nebula's stellar families at less than one million years old. The new images not only revealed a revised estimate of the cluster's age at just 500,000 years old, but also found it to be one of the most populous, with about 2000 stars. These stars range from less than one tenth the mass of our Sun up to a factor of several tens of times that mass.

A wide field view of Trumpler 14, spanning 2 arcminutes across the widest adaptive optics view of the open star cluster. Image: ESO/H. Sana.

The most prominent star is the supergiant HD 93129A, one of the most luminous stars in the Galaxy at two and a half million times brighter and 80 times more massive than the Sun. It is part of a binary system with another bright, massive star. Trumpler 14 also contains several white-blue, hot, massive stars, from which ferocious ultraviolet radiation is lighting up the surrounding gas causing it to glow. Such massive stars rapidly burn through their vast hydrogen supplies; these giants will end their lives dramatically in supernova explosions, just a few million years from now.

A few orange stars also appear in the image but these are located behind Trumpler 14; their red hue due to absorption of blue light in the vast veils of dust and gas in the cloud.