What dates are accepted for the age of the Sun?

[Robittybob1]

Is here a good reference that gives me the periods involved in the formation of the Sun?

I'm finding the various sites talk of when the Sun "formed" but I'm not sure what stage they are describing.

We start off with a nebula, how long to the stage where the Sun goes Alpha Tauri (if it did)?

Then how long before it becomes a main sequence star?

 

I once tried to calculate how long matter would take to free fall into the Sun from an estimate of the size of the nebula and from memory it was about 150,000 years and that was if each particle did not collide with any other particle or have any angular motion, so it was a direct "straight line".

 

So I suppose that is an estimate of the first stage of Sun development usually estimated at 100,000 years.

You would think as the Sun become more dense and hotter that freefall becomes more problematic.

Nebula Hypothesis https://en.wikipedia.org/wiki/Nebular_hypothesis

 

The initial collapse of a solar-mass protostellar nebula takes around 100,000 years.[1][26] Every nebula begins with a certain amount of angular momentum. Gas in the central part of the nebula, with relatively low angular momentum, undergoes fast compression and forms a hot hydrostatic (not contracting) core containing a small fraction of the mass of the original nebula.[29] This core forms the seed of what will become a star.[1][29] As the collapse continues, conservation of angular momentum means that the rotation of the infalling envelope accelerates,[30][31] which largely prevents the gas from directly accreting onto the central core.

Earlier they used a period of a million years??? So the "initial collapse" must be only part of the process.

 

A Sun-like star usually takes approximately 1 million years to form, with the protoplanetary disk evolving into a planetary system over the next 10–100 million years.[1]

That second figure seems to be more correct considering the problems of angular motion and pressure as the protosun heats up.

Has the Sun become Main sequence after that 1 million year period? What do they mean by "form" in that sentence?

[pavelcherepan]

 

 

We start off with a nebula, how long to the stage where the Sun goes Alpha Tauri (if it did)?

 

Alpha Tauri is Aldebaran, an orange giant star in the final stages of life. Did you mean T Tauri?

 

Sun should have been T Tauri-type star in the very early stages of Solar System evolution, some 4.57 bya and it's supposed to have been in that form for some 50 million years or so before finally making it onto the main sequence.

[Robittybob1]

 

Alpha Tauri is Aldebaran, an orange giant star in the final stages of life. Did you mean T Tauri?

 

Sun should have been T Tauri-type star in the very early stages of Solar System evolution, some 4.57 bya and it's supposed to have been in that form for some 50 million years or so before finally making it onto the main sequence.

Spot on, T Tauri not Alpha Tauri , sorry. So the T Tauri stage is quite a substantial period of time compared to the Sun formation and the planet formation stages they speak of. So when they say "Sun formed" in a million years is that up to the T Tauri stage, for the main sequence stage is another 50 million years later?

And there was a long time (170,000 years) between when the fusion begins in the core and the radiation appears on the surface. Is that time included in the formation time or the T Tauri period or is that an additional phase? For when you apply physics to that situation the Sun is expanding due to this heat radiation, so it sounds like a separate stage, the Sun being non radiant (no light radiation at the surface but no longer collapsing either). Is that a recognised phase?

https://en.wikipedia.org/wiki/Solar_core#Energy_transfer

 

The high-energy photons (gamma rays) released in fusion reactions take indirect paths to the Sun's surface. According to current models, random scattering from free electrons in the solar radiative zone (the zone within 75% of the solar radius, where heat transfer is by radiation) sets the photon diffusion time scale (or "photon travel time") from the core to the outer edge of the radiative zone at about 170,000 years.

You might expect the surface (solar radiative zone) would be getting progressively hotter during this phase? Or would it be a sudden change in temperature? What do you know about that?

Something I haven't considered before - neutrinos.

 

Neutrinos are also released by the fusion reactions in the core, but unlike photons they very rarely interact with matter,

But neutrinos can be detected so they must interact with something. Have you heard of a name for this phase? While it is producing neutrinos 170,000 years before it is producing white light.

