Hypervelocity stars

[Xynoplas]

http://www.sciencere...velocity-stars/

Astrophysicists estimate that a star must get a 1,000,000+ mile-per-hour boost relative to the motion of the Milky Way to achieve escape velocity.

According to a January 9 news release from Vanderbilt University, an international team of astronomers has discovered a new class of hypervelocity stars – single stars traveling at speeds that enable escape from the Milky Way’s gravitational pull. Announced earlier this week at the annual meeting of the American Astronomical Society in Washington, DC, the complete research findings first appeared in the January 1 issue of the Astrophysical Journal.

“These new hypervelocity stars are very different from the ones that have been discovered previously,” said Vanderbilt University graduate student Lauren Palladino, the lead author of the study. ”The original hypervelocity stars are large blue stars and appear to have originated from the galactic center. Our new stars are relatively small – about the size of the sun – and the surprising part is that none of them appear to come from the galactic core.”

Now this interests me for a couple of reasons.

1. Is this really a star or an interstellar spacecraft? Given the chances of the existence of a spacegoing extraterrestrial civilization, what is the likelihood of such a craft being misinterpreted by myopic science?
   
2. Viv-a-vis the big bang: here is an example of a star that is not "banging" with the rest of the stars. Is there an explanation for this?
   

Edited January 9, 2014 by Xynoplas

[Taun]

I seriously doubt it would be a space craft for a couple of reasons, the two main ones are:

1. These hypervelocity stars are many light years away from us... the only reason they are visible is because they are luminous - like our sun... A space craft would presumably

only be luminous if the engines were pointing directly away from us and that would be extremely dim in comparison to a star...

2. Even traveling at an apparent speed of 1,000,000 MPH, it would still take one of these objects nearly 700 years to travel a single light year... Not practical ....

[Gumball]

Still pretty amazing though. What if these Suns were to hit other bodies out there? I know the cosmos is a big place but stars are also pretty big. Not going down the alien path but would any types of inhabitants even see a thing like this coming before it was too late?

[highdesert50]

This would be an interesting method for an advanced civilization to explore; accelerate an entire solar system while living relatively comfortably on a habitable self-sustaining planet.

[Frank Merton]

As I understand it these are stars that once were companions of stars that exploded, becoming runaways as because of the ensuing slingshot effect.

Not having access to the entire article, I can't say why they report this as a new discovery, since such stars have been known about for quite awhile.

The odds of two such systems coming close enough to be a hazard have been calculated and if memory serves it is too small to worry about -- like maybe one or two such encounters might happen over the life of the galaxy.

[Sundew]

Still pretty amazing though. What if these Suns were to hit other bodies out there? I know the cosmos is a big place but stars are also pretty big. Not going down the alien path but would any types of inhabitants even see a thing like this coming before it was too late?

The space between stars is so vast that supposedly two galaxies can collide without the individual stars ever (or extremely rarely) colliding. There was an experiment you could do I saw on a website a year or so ago, I may have the relative distances wrong (since it was quite a while ago), but I think as an example if you draw a period sized dot on the ground, then you walk about five miles and draw another dot and that gives the relative distance between our sun and the nearest star. Again, I may have the relative sizes and distances off but you get the idea of how big space is and why stars rarely collide.

Or as Douglas Adams put it: "Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space." The Hitchhiker's Guide to the Galaxy

[Frank Merton]

I had an astronomer once say to me that if I were the Sun here in Ho Chi Minh City, and he were the nearest system (the Alpha-Beta-Proxima three star system), he might be wandering about London.

[Sir Smoke aLot]

Gravity 'plays' a big role in such great colision scenarios. Every object inside galaxies would follow some imaginary gravity influence lines and dance in harmony with other objects. Thats what i read about future Milky way and Andromeda 'colision'. Black holes which are in centres of galaxies would perform long, almost ethernal dance ( millions of years long untill finally combine in most amazing way )

And colision simulation Andromeda and the Milky Way

[media=]

There are many more ofc its just amazing to watch this videos and think about the size of objects, not to mention the area that such events cover. So gravity is, amongs other possible reasons, mostly guilty that no crash would occur.

But star systems... Some could get ejected in outer space.

Edited January 15, 2014 by Sir Smoke aLot

[Xynoplas]

I had an astronomer once say to me that if I were the Sun here in Ho Chi Minh City, and he were the nearest system (the Alpha-Beta-Proxima three star system), he might be wandering about London.

That depends on the scale that you assume of course.

[Gumball]

The space between stars is so vast that supposedly two galaxies can collide without the individual stars ever (or extremely rarely) colliding. There was an experiment you could do I saw on a website a year or so ago, I may have the relative distances wrong (since it was quite a while ago), but I think as an example if you draw a period sized dot on the ground, then you walk about five miles and draw another dot and that gives the relative distance between our sun and the nearest star. Again, I may have the relative sizes and distances off but you get the idea of how big space is and why stars rarely collide.

Or as Douglas Adams put it: "Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space." The Hitchhiker's Guide to the Galaxy

But still random things can happen and would they see it coming?

[wuhugm]

Still pretty amazing though. What if these Suns were to hit other bodies out there? I know the cosmos is a big place but stars are also pretty big. Not going down the alien path but would any types of inhabitants even see a thing like this coming before it was too late?

was what I thought as well

even a near miss will bring doom to any planetary bodies and kills off potential lifeforms

[Peter B]

But still random things can happen and would they see it coming?

Oh yes. If such a star was to come fanging towards our Solar System, we'd certainly see it, and from a lo-o-ong way away. For one thing, it's a star, and stars are bright. For another, it's motion would be measurable (not across the sky but in terms of red shift). There's no reason that a fast-travelling star would be invisible just because it's moving quickly.

But it's not as though we'd have no warning: as Taun pointed out, at that speed it would take 700 years to travel 1 light year; the nearest star to our Sun is about 4.5 light years away.