Located roughly 5,000 light-years from our solar system, NGC 6559 isn't one of the galaxy's bigger stellar nurseries, only measuring a few light-years across. But it packs a whole lot of cosmic chaos into that relatively small patch of space, as stars keep popping up inside the cloud.
You can see into NGC 6559 with this new image from the La Silla Observatory in Chile. As with just about everything else in the universe, the cloud is primarily composed of hydrogen atoms, but it's some of the other elements found inside the cloud that gives it all its amazing colors. The European Southern Observatory explains:
These brilliant hot young stars born out of the cloud energize the hydrogen gas still present around them in the nebula. The gas then re-emits this energy, producing the glowing threadlike red cloud seen near the center of the image. This object is known as an emission nebula.
But NGC 6559 is not just made out of hydrogen gas. It also contains solid particles of dust, made of heavier elements, such as carbon, iron or silicon. The bluish patch next to the red emission nebula shows the light from the recently formed stars being scattered — reflected in many different directions — by the microscopic particles in the nebula. Known to astronomers as a reflection nebula, this type of object usually appears blue because the scattering is more efficient for these shorter wavelengths of light.
For more, including a complete, hi-res look at the entire cosmic vista, check out the ESO website.