Edited February 9, 2016 by Robittybob1

[Mordred]

The first detection of Neutrinos from the sun was in the 1960s and involved a chlorine Neutrino detector.

 

https://en.m.wikipedia.org/wiki/Neutrino_detector.

 

neutrinos being weakly interactive will escape the Suns core earlier than photons.

 

I don't know the temperature contribition in the sun but I believe but will have to check in a paper entitled "Physics of the interstellar medium". As a Lepton it can be determined via the Fermi-Dirac statistics but I wouldn't know the chemical reaction value for that formula in the Suns interior. Let alone the decay rate influence.

Edited February 9, 2016 by Mordred

[pavelcherepan]

 

Is that time included in the formation time or the T Tauri period or is that an additional phase? For when you apply physics to that situation the Sun is expanding due to this heat radiation, so it sounds like a separate stage, the Sun being non radiant (no light radiation at the surface but no longer collapsing either). Is that a recognised phase?

 

During T Tauri stage the proto-Sun is still contracting, not expanding. And it keeps heating up due to contraction. It still does radiate, but he radiation pressure is too weak to stop gravitational attraction. Once thermonuclear fission starts in the core, some 50 million years later the radiation pressure finally equalizes with gravity and the star enters the main sequence.

 

 

You might expect the surface (solar radiative zone) would be getting progressively hotter during this phase? Or would it be a sudden change in temperature? What do you know about that?

 

Correct. I will be getting progressively hotter as per ideal gas law.

 

EDIT: Had a look at some more stuff and during T Tauri stage stars might also might do thermonuclear lithium burning. It still doesn't classify as a separate stage, though.

Edited February 9, 2016 by pavelcherepan

[Robittybob1]

There seems to be a phase where for the previous million years particles in the nebula are screaming into the protosun and then a period later when the dust in the inner regions clear. Is that clearing from the inner to the outer or the other way around? I have always struggled with the physics of that.

From memory it was from the aberration of light. I'll have to look it up again but it was a very important finding years ago.

 

http://arxiv.org/pdf/1203.0005.pdf

..... in the case of dust dynamics dominated by Poynting-Robertson drag ....

Have you ever studied that effect? That stage where the Sun clears the inner regions with this Poynting-Robertson effect needs to have a name, and we need to know in what period it is included. Since it is mediated by photons it would become stronger as more light is produced but that is where my physics breaks down for at some stage radiation pressure seems to dominate and that AFAIK drives particles outward not inward.

What I am trying to get at is that "tidal reversal phase" where the movement of the dust disk stops being inward to predominantly outward.

I know there is a name for this wave that goes along a river when the tide changes, but has that effect ever been attributed to the tide change in star (Sun) formation? It is called "river bore" or more simply tidal wave in tidal rivers.

 

They seem to say that dust disks are found on all newly formed stars. I would like to know (in basic terms) all the stages involved in the formation of the Sun and the effects these stages have on the dust disks.

 

During T Tauri stage the proto-Sun is still contracting, not expanding. And it keeps heating up due to contraction. It still does radiate, but he radiation pressure is too weak to stop gravitational attraction. Once thermonuclear fission starts in the core, some 50 million years later the radiation pressure finally equalizes with gravity and the star enters the main sequence.

 

 

Correct. I will be getting progressively hotter as per ideal gas law.

 

EDIT: Had a look at some more stuff and during T Tauri stage stars might also might do thermonuclear lithium burning. It still doesn't classify as a separate stage, though.

I think you are right but then I think you are wrong for at some stage the Sun's internal pressure stabilises the contraction. Whether there is some expansion I'll have to find out.

This is about my level of physics: The heat coming from the fusion should make the gas of the Sun expand depending on the pressure. As you say due to the ideal gas law.

It does not keep on getting smaller, for there is a period of long term stability (that is during the main sequence stage) but when does the contraction stop, when is it at the minimum size?

