Westerlund 2 is believed to be the youngest star cluster in the Milky Way, with an estimated age of about one to two million years. Is is located about 20,000 light years away from Earth in the general direction of the Carina constellation. However, not much is known about this cluster due to the fact that it is surrounded by a massive thick dust and gas cloud that prevents optical observations. NASA's Chandra X-ray Observatory will have the mission to penetrate the heavy cloud to reveal the mysteries related to Westerlund 2.

As you might expect, the large amount of material in the respective area of space gave birth to some of the heaviest and brightest stars ever observed. Except that, however, little is known about the system. On the other hand, infrared and X-ray wavelengths can penetrate through the most massive dust clouds, and could even create an image of the galaxy all the way to the galactic central core.

Chandra recently produced one of the best pictures of the Westerlund 2 star cluster. You can see how the low energy X-ray emissions are represented in the optical spectrum by the color red, the medium energy X-ray in green and the high energy emissions in blue, revealing a high density population of stars shinning bright in the X-ray wavelength.

The most massive of these stars is the binary system WR20a with an approximated mass of about 82, respectively 83 times that of the Sun and can be viewed in the image provided by Chandra, to the right, just under the core of the star cluster. The two stars are relatively young, absolutely massive and extremely unstable, ejecting high quantities of matter in the form of stellar winds which collide with each other and determine the emission of powerful X-ray radiation. Most of these emissions can be viewed from different perspectives due to the fast rotation of the binary system, which completes an orbit around each other every 3.7 days.