This the SECOND entry for my "Astronomy" series of articles. IF you have NOT read entry number ONE, please find it (Basic Astronomy) in this blog and read it first.
You Can Find It HERE
Our Sun and relative size to other stars
In the previous article regarding "Basic Astronomy", a short outline of our own Solar System was presented. Here is a visual of
comparative sizes not only of our own Solar System but other large stars "out there":
In the above video, you saw the our "nearest" star (other than our own Sun) is Sirius whichis a brilliant white binary star that is
the brightest star in the night sky and is about 8.6 light-years away from the Sun.
LIGHT YEARS: What is that??
Light travels at approximately 180,000 miles per SECOND ...YES, PER SECOND!
Light travelling at this speed from our own Sun reaches earth is about 8 minutes. But when you go "outside" our own solar system,
the distances are SO VAST it takes a MUCH LONGER time for light from these objests to reach us. So, look at the distance from us
given above regarding another "small" (but larger than our Sun) star, Sirius, when states: "about 8.6 light years away.
WHAT does that mean? That means the light YOU see in the night sky coming FROM the star Sirius has take 8.6 YEARS to reach us AND
it is the CLOSEST "other" star to us! As you go further into the study of astronomy, you will find references to objects in DEEP
space (well OUTIDE our Solar System) as being THOUSANDS, MILLIONS AND BILLIONS of LIGHT YEARS AWAY. Recently (July 2011), there
were articles in the news regarding a large star which astronomers THOUGHT would be "exploding" soon. Everyone was worried as to
HOW that would affect EARTH!! IF it did explode, it happened some million years ago!! The light, when it DOES happen, would just
now be getting to us here on earth!
Pollux is the brightest star in Gemini and is part of a double star system. It is about 33.7 light-years from the Sun. Arcturus is
the brightest star of the northern hemisphere in the spring and the fourth brightest star in the Earth's night sky. It is located
about 36.7 light-years from the Sun.
Our "Sun" is a STAR. As you saw in the video above, they come in all kinds of sizes and even colors. Some stars "live alone" like
our "star" (even though there is some speculation it DOES have a distant companion), many, if not most stars have a "companion
star. Take Sirus we discussed above. In the night sky you "see" only ONE point of light when actually there ARE TWO: Sirius A and
Stars are "born", live for varying times (astronomers are constantly finding stars that are "dying" or have "died"). These changes
take place over VERY long periods of time and that is why we do not notice that .... even IF we could see them without a telescope.
It is entirely possible that MANY of the stars we see in the night sky NO LONGER exist but THEIR light keeps coming to us anyway!
Our Sun has already given earth about one half of it's life expectancy. The larger the star, the faster they will blow themselves
up called a "Supernova".
Stars including our Sun come in all sizes, colors, temperature and age. Stars the size of our own Sun are classified as "Dwarf"
stars due heir small size. The largest stars are called "Giant" or "Supergiant" stars depending upon their size. Colors of stars
range from red to bluish-white depending upon how hot they are.