It might be like that pressure wave along the river, so then you would have to think in terms of the inside expanding due to fusion but the outer parts still contracting under gravity.

The first detection of Neutrinos from the sun was in the 1960s and involved a chlorine Neutrino detector.

https://en.m.wikipedia.org/wiki/Neutrino_detector.

neutrinos being weakly interactive will escape the Suns core earlier than photons.

I don't know the temperature contribition in the sun but I believe but will have to check in a paper entitled "Physics of the interstellar medium". As a Lepton it can be determined via the Fermi-Dirac statistics but I wouldn't know the chemical reaction value for that formula in the Suns interior. Let alone the decay rate influence.

I had read that before but it is quite technical specifically for detecting neutrinos in the lab. What I was wondering was if this new phase of neutrino production had any effect on the developing dust disk. When you consider it the elements needed to interact with neutrinos in the lab were also in the dust disk.

The whole topic is daunting, so I'm trying to keep it fairly simple if possible basically describing stages of Sun development.

I'll have to see what effect these neutrinos have on the momentum of the matter they interact with.

I've always thought of neutrinos as something that just flies off into space, so they are not something I can discuss confidently.

So would that be a transfer of momentum to the molecule that "detects" it?

Edited February 9, 2016 by Robittybob1

[Mordred]

I can't answer the influence of Neutrinos on the disk dust till I do some digging. It's viable to have an influence but as neutrinos are so weakly interactive the question is how much and of what nature. Flying today I'll look into it later on

[Robittybob1]

I can't answer the influence of Neutrinos on the disk dust till I do some digging. It's viable to have an influence but as neutrinos are so weakly interactive the question is how much and of what nature. Flying today I'll look into it later on

Chlorine reacts with neutrinos producing Argon

 

https://en.wikipedia.org/wiki/Chlorine-37

Neutrino detection[edit]

Main article: Homestake experiment

One of the historically important radiochemical methods of solar neutrino detection is based on inverse electron capture triggered by the absorption of an electron neutrino.[3] Chlorine-37 transmutes into Argon-37 via the reaction[4]

37Cl + ν

e → 37Ar + e−.

Argon-37 then de-excites itself via electron capture (half-life = 35 d) into Chlorine-37 via the reaction

37Ar + e− → 37Cl + νe.

Does this logic work?

37Cl is a very common isotope. All the neutrinos coming from the Sun would have a momentum heading in the outward direction (away from the Sun), but the neutrino released after the de-exiting would presumably be in random directions.

This would suggest there is a local net change of position of the chlorine atoms

Edited February 9, 2016 by Robittybob1

[imatfaal]

Rob - you might want to do a little quantitative analysis on that.

 

The mass of the neutrino is not well defined (most calcs you find for its momentum will assume the mass is zero) - but it is a fraction of an electron volt

 

1 ev/c^2 is 5e-37 kg

1 amu is 1.66e-27 kg

Cl is about 37 amu - you have 11 or so orders of magnitude difference in mass

 

Even in an old fashioned momentum conservation equation you will get a max velocity change of about 10e-3 m/s - a millimetre per second. Noticeable if you are looking in advance but not otherwise

[swansont]

Rob - you might want to do a little quantitative analysis on that.

 

The mass of the neutrino is not well defined (most calcs you find for its momentum will assume the mass is zero) - but it is a fraction of an electron volt

 

1 ev/c^2 is 5e-37 kg

1 amu is 1.66e-27 kg

Cl is about 37 amu - you have 11 or so orders of magnitude difference in mass

 

Even in an old fashioned momentum conservation equation you will get a max velocity change of about 10e-3 m/s - a millimetre per second. Noticeable if you are looking in advance but not otherwise

A mm/sec would be swamped by thermal motion. If you wanted to see it you could look at a beta decay where the emitted neutrino has many keV or even MeV of energy, and you've laser-cooled/trapped the parent nuclide. It's something I worked on in my first postdoc.

[pavelcherepan]

 

 

I think you are right but then I think you are wrong for at some stage the Sun's internal pressure stabilises the contraction.

