The sun dominates in our solar system.
I wonder whether in every aspect the sun plays the most important role in our system.

For example, all kinds of metals are mainly located in the sun instead of the rest combined together in our system?

Is there any complementary relation between the sun and its children (all the planets, asteroids etc..)?
I mean: for one kind of metal, if the sun has more, her children should have less.

According to Abundance in the Sun of the elements, at least Li and Tb abundance of the sun are very low ($\approx1e-8$). Furthermore, these abundances are from the solar atmosphere which is near the surface of the sun.

  • $\begingroup$ The sun dominates our solar system by mass. For the z-component of angular momentum for example, this is not true. $\endgroup$ Commented Dec 31, 2017 at 15:44

3 Answers 3

  1. The metal content of the Solar system is completely dominated by the Sun. The Sun contains $\sim1\%$ of 'metals' (in astronomical language anything but hydrogen and helium is a 'metal'), but all the other bodies of the Solar system combined have less mass than that. So even if they were only made of metals (but the outer planets are mostly made of H and He) the Sun would still dominate the metal budget.

  2. The Sun does not dominate the angular momentum of the Solar system, which is dominated by the orbital angular momentum of Jupiter. The angular momentum due to the spin of the Sun is rather modest. This is easy to estimate: the orbital angular momentum of a planet is $\sim m\sqrt{GM_\odot a}$ which increases with semi-major axis $a$, while the spin of the Sun contributes $\beta \omega M_\odot R_\odot^2$ with $\omega$ the Solar spin frequency, $R_\odot$ the Solar radius, and $\beta\sim0.1$ a factor depending on the inner structure of the Sun. The ratio of the latter to the former is $$ \beta \frac{M_\odot}{m} \frac{R_\odot^2}{a^2} \frac{\omega}{\Omega} \sim0.01 $$ For Jupiter, the first factor is $\sim10^3$, the second $\sim10^{-6}$, and the third $\sim180$ is the ratio of the Solar spin frequency (once in 25 days) to the orbital frequency $\Omega=\sqrt{GM_\odot/a^3}$ of Jupiter (once in 12 years).

  • $\begingroup$ could you please give a reference about the first question? $\endgroup$ Commented Sep 12, 2014 at 10:10
  • $\begingroup$ The Sun's angular momentum about the solar system barycenter is also a lot smaller. While it's mass is ~1000x larger than that of Jupiter's, both it's velocity and distance are each ~1000x smaller than that of Jupiter's, resulting in an orbital angular momentum that's roughly 1E-03 that of Jupiter, although it varies a lot depending mostly on the positions of Saturn, Uranus and Neptune. $\endgroup$
    – uhoh
    Commented Dec 31, 2017 at 9:24

The sun currently accounts for more than 99.86% of the mass of the solar system. Based on spectrographic estimates of the composition of the sun and its centrifugal position and the mass of metals, you can deduce it also contains the most of all kinds of metals.

Here is an example to illustrate:

  • The milky way contains roughly 0.00011% of $\mathrm{Fe}$ (1.1ppm).
  • The sun contains roughly 0.1% of $\mathrm{Fe}$, it contains about 333 earth masses of $\mathrm{Fe}$.
  • The planets combined weigh about 500 earth masses.
  • The sun contains only about 3% of our planet's weight of gold.
  • The sun contains about 30% of our planet's weight of platinum.
  • If you have time to do the maths, I think you will find here the same is true for other metals.

The best thing to do is probably to compare graphs of elemental abundance of the earth, and of the sun, and multiply by weight, as the earth contains a lot of heavy elements compared to further away planets.

It is estimated that the mass of the average newborn star is between 1 and 10% of baryonic elements held in a surrounding dust cloud that later forms an accretion disc.

It's my understanding that 90+ percent of the accretion disk falls into the star, depending on the star's mass compared to that of the cloud, and the rest of the metals and other elements have time to condensate into ice and asteroids and planets. I am told that about 1 percent of our solar system's composition was originally held in the dust cloud, and 99% was in the sun.

Currently, the elements in our solar system measure no more than 500 earth masses in all the planets and the Oort cloud. And the sun is 330 000 earth masses.

