SUPERNOVAE TO NEBULAE

The sky is deeper than one may think. Many things are going on or have gone on that need to be seen. There are many objects to view,but we are going to view the subjects of supernovae and nebulae. These two subjects are very interesting and include the death and birth of stars.

Supernovae do not happen to all stars,but when they do we know. The Chinese have recorded the display of "guest stars" was a supernova remnant. The supernova remnant could be seen because of its emission of light.

A supernova is a spectacular phenomenom,but rare. After the red gaint stage the core's composition mutates. During this mutation the outer layer undergoes fussion. The star explodes,yet the core remains. Usually, the remaining core is pure iron. The expanding gases become supernova remnants and from there many possibilities could occur. Supernova remnants consist of ionization and chemical composition.

This type of supernova is known as a Type II supernova. There are several types of supernovae,but Type II is the best known. A Type I occurs when a white dwarf accretes or accumulates enough matter to past the Chandrasekhar Limit;it then collapses and explodes. Supernova types depend on the surrounding environment.

There have been about 5 supernovae in this galaxy. The latest has been seen in 1987 in the Large Magellanic Cloud(LMC) Galaxy. The pioneer in observing supernovae are Tycho Brahe and Johannes Kelper.

Nebulae can be the next step for rebirth of a star. Nebulae are interstellar matter that expand. We usually see them due to nearby emitting stars that reflect its light on the nebula. When the nebula becomes condensed a star is born.

There are many types of nebulae in outer space. We, as a civilization, have witnessed almost each one. The four known nebulae are Dark,Emission,Diffusion Emission,and Planetary nebulae. Some nebulae are too thin to even be seen.

Aspects of the nebula are numerous. The temperature of a nebula depends greatly on the closeness to a radiation sources. On the average, the nebula is 100 Kelvin and it is not too dense. The density is low and is estimated at 10^6 of gas and dust per every cubic meter, which is thin. We can not create a great enough vacuum to experiment with a synthetic nebula.

Composition shows that the presence of interstellar gas is greater than that of the interstellar dust,of that gas 90 percent of it is atomic or molecular. From that,9 percent is Helium and the remaining 1 percent consist of heavier elements(C,O,Si, Mg,and Fe).

Not all nebulae show the birth of a star. For example, the planetary nebula. The planetary nebula escapes the core at about 20-30 km/s and originate from red giants. All stars must must past through this stage.

I have presented a lot of information about supernovae and nebulae as I promised. Supernovae are spectacular phenomenons as are the views of nebulae. Along with our neighbor galaxies, we will experience many phenomenons similar to what I have shown here. The sky is greatly deeper than some think.