Mass Extinction and the Structure of the Milky Way (2013)

Re:Mass Extinction and the Structure of the Milky Way (2013) by PhantomGremlin on Monday May 08, 2017 @03:19AM (#14289850)

It's hard to be sure. But observing both the Wiki animation and this GIF, it appears that stars don't orbit at a constant radius from the galactic center. Rather, they appear to move significantly closer and further.

Does that seem right? If so, that's much different than planets orbiting our solar system. To a first approximation our orbits appear circular. Yes I know there's a certain eccentricity but for most planets it's not much.

I don't like the idea of our solar system getting too close to the galactic center. It gives me a vague sense of dread, like "bad things can happen there".

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Re:Mass Extinction and the Structure of the Milky Way (2013) by Keysh on Monday May 08, 2017 @12:20PM (#14292980)

That's an exaggerated, simple model of spiral density waves; it's not a model for the Sun's orbit, which probably only varies in radius by about 10-15%.

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Re:Mass Extinction and the Structure of the Milky Way (2013) by LoSboccacc on Monday May 08, 2017 @03:41AM (#14289912)

The orbit in the model are supposedly eccentric, but the period for a complete prbit is quite long, allegedly around 220milliom years, and yes the paper is all about bad things happening periodically as we change our local neighboors. But not something we'll have to worry about in quite a while

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Re:Mass Extinction and the Structure of the Milky Way (2013) by iand on Monday May 08, 2017 @05:11AM (#14290203)

I think that's just a side effect of the compressed scales used by the animation. If they didn't do that then you would not be able to see the wave effect as clearly.

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