Astronomers Find Star-Within-a-Star, 40 Years After First Theorized 72
derekmead writes: After 40 years, astronomers have likely found a rather strange celestial body known as a Thorne–Zytkow object (TZO), in which a neutron star is absorbed by a red supergiant. Originally predicted in the 1970s, the first non-theoretical TZO was found earlier this year, based on calculations presented in a paper forthcoming in MNRAS.
TZOs were predicted by astronomer Kip Thorne and Anna Zytkow, who wasthen postdoctoral fellow at CalTech. The pair imagined what might happen if a neutron star in a binary system merged with its partner red supergiant. This wouldn't be like two average stars merging. Neutron stars are the ancient remnants of stars that grew too big and exploded. Their cores remain small — about 12.5 miles across — as they shed material out into space. Red supergiants are the largest stars in the galaxy, with radii up to 800 times that of our sun, but they aren't dense.
TZOs were predicted by astronomer Kip Thorne and Anna Zytkow, who wasthen postdoctoral fellow at CalTech. The pair imagined what might happen if a neutron star in a binary system merged with its partner red supergiant. This wouldn't be like two average stars merging. Neutron stars are the ancient remnants of stars that grew too big and exploded. Their cores remain small — about 12.5 miles across — as they shed material out into space. Red supergiants are the largest stars in the galaxy, with radii up to 800 times that of our sun, but they aren't dense.
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I thinkyou mean:
"It isnot exactlyEnglish, but definitelyin theGermanic family."
It isokay noteveryone is goodat grammar.
Re:Wait, these are for real? (Score:5, Informative)
- Is the research reliable?
Well, the Monthly Notices of the Royal Astronomy Society is one of the longest running astronomy journals in the world, and, to my knowledge, has never done anything substantial to impugn its reputation. It also has a comparatively large impact factor. All signs that the peer review is considered of good quality.
- How can such a thing be stable? Is there any particular process that keeps one star inside the other?
Why wouldn't it be stable? More gravity means more fusion, not less.
The theory says it's a companion star that goes nova, and then is gradually de-orbitted into the larger gas giant.
- What even /is/ such a body? If you were to travel from the outside to the midpoint of the body, would you encounter two barriers of destructing heat, with some emptiness (I'd like to say "vacuum" but of course space is not exactly a vacuum) in between?
Or is it actually just something entirely unlike what you would imagine when someone says "star within a star"?
Oh, and just now I realize you hadn't read the summary. It's a neutron star inside a star. A neutron star is essentially a block of neutronium(essentially a gigantic neutron only nucleus) with some attached hanger on high energy plasma around.
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Why wouldn't it be stable? More gravity means more fusion, not less.
That's exactly why you might expect it not to be stable for long. The mass transfer to the neutron star would be presumably quite large since it is inside the companion, and then, at some point, it will go nova again. Would the companion star survive that?
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Why wouldn't it be stable? More gravity means more fusion, not less.
That's exactly why you might expect it not to be stable for long. The mass transfer to the neutron star would be presumably quite large since it is inside the companion, and then, at some point, it will go nova again. Would the companion star survive that?
I wouldn't really expect the mass transfer to be that great. The neutron star is quite small and the red giant, quite large. Also, the neutron star, while inside the red giant, is most likely in a very low density region, it just happens that what is in that low density region is very hot plasma. There might even be other conditions such as a hot boundry layer around the neutron star that prevents too much from falling in like a stellar Leidenfrost effect. Sure, it's not stable, but the lifetime of such a t
It is not stable (Score:5, Informative)
It lasts for several hundred thousand years but the red giant is eventually absorbed into the neutron star which becomes a slightly larger neutron star or possibly a black hole.
So the red giant is just a big meal that takes a while to eat. But if you look around enough, you can find one in the middle of its course.
Re:Wait, these are for real? (Score:5, Insightful)
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Just the way they write about it, it's like we can watch the entire process from almost start to finish in less than 10 lifetimes. Seems rather fast.
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Re:Wait, these are for real? (Score:4, Insightful)
^^^ That's a place where "average" can be quite deceiving. The sun's atmosphere is rarefied but its core's density is up to 150 g/cm3, or 150x that of water.
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yeah, that 2 order of magnitude correction did a lot :)
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I think it should have been multiple times more massive then the sun.
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...a BB gun pellet...
Typical scientist. Explain away all these "hard-to-understand" principals, but totally crash on a simple analogy. ;)
I'm assuming that you meant "BB".
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Quite honestly, some people here wouldn't know what a BB is.
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Quite honestly, some people here wouldn't know what a BB is.
...but they know what a "BB gun pellet" is?
Just havin a laugh mate. Cheers!
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Well sure, everyone knows what a BB gun is.
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I should have phrased this better. I realize it sounds like I am making a derogatory statement about people who don't know what a BB is. In fact, I was doing just that, but in jest. I'm not sure if the 'in jest' part comes through.
Some people are not raised in a place that every other kid has a BB gun. I didn't have one myself, actually, but the neighbor kid did. Also, there are so many things classified by letters, the term BB could mean a credit score or, as an AC pointed out, pencils.
I even just now goog
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That would be a bummer man. Let's go with the star in a star thing. Almost as cool as guns that shoot guns.
Re:Wait, these are for real? (Score:5, Funny)
Guns don't shoot guns. Guns that shoot guns shoot guns.
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Guns that shoot bees are better.
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Yeah I clicked through to the article. No idea why I did that but:
It's red supergiant with too much lithium, molybdenum and other metals. There's 'something' in there.
