Milky way galaxy

Discussion in 'Astronomy, Exobiology, & Cosmology' started by timojin, Nov 20, 2015.

  1. timojin Valued Senior Member

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    How fast does our galaxy spins ? Does it spins into the same direction ?
     
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  3. Russ_Watters Not a Trump supporter... Valued Senior Member

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    A galaxy is not a single object, it is a collection of stars and solar systems, all in separate orbits -- but pretty much all orbiting in the same direction. Ours takes about 250 million years to complete an orbit.
     
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  5. timojin Valued Senior Member

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    Thank you I know a galaxy have large number of solar systems . I understand the galaxy have a black hole . So are you saying the spin of one revolution take 250 million years ?
    My other question is our solar system spinning in the same direction ?
     
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  7. paddoboy Valued Senior Member

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    Give or take a million years or so, yes. And to put that 250 million years in perspective, the speed of solar system about the galactic center is around 250kms/sec.
    Our solar system's spin axis is not aligned with the galaxy's spin axis and is inclined at about 60 degrees, and many other variations with other stars are likely. But all stars are essentially spinning in the same direction as Russ has told you.

    Each star and its system of planets is somewhat influenced by other stars and their system of planets, which are all originally governed by the initial gaseous nebula from whence it collapsed.
    While all are though influenced by other nearby stars and of course by the central SMBH in the direction of the galactic center and Sagittarius A.
     
  8. Russ_Watters Not a Trump supporter... Valued Senior Member

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    Just for our solar system. Solar systems closer to the center orbit faster and ones further away orbit slower.
     
  9. timojin Valued Senior Member

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    Where are we locate within the galaxy ( inside or outside of the spiral ?
     
  10. Janus58 Valued Senior Member

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    The galaxy has two major spiral arms, We are in neither, but are in a minor arm (or spur) called the Orion arm/spur.
     
  11. paddoboy Valued Senior Member

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    In what is sometimes called the outer suburbs or the Orion arm.
    Nothing in anyway special.
     
  12. Russ_Watters Not a Trump supporter... Valued Senior Member

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    We're something like a third to halfway out.
     
  13. timojin Valued Senior Member

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    Is there a a gap in between , were there is a dark space ?
     
  14. paddoboy Valued Senior Member

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    ??There are other stars in between separated by distances measured in light years, with the conglomerations of stars in the galactic bulge and spiral arms, and sprinkling of stars between the spiral arms.
    The spiral arms by the way are thought to be caused by what we call "density waves" analogous to a traffic jam on a H/Way.
    There are also stars more sparsely observed above and below the galactic plane of the galaxies and again around the central bulge.
     
  15. KilljoyKlown Whatever Valued Senior Member

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  16. timojin Valued Senior Member

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    It is a nice picture . That makes me ask .How can I see the whole galaxy if I am inside in it as a small dot, The picture taken is from a great altitude . It have taken several decades for Voyager to exit the most outer planet in our solar system . So what technique is used to take such photograph ?
     
  17. Russ_Watters Not a Trump supporter... Valued Senior Member

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    It isn't a photograph, it is a simulation.
     
  18. timojin Valued Senior Member

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    I see, so directly speaking we don't know our position ,
     
  19. AlexG Like nailing Jello to a tree Valued Senior Member

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    By 'know' you mean visually see? We know our position the same way a ship at sea knows it's position, by observation and calculation.
     
  20. paddoboy Valued Senior Member

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    Directly speaking, there are ways and scientific methods by which we are able to reasonably and logically calculate where we are.
     
    Last edited: Nov 23, 2015
  21. Russ_Watters Not a Trump supporter... Valued Senior Member

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    No, we most certainly do know our position. Do you know where you are right now, without a satellite photo to show you?
     
  22. timojin Valued Senior Member

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    I can tell you in what parallel and what meridian I am located and at night I have to look for the polar star for reference
     
  23. KilljoyKlown Whatever Valued Senior Member

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    Looks like others answered your question. I did want to point out that when you go to that picture you can page through many pictures. I picked that one as it clearly shows the Milkyway as a Bar Spiral which it is. For most of my life they always showed it as a regular spiral galaxy. Also before you ask, no I don't know how they determined that, but I am willing to take their word for it.
     

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