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When I look at the Milky Way, what am I looking at?

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  1. Sep 1, 2014 #1

    kmm

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    More specifically, when I look at the milky way am I seeing another arm of the galaxy or am I looking towards the center of the galaxy? I'm having a hard time finding a specific answer to this question. Thanks!
     
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  3. Sep 1, 2014 #2

    phinds

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    Well, the farthest away star visible to the naked eye is about 4,000 light years away but the milky way is 100,000 light years across and we are something like 1/3rd of the way from the edge towards the center, so you're not seeing much of it.

    A few of the things you see are galaxies that are as much as 2 to 3 million light years away, but they are so small that they look like stars, I'm pretty sure.
     
  4. Sep 1, 2014 #3

    kmm

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    Thanks! Ok so I won't actually see the center of the galaxy, but are you saying that I actually am I looking towards the center of the galaxy?
     
  5. Sep 1, 2014 #4

    phinds

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    I THINK, but don't know for sure, that yes we are looking towards the center when we look at the center of the white band that is the Milky Way as we see it. You definitely can't see anywhere near as far as the center without a telescope.

    Some of our astronomers can likely provide a more solid answer, so I hope one of them will jump in here.
     
  6. Sep 1, 2014 #5
    It depends on which part of the Milky Way you are observing. In the direction of Sagittarius lies the galactic center. If you were viewing the constellations of Taurus/Auriga, you would be looking in the opposite direction towards the edge of the galaxy.

    Try using this map to orient yourself:
    http://maps.nationalgeographic.com/maps/print-collection/milky-way.html
     
  7. Sep 1, 2014 #6

    kmm

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    I'm referring to what phinds said. As he said, "..when we look at the center of the white band that is the Milky Way as we see it." In that case am I looking towards the center?
     
  8. Sep 1, 2014 #7

    davenn

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    Yes correct

    phy_infinite

    the thing that stops us seeing the core of our galaxy isn't the distance, its all the dust and gas
    that is between us and it.
    We observe the core by the infra-red light, gamma rays and X-rays that are emitted from it
    we cannot see the visible light because of the intervening dust etc

    Dave
     
  9. Sep 1, 2014 #8

    kmm

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    I understand why I can't see the core of our galaxy. I only want to know that when I look at the center of the white band in the sky, whether or not I am looking in the direction of the core of the galaxy.
     
  10. Sep 1, 2014 #9

    russ_watters

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    The center of the galaxy is in the direction of the constellation Sagittarius.
     
  11. Sep 1, 2014 #10
    The band of the Milky Way surrounds us so there really isn't a center in that sense. In the summer—for the northern hemisphere—the galactic center can be seen* in the direction of Sagittarius. It will be the brightest part of the MW. In the winter, the sun obscures our view of the center but you can still see the faint glow of the spiral arms away from the center if you are at a dark site.

    Winter MW left, Summer MW right:
    http://twanight.org/newTWAN/photos/3001899.jpg

    * The galactic center can't really be seen visually due to the intervening gas and dust, as davenn pointed out in post #7. I simply mean that that is the direction in which the center lies.
     
    Last edited: Sep 1, 2014
  12. Sep 1, 2014 #11

    kmm

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    Cool! Thanks for the clarification Jimmy!
     
  13. Sep 4, 2014 #12
    Any galaxy that is small enough to be star sized is much too dim to be seen by the naked eye. The Small and Large Magellenic Clouds (close dwarf galaxies visible from the souther hemisphere) and the Andromeda galaxy is visible as patches of dim light from a dark site and the Triangelum Galaxy is visible from a very dark site if you have good enough eyes. If you count Omega Centauri as a dwarf galaxy that one is very easy from a darkish site (also an southern object and almost star sized). On top of that there is a couple of galaxies that might just about be possible if you have extremely good eyes and skies.

    More info on wikipedia
     
    Last edited: Sep 4, 2014
  14. Sep 4, 2014 #13

    phinds

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    OK, my "pretty sure" was wrong. Thanks for that correction.
     
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