System accumulation of matter after Planetary Formation

[berner]

Just had a thought, since I didn't have an answer I looked and found this forum to get it.<br /><br />Does a Stellar system (like Sol and it's planets) accumulate more matter after the star ignites or is this prevented by the solar wind?<br /><br />I know that additional matter does pass through the system as highly charged particles, I don't however know if particles with lesser energy can enter the system. Of the matter I know to have enough energy to enter the system is there enough of it to outweigh the matter lost from the system by for example the solar wind?

 

[h2ouniverse]

Hi Berner,<br /><br />That is a good question indeed. I am not sure there is an evidenced answer to your question, especially in terms of quantified budget.<br /><br />The Sun's gravity well extends over several tens of thousands of AU. Very light particles coming from the rest of the galaxy are stopped by solar wind quite close, with a bow shock (between 50 and several hundreds of AU depending on interstellar medium intensity). The bow shock is well inside the Sun's grav well. Once stopped or slowed down they can be captured. Heaviest elements, including dusts, rocks and exoplanetesimals can penetrate the bow shock and be deviated or captured, e.g. on orbits with large semi-major axis. <br />The H2O for instance, vaporized beneath the frost line, is flushed by the solar wind towards the outer system but not with enough energy to leave the grav well. Many molecules should be re-accreted.<br /><br />You mention the solar wind as a way to lose matter. But there is another way. Planetesimals or asteroids might be expelled by orbit instability / close encounters. Half of them are predicted to be expelled along their life. Some are injectd on higher orbits. Others may be expelled.<br /><br />Btw this means too that the Solar System should capture such objects all along Sun's wandering around the Milky Way. <br /><br />Best regards.

 

[berner]

So does anyone have any figures to say if a system loses or gains matter over it's life cycle? <br />If enough matter gets caught in the bow shock does it form massive bodies?<br />

 

[robnissen]

My WAG is that the solar system is slowly losing matter. The matter that is gained by capture in the sun's gravity well, I would think is less than the amount lost by the sun turning hydrogen into helium. Although this is just a WAG on my part, and could be completely wrong.

 

[h2ouniverse]

Good observation Rob!<br />In terms of mass, you are right.<br />But in terms of number of baryons (which may be of interest in terms of capability to build molecules)?<br />I am not sure too what the sign of the balance is...

 

[h2ouniverse]

Berner,<br />I do not think the matter in the bow shock can form bodies. Its density is very low, about 1e-21 kg/m3. Spread Pluto over a 100 AU disc, and you will get about 1e-19 kg/m3, one hundred times more. It is also deviated towards the tail. In addition, the bow shock is crossed by some outer Kuiper Belt objects or Oort cloud objects. So I rather think the heaviest particles/molecules/nuclei should be re-accreted. Probably not the H and He. <br />Best regards.

 

[berner]

Ok, to bad. Me and a friend have been having a discussion about different models of the universe. Having gone through the most common one (big bang) we are now discussing the less supported ones. <br /><br />The one we are checking now is steady state (read "the Genesis Machine", had to check it out), doesn't look good. Even if you bend the observed data totally out of shape nothing seems to fit. If you use the expanding-contracting model (universe like pendulum, big-small-big-small...) it fits a little better but still not close. <br /><br />Quasi Steady is the next one we check so there is no reason to mention it here. <br /><br />PS. Best discussion this year... <img src="/images/icons/smile.gif" />

 

[MeteorWayne]

Thta's not really related to the topic of this thread, which has to do with stellar/planetary system fomation.<br /><br />There's plenty of other formation and structure of the Universe threads.<br /><br />Welcome to SDC, at least you're discussing these types of issues!!! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[berner]

The topic of this thread was born due to that discussion... So it's related, however distantly.

 

[yevaud]

I actually have read that.<br /><br /><i>Milli-Abs</i>, oh my! <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>