 

Please read my posts carefully. I did say that once hydrogen fusion begins radiation pressure stops the contraction and the star becomes a main sequence star.

 

 

 

but when does the contraction stop, when is it at the minimum size?

 

Just as I said before. Contraction stops normally when temperatures in the core become sufficient for hydrogen fusion.

 

 

 

There seems to be a phase where for the previous million years particles in the nebula are screaming into the protosun and then a period later when the dust in the inner regions clear. Is that clearing from the inner to the outer or the other way around? I have always struggled with the physics of that.

 

Aberration has nothing to do with it.

 

I believe that clearing proceeds from the inner regions to the outer. Models show that water and some other volatiles would be expelled from the inner SS but then will gather in a relative large quantities just behind the frost line, and so it's no surprise that Jupiter formed there.

[Robittybob1]

 

Please read my posts carefully. I did say that once hydrogen fusion begins radiation pressure stops the contraction and the star becomes a main sequence star.

 

 

Just as I said before. Contraction stops normally when temperatures in the core become sufficient for hydrogen fusion.

 

 

Aberration has nothing to do with it.

 

I believe that clearing proceeds from the inner regions to the outer. Models show that water and some other volatiles would be expelled from the inner SS but then will gather in a relative large quantities just behind the frost line, and so it's no surprise that Jupiter formed there.

Is it the aberration explanation or don't you accept that the Poynting Robertson Drag has got anything to do with the clearing of the inner solar system?

https://en.wikipedia.org/wiki/Poynting%E2%80%93Robertson_effect

 

 

The Poynting–Robertson effect, also known as Poynting–Robertson drag, named after John Henry Poynting and Howard P. Robertson, is a process by which solar radiation causes a dust grain orbiting a star to lose angular momentum relative to its orbit around the star. This is related to radiation pressure tangential to the grain's motion.

This causes dust that is small enough to be affected by this drag, but too large to be blown away from the star by radiation pressure, to spiral slowly into the star. In the case of the Solar System, this can be thought of as affecting dust grains from 1 µm to 1 mm in diameter. Larger dust is likely to collide with another object long before such drag can have an effect.

I found it difficult to accept in anycase.

 

I'll see if I can confirm your other ideas re the contraction stopping once the main sequence starts. So you would not expect a stage of Sun expansion during this heating stage.

Rob - you might want to do a little quantitative analysis on that.

 

The mass of the neutrino is not well defined (most calcs you find for its momentum will assume the mass is zero) - but it is a fraction of an electron volt

 

1 ev/c^2 is 5e-37 kg

1 amu is 1.66e-27 kg

Cl is about 37 amu - you have 11 or so orders of magnitude difference in mass

 

Even in an old fashioned momentum conservation equation you will get a max velocity change of about 10e-3 m/s - a millimetre per second. Noticeable if you are looking in advance but not otherwise

Still could add up due to the share number of neutrinos so close to the Sun. But thanks for converting that momentum into a change in velocity (which in the case of the dust disc is converted to an increase in the orbital radius (more gravitational potential energy, I think??) I'll have to think it through a bit more.

A mm/sec would be swamped by thermal motion. If you wanted to see it you could look at a beta decay where the emitted neutrino has many keV or even MeV of energy, and you've laser-cooled/trapped the parent nuclide. It's something I worked on in my first postdoc.

So what is the energy range of the neutrinos emanating from the Sun? We'll need to see if this has been measured.

So in the experiment did you get a change in the position of the "parent nuclide"?

Edited February 9, 2016 by Robittybob1

[pavelcherepan]

Is it the aberration explanation or don't you accept that the Poynting Robertson Drag has got anything to do with the clearing of the inner solar system?

No. I was talking mostly about volatiles and gas, not about dust.

 

Ok, so abberration should have something to do with clearing of dust. But any case it would start from the inner system and going outwards.

