Star Flung From Milky Way at High Speed

fenimor writes "Using the MMT Observatory in Tucson, astronomers have discovered a star three times bigger than the sun, leaving our galaxy at a speed of over 1.5 million miles per hour (670 kilometers per second). The first-of-its-kind finding not only confirms an earlier theory about the existence of such speeding stars, but also reinforces the notion that the Milky Way spins around a black hole."

Comments

That's Life

[Doc Ruby]

It's a glider!

Re:That's Life

[Loadmaster]

It's a big ball of garbage from Old New York. I checked it with my smell-o-scope.

Outcast Star

[lecithin]

"We're tempted to call it the outcast star because it was forcefully tossed from its home."

Instead they are going to call it a galaxy challenged star.

Re:Outcast Star

[lucabrasi999]

Instead they are going to call it a galaxy challenged star.

The Mayor Star of the Milky Way decided to form a committee to review the causes of "Outcast Star Syndrome". That committee, which will be composed of various leaders in the Star Community, along with interested Asteroids, Planets and Comets, will interview other Stars that have, through no fault of their own, also been cast out of the galaxy.

In six months, the Committee will issue a report that includes recommendations on how we can prevent Outcast Star Syndrome along with a 12 step program to re-integrate former Outcast Starts into the entire Milky Way community, with the hopes that they will become productive members of the community again.

a giant ball of flame at a million miles an hour

[essreenim]

galactic pin ball here we come!!

Yep.

[inertia187]

Just like my screen saver predicted.

Fling out of the galaxy

[falser]

Ok, now how do we apply this knowledge to do the same to Microsoft/Paris Hilton/Terrel Owens/Celine Dion.... ?

Re:Fling out of the galaxy

[Rude Turnip]

Between Microsoft and Paris Hilton alone, there is so much suction I'm surprised the rest of us haven't been flung into space.

Wish Upon A Star...

[FIGJAM]

Starlight, star bright, first-of-its-kind star I see tonight, I wish I may, I wish I might, get laid tonight.

Re:All kinds of morons on Slashdot...

[Hyecee]

I think he might have meant if we were to be run over by a random sun moving at that speed. Could be wrong, though.

Speed is relative

[Hoi Polloi]

What are they measuring the star's speed against? The center of our galaxy? The earth?

Re:Speed is relative

[grahamsz]

Presumably if it's leaving our galaxy then that'd be the normal way to look at it.

Alternatively maybe it's staying still and we are being flung away from it at 1.5M mph.

Re:Speed is relative

[jridley]

It's moving like hell compared to any large body in the galaxy, or the average.

I remember this story:
Professor: The temperature in this kind of reaction is about 3 million degrees.
Student: Is that Celcius or Kelvin?
Professor: It doesn't matter!

IOW, the difference between C and K at ~3m* is insignificant. In the same way, the speed of this star is practically the same from any point of reference near any star in the galaxy.

Relative speeds

[FirienFirien]

A bit of googling pulled up:

Meteorites: 10ish miles per second, depending (yukon = 9.3)
Earth through space: 18.5 miles per second
Sun through space: around 155 miles per second

This thing is moving really quite scarily fast. The energy in that thing must be huge, since it's already 3 times the size of the sun.

Questions: what would the effects of the speed be? Would the galaxial dust clouds be dense enough to 'fan the flames'? How does something that gets accelerated to that speed stay together - or, how big was it before it shed all the mass that couldn't stay together!

There was a monty python song about this... *hums*

Re:Relative speeds

[Viking Coder]

Come on! You gotta do the whole thing!

Just remember that you're standing on a planet that's evolving
And revolving at nine hundred miles an hour,
That's orbiting at nineteen miles a second, so it's reckoned,
A sun that is the source of all our power.
The sun and you and me and all the stars that we can see
Are moving at a million miles a day
In an outer spiral arm, at forty thousand miles an hour,
Of the galaxy we call the 'Milky Way'.

