Ronn!Blankenship wrote: > >> Ok, so we can assume that the Sun will keep its current orbit around >> the Galaxy. But what about other stars? > > Then you could always do what you do to extrapolate solar system > positions: start with the current positions and velocities of all the > stars for which you have data, compute the gravitational forces between > each pair of stars, then do a stepwise integration. (Of course, you do > have access to large blocks of time on a Cray, don't you?) > :-)))))))))
No, but I guess I have some quite weird ideas that I _could_ use if I needed to do that
> And you'll need > to approximate the general gravitational field of the galaxy as a > whole. For a description of that, as well as the kind of orbits stars > follow in the galactic gravitational field, probably the standard text > Ok, I will take a look at them when I am (allegedly) working O:-) [anything that has any semblance to orbital dynamics is fair game in my job]
>
>However, I suspect that over the time periods you're talking about (a few
>x10^6 years), there will be at most only a few close enough encounters
>between stars to significantly affect the paths of the stars. Stars are
>really w�i�d�e�ly separated in our neighborhood of the galaxy. (You are
>not concerned with the stars in the central regions of a globular cluster
>or near Sgr A*, which are about the only places they are really crowded . . . )
>
Unless I am trying to identify Trantor :-)
<<http://www.eso.org/outreach/press-rel/pr-2002/pr-17-02.html>> <<http://antwrp.gsfc.nasa.gov/apod/ap021025.html>> <<http://antwrp.gsfc.nasa.gov/apod/ap020707.html>> <<http://antwrp.gsfc.nasa.gov/apod/ap020521.html>> <<http://antwrp.gsfc.nasa.gov/apod/ap011229.html>>
BTW, is Proxima gravitationally bound with Alfa Centauri A and B?
Short answer: It seems to have the same space motion, but the orbital period (if it is in orbit) is so long that no one has observed any orbital motion.
For the latest information on the system:
<<http://antwrp.gsfc.nasa.gov/apod/ap030323.html>> <<http://www.eso.org/outreach/press-rel/pr-2003/pr-05-03.html>> <<http://antwrp.gsfc.nasa.gov/apod/ap020715.html>> <<http://www.eso.org/outreach/press-rel/pr-2002/pr-22-02.html>>
Some other information on the solar neighborhood:
<<http://antwrp.gsfc.nasa.gov/apod/ap010318.html>> <<http://antwrp.gsfc.nasa.gov/apod/ap000411.html>> <<http://antwrp.gsfc.nasa.gov/apod/ap000412.html>>
On a tangential note, the Jijo books mention that Izmunuti is 1 light-year away from Jijo-S [whose name is Ganjoo - I guess]. Is it possible that they can keep such a long distance for millions of years? I don't think they can be gravitationally bound that far
Maybe. Maybe not.
<<http://www.space.com/scienceastronomy/solarsystem/nemesis_010320-1.html>>
(If you really want to know what the author had in mind, I suppose you could always try asking him . . . ;-) )
-- Ronn! :)
Ronn Blankenship Instructor of Astronomy/Planetary Science University of Montevallo Montevallo, AL
Disclaimer: Unless specifically stated otherwise, any opinions contained herein are the personal opinions of the author and do not represent the official position of the University of Montevallo.
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