Tuesday, June 7, 2011

A Star goes BOOM in the Whirlpool

Hey Space Placers!

Did you know that all of the elements in the Universe beyond the Hydrogen and Helium present after the creation of the Universe during the Big Bang come from stars? That's right. In a process called nuclear fusion, all stars spend their lives making the elements out of hydrogen. The tremendous pressure and temperature at a star's core is the only place where Nature can make the Periodic Table of Elements! Decades ago I delighted in telling my chemist-to-be nephew about nucleosynthesis - the formation of the elements from stellar fusion. Read More About It: http://helios.gsfc.nasa.gov/nucleo.html

Galaxies like ours are composed of hundred of billions of stars. They have different masses which in turn determines the length of their lives, their temperatures and their ultimate fate.

Stars like our Sun last about 10 billion years or so before they become Red Giant stars enveloped in a huge nebula of elements such as hydrogen, helium, oxygen, carbon, neon. At the center of the nebula the remains of the star's fusion core, now a white dwarf star, blazes white hot, slowly cooling until it is no longer visible. A white dwarf is a dead star the size of the Earth.

If a star is roughly 8 times as massive as our Sun it has a far different ending and in far less time - a hundred million years or so. A massive star undergoes a cataclysmic end as a supernova, an event in which the star literally blows itself to smithereens and in the process manufactures all of the heavy elements beyond iron. Stars in their normal lives cannot manufacture elements beyond iron as iron absorbs the star's energy at its core and essentially shuts down the nuclear fusion cycle. But in the following stupendous blast as a supernova the destroyed star outshines all of the stars in its home galaxy.

A supernova was observed recently in a nearby galaxy called the Whirpool Galaxy. This is a beautiful galaxy that does indeed look like its name. Read more about it: http://apod.nasa.gov/apod/ap110605.html and http://www.skyandtelescope.com/observing/home/123110228.html

Sky Guy in VA

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