Huge Ass Star

[213374U]

http://www.space.com/scienceastronomy/eso-...red-100721.html

 

Estimates point at a mass at birth of ~320 solar masses. Observation once again trumps theoretical predictions.

 

"Our new finding supports the previous view that there is also an upper limit to how big stars can get, although it raises the limit by a factor of two, to about 300 solar masses."

 

[Gorth]

...I knew I was gonna be a big star some day

 

My astronomy is a bit rusty. Do these things explode or implode? Probably going to leave a bit of a mess behind.

[Azdeus]

As far as I can remember they explode with a supernova, and then the core implodes - most probably leaving a black hole in it's place.

Or was it that they implode and then explode? Hmm.

I wonder if NGC 3603 going supernova is close enough to impact us here on earth, I know some people have spoken of Beetlegeuse going supernova will. But is 22.000 lightyears out of our "range" so to speak?

 

 

300 solar masses. Damn, that's big...

[Meshugger]

As far as I can remember they explode with a supernova, and then the core implodes - most probably leaving a black hole in it's place.

Or was it that they implode and then explode? Hmm.

I wonder if NGC 3603 going supernova is close enough to impact us here on earth, I know some people have spoken of Beetlegeuse going supernova will. But is 22.000 lightyears out of our "range" so to speak?

 

 

300 solar masses. Damn, that's big...

 

Something like that, yeah. I remember our physics teacher tried to prove mathematically to the class about the threshold of a single object collapsing due to its weight and forming a black hole. I wish that i would remember it. It was quite fascinating and fat jokes ensued.

[213374U]

...I knew I was gonna be a big star some day

 

My astronomy is a bit rusty. Do these things explode or implode? Probably going to leave a bit of a mess behind.

Actually, these things shouldn't even exist, according to current stellar development models anyway. As a star accrues gas, outwards radiation pressure caused by fusion at the core prevents the star from gaining more and more mass... or so the theory goes, anyway. Wolf-Rayet stars lose mass rapidly this way, although not quite as fast as this one should. There is supposedly a limit where outwards pressure and gravitational force even out, capping the upper mass for stars. A limit that just got revised by a factor of about 2.

 

And yeah, supermassive stars explode leaving not even a black hole behind. Again, in theory...

[Azdeus]

I love these things, I've basically got bugger all clues to the machinations or maths, but I love it anyway.

 

Thought that some supermassive stars that don't quite have the mass to produce a black hole produced neutron stars? ... in theory.

[kirottu]

Wow. Kirstie Alley has really let herself go.

[Thorton_AP]

And yeah, supermassive stars explode leaving not even a black hole behind. Again, in theory...

 

This is the difference between the various classifications of supernova isn't it? How many solar masses for this to be the case?

[Azdeus]

If I remember correctly, Type II supernovae are from stars with ten times the mass of the sun, but I'm not certain.

Edited July 22, 2010 by Azdeus

[Archmonarch]

As I understand it, there are two theoretical factors limiting the size of stars: 1) a pressure gradient formed by the radiation huge stars produce, which eventually would prevent any material being added to the star and 2) the amount of gas and dust physically present in the star's vicinity. In other words, a star can't grow beyond the amount of material available to it, but if it gets big enough, then its own radiation physically prevents it from going larger.

 

My own astronomy is a little rusty, but, if I recall correctly, massive stars such as this follow the Type-II Supernova model which is described further here. Basically, such stars are massive enough to form heavier elements through fusion, including iron, plutonium, etc. Eventually, an iron core is created, which provides no energy for the star, and once the core reaches a certain mass (the Chandresekhar limit) the star can no longer support it and the core implodes. The heat produced as the core implodes results in nuclear reactions, creating neutrons and neutrinos which reverse the implosion and detach stellar material, resulting in a supernova. Because the supernovae of these stars are so violent, they do not leave behind their metal core or collapse into a black hole like other stars, but instead blast the material of their core across space. It is theorized that stars similar to this are what existed in high proportions after the Big Bang and are responsible for approximately half the amounts of elements heavier than iron.

