Scientists Discover Biggest Star 202
Hugh Pickens writes "Scientists at the University of Sheffield have discovered the most massive stellar giant, R136a1 measured at 265 solar masses, using the European Southern Observatory's Very Large Telescope in Chile and data from the Hubble Space Telescope. It's in the Tarantula Nebula in the Large Magellanic Cloud, a small 'satellite' galaxy which orbits the Milky Way. Previously, the heaviest known stars were around 150 times the mass of the Sun, known as the 'Eddington Limit,' and this was believed to be close to the cosmic size limit because as stars get larger, the amount of energy created in their cores grows faster than the force of gravity which holds them together. 'Because of their proximity to the Eddington Limit they lose mass at a pretty high rate,' says Professor Paul Crowther, the chief researcher in the Sheffield team. Hyper-stars like R136a1 are believed to be formed from several young stars merging together, and are only found in the very heart of stellar clusters. R136a1 is believed to have a surface temperature of more than 40,000 degrees Celsius, and is 10 million times brighter than the Sun. Crowther adds that R136a1 is about as big as stars can get. 'Owing to the rarity of these monsters, I think it is unlikely that this new record will be broken any time soon.'"
Re:You think that's big!?!?!? (Score:5, Insightful)
Two theories, now let's sit back and see who's right!
I think he'll be right for human scales of "soon", and you'll be right for cosmological scales.
Re:You think that's big!?!?!? (Score:5, Insightful)
No theories, but two hypotheses. One of which is actually based on modelling and thought, the other on intuition that the Universe is a big place.
You may be right, but because the Universe is such a big place I *don't* think it's likely to be broken soon, since it's bloody hard to look around. The Tarantula Nebula is nice because it's recent, dense and relatively close, which means this could be found. Of course, they're all relative terms. We've been looking at the Tarantula Nebula for at least 250 years, and we've only found this one now...
Mass vs Radius (Score:5, Insightful)
Re:You think that's big!?!?!? (Score:4, Insightful)
We can't readily measure the size of stars across the whole universe, and you think that our likelihood of finding a star even closer to the Eddington limit is a slam-dunk? I think the guy who found this one has a pretty good idea how hard they are to come across.
Re:You think that's big!?!?!? (Score:2, Insightful)
One of which is actually based on modelling and thought
Except that the Eddington Limit was also based on modeling and thought, but was then smashed by reality.
2.5 years ago, astronomers with a spreadsheet "discovered" that the Milky Way is really 2x thicker than previously accepted.
While I'm glad that Science allows scientists to alter their theories and beliefs, ISTM that too many astronomers/cosmologists think they know far more than they really know.
"Unlike humans ..." (Score:4, Insightful)
From article: "Unlike humans, these stars are born heavy and lose weight as they age," Crowther said.
This is obviously wrong. Some humans are plump when young, and turn into skeletons as they age.
In fact, this is commonly observed among those humans who, ironically, are called ``stars''.
Re:You think that's big!?!?!? (Score:2, Insightful)
Yep. Is there a bigger star out there? Almost certainly. Is there a bigger star out there where we have to ability to observe it? This is where it gets difficult.
Much ado over Pluto (OT) (Score:4, Insightful)
then again, it goes on to state that our solar system has nine planets, so trust NASA at your own risk
Argh, this nonsense again. The IAU dropped the ball and we remain without an adequate definition of what a planet is. "Clearing the neighborhood" remains undefined and there are ways to define "neighborhood", as a large loci in space-time around the trajectory of the object in question, so that Pluto, and perhaps even Ceres and some of the dwarf planet candidates, clear their neighborhoods. The point here is that while a considerable number of astronomers intend a particular definition of "neighborhood" (as a spherical shell around the Sun), that definition has not been adopted nor, I might add, does it seem all that useful.
Semantically, it's also a mess since we have "minor planets" and now "dwarf planets" which are not "planets". Also, it just confuses the issue for the billions of people who were taught for decades that Pluto was a planet. I find the redefinition of "planet" to be inconsiderate of their needs and as a result rather frivilous abuse of IAU's power. Just because we had a similar screw up back when Ceres was demoted as a planet, doesn't mean that we need to repeat this error.
Finally, this definition only applies to the Solar System. We'd have enormous difficult applying this definition anywhere else. It would be hard and time consuming to verify the dynamics of other star systems in enough detail to distinguish between planets and dwarf planets using such a definition. And those systems may have orbital dynamics that are far different from the nearly circular orbits of planets in the Solar System.
Personally, I have no problems with eight, nine, or hundreds of planets. But I think it reasonable that the definition of planet have a scientific basis. That bit is the common view I share with the people who came up with the current definition. But I think it's been an embarrassment to come up with the current weak and unuseful definition and then attempt to sell it as being scientific (remember the old definition happens to be much more well-defined and hence, scientific than the new one, people were just concerned about the growing number of objects that would be considered planets).
Personally, I find it more credible that we're just seeing a continuation (in intellectually mutated form) of the old, irrational opposition to Pluto's original naming. Its first two letters, "P" and "L" happen to be, either by coincidence or artifice, the initials of Percival Lowell, the man who had established and funded the observatory that discovered Pluto.
Re:not unlikely to be broken (Score:2, Insightful)
If a really freakin' huge star is created in the universe and no one is around to observe it, does it break a record?
That one's easy, as there are no unrecorded records, by definition. The real question is, lacking any observation, does it even exist, or does it just probably exist, or "exist" in an undetermined state until observed? And what counts as "observation"?
Re:You think that's big!?!?!? (Score:3, Insightful)
>intuition that the Universe is a big place.
Dude, the universe is a big place. 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 drug store, but that's just peanuts to the universe.
"Dude?" "Drug store?" Please don't tell me they translated the Hitchhiker's Guide into American English!