Sunday, February 13, 2011

The Sun


     The Sun, approximately 6 billion years old, is the sole source of light and heat for the maintenance of life on Earth. It is a star, a glowing ball of gas held together by its own gravity and powered by nuclear fusion. Nuclear fusion is a process in which two or more atomic nuclei combine and release energy at its center. The Sun is very similar to most other stars considering its physical and chemical properties, and regardless of when and where the other stars were formed. Our knowledge of the cosmos rest squarely on our understanding of solar physics.

      The Sun has a radius larger than 100 times the earth, and a mass that is greater than 300,000 times the Earth's mass. The surface temperature of the Sun is well above the melting point of any known material. When we mention the Sun's surface, it is not a solid surface, nor does it contain any solid material at all. The Sun has several varying layers to it, including the part of the Sun that emits the radiation we see, the photosphere. After the photosphere comes the chromosphere, the transition zone, and finally the solar corona, the thin hot upper atmosphere. At even greater distances away, the solar corona turns into solar wind, which flows in great speed away from the sun, permeating the entire solar system.

      Below the photosphere is the convection zone, a region where the material of the Sun is in constant convective motion. Below the convection zone lies the radiation zone, where solar energy is transported toward the surface by radiation rather than by convection zones. Finally after that lies the central core, which is roughly 200,000km in radius. This is the site of powerful nuclear fusion which is the key to the enormous energy output of the Sun.


    
     As you can see above, the suns surface is not simply glowing and yellow.  There are many imperfections including the dark spots that can sometimes be seen called sunspots.  Sunspots typically measure about 10,000 km across, about the size of earth.  At any given second the Sun may have hundreds of sunspots, and inversely it could have none at all.  Further inspection of sunspots show an umbra, or dark center, surrounded by a grayish penumbra.  Sunspots appear black, but they are in reality only relatively cooler regions of the photospheric gas.  The temperature of the umbra is around 4500 Kelvin, where the background of their surroundings is 5800 Kelvin.  Sunspots were one of the first indications that the Sun does not rotate as a sold body.  Instead, it spins differentially, which means faster at the equator and slower at the poles.  Sunspots are not steady.  Most change their size and shape, and all come and go.  Some spots may last anywhere from 1 to 100 days, and a large group of spots typically last 50 days.  After centuries of observations, it is clear that there is a distinct sunspot cycle.  The solar cycle is 22 years long, with repeating fluctuating sunspot occurrences throughout the years.  Below is a short video of half of the sunspot cycle.
 

83 comments:

  1. Do you know there are no green or violet suns?

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  2. I always suspected the sun of being badass.

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  3. Nice post man, I love looking at the stars. This blog could be great if you keep putting work into it like this, keep it up.

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  4. This is such an interesting article. good job man.

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  5. really interesting video, keep it up!

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  6. i didnt knew half the stuff u said

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  7. This will be good for my earth science class lol

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  8. I didnt know it had so many layers yet alone its age.

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  9. this is so hot(lol), cant wait to read more

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  10. Lol "the only source of light and heat" that's a scary thought. even with all the electric heaters and blankets we'd still be dead without that big ball of gas.

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  11. Hey I found an astronomy blog!! My favorite! You should add that our sun is like the third sun we've had also.

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  12. have to wonder how they actually can be srue about waht's inside the sun O_O

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  13. Good read, I learned a thing or two about the sun reading it.

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  14. MORE OF THIS!

    Astronomy fascinates the hell out of me! :D

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  15. this is great one of the few blogs that mentions our universe our galaxy.. im with you.. the sun is a big star.. sometimes i even think thats hell!!

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  16. earth wouldn't exist without the sun, let's adore it.

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  17. i love this stuff... my gf hates it when i bang on about the sun and black holes!

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  18. realy nice info here keep it going :D

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  19. I dont get how the atmosphere just above the surface is hotter than inside - or did i just make that up?

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  20. Followed. Amazing that the sun is the source of all energy on earth.

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  21. Good info. I've always been amazed by all that lies beyond.

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  22. Sun can take our lives as easily as it gave us.

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  23. Very interesting start for your blog.

    Keep it going.

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  24. this is all so fascinating ! looking forward for more !

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  25. interesting stuff u got here keep it up

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  26. I love pictures of space... everything always looks so beautiful.

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  27. Cool story, I regularly get to use a Hydrogen-Alpha telescope to look at the sun, so cash.

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  28. interesting stuff i've always wondered about these kinds of things...

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  29. The solar system is fascinating to me. Thanks for the good read!

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  30. great article!!
    also cool fact!!
    The light from the sun takes 8 minutes to reach earth!!

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  31. Very interesting article!

    Following from now on!

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  32. I enjoyed reading this, thanks for the video as well

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  33. Interesting stuff, can't wait for the next post. Perhaps do it on pulsars?

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  34. Ooo, very informative post. I'm pretty interested in astronomy. Definitely gonna be checking this place out more.

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  35. its crazy how much we rely on the sun, can't imagine how much our race would be screwed if it burnt out on us, hopefully by then we will have an alternate form of sunlight.

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  36. Nice input, it's also the Eye of Horus/Ra.

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  37. I like how even though we're so far from the Sun we can still determine what makes it tick.

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  38. What an incredible star, do you know how long it will exist for - without it we would have never been formed!

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  39. Thats interesting stuff about the sun!

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  40. yes it is very interessting :)

    followed :)

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  41. Thats some pretty incredible stuff, kind of mind-blowing when you think about how this all came about.

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  42. are solar flares what cause gps issues sometimes?

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  43. love this. Very interesting. Thanks

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  44. The Sun rocks! Too bad I don't see much of it in the UK. Keep up the good work. Following.

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  45. I've been reading your blog and I like it :) I'll be following for sure!

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  46. just dont look straight at the sun!

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  47. did you know the sun heats the earth, and this is the cause of global warming.

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  48. Very informative and wonderful blog. It's quite nice to look at. Kudos.

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  49. ah compared to the sun we are nothing

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  50. You should do more posts, man! This is really interesting!

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  51. cool blog man! looking forward to future posts

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  52. If the sun's light reflects to make the sky blue, how come the sun appears yellow?

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  53. now i know why some cultures worshiped it.

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  54. that was fascinating, great work

    Followed.

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  55. Nothing amazes me more than the universe, and the sun is a big part of it. Or.. "small" part rather.
    Damn it's so fascinating.

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  56. nice blog... I love all Astronomic things.

    Follow!

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  57. things like this make me wish i had the internet as a child

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  58. Following and supporting anything with astronomy. Nice blog, keep it up.

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  59. Our sun is really small compared to the biggest stars known to man, it really is amazing how small we are

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  60. I love knowing more about space. thanks for sharing.

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  61. Great info bro! Followed! alphabetalife.blogspot.com

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