Our Sun

[astroenthusiast]

I was just watching a video on www.space.com and in the video a lady said that "our sun will begin to die within miliseconds of creating iron through fusion". My question is, what if an asteroid or comet containing iron were to crash into the sun? I know that it would most likely be disintegrated by the suns intense heat, but what if iron atoms made their way to the sun's surface? Would they cause the sun to die?<br /><br />Another question. Do objects hit our sun? It is a very large target in relation to Earth and the other planets, yet we know of them being hit on numerous occasions. I would say yes by common sense, but I would just like an explanation if one is available.<br /><br /> Any answers would be greatly appreciated. Thank you all for your time!

 

[qzzq]

It's not so much the iron that causes the problem in stars, but the fusion process which gets you the iron. Fusing iron consumes energy, instead of producing it, like we see in other fusion pairs.<br />See also: http://en.wikipedia.org/wiki/Iron_peak <br />I don't think our Sun is massive enough to fuse iron.<br /><br />Objects do hit our Sun; comets and asteroids are occasionally absorbed for example. SOHO has captured quite a few. <div class="Discussion_UserSignature"> <p> </p><p>***</p> </div>

 

[wick07]

If I may, I think what the lady is talking about (not sure because my computer won't run videos), is how when the sun get's to the point in it's lifecyle where it is fusing different atoms to make iron it will be begining it's long collapse to becaome a white dwarf.<br /><br />To help explain, we can talk about how the sun works now. The fusion of hydrogen to helium within the sun right now creates energy, this energy as it radiates outward creates a pressure within the sun pushing out. The gravity of the sun causes all the matter within the sun to fall inwards. Right now that presure is balances, the outward pressure equals the inward pressure, so the sun's size is stable.<br /><br />However as you start to fuse large and larger elements the energy released from those reactions declines. Iron, as it turns out is about the biggest atom you can create using fusion and still get energy out of the reaction. So when the sun get's to the point of creating iron it will be using up the last of it's avaliable fuel.<br /><br />Since it will not be creating enough energy to balance the inward pressure from gravity it will begin to collapse, and eventually become a white dwarf.<br /><br />So you can see that adding some iron to the sun (BTW there is already some present now), you will not really be changing the dynamics of the reaction, since the sun is not yet creating it's OWN iron.<br /><br />As for your second question, I am sure things hit the sun all the time, but since 99% of the mass in the solar system is in the sun already, it has no effect.<br /><br />I hope my explaination helped. As usual if anyone sees me mistating something please jump in and correct me. <div class="Discussion_UserSignature"> <p><font color="#3366ff"><strong>_______________________________<em> </em></strong></font></p><p><font color="#0000ff"><em>"</em>If you are surrounded by those who constatly agree with you, then you're in an intellectual vacuum.  If you feel like trying to make a difference, you have to BE different.  How can you do that without interacting with those who are different from yourself?"</font></p><p><font color="#0000ff">-  a_lost_packet_</font></p> </div>

 

[MeteorWayne]

The most common type object that hits the sun is comets.<br />Almost all asteroids (and the planets) have orbits that keep them far away, but comets, particularly the Kreutz group, come close enough that their orbit can be shifted to intersect the surface.<br /><br />OK, Sungrazing Comets 101 <br /><br />There are two basic classes, Sungrazing comets, and Sunskirting comets, difference in perihelion defining them <br /><br />Sungrazing Comets <br /><br />About 90% belong to the Kreutz sungrazing group. <br />These have 600-1100 year orbits with q (perihelion)= 0.0047-0.0095 AU <br />(703,000-1.4 million km, 437,000-883,000 miles). The inclination is 144.0 degrees (retrograde). <br /><br />Most are small, about 16-130 meters (50-425 feet) in diameter, and only the largest, <br />with q /> .005 AU survive the trip around the sun. <br /><br />They are thought to have originated from one large (D=~120km) comet with a period of ~1000 years. <br />Between 10 and 20,000 years ago, this comet was disrupted by violent outgassing and/or tidal disruption. <br />The largest piece lasted until about 371 BC, when it split into 3. <br /><br />The largest remaining fragment, with a period of ~350 years survived intact and was observed during returns in the 1st, 4th, 8th, and 11th centuries, and the remains may have been the Comet of 1847. <br />This fragment was disrupted (by the same mechanisms again) during the 11th century appearence, and gave rise to Kreutz Subgroup I <br />Well known comets derived from this are: <br />C/1443 D1 (The Great March Comet) <br />C/1963 R1 (Peroyra) <br />It also includes all the comets discovered by the SMM (10) and SOLWIND (6) satellites, and about 67% of those discovered by SOHO. ~ />840 of SOHO's > 1259 comets <br /><br />The next largest fragment from the 11th century breakup, with a period of ~700 years gave rise to Kreutz Subgroup II <br />These include: <br />C/1882 R1 (The Great September Comet) <br />C/1965 S1 (Ikeya-Seki) <br />and about 19% of the comets disco <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>

 

[wick07]

Are you saying that all those comets originated from a single comet that broke up? That's pretty cool! <div class="Discussion_UserSignature"> <p><font color="#3366ff"><strong>_______________________________<em> </em></strong></font></p><p><font color="#0000ff"><em>"</em>If you are surrounded by those who constatly agree with you, then you're in an intellectual vacuum.  If you feel like trying to make a difference, you have to BE different.  How can you do that without interacting with those who are different from yourself?"</font></p><p><font color="#0000ff">-  a_lost_packet_</font></p> </div>