Posted on 10/21/2015 3:19:56 PM PDT by LibWhacker
Astronomers say the two stars might be heading for catastrophe. They will likely either merge to create a single giant star or form a double black hole.
This artist’s impression shows VFTS 352 — hottest and most massive double star system known to date where the two components are in contact and sharing material. Image via ESO
We know that many stars in our galaxy are in double or multiple systems, but here are two stars so close they touch. An international team of astronomers said this week (October 21, 2015) that this system – known to them as VFTS 352 – is the hottest and most massive touching double star system observed so far. What’s more, they said, the two stars might be heading for a catastrophe. The two stars will likely either merge to create a single giant star or form a double black hole.
They used the European Southern Observatory’s (ESO) Very Large Telescope to make their observations.
VFTS 352 is located about 160,000 light-years from Earth in the Tarantula Nebula, which itself is in the Large Magellanic Cloud visible from Earth’s Southern Hemisphere. The Tarantula Nebula is known as the most active region of star formation in the nearby universe, and the VFTS 352 system is said to be:
…among the most extreme and strangest yet found.
The two stars of the VFTS 352 system are very hot, bright and massive, and they whirl around each other in slightly more than one Earth-day. Their centers are separated by just 7.5 million miles (12 million km). ESO said in a statement:
In fact, the stars are so close that their surfaces overlap and a bridge has formed between them. VFTS 352 is not only the most massive known in this tiny class of ‘overcontact binaries’ — it has a combined mass of about 57 times that of the sun — but it also contains the hottest components — with surface temperatures above 40,000 degrees Celsius [ed note: 70,000 degrees Fahrenheit; in contrast to about 10,000 degrees Fahrenheit for our sun’s surface].
Extreme stars like the two components of VFTS 352, play a key role in the evolution of galaxies and are thought to be the main producers of elements such as oxygen. Such double stars are also linked to exotic behavior such as that shown by vampire stars, where a smaller companion star sucks matter from the surface of its larger neighbor.
In the case of VFTS 352, however, both stars in the system are of almost identical size. Material is, therefore, not sucked from one to another, but instead may be shared. The component stars of VFTS 352 are estimated to be sharing about 30 per cent of their material.
This image shows the location of VFTS 352, about 160,000 light-years from Earth in the Large Magellanic Cloud. This composite view of the Tarantula star-forming region includes visible-light images from the Wide Field Imager at the MPG/ESO 2.2-meter telescope at La Silla and infrared images from the 4.1-meter infrared VISTA telescope at Paranal. Image via ESO
These are very massive stars, and thus they burn brightly and quickly, and their lives are short. So catching two such massive stars in the act of touching is rare, and astronomers feel fortunate to have done it.
They say that the two stars of VFTS 352 are facing a dramatic end, with one of two outcomes possible.
The first potential outcome is the merging of the two stars, which would likely produce a rapidly rotating, and possibly magnetic, gigantic single star. Lead scientist of the project, Hugues Sana, of the University of Leuven in Belgium said:
If it keeps spinning rapidly it might end its life in one of the most energetic explosions in the universe, known as a long-duration gamma-ray burst.
The second possibility is explained by the lead theoretical astrophysicist in the team, Selma de Mink of University of Amsterdam:
If the stars are mixed well enough, they both remain compact and the VFTS 352 system may avoid merging. This would lead the objects down a new evolutionary path that is completely different from classic stellar evolution predictions. In the case of VFTS 352, the components would likely end their lives in supernova explosions, forming a close binary system of black holes. Such a remarkable object would be an intense source of gravitational waves.
These astronomers add that:
….Proving the existence of this second evolutionary path would be an observational breakthrough in the field of stellar astrophysics.
Click here to see a 30-second YouTube video simulation of these two stars in orbit about one another.
Bottom line: ESO’s Very Large Telescope has found the hottest and most massive touching double star. The system – located in the Tarantula Nebula – is called VFTS 352. The two stars might eventually either merge to create a single giant star or form a double black hole.
