batteryklion.blogg.se - The end of the sun

The shells chronicle the history of the dying star's outbursts. On the left of the image above, a near-infrared image shows spectacular concentric shells of gas in the Southern Ring Nebula, a planetary nebula that lies around 2,500 light years away in the constellation Vela. This second star shapes the transformation into a planetary nebula, much as a potter shapes a vessel on a potter's wheel. Observations and computer models are now pointing to an explanation that would have seemed outlandish 30 years ago: most red giants have a much smaller companion star hiding in their gravitational embrace.

How supermassive black holes got so big.

How does a cosmic butterfly emerge from the seemingly featureless, round cocoon of a red giant star? But as beautiful as they are, they have also been a riddle to astronomers. (More massive stars have a much more violent end, an explosion called a supernova.) Planetary nebulae come in a stunning variety of shapes, as suggested by names like the Southern Crab, the Cat's Eye and the Butterfly. They are the normal end stage for stars that range from half the Sun's mass up to eight times its mass. The galaxy is studded with thousands of these jewel-like memorials, known as planetary nebulae.

In a glorious denouement, it will eject these layers into space to form a beautiful veil of light, which will glow like a neon sign for thousands of years before fading. After swallowing Mercury, Venus and Earth with hardly a burp, it will grow so large that it can no longer hold onto its outermost layers of gas and dust. Billions of years from now, as our Sun approaches the end of its life and helium nuclei begin to fuse in its core, it will bloat dramatically and turn into what's known as a red giant star.