SUN


  • NAME
    (Greek: Helios)

  • ABOUT THE SUN
    The sun is the center of the Solar System and is also
    a star. It is primarily composed of Hydrogen and
    Helium. The sun is not a big ball of fire. It releases
    radiation from nuclear reactions. It's immense
    gravity forces the fusion of hydrogen into
    helium. In this case the sum of the parts does not equal
    the whole. When the hydrogen fuses to helium, the
    excess matter is converted to energy ( E=MC2,
    Where E=Energy in Joules, M=Mass in Kilograms and
    C=the speed of light squared [3 x 108 M/S]2 ).
    This is the same process that fuels the Hydrogen Bomb.
    The Sun produces the heat and pressure necessary to
    fuse hydrogen from gravity. The hydrogen bomb
    requires other methods to generate the necessary
    heat and pressure.

    The sun has spots. They were noticed long ago but the
    belief that the Sun was perfect made most distrustful
    of such observations. Sunspots have been watched and
    counted since the 1600's. The Sunspot cycle (there are
    other cycles as well) is 11 years. The peaks and valleys in
    the Sunspot Cycle are called solar maximum and
    solar minimum. The peaks correspond with considerable
    solar activity. Many flares occur at maximum. These
    flares can disrupt communications and overload some
    electrical circuits. They can bring about intense auroral
    activity. The last solar peak and attendant flare caused
    auroras to be seen as far south as the bahamas. Another
    interesting fact is what's called the Maunder Minimum.
    This was a long period when sunspots were largely
    absent. At the same time Europe experienced the 'little
    ice age' when the climate grew dramatically colder. (1600's)

    What lies ahead for the Sun? The sun is a quite ordinary star.
    In another 5 billion years it will have exhausted it's
    supply of hydrogen. The contraction of the core at this
    stage produces greater pressures causing the star (Sun)
    to begin fusing helium. At the same time the outer layers
    of the sun will have expanded creating a 'Red Giant' star.
    It's size will have expanded to the Earth's orbit. Our
    home is gone. The Sun may become unstable and pulsate.
    Soon it will have exhausted all sources of fuel and
    with no internal heat source exerting outward pressure,
    the Sun collapses. It will become a 'white dwarf'. A small
    fraction of it's present size. Over several billion years
    it will slowly cool and finally become a cold dark
    lifeless hulk. Fear not, in a few billion years, I'm sure
    we can find another place to live.

  • DISCOVERY DATE
    ?

  • MOONS
    The planets?

  • OBSERVING - NAKED EYE
    Don't do it. Actually when the Sun is low in the sky and
    highly reddened, it can be glimpsed briefly (I am not
    endorsing this). It is possible to see a naked eye sunspot
    but these are rare. A total solar eclipse is another
    naked eye sight but being in the path of totality is often
    an expedition.

  • OBSERVING - TELESCOPE
    With a proper solar filter, sunspots can easily be
    observed. A special (and expensive) hydrogen-alpha filter
    allows the observance of other details like Prominences
    and bright Solar Flares. Another method is the projection
    method. You can hold a cardboard screen behind the
    telescope eyepiece to project the Sun's image. Sunspots
    can be seen this way and drawn accurately. The telescope
    can be pointed at the sun by observing the telescope's
    shadow on the ground, do not look through it.
    Also because of the intense heat at the eyepiece, do
    not use a high quality eyepiece. It may be damaged.


A Solar Prominence. It is many times larger than the earth.


Solar Prominence in ultraviolet light from Skylab.


Sunspots


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