Our galaxy itself contains a hundred billion stars.
It's a hundred thousand light years side to side.
It bulges in the middle, sixteen thousand light years thick,
But out by us, it's just three thousand light years wide.
We're thirty thousand light years from galactic central point.
We go 'round every two hundred million years,
And our galaxy is only one of millions of billions
In this amazing and expanding universe.

The universe itself keeps on expanding and expanding
In all of the directions it can whizz
As fast as it can go, at the speed of light, you know,
Twelve million miles a minute, and that's the fastest speed there is.
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth,
And pray that there's intelligent life somewhere up in space,
'Cause there's bugger all down here on Earth.

Re:Relative speeds

[Spackler]

You seem to be using "through space" as a non-relative term. If the sun is moving "through space" at 155 miles a second, how can earth be moving "through space" at only 18 miles a second. It that was the case we would be 16,000 miles farther from the sun since I started writing this email. 3 million miles more than when I woke up this morning and 180,795,888,000 miles since I was born.

Re:1.5 million miles per hour!!

[merlin_jim]

I just wonder why the star and the planets are not torn apart by such huge speeds?

a) we're not sure it has planets.

b) it's not velocity that kills, it's acceleration.

c) this acceleration can only be explained by current theory if it was a gravitational acceleration.

d) gravitational acceleration acts on all elements of an object equally, meaning that there was no force from the acceleration itself acting to tear the object apart. Just like when you're in freefall, you don't feel gravity acting on you.

Now TIDAL gravity can tear objects apart, but since the gravitationally assisted acceleration likely happened in the galactic core, the tides were probably pretty gentle... the tidal force at a black hole's horizon can be expressed as a function of mass over surface area; the bigger the hole, the less the tides.

To put that in perspective...

[GillBates0]

That's 0.002 times the speed of light or only about 1/500th the speed of light.

Plugging 670*10^3m/s into Lorent'z equation:

t = t'/(sqrt(1-(v^2/c2))
where v=6.7*10^5m/s
and c = 2.99*10^8,

I got a time dilation of factor of 1.00000249. That is, time in the moving system (the star) will be observed by a stationary observer to be running slower by a factor of 1.00000249.

Not as impressive as I hoped it would be when I started the calculations.

Re:To put that in perspective...

[catdevnull]

I genuflect in the general direction of your geekitude....

Re:To put that in perspective...

[Alsee]

The time dilation may not be impressive, but the raw energy involved certainly is. Energy(non-relativistic)=1/2mv^2. The star is three times the mass of our sun, times v^2, times 1/2, equals 4.5*10^41 kg-m^2/s^2. That is 4.5*10^41 joules. Our entire sun produces a measly 3.9^10^26 joules per second.

It would take the entire energy output of our sun for about 36.5 million years (at a magical 100% efficiency) to accellerate that star to that speed.

-

Hindmost

[Rorschach1]

Goddamned Puppeteers. Before you know it, they'll be fleeing with all the good stars.

Re:Hindmost

[chiph]

FYI: the 5-planet Klemperer Rosette used as a plot device by Larry Niven for the Puppeteer's home worlds has been shown to be unstable:
http://burtleburtle.net/bob/physics/kempler.html

(warning, contains java applets which will probably freeze up Firefox)

Chip H.

Lever

[suso]

I guess someone finally found a really long plank and a place to stand.

Inertia & Momentum

[mreed911]

While this seems astounding, leaving some to wonder "how's a star stay together at 1.5MM mph?", it's important to remember that, for all intents and purposes, it's travelling through NOTHING, through a vacuum. As long as its velocity is stable (not running into things to slow it down), there's no inertia to change it's shape, etc.

Is there *really* a difference, physically, on an object moving at 1.5MM mph and one standing completely still, if they're not interacting with anything else? No. Their inertias are the same, so their physical properties and interactions are the same.

Momentum, however, could be a bitch. Imagine this star slamming into another star (or, a la the Death Star, a small planet in the Aldeberan system). Ka-pow, with the graphic like on the old Batman series! Would make Levy-Shoemaker look like a BB gun (you're gonna put your eye out!)...

