Inter-galactic stars?

lnelson · Post by **lnelson** » Fri Dec 23, 2005 8:09 pm

I have what may be a dumb question, but then again, maybe not...
I'm also not sure if this has ever been asked or discussed before in this forum, having just joined.

I, like many, am inspired and awed by such pictures as the 12/22/05 picture of M31, the Great Andromeda Galaxy. Last evening, I ventured out to a fairly clear evening sky around 11PM local time and looked up to see many of the usual night time stars and constellations and wondered if all the stars I can see with the naked eye are, in fact, members of our own galaxy. (Ok, that's question No. 1).

Secondly, I wondered whether there are any stars out there (visible or not to the eye) that are not in a galaxy. In other words are there inter-galactic stars, stars that ihabit the space that makes up the vast distance between galaxies?

- Larry

lnelson · Post by **lnelson** » Fri Dec 23, 2005 8:43 pm

Well, I believe I've answered my own questions. After posting my original query, I decided to try Google and came up with the following tidbit from Garry Telford's website, "Astronomy with Garry" (http://www.astronomywithgarry.net/abstract.htm).

About halfway down this particular page I found:

"Almost all stars find themselves members of cosy little communities like galaxies, or at least a globular cluster. Our Sun is no exception, choosing to materialise in a nice spiral galaxy we call The Milky Way.

There are some unfortunate stars though which find themselves wandering the unimaginably huge voids of inter-galactic space, far from any galaxy or neighbouring stars. In most cases these stars have been the victims of galactic collisions billions of years ago. The relatively rapid movements of colliding galaxies can result in stars in the outer arms being ‘whipped out’ into space. They are then destined to forlornly wander the starless voids almost forever on the trajectory they left their galaxy with, unless they are ‘lucky enough’ to encounter another galaxy along the way. It is possible some stars actually form outside of galaxies from tenuous wisps of hydrogen gas existing in inter-galactic space.

Now consider this. If the Sun was such an inter-galactic wanderer, the Earth was it’s only planet and lacked a moon as well, the night sky would be totally black, devoid of anything visible to the naked eye. Even the nearest star or galaxy would be much fainter than 6th magnitude. The development of Astronomy would have been retarded by hundreds of years perhaps. Why invent the telescope when there’s ‘nothing to see’? "

harry · Post by **harry** » Fri Dec 23, 2005 10:43 pm

Hello

I liked the link
http://www.astronomywithgarry.net/abstract.htm

Does anybody have a link for an image of a Lone Star between
galaxies.

lnelson · Post by **lnelson** » Sat Dec 24, 2005 7:55 pm

Haven't been able to find an actual Hubble photo, but this link has a press release and an artist's concept.

http://hubblesite.org/newscenter/newsde ... s/1997/02/

This link references a gif and jpeg image but have been unable to track them down.

http://www.xs4all.nl/~carlkop/lonely.html

- Larry

harry · Post by **harry** » Sat Dec 24, 2005 9:41 pm

how do these lone stars get out there.

nice links

Empeda2 · Post by **Empeda2** » Sat Dec 31, 2005 1:27 pm

They get thrown off by galactic collisions - the distortion of their orbits by the two galaxies colliding can 'jettison' them out. Other possibilities could be the results of slingshot effects from triple-star systems (check out N-body simulations with google for more info).

Every naked-eye star in within our galaxy - only a very very small portion of it though... The only thing visible to the naked eye that is outside our galaxy is M31 - the Andromeda Galaxy.

harry · Post by **harry** » Mon Jan 02, 2006 12:53 am

The question is can a lone star form outside of a cluster of stars of galaxy

Empeda2 · Post by **Empeda2** » Tue Jan 03, 2006 4:30 pm

As longs as there's sufficient energy/mass/pressure I suppose - which I would think unlikely, unless some extraordinary event triggered a gigantic shockwave?

BMAONE23 · Post by **BMAONE23** » Tue Jan 03, 2006 8:22 pm

I would think it would be possible (as Empeda states though there would need to be a gas cloud of sufficient quantity with a central mass large enough to start the gravitational crunch nnecessary to cause a star to evolve.) If it weren't possible, then the first stars might not have formed in the beginning. After all, they formed outside of a galaxy as there wasn't yet a galaxy formed. (kinda like the chicken - egg thing) Which came first, the Star or the Galaxy? The star would need to form first.

S. Bilderback · Post by **S. Bilderback** » Wed Jan 04, 2006 2:37 am

It is believed that most of the "Wandering Stars" were ejected from galactic collisions.

harry · Post by **harry** » Wed Jan 04, 2006 7:50 am

The Chicken or the egg.

If the universe has been here all the time. Than a recycling process would be going on. The egg would follow the chicken than the egg and so on.

If you think along the lines of the Big Bang. Than you would have no chicken or egg.

As for lone stars:

1) Galaxy collisions would be one option.
2) Active galactic centres would eject material out into space and by chance some of this matter may have escaped from the gravity of the galaxy aided by maybe a gravity pull from a close encounter with another galaxy.
3) Again if you agree with the Big Bang, maybe there is some excess matter floating around.
4) Was created,,,,,,,,smile

Happy New Year

harry · Post by **harry** » Thu Jan 26, 2006 7:27 am

Sometimes isolated stars are created just by another galaxy coming close to another without colliding

see link

http://antwrp.gsfc.nasa.gov/apod/ap060108.html

astroton · Post by **astroton** » Thu Jan 26, 2006 9:41 am

This link has an image attributted to Hubble.

http://www.pparc.ac.uk/frontiers/archiv ... yle=update

This article has an image of stars turning into wonderers.......

http://www.mpa-garching.mpg.de/mpa/rese ... 11-en.html

This picture / post speculates about intergalactic supernova close to Abell cluster...

http://wise-obs.tau.ac.il/~avishay/woot ... age10.html

.....

harry · Post by **harry** » Thu Jan 26, 2006 9:59 am

Hello Astroton

I liked the links,,,,,,,,,,,,,,thankyou

makc · Post by **makc** » Thu Jan 26, 2006 12:05 pm

lnelson wrote:I'm also not sure if this has ever been asked or discussed before in this forum, having just joined.

Please scroll up and examine top 3cm of this page carefully: you probably will find a handy

Search link there. Then again, maybe you will not.

EDIT: damn, it looks like I was a month late with this...

Starship Asterisk*

Inter-galactic stars?

Inter-galactic stars?

Re: Inter-galactic stars?