Image of the Week – Stars in a Twin Colour World -17/09/2011

The stunning open star cluster NGC 2100 has been captured like never before in this ESO image.

NGC 2100 Credit: ESO

The cluster is located in the fringes of the Tarantula Nebula within the Large Magellanic Cloud.

The blue regions of the image show the presence of ionised oxygen. The energy required to ionise the oxygen is supplied by the massive stars located deeper within the Tarantula Nebula, specifically within the large star cluster RMC 136. The red glow at the base of the image displays the presence of less energetic excited hydrogen marking the edge of the influence of the monster stars within RMC 136 and where smaller, cooler and less energetic stars dominate.

As NGC 2100 is a reasonably dense open cluster, it is at most a few hundred million years old, and is likely to be considerably younger. Open clusters form from the same general region of nebulosity and their stars are loosely held together by their mutual gravity. They then drift apart over time under the effect of gravitational perturbations from other objects and eventually disperse entirely with each individual star travelling on its own way through the cosmos.

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