No way to know which way that gamma ray burst will go.....better have the hot dogs ready for grilling.
I chased down some of the links (to ESO and the preprint, etc.) and they’re saying there is a “paucity of data” at the moment. So no, I don’t believe they know that yet, although ESO has always been stingy about sharing its data with others. I’m sure once Hubble gets on it, we’ll have an answer shortly.
You’re right. They’re doomed to collide, imo. It’s just a question of when.
But remember, they are in orbit, millions of miles apart. There is a “bridge,” but it’s made of gas, plasma.
We just have to wait for the science teams to finish their analyses. The most exciting possibility for me is that we might get a gamma ray burst out of the merger! Wonder when the Earth was that close to one of those things? It’s only 160K ly away, in one of the Magellanic Clouds.
Oxygen producers. That’s hot!
Lol, we think alike!
I always thought that the “hottest, heaviest touching twin stars” were the twin red-heads I dated in college, but I could be wrong.
Yup, two O-type stars. Blue giants. A merger would be spectacular!
It'll be a massive Zot!
why is it not instantaneous??? the laws of gravity no longer apply?
They’re in orbit around one another. The Moon doesn’t instantly crash down on the Earth. It’s horizontal velocity guarantees it won’t. Same thing with these two stars. They are in orbit, with a greater separation than between the Earth and the Moon.
Now, in the case of these two blue giant stars, the gas "bridge" between them adds friction to the equation and slows them down. And just like the cannon ball, if you slow it down, they'll eventually fall out of orbit and collide.
OK, that i can understand, but i still don't see how they could ever touch without merging would they not have to orbit faster and faster the closer they got in order to keep separated with their own gravity and not a unified field forcing them to merge?
seems there should be something akin to an event horizon that once crossed gravity would simply take over
again i'm simply trying to understand it all
Thanks; I learned something (I think) just reading your replies to everyone.
I still can’t picture a Massive Moon and a Massive Earth, with a Plasma Bridge, not colliding in a shorter time than it even takes for their image to be observed by astronomers, but I defer to those who are more learned in these things.
I’d hit that....
With long-duration gamma-ray burst headed this way.
The only thing that can slow them down is that gaseous bridge connecting them. It, the bridge, is not a solid thing. It's not strong. It's more like a cloud than a solid thing.
How can a cloud slow down something that "weighs" millions of times more than the Earth? There is only one way, lots and lots of time. If we ignore the melting effect of the extremely high temperatures for a moment, I wonder how long it would take that gas to slow an actual freight train down to a crawl? One orbit? Two? It would depend on the density of the gas...
I'm just saying a freight train has a lot of momentum behind it, but nothing, NOTHING compared to the momentum of those two stars, each of which has the momentum of billions, trillions, of freight trains, and only a puny little cloud of gas to stop them.
Don't be offended at anything I say. I'm not talking down to you. I'm not trying to be offensive. I'm trying to make it fun for you, because learning should be fun. It was for me. In my first day in a physics class, the professor wrote on the board, "PHYSICS IS PHUN," and was it ever, and I've never forgotten it. :-)
none taken, just having a hard time with that much gravity, from both stars, combining yet not overwhelming
Now in truth, I don't know how long it would take exactly. We would have to get into the mathematics. It depends, among other things, on how dense the bridge is and how fierce the winds are (which I'm sure now I shouldn't have described as "a puff of air").
Another way to look at it is if such a merger happened almost instantaneously every time it happened, what would the probability be that we would ever get lucky enough to see one actually happening before our eyes?
“The stars are falling toward each other. But because of their horizontal velocity they continuously miss and just keep going around one another for a very long time.”
Same thing with the space station.
I always thought it was neat of Sir Issac Newton to explain how/why to make an artificial satellite orbit the earth.
Thank you, again, LibWhacker.
Auugh! — Don’t get into the mathematics!
Your skeptical side says: “If a catastrophic merger happens so quickly, how could we happen to catch it in the act of happening?”
and my skeptical side says,
“Exactly.”
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