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Vega. Are Sol and Vega destined to collide?

  1. Sep 15, 2011 #1
    Am I misunderstanding the measurements or what? The SIMBAD site has archived 17 measurements or Vega's radial velocity over the past 150 years and they are all negative (blue-shifted) averaging out to about 9.0875 miles per second. Since Vega is only 25.29 lightyears away this seems to indicate that Vega and our star will be right on top of one another in 518,000 years. A very short time on a planetary scale. Not even as long as mammals have been dominant on Earth.
    Granted that's not an immediate concern, but if that was true I'm pretty certain I would have heard about it by now. I haven't heard anything about this anywhere. I just came to this apparent conclusion from bits and pieces I've read and watched while learning about stellar masses, types, etc.
    It would also seem to me that you can't ascribe our movement towards Vega our planetary orbit of the Sun nor Vega around a companion star. Vega is solitary, and is almost perfectly aligned with our North pole and we with one of it's poles.
    Also, Vega is expected to survive as a main sequence star for another 500 million years, so if it's on a collision course it will be here long before it becomes a red giant.



    http://en.wikipedia.org/wiki/Vega" [Broken]

    http://www.solstation.com/stars/vega.htm" [Broken]
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Sep 15, 2011 #2
    It's proper motion is about 350 milli-arc seconds per year, which means it's moving sideways with respect to the Sun. Thus not a collision risk.
  4. Sep 15, 2011 #3


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    even when entire galaxies collide, the chances of any stars hitting other stars is extremely close to zero.
  5. Sep 15, 2011 #4


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    As graal points out, just because it has a component of movement towards us does not mean it's on a collision course. In order for it to be on a collision course, it would have to also have a transverse component of zero, which would be a fabulously small probability (for any set of objects that are moving toward us).
  6. Sep 16, 2011 #5
    OK, thanks. Where do you find the info on it's transverse motion?
    I of course realize the stars wouldn't actually "collide," but having a star as massive as Vega pass too close would probably rip our solar system apart, and in the very least purterb the system enough to move the earth out of the 'goldilocks zone.'
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