Edited July 22, 2010 by Archmonarch

[Calax]

I think the weight for a black hole is 100 or so solar masses. Basic life cycle of the star is going to be that it's burning, then it'll go supergiant (when our son poofs earth at minimum mercury and venus will be inside it's radius) as it starts reactions that loose it energy rather than create because it's got so little hydrogen and helium left. Basically it'll start creating elements above Iron on the periodic table. Once the core no longer has the energy to fuse things the star will eject most of the materials leaving behind a neutron star which will have high mass, but will be VERY small... A neutron star the size of Detroit would turn the earth into a 1/4 inch layer of dust on it's edge. And then the ejections leave enough hydrogen and helium in space that it forms a nebula/stellar nursery to create smaller, longer lived, stars. This sucker will eject a lot of material but the core will implode into a black hole. I'm unsure if the left over materials will create a nebula nearby, or just enter the black hole, but one awesome thing that you see with black holes are accretion disks where the hole is siphoning off the mass from a nearby star.

 

Black hole + accretion disk (ironically taken from the only other state school in Iowa from the one I'm going to):

 

 

Interestingly we've been able to determine that our sun is NOT the first star in this general vicinity of space due to the fact that we have iron and higher elements. I think we're 3rd generation or older star, but I'm not sure.

 

Factoids!

 

Earth has 3 moons, we just can't see two of em. Also the milky way is in the process of absorbing a pair of smaller galaxies that they recently found (the Magellanic clouds) on the OTHER side of the galaxy from us.

Edited July 22, 2010 by Calax

[Gfted1]

Earth has 3 moons, we just can't see two of em.

 

Eh? Whats this crazy talk?

 

Link?

[Calax]

http://www.space.com/scienceastronomy/sola...oon_991029.html

 

That's one... My astro teacher said two but I could be screwing things up and mixing moons with the Magellanic clouds.

[HoonDing]

I think the weight for a black hole is 100 or so solar masses.

No, between 3 and 20 solar masses is enough: Tolman-Oppenheimer-Volkoff limit

 

Basically it'll start creating elements above Iron on the periodic table.

The nuclear fusion inside the star stops when the core is iron, because after this it is no longer energy effective: Binding energy curve

 

First hydrogen is fused to helium, then helium to carbon, then carbon to oxygen, then oxygen to silicon, and silicon to iron. That is the moment where the star cannot longer withstand its gravitational collapse and becomes either a white dwarf, a neutron star or black hole depending on its mass.

 

Something like that, yeah. I remember our physics teacher tried to prove mathematically to the class about the threshold of a single object collapsing due to its weight and forming a black hole. I wish that i would remember it. It was quite fascinating and fat jokes ensued.

Any object can become a black hole if it is compressed to a certain radius. For the Earth, for instance, this is 9 mm.

Edited July 22, 2010 by virumor

[Calax]

Basically it'll start creating elements above Iron on the periodic table.

The nuclear fusion inside the star stops when the core is iron, because after this it is no longer energy effective: Binding energy curve

 

First hydrogen is fused to helium, then helium to carbon, then carbon to oxygen, then oxygen to silicon, and silicon to iron. That is the moment where the star cannot longer withstand its gravitational collapse and becomes either a white dwarf, a neutron star or black hole depending on its mass.

Not quite, it'll keep fusing but it'll loose energy due to the fusion. Otherwise we wouldn't find elements higher than iron on the table occurring naturally in the environment. That fusion is what drains the energy to leave behind the less energy filled neutron star.

[213374U]

Basically it'll start creating elements above Iron on the periodic table.

The nuclear fusion inside the star stops when the core is iron, because after this it is no longer energy effective: Binding energy curve

 

First hydrogen is fused to helium, then helium to carbon, then carbon to oxygen, then oxygen to silicon, and silicon to iron. That is the moment where the star cannot longer withstand its gravitational collapse and becomes either a white dwarf, a neutron star or black hole depending on its mass.

Not quite, it'll keep fusing but it'll loose energy due to the fusion. Otherwise we wouldn't find elements higher than iron on the table occurring naturally in the environment. That fusion is what drains the energy to leave behind the less energy filled neutron star.

It was my understanding that heavier elements weren't created through "regular" fusion at the star's core, but rather as a consequence of the extreme pressures the material is subjected to during the *BANG!* phase of the supernova.

[HoonDing]

Not quite, it'll keep fusing but it'll loose energy due to the fusion. Otherwise we wouldn't find elements higher than iron on the table occurring naturally in the environment. That fusion is what drains the energy to leave behind the less energy filled neutron star.

No, fusion inside a star stops at iron.

 

Heavier elements come to be formed in the 'blow-off' from stars & supernovae, when neutrons bombard iron cores.