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ToSeek
2003-Nov-19, 05:29 PM
Is iron causing all the flares? (http://www.universetoday.com/am/publish/iron_causing_flares.html) - controversial claim that the Sun formed around an iron-heavy supernova core. (If so, how long have we got?)

tjm220
2003-Nov-19, 06:25 PM
Not the iron sun theory (http://www.badastronomy.com/phpBB/viewtopic.php?t=1805&highlight=iron+sun) again! #-o

Supernova core sounds a lot like 'neutron star' which is not a likely explanation for the formation of our sun.

TriangleMan
2003-Nov-22, 03:04 PM
(If so, how long have we got?)

According to my astrophysics textbook (Caroll & Ostlie) around 2 days or so if its using iron for energy. :o

I'd better get more lightbulbs! :wink:

mutant
2003-Nov-22, 04:32 PM
Only 2 days!!!!!!!!!???????????? Oh no. Well, I guess I can forget grocery shopping this weekend. :cry:

Vermonter
2003-Nov-25, 10:59 PM
Well, I guess we're pretty much chu-ed then! 8)

ToSeek
2003-Nov-26, 01:40 AM
Eat that turkey now - don't wait till Thursday!

tuffel999
2003-Nov-26, 02:23 AM
Is iron causing all the flares? (http://www.universetoday.com/am/publish/iron_causing_flares.html) - controversial claim that the Sun formed around an iron-heavy supernova core. (If so, how long have we got?)

Until I actually see that manuscript I would say no.....he is wrong...but I am not a nuclear chemist. Maybe he presents some real data in the manuscript.

Oops
2003-Nov-27, 12:52 AM
What effect would a uranium core have?

The Shade
2003-Nov-27, 03:05 PM
Depends on the size. If it's big enough to have already achieved critical mass, it would have detonated long ago.

(Edited for missing word) #-o

jscotti
2003-Nov-29, 02:20 AM
(If so, how long have we got?)

According to my astrophysics textbook (Caroll & Ostlie) around 2 days or so if its using iron for energy. :o

I'd better get more lightbulbs! :wink:

If you dig up an old Astronomy text from the 19th century and assume the Sun's output is entirely due to gravitational contraction, I think you can expect the sun to last another million years or so..... There are similar limits on that from the size of the sun and the orbital distance of the inner planets constraining the maximum age of the solar system if that were the source of energy. It's fun to read historic Astronomy texts since they had to use the Physics of the day to explain things before the days of nuclear physics.

Jim.

Madcat
2003-Nov-29, 10:22 PM
What did they use to explain the formation of the sun in the first place? I've never read a book from that period. Also, did they understand that the sun is a star?

The Supreme Canuck
2003-Nov-29, 10:58 PM
What effect would a uranium core have?

I don't think that's possible. Uranium has a huge atomic number (92) when compared to the main element that the sun uses for fusion, hydrogen (1). When a star gets to the point that it starts to fuse higer numbered elements, it doesn't have much time left. So really, the sun would be gone before it could create any uranium to fuse.

Or so is my understanding. :wink:

Oops
2003-Nov-29, 11:10 PM
We have uranium in the Earth's crust, and I've heard there is a theory that the reason the core has stayed hot so long is that it is a giant nuclear power plant. The uranium wasn't created by our Sun; it was created by a star that blew up long ago. If Earth has a significant amount of uranium (well, I'm not sure what counts as significant, but you know what I mean), then the Sun should have considerably more.

The Supreme Canuck
2003-Nov-29, 11:28 PM
The uranium in the sun (and I'm sure that there must be some) is insignificant when compared to the rest of the sun. Really it has no effect on it.

Quite simply, there is much more hydrogen and helium than uranium or any other heavy element in the sun.

I'm really not sure on uranium formation, though. I wish I could remember... anyone know?

Kaptain K
2003-Nov-30, 01:40 AM
The Sun is mostly hydrogen (91.2% of the total number of atoms - 71.0% of the mass) and helium (8.7% of atoms - 27.1% of mass). Everything else is 0.1% of the atoms and 1.9% of the mass and most of that is concentrated in the lower end of the periodic table.

The Supreme Canuck
2003-Nov-30, 01:51 AM
Basically then, uranium would come from remnants of other stars and/or would have been created in some freak fusion reaction, yes?

Kaptain K
2003-Nov-30, 02:07 AM
Considering that the solar interior is a bath of high energy particles, my guess would be that any fissionable elements (such as uranium, thorium, etc.) that the Sun originally had would have been consumed long ago.

The Supreme Canuck
2003-Nov-30, 02:09 AM
Sure, but there must still be bits and pieces hitting it even now. Say, a meteor. They quite commonly have uranium. It isn't much at all, but it's there.

The Bad Astronomer
2003-Nov-30, 02:15 AM
The idea that the Sun has an iron core is so wrong it's difficult to know where to start.

For example, the process of fusing hydrogen to helium in a stellar core is understood well enough to predict the number of neutrinos that come out of the Sun. When that number was found to be a factor of 3 too small, it was determined that it was particle physics that needed updating, not the solar model.

