Friday, June 26, 2009

St Michael of the under-equipped hikers is gone.

The North Star no longer exists!

Apparently, it has supernovaed. The north star will outshine the combined output of an entire galaxy for a brief time and then die over several weeks or months.

What the supernova?

Temperature and pressure in a star's core is so great that it triggers a continuous nuclear fusion inside the star. The star relies on this power to make up for the energy it looses in the form of light and heat. When the hydrogen source runs out, its star can no longer sustain this nuclear fusion.

When this happens, the star is incapable of maintaining its size. The force of gravity makes a star want to shrink, and the above mentioned reactions make the star want to expand. During the life span of a star these forces are balanced, so the star remains at a fixed size. However, when there is no hydrogen to fuel the reactions, gravity wins. The inner parts shrink and the outer parts are discarded into the space.

When a star has 8 times more mass than the sun like the North Star, the outer shell breaks with the catastrophic supernova explosion. So, the sun can not go supernova.

The Little Dipper just got smaller!

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