[Robittybob1]

From Wikipedia https://en.wikipedia.org/wiki/Solar_neutrino

 

The highest flux of solar neutrinos come directly from the proton-proton interaction, and have a low energy, up to 400 keV. There are also several other significant production mechanisms, with energies up to 18 MeV.

No. I was talking mostly about volatiles and gas, not about dust.

Ok, so abberration should have something to do with clearing of dust. But any case it would start from the inner system and going outwards.

But as I understand it the PR drag makes the dust fall toward the star. That seemed to go against my perception of solar winds etc.

I can't see how moving dust inward clears the inner region for there will always be more coming in from further out. So how does it clear from the inner going outwards using the PR drag? Can you really understand that? I personally find it difficult. Maybe I need someone to explain it in another way.

 

But I do think you are right for the volatiles and gas they go outward, and really when I imagine a wind made of gas and volatiles I can't see why that wind doesn't blow the dust outward as well.

It seems illogical to have wind in one direction and the dust moving against the wind. But that is said just from my confused state trying to understand the Poynting Robertson drag.

Edited February 10, 2016 by Robittybob1

[swansont]

So what is the energy range of the neutrinos emanating from the Sun? We'll need to see if this has been measured.

Not sure. What does Google say?

 

So in the experiment did you get a change in the position of the "parent nuclide"?

Yes. We did a time-of-flight measurement. But there's also a recoil from the beta. You detect the daughter and the beta and reconstruct the momentum of the neutrino from that.

[pavelcherepan]

 

But as I understand it the PR drag makes the dust fall toward the star. That seemed to go against my perception of solar winds etc.

I can't see how moving dust inward clears the inner region for there will always be more coming in from further out. So how does it clear from the inner going outwards using the PR drag? Can you really understand that? I personally find it difficult. Maybe I need someone to explain it in another way.

 

OK, let's try and explain it.

 

Imagine standing in the rain. Let's assume rain is very consistent and there is x drops of water falling on you every second and these drops are pretty evenly distributed. Now you start running. There will still be x drops of water falling on you every second, but there will be disproportionally more of them falling on the front of your body compared to the back.

 

Also in your rest frame droplets falling on your front will have a higher momentum, because you'll have to add your own velocity v to droplet's velocity. And so if you were going at a constant velocity you'd end up losing momentum and slowing down.

 

Same story here. There's a "rain" of particles coming from the sun and dust particles are moving in orbits around the sun. Normally solar wind particles would hit the dust particle in the direction perpendicular to it's direction of travel and so you'd expect them to be slowly moving to a higher orbit, but because they are "running" into this "rain" there is a discpropotionally high number of collisions to the front of the particle.

 

These collisions would decrease particle's orbital velocity and cause it to spiral into the sun. But it only applies to a particular size range somewhere between 1 micron and 1 mm. Because the volume and hence the mass and hence the momentum of a particle increases by the cube of it's radius. At the same time the number of collisions with solar wind particles depends on surface area which is proportional to the square of radius. Hence the larger a particle gets, the higher the ratio becomes between momentum and number of collisions. As a result large particles won't be very affected by this effect.

 

Smaller particles are so light that they will be blown to the outer reaches of the system. That's it in a nutshell.

Edited February 10, 2016 by pavelcherepan

[Robittybob1]

 

OK, let's try and explain it.

 

Imagine standing in the rain. Let's assume rain is very consistent and there is x drops of water falling on you every second and these drops are pretty evenly distributed. Now you start running. There will still be x drops of water falling on you every second, but there will be disproportionally more of them falling on the front of your body compared to the back.

 

Also in your rest frame droplets falling on your front will have a higher momentum, because you'll have to add your own velocity v to droplet's velocity. And so if you were going at a constant velocity you'd end up losing momentum and slowing down.

 

Same story here. There's a "rain" of particles coming from the sun and dust particles are moving in orbits around the sun. Normally solar wind particles would hit the dust particle in the direction perpendicular to it's direction of travel and so you'd expect them to be slowly moving to a higher orbit, but because they are "running" into this "rain" there is a discpropotionally high number of collisions to the front of the particle.