Supermassive black holes

[Spy der Mann]

Recently I saw on Discovery that many galaxies (if not all) were orbiting around supermassive black holes. And that the orbiting speed of the stars is proportional to the black holes' mass. This is known as the "M-sigma" relation.

This meant that the supermassive black holes actually contributed to the process of galaxy formation.

The theory is more or less the following:

In the center of a galaxy-sized gas cloud, a star collapsed, forming a black hole. The black hole began eating the gas around it, forming a quasar (quasars are the matter just about to be swallowed by a black hole, disintegrating and generating enormous amounts of energy).

The quasar, due to its high temperature and rotational speed, heated the surrounding gas cloud, activating a chain reaction that gave birth to all the stars in the new-forming galaxy.

Eventually, the quasar pushed away the stars, so the black hole could only be fed by the quasar itself. After that, the black hole enters a dormant phase (it has nothing else to eat), and the galaxy is already formed (of course, I'm talking about a process that takes billions of years).

Re:Supermassive black holes

[bigmaddog]

Call me a bitch about details, but... (I know, someone else will be a detail bitch about my details.)

Quasars radiate tremendous amounts of energy not because matter "disintergrates" as it falls inwards but merely because it falls inwards.

It's as if a bucket of bricks fell on your head from ten stories up (well, almost) - while up there, the bricks & bucket have potential gravitational energy. As the whole thing falls, gravitational potential energy is converted to kinetic energy, some of which is lost to friction with the surrounding air. It may generate sound, like a low whistle or thunderous roar, depending on the aerodynamic properties of the bucket. When the bucket hits, all the remaining kinetic energy is dissipated by your skull and brain, and "radiates away" as sounds and splattering gore. (This last part about the brain and plattering is not necessary for the analogy but I just like talking about gore.)

So, same thing with quasars, more or less. Stuff far away from the quasar has a lot of gravitational potential energy because quasars are so damn massive, which leads to powerful gravity. As it falls inwards, it trades this energy for kinetic enrgy, moving faster, and, as it grinds against other stuff in the accretion disk around the quasar, some of which is moving slower, some of this energy is lost to friction, except instead of sound (whistling) with the bucket & bricks, you get EM radiation. (If the bucket fell from really high up, it might heat up from friction and start emmiting some radiation of its own, in infra red and then in visible light.)

Sice the black holes at the centre of galaxies are so damn huge, and because falling into a black hole release several orders of magnitude more of the massenergy of a piece of matter than fission or fusion ever could (astronomy textbook not at hand, so can't quote the numbers), we get a whole lot of radiation this way, and so quasars are really really bright.

Re:1.5 million miles per hour!!

[Dana P'Simer]

First, there is no indication that they have any evidience that the star has planets. Second, how exactly would mere velocity tear the start apart? I would not be suprised if, in the star's distant past, when it had it's close encounter with the super massive black hole at the center of the galaxy that some significant tidal forces were not placed on the star's contents. However, it appears that the star is stable, for the moment, ( moments in stellar lifetimes take millions of years ). The mere fact that the star is moving fast is not enough to tear it apart, there would have to be some other gravitational or kinetic forces at work. Do you realize that,

simply owing to the earth's rotation, you are, at this moment, moving at a rate of approximately 1000 mph? Probably less since you are probably not at the equator.

Also, Due to the earth's orbit around the sun, were are traveling at approximately 67000mph.

According to findings of COBE, our galaxy is traveling at 300 k/s or about 1.34 million mph.

Why aren't you torn apart?

milky way munching stars and galaxies

[peter303]

I thought last year they found four "drawf" galaxies in vicinity of the Milky Way, about to be absorbed.

The big Kahuna of course will be the merger with Andromeda about two billion years hence. Our mutual gravitational attraction is drawing us together. In practical terms, both galaxies are essentially empty space. However Andromeda will grow from its present size in the sky of six full moons (192 arc minutes; but just a faint smudge) to fill the entire sky. See the collision simulation here.

Re:milky way munching stars and galaxies

[corngrower]

there probably would be no kinetic interaction between the two if they were to "collide".