Gravity keeps one star inside the other, as in, the neutron star fell into the supergiant. It sank to the center.
Around the surface of the neutron star is now where the 'core' of the red supergiant is, still burning hydrogen (or was it helium?) as a red supergiant should.
Sounded like some subtle measurements to distinguish this one from all th
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Did we have a recent article about missing lithium.... maybe this star is the culprit that stole it all.
are you for real? (Score:1)
I'm impressed, you wrote all that an couldn't even be bothered to read the summary.
Perhaps, yeah, um, you could go back and actually, you know, read the summary?
Yeah. That would be nice.
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I'm just glad that Slashdot nerds are arguing about this, instead of physicists. That could get ugly.
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What do you mean by a stable star anyway?
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No star is stable, if you look at long enough timescales :)
But you're right, this isn't a stable configuration at all. It only lasts thousands of years, compared to millions or billions for other star types. That's partly why it was so hard to find one.
Red giants are huuuuge, we're talking a hundred million kilometers in diameter at least. Neutron stars, on the other hand, are only about 20 km in diameter. So you'd have to go really deep - basically to the exact center - to actually find the neutron star. B
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Actually if the neutron star is in the center then the added gravity in the layer near it will cause greater fusion, when increases pressure causing the layer to expand outward. As it expands it encounters the next layer, which will absorb the energy and begin the same process on a smaller scale. So forth untill it reaches the photosphere. In the mean time the inner layer has transfer excess momentum, has cooled some from it's expansion, it rate of fusion decreases and it collapses to the point it was befo
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If only there was an answer to your questions. Perhaps some reliable source on the subject could publish details on it that we could link to. We could then RTFA.
The merging must be dramatic (Score:5, Interesting)
Just imagine a block of the most dense visible thing in the universe crashing into a star so large you could fit a good chunk of the inner solar system in.
I can't be the only person who'd want to watch that firework display.
The merging must be dramatic, explosive even... (Score:5, Interesting)
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I think it would take too long. Even if the explosion was relativistic it would still be days in the unfolding, wouldn't it? An explosion worth looking at would be weeks? Months in the unfolding? I guess I'm asking as mush as saying.
But no matter, I have a method to see the whole thing in a couple of hours. You.. just.. fly towards it at relativistic speeds, compressing the 'video stream' into a fast forward. You can run it as fast as you can go. You'll need a fancy screen to downsample the view, as what sh
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The only sad thing about living when we do, is we will never get to watch solar collisions from under 100 AU.
Given that the only star within 100AU is our sun and we are rather reliant on that continuing in a very stable way for our continued existence "sad" is not exactly the word I would use.
To my moderator above... (Score:2)
If you strike me down, I shall become more powerful than you could possibly imagine.
Also, knocking me down to -1 won't bring you the love of your father or the respect of your superiors which you crave.
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Hmm ... interesting to think about. A red giant is much bigger than our sun, yes, but its mass is typically similar. Think of it as red-hot vacuum, except for the core. But as the neutron star fell into it, it would draw out a visible tendril of material - and when that tendril touched the neutron star, *then* you'd see fireworks. Gravitational accretion is more efficient than fusion at releasing energy: you'd see a point of bright blue light (peaking in x-rays) at the neutron star, with the pressure of
Tequila Sunrise? (Score:4, Funny)
Yo (Score:5, Funny)
Yo Dawg, we heard you like stars.
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I'm sure there's a "yo mama" joke in there, but I can't be bothered.
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It's the Dawg Star, but navigating with it will be difficult. Too dim.
Are you sirius?
Readers Find Post-Within-Post (Score:5, Funny)
http://science.slashdot.org/st... [slashdot.org]
recursive... (Score:2)
with in a post - within a post - within a post - (it's posts all the way down!)
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Yeah, but that one was posted by Soulskill 3 months ago, and this one is posted by... Oh, I see now, is the same 3-seconds-attention-span gold fish....
Some fucker tried the Klikiss torch *again*? (Score:2)
Shit people, the Oncier [wikipedia.org] experiment with the Klikiss torch was the beginning of a fucking mess with the Hydrogues. Some race or two, somewhere, are gonna get annihilated over that.
Compulsory (Score:2)
Star Star (Score:2)
Hmmm. (Score:1)
If Kip Thorne can win a year's worth of Playboys for his bet that Cygnus X1 was a Black Hole, when current theory from Professor Hawking says Black Holes don't really exist, then can Professor Thorne please give me a year's subscription to the porno of my choice due to the non-existent bet that this wasn't such a star?
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Will the original Hawking please stand up?
Dr. David Bowman was contacted for comment... (Score:1)
Oblig (Score:1)
http://xkcd.com/224/ [xkcd.com]
Dupe ... (Score:2)
Bad translation into American (Score:2)
Their cores remain small — about 12.5 miles across
Looks like a vague "20km" gained a couple of orders of magnitude in precision (2 extra significant figures).
This is bad journalism even when its not science.
"Mr Smith was reported as saying 'You look like 772,000 Euros!'"
Wouldn't it punch right through it? (Score:2)
You have a few stars worth of neutornium the size of a big asteroid or maybe a small moon moving towards a red giant that is perhaps similar in mass to our own sun.
I can buy that eventually the one ends up inside the other. What I wonder about is how you get from a neutron star falling towards a red giant to a neutron star inside a red giant.
I'd think the neutron star would have so much momentum that it would basically blast right through the star and come out the other side.
Of course, a more likely scenar
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Hate to self reply, but think of it like shooting a rifle round at a blimp. The bullet is going to just sail right through both sides, with neither object being affected all that much.