Formation d'etoiles massives
This wispy, vast structure in the constellation Perseus has a small bubble right in its center puffed out by the spasms of fresh-formed, heavyweight stars. A bubble far larger with age, down below it, has a tendril of gas sneaking across its mostly empty inner space. Along this dusty thread stars are budding at the ends of matter columns, much like the famous "Pillars of Creation" seen by the Hubble Space Telescope in the Eagle Nebula. To the middle right and out of the fray sparkles an older star cluster that has since thrown off its green shroud of PAHs, chemical compounds found in space and on Earth. Below this jewel-like collection, hydrogen atoms energized by starlight emit a rosy glow. This hue, common to many nebulae, also appears red to our eyes in visible light. The verdant PAHs signify neutral, less energized regions around this luminous hydrogen patch, and help researchers gauge the size and age of cosmic clouds.