I would bet that there would be a number of stars in the galaxies that would have their motions markedly changed. You'ld probably have a number of stars being scattered around and exiting the galaxies at high velocities relative to other stars . There may even be an actual collision or two.

Weapon Testing, Anyone?

[Trifthen]

Who wants to be the first to claim this is simply a huge plasma burst fired by an even larger weapon? Maybe it's just some alien race out there who wants to illustrate that they too, emjoy blowing things up with oversized guns. ^_^

Let me be the first to say...

[fizban]

"Fore!"

Re:1.5 million miles per hour!!

[merlin_jim]

That's not entirely true. The force excerted by gravity goes as 1/r^2, where r is the distance between both masses.

If you have for example two large m1 and m2 each attached one end of a very long pole in a gravitational field caused by another mass M, the mass nearest to the M would experience a slightly stronger force than the other one. So that could, in theory, break the pole.

What you're talking about is tidal gravity. And tidal gravity is exactly what caused one star of a companion to be accelerated away while the other one was captured into an orbit.

On the scale of the objects themselves, though, the tides were probably extremely gentle. AFAIK companion stars are generally light-months apart. Even if this star was a planetary system, it's nearest planets are probably only a few light-minutes away...

Re:Man...

[Mindwarp]

Mass of the star: approx 6x10^30 kg Velocity: 670,000 m/s Kinetic energy = 0.5 x m x v^2 Energy is very approximately 1.3x10^42 Joules, which I believe is enough to heat a Googleplex of Libraries of Congress for 3.141 Millenia.

Re:Does anyone know...

[Overzeetop]

Well, if we can simplify the motion to (1) the galactic core and (2) the star, Kepler's equations require that it be decelerating. Based on the fact that it has 2x the escape velocity of the galaxy, that would put it on a hyperbolic path with the galactic core at its focus (the real one). After an (infinite) period of time, it will slow to a spped which is 1.7x escape velocity (v-inf^2=v^2 - v-esc^2) based on the 2x number being the maximum velocity obtained. This is more commonly known as the "hyperbolic excess speed".

This post brought to you in part by Bates, Mueller, and White...the best textbook value in the world ($6 for an astrodynamics text...and a pretty good on at that).

Explanation

[af_robot]

For those, who didnit get it.
Puppeteers are alien race from novel "Ringworld" by Larry Nivel. They were moving their home star system to a new galaxy to escape from the Core explosion.

Re:Little relativistic phenomena

[EulerX07]

The speed of light (c) is 300 000 km/s. 670/300000 = 0.0022. It's going at 0.0022c.

Don't worry, you're the not the first person to post disinformation on this site and get modded up as informative. Also, you should have worked with the metric values instead of messing around with the imperial values. Ye olde english system is great for measuring stuff in your trousers, but not as great for astrophysics.

Black hole?

[The One and Only]

I thought it was well established that at the center of the galaxy there is a planet, that God is on that planet, and that (as it is becoming abundantly clear), he needs a fucking starship!

What about relativity?

[aiken_d]

From the SDSS J090745.0+24507 Daily News:

Universe Takes Off
The entire rest of the Universe suddenly accelerated to over 670km/sec and is fleeing our vicinity at an astonishing rate. In fact, the Universe seems to have decided to move a large region of intergalactic space into our vicinity, which will have a dramatic negative effect on property values.

Scientists are at a loss to explain the sudden move by the entire Universe, but have assured the Theocracy that the subspace ether is still intact and that our sun is still planted firmly in exactly the same spot it always has been. The scientists did say that the sudden movement by the entire Universe may have stressed the subspace ether, and that concerned citizens should at least double their daily offerings to Zugbat lest our sun lose its attachment to the ether and be sucked across space with the rest of the Universe.

There will be an execution of two atheists who suggested that our sun had begun moving at a high rate of speed, and not the rest of the universe. See page 6.

Cheers
-b

Re:Any astronomers out there?