Using the standard solar model of H -> He fusion, astronomers have been able to accurately make maps of the far side of the Sun, seeing sunspots there. They can track the way gases convect (hot air rises, cool air sinks). They can use this model to see how other stars evolve.

It is a phenomenally successful model.

Now, back to the iron core model: how does a star form around such a thing, a remnant of an old supernova? Is the Sun special this way, or do all stars form this way according to the iron core model? If so, why don't we see supernovae far more often (there are, after all, 200+ billion stars in the Milky Way alone)? And why don't we see the effects of billions of supernova in the past few hundred million years? Why do we see stars stars forming in molecular clouds and emission nebulae pretty much as standard astrophysical models predict?

That press release is also extremely misleading. It says that many stars are "iron rich", but relative to what? Astronomers call any star iron rich if it has similar to solar amounts of iron. If I read the numbers correctly, that amount in the Sun (http://aa.springer.de/papers/9342002/2300610/sc4.htm) is about 1 iron atom for every 100,000 or so hydrogen, I believe. So it's not like we're talking a lot of iron. In the Earth's crust (http://www.webelements.com/webelements/elements/text/Fe/geol.html), iron abundance is about 1 part per 40 or so! So in everyday terms, we're used to iron rich meaning really iron rich, but in astronomy it's a much lower amount.

Getting the picture? Unless extremely strong cases are made that (a) the current solar model has fatal flaws, and (b) the iron core model doesn't, I would place this one firmly in the "crank" category.

Oops
2003-Nov-30, 04:36 AM
Would heavy elements sink, or would they stay suspended within the H and He? If the heavier elements were collected together into a single object, how big would that object be? How is the boundary of the Sun's core defined, and about how big is it?

Sister Ray
2003-Nov-30, 08:31 PM
Well, if this turns out to be true, I can't tell my best friend the sun can't go supernova anymore...

eburacum45
2003-Nov-30, 08:50 PM
As far as I am aware, the metallic and other elements heavier than Helium are evenly distributed in the Sun; they are certainly detectable by spectrograph measurements of the surface emissions.

The interior of the Sun looks something like this (http://www.spacescience.org/ExploringSpace/SpaceWeather/TrackingTheSun/SunSchematic80.JPG)...

there is no way that there is an iron core in the middle; our Sun is a normal, main sequence star, and not a supernova remnant.

ljbrs
2003-Dec-01, 12:04 AM
From what I understand, the Sun is not massive enough to develop an iron core. Then again, I am no astrophysicist...

ljbrs #-o

Jetmech0417
2003-Dec-01, 04:10 AM
I'm just curious about something. Would it even be possible for planets to form around a star that was a supernova remnant?

The Bad Astronomer
2003-Dec-01, 04:22 AM
Would it even be possible for planets to form around a star that was a supernova remnant?

Yup (http://www.google.com/search?hl=en&q=pulsar+planets).

Jetmech0417
2003-Dec-01, 04:25 AM
Thanks BA.

skyglow1
2003-Dec-01, 04:38 AM
Back tot he uranium thing, I thought the heaviest element that any star could make was iron and thats the end of the road of a massive star. Our sun sol is not massive enough to fuse elements to create iron if I can remember right.

skyglow1

sarongsong
2003-Dec-03, 05:34 AM
"...The real problem is the huge intellectual investment astronomers have made in the hydrogen-based model of the sun. After all these years, they are going to need a lot of persuading to give that up and turn to the iron sun theory. Or rather, to return to it. For the truth is that astronomers have been here before. Astonishingly enough, the idea that the sun is chiefly made of iron was the prevailing theory until after World War II..."
http://www.smh.com.au/articles/2003/12/01/1070127350112.html

Musashi
2003-Dec-03, 07:54 AM
Well, if it was good enough for scientists before WWII, then it must be good enough for scientists now... down with progress!!

sarongsong
2003-Dec-03, 08:56 AM
Would anything in those polar ice-core samples prove Sun's composition?

Diamond
2003-Dec-03, 09:41 AM
"...The real problem is the huge intellectual investment astronomers have made in the hydrogen-based model of the sun. After all these years, they are going to need a lot of persuading to give that up and turn to the iron sun theory. Or rather, to return to it. For the truth is that astronomers have been here before. Astonishingly enough, the idea that the sun is chiefly made of iron was the prevailing theory until after World War II..."
http://www.smh.com.au/articles/2003/12/01/1070127350112.html

I hear this all the time from cranks on sci.physics.relativity. They even have a name for people who "blindly" accept Einstein's Special Theory of Relativity: "SR-ians".

