Tour of the Solar System: The Sun

Today marks the start of new blog series that I have been thinking about starting for a little while.  We will be taking a tour of our solar system, and I have simply titled the series: Tour of the Solar System.  First, we will take a look at our most familiar star, then trek outwards to each of the planets.   I also hope to write a little bit about planetary satellites, comets and some of the larger asteroids that grace our solar system in the near future, perhaps a new post each day or two.

This will be a learning process on my part, and if you subscribe to the blog, I hope you will learn something along the way, too.  Coverage of these beautiful solar system entities will not be comprehensive. I will simply offer various facts about each body that I have learned over the years, and will seek out a few more interesting tidbits to share.

So, for this first post in the series,  we take a look that the center of our solar system, at an object that is so large that it accounts for nearly 100% of the mass of our solar system,  99.86% of the mass to be exact: our Sun.

When you compare our Sun to other stars in the universe ours is relatively bright. However, size wise, it is quite ordinary.  It has been classified as a G2V type star otherwise known as a yellow dwarf.

Even though the Sun sits at the center of our solar system, it is not stationary.  It is orbiting and wobbling around the Milky Way Galaxy, just as our own planet is orbiting around the Sun. The Sun takes about 250 million years to complete on revolution about the Milky Way Galaxy.

The surface of the Sun is a stormy place, especially when it hits the peak of its 11 year solar cycle.  We are about to enter once such peak on the next couple of years.  This is one reason that there have been increased reports of Aurora Borealis sightings.  This trend should continue over the next couple of years.  Look for increased “Northern Lights” activity during the cold winter nights of 2011, 2012 and 2013.

So How Hot is our Sun?
Since the Sun is such a stormy place, and is made up of different layers, the temperature has tremendous variation.  At the center of the Sun, the temperature reaches 14.5 million degrees Kelvin.  It gets cooler as you move away from the core and at the surface the sun is only about 6000 degrees K.  The temperature drops off rapidly as you move into the “atmosphere” of the Sun, also known as the solar atmosphere.  Out in the these regions expect to see a temperature of about 4000 degrees K.

What Causes the Solar Cycle?
Wondering why there is an 11 year solar cycle on the Sun?  This is because the Sun is not only highly radioactive.   It is also magnetically active, and each year the magnetic pole of the Sun decides to do a reversal. The pole reversal cause sunspots, flares and solar wind fluctuations.

Source of various facts from: Wikipedia