[Somegeek]

All of the real astronomers are busy right now. Press 1 to be connected to a geek instead or 2 to leave a message.
-1-
Thank you.
The answer is : Black holes can be compilations of many stars. The one at the center of our galaxy that they are talking about is currently believed to be 3.7 million times the mass of our Sun (give or take 1.5 million).
This is just like we slingshot space probes past planets to get a gravitational speed boost, this star got pulled in towards the black hole but barely missed and got a the mother of all gravitational slingshots. I would guess that the fact that it had a companion was unimportant, and could have happened if it had been it had been a single star on the right trajectory.

IANAA.

Re:Inertia & Momentum - Star Stampede

[m0smithslash]

How do we know that the star is being ejected from the solar system? According to relativity, to an observer in the galaxy, a star being ejected from the galaxy looks the exactly the same as using the star as the frame of reference and the whole of the milky way galaxy is moving away from it. Since we didn't actually see where this star was coming from, the star could have been holding still for a long time while the galaxy far,far away came stampeding past like the wildebeast stampede in Lion King. To us stuck here on earth it would look exactly the same either way. So its not so much tht the star is being ejected, but that it survived the stampede.

Re:Any astronomers out there?

[SirBruce]

I think the correct verb is "slingshat".

Bruce

Black holes have no hair

[Ohreally_factor]

'cause black holes don't have a size limit.

Do you mean that they don't have a mass limit? Because they definitely have a size limit. They're 0-dimensional.

Or are you thinking of the Schwarzschild radius?

Looks like

[Ohreally_factor]

Someone went and taunted the happy fun ball.

Re:1.5 million miles per hour!!

[LurkerXXX]

Right on the tidel forces.

As for his body being accelerated and his blood isn't... That's only the case in as much as right now your body is trying to accelerate at 9.8 m/s/s toward the center of the earth. Your bone structure and muscles lets you resist it. Your blood is also trying to accelerate towards the center of the earth at the same rate. Your arteries and veins and your heart let you resist that as well.

Your body and blood aren't accelerating at different rates. They both deal with the same acceleration in the same way, with it acting as 'weight'. The problem with weight/acceleration is that your body was designed to handle only so much of it.

Now let's kick it up a notch. blood pooling...

Imagine a test pilot in a centrafuge machine. It takes him up to 6 G's and holds him there for an hour. Just like he was on a planet with 6x earth's gravity.

His body is accelerating at 6 G's.
His blood is also accelerating at 6 G's (otherwise it would all leak out the back of his chair and that would be a 'bad thing' ;)

His blood resists accelerating as you say, but so does his body (Bodies at rest tend to stay at rest tend to stay at rest, bodies in motion tend to stay in motion and all that). Nevertheless, the back of his chair is causing the lot of them to accellerate at 6 G's.

His heart, however is now trying to pump blood that 'weighs' 6x as much. The heart can't pump the heavier blood as easily or 'high' (relatively) as it could normally. His veins can't constrict as much as they normally would to force blood back into the right areas of the body, because the blood is pushing against them with much greater force. The veins also have valves to prevent blood from flowing back the wrong way, but these may give way under the additional pressure.

The blood is not accelerating at a different rate from the body, it's still in his veins and artieris, and so still in his body. His body is being accellerating at 6 G's and the blood, being trapped inside, is going along for the ride. But it acts as a much heavier fluid. So it starts to pool in the lower extremeties since it can't be pumped efficiently. Depending on how strong his heart is (and resilient his veins are), he might be able to handle 6 G's for a good long while. But if they aren't in quite as good of shape he might not be able to pump the blood well enough and might black out after a few seconds or minutes.

Once again the blood isn't accelerating at a different rate than the body (both are resisting being accelerated), anymore than your blood and body accelerate at different speeds on earth, it just has a higher 'weight' then the body was structurally designed to pump.

The next stage is to crank up the centrifuge chair/other-planet to 1000g's density. 1000 G's. Now the test pilot's ribs are trying to hold up themselves and the muscles etc attached to them. But they weight 1000x as much. The bones werent' constructed to hold such a high weight, so they snap. The 'body' isn't accelerating at a different rate than the... 'body', but it breaks down because it wasn't designed for such mechanical forces. Everything is being accelerated (and trying to resist it). Everything is accelerating at the same rate. It just can't handle the rate.