1/4/07

37. STARDUST

It is true that looking to the Milky Way on a cloudness night you still will see black smudges, as if there are many interruptions. But that is the result of a lot of dust clouds, “stardust” as it is named, filling the emptiness a bit.
What’s that: stardust?
We should distinguish between gasses, stardust and dark matter if speaking of clouds in space.
Gasses consists of atoms and/or molecules.
Stardust consists of very small molecular structures of the order of 1 to .001 micron.
Dark matter enclose matter particles not radiating light or very little particles as neutrino’s but also minor black holes, but for the main part perhaps unknown exotic particles. So in fact all what has a certain mass but always extreme dim. The most important feature of dark matter is that it must necessarily contribute to the gravitation but without any mutual attraction what means no pressure effects as in a gas. The reason for supposing such matter is that e.g. movements of stars in galaxies can not be explained by gravitation from centres of mass or other visible objects, so other sources of gravitation are necessary.

Eta Carinae, located 10,000 light-years from Earth, was once the second brightest star in the sky. It is so massive, more than 100 times the mass of our Sun, it can barely hold itself together. Over the years, it has brightened and faded as material has shot away from its surface. Some astronomers think Eta Carinae might die in a supernova blast within our lifetime.
Eta Carinae's home, the Carina Nebula, is also quite big, stretching across 200 light-years of space. This colossal cloud of gas and dust not only gave birth to Eta Carinae, but also to a handful of slightly less massive sibling stars. When massive stars like these are born, they rapidly begin to shred to pieces the very cloud that nurtured them, forcing gas and dust to clump together and collapse into new stars. The process continues to spread outward, triggering successive generations of fewer and fewer stars. Our own Sun may have grown up in a similar environment.

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