Thor's HelmetNGC 2359, also known as Thor's Helmet, surrounds an example of a peculiar class of star known as a Wolfe-Rayet star. These stars are much more massive than our own Sun - 10 times and more - and produce energy at rates that are thousands of times greater.Many such Wolfe-Rayet stars are producing so much energy that they are literally blowing bubbles into interstellar space. Their outer layers are lifted away by the intense radiation, and the wind outwards produces denser nebulae that surround the star and expand outwards, at speeds of up to 2000 kilometers per second!. The radiation from the central star causes this material to glow (much like neon signs). In this enhanced color image, hydrogen gas appears red, oxygen appears green. The nebula itself is about 30 light-years across, and lies 15,000 light years from Earth. |
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