Outcast star zooms out of Milky Way galaxy

[Leovinus]

<i>An outcast star is zooming out of the Milky Way, the first ever seen escaping the galaxy, astronomers reported on Tuesday. </i> <div class="Discussion_UserSignature"> </div>

 

[robnissen]

Thx for the link. That paper is really cool. Its just too bad the star doesn't show up on the old star surveys. All well, I guess 50 years from now, they can verify it. I guess I better stick around. <img src="/images/icons/smile.gif" />

 

[thnkrx]

There are some nearby stars with galactic orbits so wildly eccentric they might as well be headed out of the galaxy. <br /><br />Ran across some with orbits that take them to within a couple hundred lightyears of the galactic core, then out more then 10 kiloparsecs (Sol is about 8 kiloparsecs from the galactic center). Others had orbits that took them out past 25 kiloparsecs. And these are all stars within 200 lightyears (currently).

 

[jmilsom]

Great Article! Imagine if life evolved on a planet around such a star. Eventually no stars in the sky, just distant galactic blobs! <div class="Discussion_UserSignature"> </div>

 

[heyo]

If there was a planet, theoretically could it have stayed with the planet during it's losing of it's partner star, near miss with the black hole and subesequent ejection from the galaxy?<br /><br />Heyo

 

[Leovinus]

I wouldn't bet on it. <div class="Discussion_UserSignature"> </div>

 

[nexium]

My guess is sling shot manuvers (by giant black holes) fairly often acellerate stars and smaller stuff fast enough to leave our galaxy. If I understood the terminology, this was a magnetude 19 star of either A or B class, on main sequence. Less massive stars are much more common, but not bright enough to get an accurate spectrum, except with the new breed of world class telescopes. I predict we will find lots of them, now that we have the tools and know what to look for. I think planets close to their star in near circular orbits have a good chance of staying with their star during a sling shot manuver, but life forms on the planet would likely die from meteor hits and radiation from the accreation disk of the giant black hole. Small and medium size black holes are more distructive, if you get close enough for a large accelleration. Neil

 

[vogon13]

Could we perhaps clarify ejection mechanism?<br /><br /><br />Assume a single large blackhole at center of our galaxy. All kinds of stars, brown dwarfs, debris, and smaller black holes orbiting central object.<br /><br />I can imagine a binary star system 'swooping around' central blackhole and having system disrupted with result of one star being snarfed and other star being flung outward at high speed.<br /><br />I can also imagine a single or binary star having an encounter with a black hole in some kind of orbit around central object. In this case, we may have an encounter similar to Voyager spacecraft passing Jupiter, in that the object encountering a black hole orbiting central object now can possibly extract some of the orbital velocity and be accelerated to a greater extent than we may have earlier surmised.<br /><br />I realize every encounter will have different geometry, but with many encounters of both kinds, would we be expected to see in our region of galaxy two populations of objects fleeing galactic center? Seems like, on average, objects accelerated by second process may have different (greater?) speed than objects accelerated by first process?<br /><br />Do we expect to see binary stars on these trajectories? Do we see binaries on these trajectories? Can individual stars retain characteristics of having once been in binary system?<br /><br />This topic is extremely interresting to me. Appreciate all discussion/comments. <br />thanx <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[jmilsom]

Ahhh, I imagine the chance would be smaller than a new Big Bang occuring spontaneously somewhere in the universe (recently described in New Scientist as the smallest number ever contemplated).<br /><br />However, it is fun to contemplate such a view even if it is pure fantasy (just as it in fun to comtemplate the slingshot ride around the black hole! <img src="/images/icons/smile.gif" />)<br /> <div class="Discussion_UserSignature"> </div>

 

[thnkrx]

A couple of the stars with very extreme galactic orbits I mentioned earlier are either very wide binaries or fairly close set common proper motion pairs.<br /><br />Interestingly, in terms of luminosity, spectral class, and metallicity, one or two of them would also be candidates for planets.