 

These collisions would decrease particle's orbital velocity and cause it to spiral into the sun. But it only applies to a particular size range somewhere between 1 micron and 1 mm. Because the volume and hence the mass and hence the momentum of a particle increases by the cube of it's radius. At the same time the number of collisions with solar wind particles depends on surface area which is proportional to the square of radius. Hence the larger a particle gets, the higher the ratio becomes between momentum and number of collisions. As a result large particles won't be very affected by this effect.

 

Smaller particles are so light that they will be blown to the outer reaches of the system. That's it in a nutshell.

Thanks for trying. So you end up with some bits that move inward, some that don't move, and others that get blown to the outer reaches. That still means that there is only partial clearing at best unless all particles are of a specific size.

Let's move on and we'll tackle this again sometime. I'm learning about neutrinos and I've just heard they are involved in supanova explosions so they seem to have the power to move stuff around alright.

Do you think we've missed a phase of Sun formation where the neutrinos are forcing the matter in the dust disk back against the infall motion that was part of the nebula collapse? Since the Sun is all intents not shining (maybe just glowing hot) is this a phase during the late protosun period or the beginning of the T Tauri period?

How do we define the start of the T Tauri period?

[pavelcherepan]

 

 

Do you think we've missed a phase of Sun formation where the neutrinos are forcing the matter in the dust disk back against the infall motion that was part of the nebula collapse? Since the Sun is all intents not shining (maybe just glowing hot) is this a phase during the late protosun period or the beginning of the T Tauri period?

 

You've been told before that even if you have interaction between a neutrino and some particle of the disk (which would be exceedingly rare) you can't have much of momentum change, because even if neutrinos have mass, it should be minuscule.

 

Only during supernova explosions you can have a neutrino flux of such a density and matter of such a density as well that you end up having major interaction.

[Robittybob1]

 

You've been told before that even if you have interaction between a neutrino and some particle of the disk (which would be exceedingly rare) you can't have much of momentum change, because even if neutrinos have mass, it should be minuscule.

 

Only during supernova explosions you can have a neutrino flux of such a density and matter of such a density as well that you end up having major interaction.

The energy level discussed by Imatfaal was lower than what I saw in Wikipedia http://www.scienceforums.net/topic/93429-what-dates-are-accepted-for-the-age-of-the-sun/#entry904968, and also Swansont seemed to suggest they were low too. The flux of neutrinos near the Sun could be significant. I have no complete idea and will need to think about it and even try and put some figures on it.

Neutrino flux per square meter at surface of Sun.

Get an estimate of the mass of the dust disk per meter in contact with the protosun.

Assume that the dust disk is primarily in orbit around the Sun.

Calculate what sort of pressure could be expected if 100% of neutrinos absorbed by the dust disk within each 1 m^2 segment

[pavelcherepan]

 

I have no complete idea and will need to think about it and even try and put some figures on it.

Neutrino flux per square meter at surface of Sun.

Get an estimate of the mass of the dust disk per meter in contact with the protosun.

Assume that the dust disk is primarily in orbit around the Sun.

Calculate what sort of pressure could be expected if 100% of neutrinos absorbed by the dust disk within each 1 m^2 segment

 

Why are you telling me to do calculations for you? You can also try searching Google Scholar as there may be some papers on this topic.

 

Neutrino flux may be significant, but the gas cloud is still a pretty good vacuum. There's not much matter for neutrinos to interact with and the chance of neutrino interacting is tiny. For any interaction to occur a neutrino should find itself very close to the nucleus of an atom within the range of weak interaction and this is very-very unlikely. The current solar neutrino flux at the surface of the Earth is about 10¹¹/m² which is orders and orders of magnitude smaller than the number of atoms per square meter of surface and also given that over 99% of any atom is empty space it's very unlikely for any given neutrino to happen to pass within some 10^-18 m from the nucleus.