"The reason SR is accepted and not my (crank) theory is because scientists have made too much intellectual investment in SR and want it to work despite its logical flaws (see my ASCII diagram for more details)"

Oops
2003-Dec-05, 02:07 AM
Thanks for the answers given so far.
My remaining questions are:
If the heavy elements in the sun were turned into a planet, how big would it be and how massive would it be?
If the sun had a small uranium core (the Sun in this scenario would still be mostly H and He, and never mind how that core got there), what effects would that have?

fgosborn@sbcglobal.net
2006-Dec-21, 12:35 AM
[quote=The Bad Astronomer;153055]The idea that the Sun has an iron core is so wrong it's difficult to know where to start.

http://www.spitzer.caltech.edu/Media/releases/ssc2006-19/release.shtml

''The star's outer skin consisted of lighter elements, such as hydrogen; its middle layers were lined with heavier elements like neon; and its core was stacked with the heaviest elements, such as iron. ''

''Because it is young and relatively close to our solar system''

Could these findings be useful in determining the solor interior of our sun ?

11. Editing & Revisionism

Edit your posts with care. There's no problem with editing a post later to change the tone or to correct spelling and the like. But changing content is not allowed! This is a slippery path that can be seen as revisionism. You may edit your post for up to 24 hours. Also, when quoting other posters, you may trim the text down to brief snippets to address something in particular, but do not misquote others or alter their content to suggest they've stated things which they haven't.

Tinaa
2006-Dec-21, 01:00 AM
From the same page:
Cassiopeia A, or Cas A for short, is what is known as a supernova remnant. The original star, about 15 to 20 times more massive than our sun, died in a cataclysmic "supernova" explosion


This thread is three years old. Here are some threads which may help!

http://www.bautforum.com/showthread.php?t=23048

http://www.bautforum.com/showthread.php?t=8364

http://www.bautforum.com/showthread.php?t=1742

Gillianren
2006-Dec-22, 08:14 PM
This thread is three years old. Here are some threads which may help!

Erm, yes, and you're the one who resurrected it.

Nereid
2006-Dec-22, 09:32 PM
Erm, yes, and you're the one who resurrected it.Actually, it was some other BAUT member, who subsequently deleted their 'resurrecting' post!

Gillianren
2006-Dec-22, 10:05 PM
Oh. My mistake. Sorry!

Starboy
2006-Dec-23, 12:31 AM
Bingo!


For example, the process of fusing hydrogen to helium in a stellar core is understood well enough to predict the number of neutrinos that come out of the Sun. When that number was found to be a factor of 3 too small, it was determined that it was particle physics that needed updating, not the solar model.

Perfect lets change the physics to fit the model! :shifty: :whistle: :think: :naughty:

Because the model is correct, so therefor the phsyics must be wrong :eh:

It's a funny state of affairs, hey Phil

captain swoop
2006-Dec-23, 12:43 AM
yayyy! a quote mine! and no refs!

Gillianren
2006-Dec-23, 01:45 AM
Perfect lets change the physics to fit the model! :shifty: :whistle: :think: :naughty:

Because the model is correct, so therefor the phsyics must be wrong :eh:

It's a funny state of affairs, hey Phil

I don't think you understand. This is how science works--a slow but relentless process of constant clarification. For the above example, let's look at it this way.

1. The model we have has, so far, held up to all tests that have been used. The data we're getting verifies the model every single time.

2. Okay. Now, we've found something that doesn't make sense in our model. (Observe that that is doesn't make sense to qualified experts, not doesn't make sense to a person picked at random. A lot of the science that goes into computers doesn't make sense to me, but my computer still works.)

3. Now what? Do we throw out everything that's been shown to work over and over again, or do we figure out what we don't know that's skewing things?

Sure, if there's an explanation that fits every piece of evidence, or a majority, or even some of them better, we might consider it. But it's much more logical to assume we're getting one bit wrong (after all, it's not the physics that have changed but our understanding of the physics) than to throw out the whole thing.

Starboy
2006-Dec-23, 02:46 AM
Yes, you are precisley right Gillian, and the models are bringing in more and more postulations that are all to do with magnetic fields and plasma's and less to do with gravity.

So if the mainstream is saving face by slowly changing it's tune then so be it, we will just end up in the same place just far more slowly!


That's science!

Gillianren
2006-Dec-23, 06:15 AM
I hope you realize that I don't agree with you. The EU doesn't even have a model to fit the evidence.

Van Rijn
2006-Dec-23, 10:14 AM
Because the model is correct, so therefor the phsyics must be wrong :eh:

It's a funny state of affairs, hey Phil

Uhm, no. I was reading about this issue in the '70s. Scientists considered different models, experimental error, and new physics. They couldn't come up with a model that would fit observations of the sun and other stars. They checked and rechecked their experiments and kept getting the same results, but until recently were all looking for electron neutrinos. When they did the SNO experiment that was sensitive to tau and muon neutrinos as well as electron neutrinos, they found all three varieties are coming from the sun, and in the quantity needed for sufficient fusion to match luminosity. Further experiments have confirmed the neutrino results. The neutrinos are there, whether you like it or not.

So they did exactly what they should - they found a problem, considered different possibilities, and accepted what new observations were showing them.

Now, if someone else can come up with a model that matches all observations and accounts for the physics we see not just in the sun, but other stars (for instance, that can predict the ratio of luminosity to mass) they should bring it forward. The ES crowd hasn't even begun doing this.