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.
 

80 comments:

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

    ReplyDelete
  2. I always suspected the sun of being badass.

    ReplyDelete
  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.

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

    ReplyDelete
  5. really interesting video, keep it up!

    ReplyDelete
  6. i didnt knew half the stuff u said

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

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

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

    ReplyDelete
  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.

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

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

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

    ReplyDelete
  14. MORE OF THIS!

    Astronomy fascinates the hell out of me! :D

    ReplyDelete
  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!!

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

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

    ReplyDelete
  18. realy nice info here keep it going :D

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

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

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

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

    ReplyDelete
  23. Very interesting start for your blog.

    Keep it going.

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

    ReplyDelete
  25. interesting stuff u got here keep it up

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

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

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

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

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

    ReplyDelete
  31. Very interesting article!

    Following from now on!

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

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

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

    ReplyDelete
  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.

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

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

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

    ReplyDelete
  39. Thats interesting stuff about the sun!

    ReplyDelete
  40. yes it is very interessting :)

    followed :)

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

    ReplyDelete
  42. are solar flares what cause gps issues sometimes?

    ReplyDelete
  43. love this. Very interesting. Thanks

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

    ReplyDelete
  45. just dont look straight at the sun!

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

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

    ReplyDelete
  48. ah compared to the sun we are nothing

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

    ReplyDelete
  50. cool blog man! looking forward to future posts

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

    ReplyDelete
  52. now i know why some cultures worshiped it.

    ReplyDelete
  53. that was fascinating, great work

    Followed.

    ReplyDelete
  54. 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.

    ReplyDelete
  55. nice blog... I love all Astronomic things.

    Follow!

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

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

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

    ReplyDelete
  59. I love knowing more about space. thanks for sharing.

    ReplyDelete
  60. Great info bro! Followed! alphabetalife.blogspot.com

    ReplyDelete