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Astronomers Find Star-Within-a-Star, 40 Years After First Theorized
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.
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.
Sounds like a mixed-drink with specific gravity setup...
Do not look into laser with remaining eye.
Yo Dawg, we heard you like stars.
I was thinking the same thing, it would be an interesting event to witness. The only sad thing about living when we do, is we will never get to watch solar collisions from under 100 AU.
HA! I just wasted some of your bandwidth with a frivolous sig!
- 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.
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.
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One is a neutron Star. So a object multiple times more dense than the Sun but only a 5-15 miles wide. The other a red giant (when our Sun becomes a red giant it'll be as big as Earth's orbit). So the first barrier you would cross working for the middle is a iron polymer a million times stronger than steel as you crossed out of the tiny tiny neutron star into the absolutely enormous red giant. An analogy would be a BB gun pellet inside of a balloon.
Shit people, the Oncier 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.
A successful API design takes a mixture of software design and pedagogy.
Yo dawg... I heard you like shining. So I put a star inside your star, so you can shine while you shine.
you are....Rolling Stones. TFA said star within a star.
Maybe it is just a red giant with abnormally high concentrations of lithium, molybdenum, and rubidium.
The outside of a Red Giant may be thought of as very tenuous, but the core is still a very dense place. The heat of the core would supply enough energy to the plasma so that it can, on average, escape being pulled into the neutron star. The extra gravity would actually increase the nuclear fusion rate, and generate more heat. Then again, on average, some of the plasma would be pulled into the neutron star. Slowly, the star core would be consumed.
Yeah, I'm sure the postdoc herself would prefer a somewhat more polished text.
Ezekiel 23:20
with in a post - within a post - within a post - (it's posts all the way down!)
My God can beat up your God. Just kidding...don't take offense. I know there's no God.
I thinkyou mean:
"It isnot exactlyEnglish, but definitelyin theGermanic family."
It isokay noteveryone is goodat grammar.
Well.. maybe. Or Maybe not. But Definitely not sort of.
All he had to say was, "Oh my god, it's full of stars" and the line went dead.
"Multiple times more dense than the sun" is the understatement of the year. The sun in average is about 1.5 the density of water, perhaps like maple syrup. A neutron star has average density which is far denser than the densest material on Earth, about 3.7×10e17 kg/m3. A neutron star is therefore 100000000000000 times denser than the sun. It is a tad more than "multiple times".
^^^ 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.
Hail Eris, full of mischief...
E pluribus sanguinem
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.
if you see me, smile and say hello.
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 the other red supergiants they looked at.
I should get karma for this. Just sayin'.
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.
That would be a bummer man. Let's go with the star in a star thing. Almost as cool as guns that shoot guns.
http://xkcd.com/224/
Table-ized A.I.
...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.
If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
Guns don't shoot guns. Guns that shoot guns shoot guns.
If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
... and it took all of three seconds to find the article-within-the-article. Star Within a Star: Thorne-Zytkow Object Discovered (04 June 2014)
I'm just glad that Slashdot nerds are arguing about this, instead of physicists. That could get ugly.
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!'"
What do you mean by a stable star anyway?
Rethinking email
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!
Politics; n. : A religion whereby man is god.
I think it should have been multiple times more massive then the sun.
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. But once you did, you would definitely notice an abrupt phase change.
A fool and his hard drive are soon parted.
Well sure, everyone knows what a BB gun is.
If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
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?
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 before, actually a little less. Then it begins the process again. The result is a slightly variable vibrating star. I wonder is it might be possible to create sympathetic vibrations that way. Probably not, It would be most interesting.
There is however one major flaw in the above model. Supposedly the neutron star was once part of binary system with the red giant. It is not suddenly going to appear in the core. Instead, it is going to slowly absorb material until it's orbit "decays" into one below the photosphere. I don't know if parts of star will be eject when gases impinge. Certainly tides on the star will help. ( Also the neutron star will generate tides on the giant affecting it's weather. )
So the neutron star will act like a giant stirring, slowly stirring up layers of the gas. The romantic in me would like to think this is going to generate some massive and quite interesting effects. The realist though says that any effects will probably be small and hardly noticeable after a few millennium.
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.
Guns that shoot bees are better.
"Lack of speed can be overcome. In the worst case by patience." --Znork
Did we have a recent article about missing lithium.... maybe this star is the culprit that stole it all.
"Lack of speed can be overcome. In the worst case by patience." --Znork
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 thing is probably lasts far greater than our ability to watch it.
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 googled "BB", and didn't get the explanation I assumed it would give. The top references were all about BlackBerry. All of this and more could make it difficult to figure out what "a BB inside of a balloon" means.
In light of that, and having seen my original comment for a day, it does sound like a dickish line. It wasn't meant as such.
So, for those who for whatever reason don't think of air guns when seeing "BB", I do apologize for making it sound like you are stupid or ignorant.
If you think I voted for Trump because of this post, you're wrong. I voted for Dr. Jill Stein of the Green Party. Again.
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 scenario is a mutual orbit where over many orbits the stars interact via their extended atmospheres/etc slowing their orbits until they merge. Still, I'd think that neutron star would keep making orbital passes deeper and deeper into the red giant's atmosphere, basically plowing a trench into the red giant which of course fills right back in each time.
I just don't see either star changing velocity enough on a single pass for them to merge.
Massive was indeed what I meant.
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.
Mit der Dummheit kämpfen Götter selbst vergebens
yeah, that 2 order of magnitude correction did a lot :)