[Robittybob1]

 

Why are you telling me to do calculations for you? You can also try searching Google Scholar as there may be some papers on this topic.

 

Neutrino flux may be significant, but the gas cloud is still a pretty good vacuum. There's not much matter for neutrinos to interact with and the chance of neutrino interacting is tiny. For any interaction to occur a neutrino should find itself very close to the nucleus of an atom within the range of weak interaction and this is very-very unlikely. The current solar neutrino flux at the surface of the Earth is about 10¹¹/m² which is orders and orders of magnitude smaller than the number of atoms per square meter of surface and also given that over 99% of any atom is empty space it's very unlikely for any given neutrino to happen to pass within some 10^-18 m from the nucleus.

I wasn't expecting you to do the calculations

I was seeing if anyone has done it. There was one forum that looked into this.

 

 

The question is referring to neutrinos created in the photon-photon chain in the Sun. I already computed that the Sun releases 1.78∗10^38 neutrinos per second in the photon-photon chain.

Reference https://www.physicsforums.com/threads/compute-the-flux-of-neutrinos.70876/

So I will divide that by the number of square meters of the Sun' surface. That will give me flux per m^2. I'm too tired to go on today sorry.

Edited February 10, 2016 by Robittybob1

[pavelcherepan]

In T Tauri stage if the only fusion reaction that happens is ⁷Li + ¹p -> 2 ⁴He then there should be no neutrinos produced. I think you're digging in a wrong place.

[Mordred]

pavelcherepan your doing an excellent job on this thread. I wanted to mention this as astronomy isn't my strongest suit lol. I'm more into cosmology and particle physics. I just wanted to thank you for your efforts and contribution to this forum.

 

Rob from what little time I've dug into neutrinos in early star formation influence on the dust/availability on planetary formation I haven't located any significant influence including Poynting vectors.

 

(Which was my primary initial search)

Also as I've been watching your threads the last few days I can honestly say your hitting too many aspects to fully take in.

 

Your jumping into too many deep pools.

 

Study each aspect carefully, on another thread on speculation I mentioned density waves. Then included a variety of related models using... some of those models include Poynting vectors. Take some time to understand those references. You can't model build with accuracy overnight.

 

(For example I'm now 6years into my own personal model on the Cosmological constant, I only have one problem to solve... how to keep it constant?) I would be surprised to solve that puzzle lol but it helps learn if taken in the right direction

[Robittybob1]

In T Tauri stage if the only fusion reaction that happens is ⁷Li + ¹p -> 2 ⁴He then there should be no neutrinos produced. I think you're digging in a wrong place.

The whole idea was from the quote:

http://www.scienceforums.net/topic/93429-what-dates-are-accepted-for-the-age-of-the-sun/#entry904859

that said neutrinos will be coming out from the Sun for 170,000 years before the light does, so that might be the early stages of main sequence rather than the T Tauri stage. It wasn't clear in the original quote and backs the purpose of this thread: to work out precisely when the various events occur rather than just saying "when the Sun formed"

The question is did the Sun go through the T Tauri phase?

It has the right mass to be a T Tauri star but the Lithium burning is during the late pre-main sequence stage which can last up to 100 million years.

 

Instead, they are powered by gravitational energy released as the stars contract, while moving towards the main sequence, which they reach after about 100 million years.

The fusion reaction in Wikipedia has a neutrino (I think) there is a "v" which I think is the symbol for neutrino. https://en.wikipedia.org/wiki/T_Tauri_star#Characteristics

 

The P-P chain for Lithium burning is as follows ..... [rest I can't copy and paste]

So any thought that it takes just a million years for the Sun to form seems rather a massive underestimation.

Edited February 10, 2016 by Robittybob1

[Mordred]

I have to ask "what is the system your trying to model? " your direction I've perceived is the Suns influence upon early planetary formation ( for this thread specifically). Please clarify

Yes defining the stages of the Suns formation and individual formation stage influences apply.

We can help better with the target goal in mind

Edited February 10, 2016 by Mordred