This means that less than 0.15 of the solar system currently lies outside of the sun. The other 85 or 850% of the original accretion disk with all its metals must have fallen into the sun, if we follow the rule that 1 to 10% of a new born star is found in its surrounding dust cloud.

Here is a list of elemental abundance for our galaxy and our solar system that is fairly interesting, I didn't find more precise figures.

  • $\begingroup$ For every kind of element, the sun dominates in the solar system? $\endgroup$ Commented Oct 3, 2015 at 10:47
  • $\begingroup$ I'd say that is certainly true, every element is most present in the sun by mass, because the sun is 99.8 percent of the mass of the system and contains all the heaviest and lightest elements. by percentage, other planets contain higher abundances than the sun of of elements depending on theid distance from sun. everything heavy is at the centre, and 90 percent of the light stuff also is in the sun at least, if a planet contained 50 pc copper and the sun contained .1 percent, the sun would still contain more than the planet. $\endgroup$ Commented Apr 2, 2016 at 4:29
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    $\begingroup$ @comprehensible Well it depends on how pedantic you want to be. For example, about three times in 2006, for a few milliseconds each, our 1 atom of ununoctium probably dominated the solar system's ununoctium content, if not most of the observable universe's. $\endgroup$
    – Jason C
    Commented Sep 29, 2016 at 0:54
  • $\begingroup$ @questionhang It's possible that the sun's internal gamma rays and heat aren't very-heavy-element friendly due to photodisintegration. I'm not 100% sure if that's so, but for elements heavier than lead the sun might be quite low in them. I asked that question here: physics.stackexchange.com/questions/188748/… Working out the answer is a bit over my pay-grade. $\endgroup$
    – userLTK
    Commented Dec 30, 2017 at 22:02

The metals that are forming in the sun come from nuclear fusion. Everything that now exists in the sun's body came from hydrogen, which due to high temperatures is being fused into helium and helium to lithium and so on. Once hydrogen is over, that means the start of the sun's death, where the sun will shrink (meaning temperature increase) and will start expanding again and the helium will continue to be used as a fuel and there is gonna be a point were all hydrogen and helium from the core will go, due to fusion, and the sun is gonna be cool so no further fusion will occur. Eventually what will be left is a planetary nebula with a white dwarf.

I am answering to your second question:

At the beginning of creation the planets (small dust grains) where revolving around the protostar sun. Gravitational force made dust particles to come together. The inner system which includes planets up to Mars, was very hot and molecules like water could not condense so the metals and the silicates dominated and formed the inner planets. The outer planet area (after Mara) was cool enough so the water and other elements could be in a solid state. Now, about the asteroids, these are rock leftovers that did not form into planets. Asteroids mostly found in the so called "asteroid belts", which is a region between Mars and Jupiter.

  • $\begingroup$ @dim23 The metals that are forming in the sun come from nuclear fusion? nuclear fusion of the sun? not necessarily. And what is the origin of the metals in, say, our earth? $\endgroup$ Commented Sep 12, 2014 at 10:09
  • $\begingroup$ @dim23 Also the Sun will never run out of H or He. The Sun's life states change when the mass of materials in the core that result from fusion is high enough to collapse, increasing temperatures that allow heavier elements fusion. $\endgroup$
    – Joan.bdm
    Commented Sep 12, 2014 at 11:45
  • $\begingroup$ Since I don't have the reputation to comment I have to add this as an answer. In regards to @dim23's statement that metals in our solar system came from our sun is wrong because the planets were created from the same "dust" and gas cloud that the sun formed from so the metals were already there to create the earth and other rocky planets. However, he is correct that metals are created from solar fusion. Those metals created by our sun are still pretty much inside our sun. The metals in the original "dust" cloud that our solar system was formed from were certainly made in another star that $\endgroup$ Commented Sep 28, 2016 at 15:03
  • $\begingroup$ exploded long before our sun was created. So, yes, @questionhang, all metals/higher elements in the periodic table are created by solar fusion. It is the only way heavier elements are created. $\endgroup$ Commented Sep 28, 2016 at 15:03

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