1/5 of nearby stars have very elliptical orbits?

[nexium]

~Rebel stars revealed in Milky Way <br />artical in NewScientist.com news service<br />Is this mainstream?~<br /><br />Streams of "rebel" stars are blazing new trails to and from our galaxy's centre instead of travelling in circles around it, according to a new study of 6000 nearby stars. The stars appear to be nudged into their new grooves by the Milky Way's spiral arms. <br /><br />About a trillion stars trace out a pinwheel that makes up the Milky Way. Most of the stars in the five main spiral arms take more or less circular paths around the galactic centre. The Sun, located midway down one of the arms, takes about 100 million years to complete one loop. <br /><br />Now, astronomers have caught a fifth of the stars within 1000 light-years of the Sun taking detours. The stars are still moving around the Milky Way's centre, but they are taking more elongated routes, trooping more directly toward and away from the heart of the galaxy. <br /><br />But though they are flowing in orderly streams, the stars themselves are a motley crew. They vary greatly in age, which suggests they did not form at the same time and place. <br /><br />"They resemble casual travel companions more than family members," says Benoit Famaey, an astronomer at the Free University of Brussels, Belgium. He is lead author of the study, which was published in Astronomy & Astrophysics..........." <br />It's amazing how much of this article could also apply to Russell Crowe, Adrian Brody or Colin Farrell, if you take out the science part. <br />Lol!!!!! <br /><br />~We should not be surprised at some exceptions in this or other topics. The eliptical orbits can begin in the the birth place of stars where the mid mass and less massive stars get ejected by sling shot maneuvers around the super-massive stars. Minor perturbing that occurs later usually approximately cancel, but very rarely can add often enough to make the orbit highly elliptical. Please comment, refute or embellish. Neil~ <br />

 

[odysseus145]

An article on this apeared recently on space.com. Its very interesting.<br /><br />Link <div class="Discussion_UserSignature"> </div>

 

[Maddad]

As a minor nit-pick of the article, the usual number quoted for the number of stars in the galaxy is more like 200 to 400 billion (0.2 to 0.4 trillion).<br /><br />It is not at all surprising that we have a population of stars that are in eliptical orbits about galaxy. We now believe that over its lifespan the Milky Way repeatedly has absorbed numerous smaller galaxies. The stars from them will be of different ages, as the article noted, and they would still be in non-circular orbits because they have not had time to circularize from their initial collision with our galaxy.

 

[alokmohan]

I agree.

 

[nexium]

Most astronomers figure 200 billion main sequence stars in our galaxy. If there were lots of O,B,A and F stars one billion to ten billion years ago, it is not unreasonable to assume our galaxy has 800 billion compact stars plus a few million each of proto stars and red giant stars, totally about a trillion if you choose to count them all, as stars instead of only the ones on main sequence. Neil